Definition 1:Amazon DynamoDB is a fully managed proprietary NoSQL database service that supports key-value and document data structures and is offered by Amazon.com as part of the Amazon Web Services portfolio. DynamoDB exposes a similar data model to and derives its name from Dynamo, but has a different underlying implementation. Dynamo had a multi-master design requiring the client to resolve version conflicts and DynamoDB uses synchronous replication across multiple datacenters for high durability and availability.
Definition 2:DynamoDB is a fast and flexible non-relational database service for any scale. DynamoDB enables customers to offload the administrative burdens of operating and scaling distributed databases to AWS so that they don’t have to worry about hardware provisioning, setup and configuration, throughput capacity planning, replication, software patching, or cluster scaling.
AWS DynamoDB Facts and Summaries
Amazon DynamoDB is a low-latency NoSQL database.
DynamoDB consists of Tables, Items, and Attributes
DynamoDb supports both document and key-value data models
DynamoDB Supported documents formats are JSON, HTML, XML
DynamoDB has 2 types of Primary Keys: Partition Key and combination of Partition Key + Sort Key (Composite Key)
DynamoDB has 2 consistency models: Strongly Consistent / Eventually Consistent
DynamoDB Access is controlled using IAM policies.
DynamoDB has fine grained access control using IAM Condition parameter dynamodb:LeadingKeys to allow users to access only the items where the partition key vakue matches their user ID.
DynamoDB Indexes enable fast queries on specific data columns
DynamoDB indexes give you a different view of your data based on alternative Partition / Sort Keys.
DynamoDB Local Secondary indexes must be created when you create your table, they have same partition Key as your table, and they have a different Sort Key.
DynamoDB Global Secondary Index Can be created at any time: at table creation or after. They have a different partition Key as your table and a different sort key as your table.
A DynamoDB query operation finds items in a table using only the primary Key attribute: You provide the Primary Key name and a distinct value to search for.
A DynamoDB Scan operation examines every item in the table. By default, it return data attributes.
DynamoDB Query operation is generally more efficient than a Scan.
With DynamoDB, you can reduce the impact of a query or scan by setting a smaller page size which uses fewer read operations.
To optimize DynamoDB performance, isolate scan operations to specific tables and segregate them from your mission-critical traffic.
To optimize DynamoDB performance, try Parallel scans rather than the default sequential scan.
To optimize DynamoDB performance: Avoid using scan operations if you can: design tables in a way that you can use Query, Get, or BatchGetItems APIs.
When you scan your table in Amazon DynamoDB, you should follow the DynamoDB best practices for avoiding sudden bursts of read activity.
DynamoDb Provisioned Throughput is measured in Capacity Units.
1 Write Capacity Unit = 1 x 1KB Write per second.
1 Read Capacity Unit = 1 x 4KB Strongly Consistent Read Or 2 x 4KB Eventually Consistent Reads per second. Eventual consistent reads give us the maximum performance with the read operation.
What is the maximum throughput that can be provisioned for a single DynamoDB table?
DynamoDB is designed to scale without limits. However, if you want to exceed throughput rates of 10,000 write capacity units or 10,000 read capacity units for an individual table, you must Ccontact AWS to increase it.
If you want to provision more than 20,000 write capacity units or 20,000 read capacity units from a single subscriber account, you must first contact AWS to request a limit increase.
Dynamo Db Performance: DAX is a DynamoDB-compatible caching service that enables you to benefit from fast in-memory performance for demanding applications.
As an in-memory cache, DAX reduces the response times of eventually-consistent read workloads by an order of magnitude, from single-digit milliseconds to microseconds
DAX improves response times for Eventually Consistent reads only.
With DAX, you point your API calls to the DAX cluster instead of your table.
If the item you are querying is on the cache, DAX will return it; otherwise, it will perform and Eventually Consistent GetItem operation to your DynamoDB table.
DAX reduces operational and application complexity by providing a managed service that is API compatible with Amazon DynamoDB, and thus requires only minimal functional changes to use with an existing application.
DAX is not suitable for write-intensive applications or applications that require Strongly Consistent reads.
For read-heavy or bursty workloads, DAX provides increased throughput and potential operational cost savings by reducing the need to over-provision read capacity units. This is especially beneficial for applications that require repeated reads for individual keys.
Dynamo Db Performance: ElastiCache
In-memory cache sits between your application and database
2 different caching strategies: Lazy loading and Write Through: Lazy loading only caches the data when it is requested
Elasticache Node failures are not fatal, just lots of cache misses
Avoid stale data by implementing a TTL.
Write-Through strategy writes data into cache whenever there is a change to the database. Data is never stale
Write-Through penalty: Each write involves a write to the cache. Elasticache node failure means that data is missing until added or updated in the database.
Elasticache is wasted resources if most of the data is never used.
Time To Live (TTL) for DynamoDB allows you to define when items in a table expire so that they can be automatically deleted from the database. TTL is provided at no extra cost as a way to reduce storage usage and reduce the cost of storing irrelevant data without using provisioned throughput. With TTL enabled on a table, you can set a timestamp for deletion on a per-item basis, allowing you to limit storage usage to only those records that are relevant.
DynamoDB Security: DynamoDB uses the CMK to generate and encrypt a unique data key for the table, known as the table key. With DynamoDB, AWS Owned, or AWS Managed CMK can be used to generate & encrypt keys. AWS Owned CMK is free of charge while AWS Managed CMK is chargeable. Customer managed CMK’s are not supported with encryption at rest.
Amazon DynamoDB offers fully managed encryption at rest. DynamoDB encryption at rest provides enhanced security by encrypting your data at rest using an AWS Key Management Service (AWS KMS) managed encryption key for DynamoDB. This functionality eliminates the operational burden and complexity involved in protecting sensitive data.
DynamoDB is a alternative solution which can be used for storage of session management. The latency of access to data is less , hence this can be used as a data store for session management
DynamoDB Streams Use Cases and Design Patterns:
How do you set up a relationship across multiple tables in which, based on the value of an item from one table, you update the item in a second table?
How do you trigger an event based on a particular transaction?
How do you audit or archive transactions?
How do you replicate data across multiple tables (similar to that of materialized views/streams/replication in relational data stores)?
As a NoSQL database, DynamoDB is not designed to support transactions. Although client-side libraries are available to mimic the transaction capabilities, they are not scalable and cost-effective. For example, the Java Transaction Library for DynamoDB creates 7N+4 additional writes for every write operation. This is partly because the library holds metadata to manage the transactions to ensure that it’s consistent and can be rolled back before commit.
You can use DynamoDB Streams to address all these use cases. DynamoDB Streams is a powerful service that you can combine with other AWS services to solve many similar problems. When enabled, DynamoDB Streams captures a time-ordered sequence of item-level modifications in a DynamoDB table and durably stores the information for up to 24 hours. Applications can access a series of stream records, which contain an item change, from a DynamoDB stream in near real time.
AWS maintains separate endpoints for DynamoDB and DynamoDB Streams. To work with database tables and indexes, your application must access a DynamoDB endpoint. To read and process DynamoDB Streams records, your application must access a DynamoDB Streams endpoint in the same Region
20 global secondary indexes are allowed per table? (by default)
What is one key difference between a global secondary index and a local secondary index? A local secondary index must have the same partition key as the main table
How many tables can an AWS account have per region? 256
How many secondary indexes (global and local combined) are allowed per table? (by default): 25 You can define up to 5 local secondary indexes and 20 global secondary indexes per table (by default) – for a total of 25.
How can you increase your DynamoDB table limit in a region? By contacting AWS and requesting a limit increase
For any AWS account, there is an initial limit of 256 tables per region.
The minimum length of a partition key value is 1 byte. The maximum length is 2048 bytes.
The minimum length of a sort key value is 1 byte. The maximum length is 1024 bytes.
For tables with local secondary indexes, there is a 10 GB size limit per partition key value. A table with local secondary indexes can store any number of items, as long as the total size for any one partition key value does not exceed 10 GB.
The following diagram shows a local secondary index named LastPostIndex. Note that the partition key is the same as that of the Thread table, but the sort key is LastPostDateTime. AWS DynamoDB secondary indexes example
Q0: What should the Developer enable on the DynamoDB table to optimize performance and minimize costs?
A. Amazon DynamoDB auto scaling
B. Amazon DynamoDB cross-region replication
C. Amazon DynamoDB Streams
D. Amazon DynamoDB Accelerator
D. DAX is a DynamoDB-compatible caching service that enables you to benefit from fast in-memory performance for demanding applications. DAX addresses three core scenarios:
As an in-memory cache, DAX reduces the response times of eventually-consistent read workloads by an order of magnitude, from single-digit milliseconds to microseconds.
DAX reduces operational and application complexity by providing a managed service that is API-compatible with Amazon DynamoDB, and thus requires only minimal functional changes to use with an existing application.
For read-heavy or bursty workloads, DAX provides increased throughput and potential operational cost savings by reducing the need to over-provision read capacity units. This is especially beneficial for applications that require repeated reads for individual keys.
Q2: A security system monitors 600 cameras, saving image metadata every 1 minute to an Amazon DynamoDb table. Each sample involves 1kb of data, and the data writes are evenly distributed over time. How much write throughput is required for the target table?
A. 6000
B. 10
C. 3600
D. 600
B. When you mention the write capacity of a table in Dynamo DB, you mention it as the number of 1KB writes per second. So in the above question, since the write is happening every minute, we need to divide the value of 600 by 60, to get the number of KB writes per second. This gives a value of 10.
You can specify the Write capacity in the Capacity tab of the DynamoDB table.
Q3: You are developing an application that will interact with a DynamoDB table. The table is going to take in a lot of read and write operations. Which of the following would be the ideal partition key for the DynamoDB table to ensure ideal performance?
A. CustomerID
B. CustomerName
C. Location
D. Age
Answer- A
Use high-cardinality attributes. These are attributes that have distinct values for each item, like e-mailid, employee_no, customerid, sessionid, orderid, and so on..
Use composite attributes. Try to combine more than one attribute to form a unique key.
Reference: Choosing the right DynamoDB Partition Key
Q4: A DynamoDB table is set with a Read Throughput capacity of 5 RCU. Which of the following read configuration will provide us the maximum read throughput?
A. Read capacity set to 5 for 4KB reads of data at strong consistency
B. Read capacity set to 5 for 4KB reads of data at eventual consistency
C. Read capacity set to 15 for 1KB reads of data at strong consistency
D. Read capacity set to 5 for 1KB reads of data at eventual consistency
Answer: B.
The calculation of throughput capacity for option B would be:
Read capacity(5) * Amount of data(4) = 20.
Since its required at eventual consistency , we can double the read throughput to 20*2=40
Q5: Your team is developing a solution that will make use of DynamoDB tables. Due to the nature of the application, the data is needed across a couple of regions across the world. Which of the following would help reduce the latency of requests to DynamoDB from different regions?
A. Enable Multi-AZ for the DynamoDB table
B. Enable global tables for DynamoDB
C. Enable Indexes for the table
D. Increase the read and write throughput for the tablez
Answer: B
Amazon DynamoDB global tables provide a fully managed solution for deploying a multi-region, multimaster database, without having to build and maintain your own replication solution. When you create a global table, you specify the AWS regions where you want the table to be available. DynamoDB performs all of the necessary tasks to create identical tables in these regions, and propagate ongoing data changes to all of them.
Reference: Global Tables
Q6: An application is currently accessing a DynamoDB table. Currently the tables queries are performing well. Changes have been made to the application and now the performance of the application is starting to degrade. After looking at the changes , you see that the queries are making use of an attribute which is not the partition key? Which of the following would be the adequate change to make to resolve the issue?
A. Add an index for the DynamoDB table
B. Change all the queries to ensure they use the partition key
C. Enable global tables for DynamoDB
D. Change the read capacity on the table
Answer: A
Amazon DynamoDB provides fast access to items in a table by specifying primary key values. However, many applications might benefit from having one or more secondary (or alternate) keys available, to allow efficient access to data with attributes other than the primary key. To address this, you can create one or more secondary indexes on a table, and issue Query or Scan requests against these indexes.
A secondary index is a data structure that contains a subset of attributes from a table, along with an alternate key to support Query operations. You can retrieve data from the index using a Query, in much the same way as you use Query with a table. A table can have multiple secondary indexes, which gives your applications access to many different query patterns.
Q7: Company B has created an e-commerce site using DynamoDB and is designing a products table that includes items purchased and the users who purchased the item.
When creating a primary key on a table which of the following would be the best attribute for the partition key? Select the BEST possible answer.
A. None of these are correct.
B. user_id where there are many users to few products
C. category_id where there are few categories to many products
D. product_id where there are few products to many users
Answer: B.
When designing tables it is important for the data to be distributed evenly across the entire table. It is best practice for performance to set your primary key where there are many primary keys to few rows. An example would be many users to few products. An example of bad design would be a primary key of product_id where there are few products but many users.
When designing tables it is important for the data to be distributed evenly across the entire table. It is best practice for performance to set your primary key where there are many primary keys to few rows. An example would be many users to few products. An example of bad design would be a primary key of product_id where there are few products but many users.
Reference: Partition Keys and Sort Keys
Q8: Which API call can be used to retrieve up to 100 items at a time or 16 MB of data from a DynamoDB table?
A. BatchItem
B. GetItem
C. BatchGetItem
D. ChunkGetItem
Answer: C. BatchGetItem
The BatchGetItem operation returns the attributes of one or more items from one or more tables. You identify requested items by primary key.
A single operation can retrieve up to 16 MB of data, which can contain as many as 100 items. BatchGetItem will return a partial result if the response size limit is exceeded, the table’s provisioned throughput is exceeded, or an internal processing failure occurs. If a partial result is returned, the operation returns a value for UnprocessedKeys. You can use this value to retry the operation starting with the next item to get.Reference: API-Specific Limits
Q9: Which DynamoDB limits can be raised by contacting AWS support?
A. The number of hash keys per account
B. The maximum storage used per account
C. The number of tables per account
D. The number of local secondary indexes per account
E. The number of provisioned throughput units per account
Answer: C. and E.
For any AWS account, there is an initial limit of 256 tables per region.
AWS places some default limits on the throughput you can provision.
These are the limits unless you request a higher amount.
To request a service limit increase see https://aws.amazon.com/support.
Q10: Which approach below provides the least impact to provisioned throughput on the “Product”
table?
A. Create an “Images” DynamoDB table to store the Image with a foreign key constraint to
the “Product” table
B. Add an image data type to the “Product” table to store the images in binary format
C. Serialize the image and store it in multiple DynamoDB tables
D. Store the images in Amazon S3 and add an S3 URL pointer to the “Product” table item
for each image
Answer: D.
Amazon DynamoDB currently limits the size of each item that you store in a table (see Limits in DynamoDB). If your application needs to store more data in an item than the DynamoDB size limit permits, you can try compressing one or more large attributes, or you can store them as an object in Amazon Simple Storage Service (Amazon S3) and store the Amazon S3 object identifier in your DynamoDB item.
Compressing large attribute values can let them fit within item limits in DynamoDB and reduce your storage costs. Compression algorithms such as GZIP or LZO produce binary output that you can then store in a Binary attribute type.
Reference: Best Practices for Storing Large Items and Attributes
Q11: You’re creating a forum DynamoDB database for hosting forums. Your “thread” table contains the forum name and each “forum name” can have one or more “subjects”. What primary key type would you give the thread table in order to allow more than one subject to be tied to the forum primary key name?
A. Hash
B. Range and Hash
C. Primary and Range
D. Hash and Range
Answer: D.
Each forum name can have one or more subjects. In this case, ForumName is the hash attribute and Subject is the range attribute.
Definition 1: Amazon S3 or Amazon Simple Storage Service is a “simple storage service” offered by Amazon Web Services that provides object storage through a web service interface. Amazon S3 uses the same scalable storage infrastructure that Amazon.com uses to run its global e-commerce network.
Definition 2: Amazon Simple Storage Service (Amazon S3) is an object storage service that offers industry-leading scalability, data availability, security, and performance.
AWS S3 Facts and summaries
S3 is a universal namespace, meaning each S3 bucket you create must have a unique name that is not being used by anyone else in the world.
S3 is object based: i.e allows you to upload files.
Files can be from 0 Bytes to 5 TB
What is the maximum length, in bytes, of a DynamoDB range primary key attribute value?
The maximum length of a DynamoDB range primary key attribute value is 2048 bytes (NOT 256 bytes).
S3 has unlimited storage.
Files are stored in Buckets.
Read after write consistency for PUTS of new Objects
Eventual Consistency for overwrite PUTS and DELETES (can take some time to propagate)
S3 Standard (durable, immediately available, frequently accesses)
Amazon S3 Intelligent-Tiering (S3 Intelligent-Tiering): It works by storing objects in two access tiers: one tier that is optimized for frequent access and another lower-cost tier that is optimized for infrequent access.
S3 – One Zone-Infrequent Access – S3 One Zone IA: Same ad IA. However, data is stored in a single Availability Zone only
S3 – Reduced Redundancy Storage (data that is easily reproducible, such as thumbnails, etc.)
Glacier – Archived data, where you can wait 3-5 hours before accessing
You can have a bucket that has different objects stored in S3 Standard, S3 Intelligent-Tiering, S3 Standard-IA, and S3 One Zone-IA.
The default URL for S3 hosted websites lists the bucket name first followed by s3-website-region.amazonaws.com . Example: enoumen.com.s3-website-us-east-1.amazonaws.com
Core fundamentals of an S3 object
Key (name)
Value (data)
Version (ID)
Metadata
Sub-resources (used to manage bucket-specific configuration)
Bucket Policies, ACLs,
CORS
Transfer Acceleration
Object-based storage only for files
Not suitable to install OS on.
Successful uploads will generate a HTTP 200 status code.
S3 Security – Summary
By default, all newly created buckets are PRIVATE.
You can set up access control to your buckets using:
Bucket Policies – Applied at the bucket level
Access Control Lists – Applied at an object level.
S3 buckets can be configured to create access logs, which log all requests made to the S3 bucket. These logs can be written to another bucket.
S3 Encryption
Encryption In-Transit (SSL/TLS)
Encryption At Rest:
Server side Encryption (SSE-S3, SSE-KMS, SSE-C)
Client Side Encryption
Remember that we can use a Bucket policy to prevent unencrypted files from being uploaded by creating a policy which only allows requests which include the x-amz-server-side-encryption parameter in the request header.
S3 CORS (Cross Origin Resource Sharing):
CORS defines a way for client web applications that are loaded in one domain to interact with resources in a different domain.
Used to enable cross origin access for your AWS resources, e.g. S3 hosted website accessing javascript or image files located in another bucket. By default, resources in one bucket cannot access resources located in another. To allow this we need to configure CORS on the bucket being accessed and enable access for the origin (bucket) attempting to access.
Always use the S3 website URL, not the regular bucket URL. E.g.: https://s3-eu-west-2.amazonaws.com/acloudguru
S3 CloudFront:
Edge locations are not just READ only – you can WRITE to them too (i.e put an object on to them.)
Objects are cached for the life of the TTL (Time to Live)
You can clear cached objects, but you will be charged. (Invalidation)
S3 Performance optimization – 2 main approaches to Performance Optimization for S3:
GET-Intensive Workloads – Use Cloudfront
Mixed Workload – Avoid sequencial key names for your S3 objects. Instead, add a random prefix like a hex hash to the key name to prevent multiple objects from being stored on the same partition.
The best way to handle large objects uploads to the S3 service is to use the Multipart upload API. The Multipart upload API enables you to upload large objects in parts.
You can enable versioning on a bucket, even if that bucket already has objects in it. The already existing objects, though, will show their versions as null. All new objects will have version IDs.
Bucket names cannot start with a . or – characters. S3 bucket names can contain both the . and – characters. There can only be one . or one – between labels. E.G mybucket-com mybucket.com are valid names but mybucket–com and mybucket..com are not valid bucket names.
What is the maximum number of S3 buckets allowed per AWS account (by default)? 100
You successfully upload an item to the us-east-1 region. You then immediately make another API call and attempt to read the object. What will happen? All AWS regions now have read-after-write consistency for PUT operations of new objects. Read-after-write consistency allows you to retrieve objects immediately after creation in Amazon S3. Other actions still follow the eventual consistency model (where you will sometimes get stale results if you have recently made changes)
S3 bucket policies require a Principal be defined. Review the access policy elements here
What checksums does Amazon S3 employ to detect data corruption?
Amazon S3 uses a combination of Content-MD5 checksums and cyclic redundancy checks (CRCs) to detect data corruption. Amazon S3 performs these checksums on data at rest and repairs any corruption using redundant data. In addition, the service calculates checksums on all network traffic to detect corruption of data packets when storing or retrieving data.
Q0: You’ve written an application that uploads objects onto an S3 bucket. The size of the object varies between 200 – 500 MB. You’ve seen that the application sometimes takes a longer than expected time to upload the object. You want to improve the performance of the application. Which of the following would you consider?
A. Create multiple threads and upload the objects in the multiple threads
B. Write the items in batches for better performance
C. Use the Multipart upload API
D. Enable versioning on the Bucket
C. All other options are invalid since the best way to handle large object uploads to the S3 service is to use the Multipart upload API. The Multipart upload API enables you to upload large objects in parts. You can use this API to upload new large objects or make a copy of an existing object. Multipart uploading is a three-step process: You initiate the upload, you upload the object parts, and after you have uploaded all the parts, you complete the multipart upload. Upon receiving the complete multipart upload request, Amazon S3 constructs the object from the uploaded parts, and you can then access the object just as you would any other object in your bucket.
Q2: You are using AWS SAM templates to deploy a serverless application. Which of the following resource will embed application from Amazon S3 buckets?
A. AWS::Serverless::Api
B. AWS::Serverless::Application
C. AWS::Serverless::Layerversion
D. AWS::Serverless::Function
Answer – B
AWS::Serverless::Application resource in AWS SAm template is used to embed application frm Amazon S3 buckets.
Reference: Declaring Serverless Resources
Q3: A static web site has been hosted on a bucket and is now being accessed by users. One of the web pages javascript section has been changed to access data which is hosted in another S3 bucket. Now that same web page is no longer loading in the browser. Which of the following can help alleviate the error?
A. Enable versioning for the underlying S3 bucket.
B. Enable Replication so that the objects get replicated to the other bucket
C. Enable CORS for the bucket
D. Change the Bucket policy for the bucket to allow access from the other bucket
Answer – C
Cross-origin resource sharing (CORS) defines a way for client web applications that are loaded in one domain to interact with resources in a different domain. With CORS support, you can build rich client-side web applications with Amazon S3 and selectively allow cross-origin access to your Amazon S3 resources.
Cross-Origin Resource Sharing: Use-case Scenarios The following are example scenarios for using CORS:
Scenario 1: Suppose that you are hosting a website in an Amazon S3 bucket named website as described in Hosting a Static Website on Amazon S3. Your users load the website endpoint http://website.s3-website-us-east-1.amazonaws.com. Now you want to use JavaScript on the webpages that are stored in this bucket to be able to make authenticated GET and PUT requests against the same bucket by using the Amazon S3 API endpoint for the bucket, website.s3.amazonaws.com. A browser would normally block JavaScript from allowing those requests, but with CORS you can congure your bucket to explicitly enable cross-origin requests from website.s3-website-us-east-1.amazonaws.com.
Scenario 2: Suppose that you want to host a web font from your S3 bucket. Again, browsers require a CORS check (also called a preight check) for loading web fonts. You would congure the bucket that is hosting the web font to allow any origin to make these requests.
Q4: Your mobile application includes a photo-sharing service that is expecting tens of thousands of users at launch. You will leverage Amazon Simple Storage Service (S3) for storage of the user Images, and you must decide how to authenticate and authorize your users for access to these images. You also need to manage the storage of these images. Which two of the following approaches should you use? Choose two answers from the options below
A. Create an Amazon S3 bucket per user, and use your application to generate the S3 URL for the appropriate content.
B. Use AWS Identity and Access Management (IAM) user accounts as your application-level user database, and offload the burden of authentication from your application code.
C. Authenticate your users at the application level, and use AWS Security Token Service (STS)to grant token-based authorization to S3 objects.
D. Authenticate your users at the application level, and send an SMS token message to the user. Create an Amazon S3 bucket with the same name as the SMS message token, and move the user’s objects to that bucket.
Answer- C
The AWS Security Token Service (STS) is a web service that enables you to request temporary, limited-privilege credentials for AWS Identity and Access Management (IAM) users or for users that you authenticate (federated users). The token can then be used to grant access to the objects in S3.
You can then provides access to the objects based on the key values generated via the user id.
Q5: Both ACLs and Bucket Policies can be used to grant access to S3 buckets. Which of the following statements is true about ACLs and Bucket policies?
A. Bucket Policies are Written in JSON and ACLs are written in XML
B. ACLs can be attached to S3 objects or S3 Buckets
C. Bucket Policies and ACLs are written in JSON
D. Bucket policies are only attached to s3 buckets, ACLs are only attached to s3 objects
Answer: A. and B.
Only Bucket Policies are written in JSON, ACLs are written in XML.
While Bucket policies are indeed only attached to S3 buckets, ACLs can be attached to S3 Buckets OR S3 Objects.
Reference:
Q6: What are good options to improve S3 performance when you have significantly high numbers of GET requests?
A. Introduce random prefixes to S3 objects
B. Introduce random suffixes to S3 objects
C. Setup CloudFront for S3 objects
D. Migrate commonly used objects to Amazon Glacier
Answer: C
CloudFront caching is an excellent way to avoid putting extra strain on the S3 service and to improve the response times of reqeusts by caching data closer to users at CloudFront locations.
S3 Transfer Acceleration optimizes the TCP protocol and adds additional intelligence between the client and the S3 bucket, making S3 Transfer Acceleration a better choice if a higher throughput is desired. If you have objects that are smaller than 1GB or if the data set is less than 1GB in size, you should consider using Amazon CloudFront’s PUT/POST commands for optimal performance.
Reference: Amazon S3 Transfer Acceleration
Q7: If an application is storing hourly log files from thousands of instances from a high traffic
web site, which naming scheme would give optimal performance on S3?
A. Sequential
B. HH-DD-MM-YYYY-log_instanceID
C. YYYY-MM-DD-HH-log_instanceID
D. instanceID_log-HH-DD-MM-YYYY
E. instanceID_log-YYYY-MM-DD-HH
Answer: A. B. C. D. and E.
Amazon S3 now provides increased performance to support at least 3,500 requests per second to add data and 5,500 requests per second to retrieve data, which can save significant processing time for no additional charge. Each S3 prefix can support these request rates, making it simple to increase performance significantly.
This S3 request rate performance increase removes any previous guidance to randomize object prefixes to achieve faster performance. That means you can now use logical or sequential naming patterns in S3 object naming without any performance implications.
Q9: You created three S3 buckets – “mywebsite.com”, “downloads.mywebsite.com”, and “www.mywebsite.com”. You uploaded your files and enabled static website hosting. You specified both of the default documents under the “enable static website hosting” header. You also set the “Make Public” permission for the objects in each of the three buckets. You create the Route 53 Aliases for the three buckets. You are going to have your end users test your websites by browsing to http://mydomain.com/error.html, http://downloads.mydomain.com/index.html, and http://www.mydomain.com. What problems will your testers encounter?
A. http://mydomain.com/error.html will not work because you did not set a value for the error.html file
B. There will be no problems, all three sites should work.
C. http://www.mywebsite.com will not work because the URL does not include a file name at the end of it.
D. http://downloads.mywebsite.com/index.html will not work because the “downloads” prefix is not a supported prefix for S3 websites using Route 53 aliases
Answer: B.
It used to be that the only allowed domain prefix when creating Route 53 Aliases for S3 static websites was the “www” prefix. However, this is no longer the case. You can now use other subdomain.
What is the AWS Certified Developer Associate Exam?
This AWS Certified Developer-Associate Examination is intended for individuals who perform a
Developer role. It validates an examinee’s ability to:
Demonstrate an understanding of core AWS services, uses, and basic AWS architecture best practices.
Demonstrate proficiency in developing, deploying, and debugging cloud-based applications using AWS.
There are no prerequisites for taking the Developer-Associate examination, but here are the recommended AWS Knowledge:
One or more years of hands-on experience developing and maintaining an AWS based application
In-depth knowledge of at least one high-level programming language
Understanding of core AWS services, uses, and basic AWS architecture best practices
Proficiency in developing, deploying, and debugging cloud-based applications using AWS
Ability to use the AWS service APIs, AWS CLI, and SDKs to write applications
Ability to identify key features of AWS services
Understanding of the AWS shared responsibility model
Understanding of application lifecycle management
Ability to use a CI/CD pipeline to deploy applications on AWS
Ability to use or interact with AWS services
Ability to apply a basic understanding of cloud-native applications to write code
Ability to write code using AWS security best practices (e.g., not using secret and access keys in the code, instead using IAM roles)
Ability to author, maintain, and debug code modules on AWS
Proficiency writing code for serverless applications
Understanding of the use of containers in the development process
To succeed with the real exam, do not memorize the answers below. It is very important that you understand why a question is right or wrong and the concepts behind it by carefully reading the reference documents in the answers.
AWS Certified Developer – Associate Practice Questions And Answers Dump
Q0: Your application reads commands from an SQS queue and sends them to web services hosted by your
partners. When a partner’s endpoint goes down, your application continually returns their commands to the queue. The repeated attempts to deliver these commands use up resources. Commands that can’t be delivered must not be lost.
How can you accommodate the partners’ broken web services without wasting your resources?
A. Create a delay queue and set DelaySeconds to 30 seconds
B. Requeue the message with a VisibilityTimeout of 30 seconds.
C. Create a dead letter queue and set the Maximum Receives to 3.
D. Requeue the message with a DelaySeconds of 30 seconds.
C. After a message is taken from the queue and returned for the maximum number of retries, it is
automatically sent to a dead letter queue, if one has been configured. It stays there until you retrieve it for forensic purposes.
Q1: A developer is writing an application that will store data in a DynamoDB table. The ratio of reads operations to write operations will be 1000 to 1, with the same data being accessed frequently.
What should the Developer enable on the DynamoDB table to optimize performance and minimize costs?
A. Amazon DynamoDB auto scaling
B. Amazon DynamoDB cross-region replication
C. Amazon DynamoDB Streams
D. Amazon DynamoDB Accelerator
D. The AWS Documentation mentions the following:
DAX is a DynamoDB-compatible caching service that enables you to benefit from fast in-memory performance for demanding applications. DAX addresses three core scenarios
As an in-memory cache, DAX reduces the response times of eventually-consistent read workloads by an order of magnitude, from single-digit milliseconds to microseconds.
DAX reduces operational and application complexity by providing a managed service that is API-compatible with Amazon DynamoDB, and thus requires only minimal functional changes to use with an existing application.
For read-heavy or bursty workloads, DAX provides increased throughput and potential operational cost savings by reducing the need to over-provision read capacity units. This is especially beneficial for applications that require repeated reads for individual keys.
Q2: You are creating a DynamoDB table with the following attributes:
PurchaseOrderNumber (partition key)
CustomerID
PurchaseDate
TotalPurchaseValue
One of your applications must retrieve items from the table to calculate the total value of purchases for a
particular customer over a date range. What secondary index do you need to add to the table?
A. Local secondary index with a partition key of CustomerID and sort key of PurchaseDate; project the
TotalPurchaseValue attribute
B. Local secondary index with a partition key of PurchaseDate and sort key of CustomerID; project the
TotalPurchaseValue attribute
C. Global secondary index with a partition key of CustomerID and sort key of PurchaseDate; project the
TotalPurchaseValue attribute
D. Global secondary index with a partition key of PurchaseDate and sort key of CustomerID; project the
TotalPurchaseValue attribute
C. The query is for a particular CustomerID, so a Global Secondary Index is needed for a different partition
key. To retrieve only the desired date range, the PurchaseDate must be the sort key. Projecting the
TotalPurchaseValue into the index provides all the data needed to satisfy the use case.
Global secondary index — an index with a hash and range key that can be different from those on the table. A global secondary index is considered “global” because queries on the index can span all of the data in a table, across all partitions.
Local secondary index — an index that has the same hash key as the table, but a different range key. A local secondary index is “local” in the sense that every partition of a local secondary index is scoped to a table partition that has the same hash key.
Local Secondary Indexes still rely on the original Hash Key. When you supply a table with hash+range, think about the LSI as hash+range1, hash+range2.. hash+range6. You get 5 more range attributes to query on. Also, there is only one provisioned throughput.
Global Secondary Indexes defines a new paradigm – different hash/range keys per index.
This breaks the original usage of one hash key per table. This is also why when defining GSI you are required to add a provisioned throughput per index and pay for it.
Local Secondary Indexes can only be created when you are creating the table, there is no way to add Local Secondary Index to an existing table, also once you create the index you cannot delete it.
Global Secondary Indexes can be created when you create the table and added to an existing table, deleting an existing Global Secondary Index is also allowed.
Throughput :
Local Secondary Indexes consume throughput from the table. When you query records via the local index, the operation consumes read capacity units from the table. When you perform a write operation (create, update, delete) in a table that has a local index, there will be two write operations, one for the table another for the index. Both operations will consume write capacity units from the table.
Global Secondary Indexes have their own provisioned throughput, when you query the index the operation will consume read capacity from the index, when you perform a write operation (create, update, delete) in a table that has a global index, there will be two write operations, one for the table another for the index*.
Q7: You are attempting to SSH into an EC2 instance that is located in a public subnet. However, you are currently receiving a timeout error trying to connect. What could be a possible cause of this connection issue?
A. The security group associated with the EC2 instance has an inbound rule that allows SSH traffic, but does not have an outbound rule that allows SSH traffic.
B. The security group associated with the EC2 instance has an inbound rule that allows SSH traffic AND has an outbound rule that explicitly denies SSH traffic.
C. The security group associated with the EC2 instance has an inbound rule that allows SSH traffic AND the associated NACL has both an inbound and outbound rule that allows SSH traffic.
D. The security group associated with the EC2 instance does not have an inbound rule that allows SSH traffic AND the associated NACL does not have an outbound rule that allows SSH traffic.
D. Security groups are stateful, so you do NOT have to have an explicit outbound rule for return requests. However, NACLs are stateless so you MUST have an explicit outbound rule configured for return request.
Q8: You have instances inside private subnets and a properly configured bastion host instance in a public subnet. None of the instances in the private subnets have a public or Elastic IP address. How can you connect an instance in the private subnet to the open internet to download system updates?
A. Create and assign EIP to each instance
B. Create and attach a second IGW to the VPC.
C. Create and utilize a NAT Gateway
D. Connect to a VPN
C. You can use a network address translation (NAT) gateway in a public subnet in your VPC to enable instances in the private subnet to initiate outbound traffic to the Internet, but prevent the instances from receiving inbound traffic initiated by someone on the Internet.
Q9: What feature of VPC networking should you utilize if you want to create “elasticity” in your application’s architecture?
A. Security Groups
B. Route Tables
C. Elastic Load Balancer
D. Auto Scaling
D. Auto scaling is designed specifically with elasticity in mind. Auto scaling allows for the increase and decrease of compute power based on demand, thus creating elasticity in the architecture.
Q11: You’re writing a script with an AWS SDK that uses the AWS API Actions and want to create AMIs for non-EBS backed AMIs for you. Which API call should occurs in the final process of creating an AMI?
A. RegisterImage
B. CreateImage
C. ami-register-image
D. ami-create-image
A. It is actually – RegisterImage. All AWS API Actions will follow the capitalization like this and don’t have hyphens in them.
Q12: When dealing with session state in EC2-based applications using Elastic load balancers which option is generally thought of as the best practice for managing user sessions?
A. Having the ELB distribute traffic to all EC2 instances and then having the instance check a caching solution like ElastiCache running Redis or Memcached for session information
B. Permenantly assigning users to specific instances and always routing their traffic to those instances
C. Using Application-generated cookies to tie a user session to a particular instance for the cookie duration
D. Using Elastic Load Balancer generated cookies to tie a user session to a particular instance
Q14: What is one key difference between an Amazon EBS-backed and an instance-store backed instance?
A. Autoscaling requires using Amazon EBS-backed instances
B. Virtual Private Cloud requires EBS backed instances
C. Amazon EBS-backed instances can be stopped and restarted without losing data
D. Instance-store backed instances can be stopped and restarted without losing data
C. Instance-store backed images use “ephemeral” storage (temporary). The storage is only available during the life of an instance. Rebooting an instance will allow ephemeral data stay persistent. However, stopping and starting an instance will remove all ephemeral storage.
Q15: After having created a new Linux instance on Amazon EC2, and downloaded the .pem file (called Toto.pem) you try and SSH into your IP address (54.1.132.33) using the following command.
ssh -i my_key.pem ec2-user@52.2.222.22
However you receive the following error.
@@@@@@@@ WARNING: UNPROTECTED PRIVATE KEY FILE! @ @@@@@@@@@@@@@@@@@@@
What is the most probable reason for this and how can you fix it?
A. You do not have root access on your terminal and need to use the sudo option for this to work.
B. You do not have enough permissions to perform the operation.
C. Your key file is encrypted. You need to use the -u option for unencrypted not the -i option.
D. Your key file must not be publicly viewable for SSH to work. You need to modify your .pem file to limit permissions.
D. You need to run something like: chmod 400 my_key.pem
Q16: You have an EBS root device on /dev/sda1 on one of your EC2 instances. You are having trouble with this particular instance and you need to either Stop/Start, Reboot or Terminate the instance but you do NOT want to lose any data that you have stored on /dev/sda1. However, you are unsure if changing the instance state in any of the aforementioned ways will cause you to lose data stored on the EBS volume. Which of the below statements best describes the effect each change of instance state would have on the data you have stored on /dev/sda1?
A. Whether you stop/start, reboot or terminate the instance it does not matter because data on an EBS volume is not ephemeral and the data will not be lost regardless of what method is used.
B. If you stop/start the instance the data will not be lost. However if you either terminate or reboot the instance the data will be lost.
C. Whether you stop/start, reboot or terminate the instance it does not matter because data on an EBS volume is ephemeral and it will be lost no matter what method is used.
D. The data will be lost if you terminate the instance, however the data will remain on /dev/sda1 if you reboot or stop/start the instance because data on an EBS volume is not ephemeral.
D. The question states that an EBS-backed root device is mounted at /dev/sda1, and EBS volumes maintain information regardless of the instance state. If it was instance store, this would be a different answer.
Q17: EC2 instances are launched from Amazon Machine Images (AMIs). A given public AMI:
A. Can only be used to launch EC2 instances in the same AWS availability zone as the AMI is stored
B. Can only be used to launch EC2 instances in the same country as the AMI is stored
C. Can only be used to launch EC2 instances in the same AWS region as the AMI is stored
D. Can be used to launch EC2 instances in any AWS region
C. AMIs are only available in the region they are created. Even in the case of the AWS-provided AMIs, AWS has actually copied the AMIs for you to different regions. You cannot access an AMI from one region in another region. However, you can copy an AMI from one region to another
A. The ability to create custom permission policies.
B. Assigning IAM permission policies to more than one user at a time.
C. Easier user/policy management.
D. Allowing EC2 instances to gain access to S3.
B. and C.
A. is incorrect: This is a benefit of IAM generally or a benefit of IAM policies. But IAM groups don’t create policies, they have policies attached to them.
Q22: What should the Developer enable on the DynamoDB table to optimize performance and minimize costs?
A. Amazon DynamoDB auto scaling
B. Amazon DynamoDB cross-region replication
C. Amazon DynamoDB Streams
D. Amazon DynamoDB Accelerator
D. DAX is a DynamoDB-compatible caching service that enables you to benefit from fast in-memory performance for demanding applications. DAX addresses three core scenarios:
As an in-memory cache, DAX reduces the response times of eventually-consistent read workloads by an order of magnitude, from single-digit milliseconds to microseconds.
DAX reduces operational and application complexity by providing a managed service that is API-compatible with Amazon DynamoDB, and thus requires only minimal functional changes to use with an existing application.
For read-heavy or bursty workloads, DAX provides increased throughput and potential operational cost savings by reducing the need to over-provision read capacity units. This is especially beneficial for applications that require repeated reads for individual keys.
Q23: A Developer has been asked to create an AWS Elastic Beanstalk environment for a production web application which needs to handle thousands of requests. Currently the dev environment is running on a t1 micro instance. How can the Developer change the EC2 instance type to m4.large?
A. Use CloudFormation to migrate the Amazon EC2 instance type of the environment from t1 micro to m4.large.
B. Create a saved configuration file in Amazon S3 with the instance type as m4.large and use the same during environment creation.
C. Change the instance type to m4.large in the configuration details page of the Create New Environment page.
D. Change the instance type value for the environment to m4.large by using update autoscaling group CLI command.
B. The Elastic Beanstalk console and EB CLI set configuration options when you create an environment. You can also set configuration options in saved configurations and configuration files. If the same option is set in multiple locations, the value used is determined by the order of precedence.
Configuration option settings can be composed in text format and saved prior to environment creation, applied during environment creation using any supported client, and added, modified or removed after environment creation.
During environment creation, configuration options are applied from multiple sources with the following precedence, from highest to lowest:
Settings applied directly to the environment – Settings specified during a create environment or update environment operation on the Elastic Beanstalk API by any client, including the AWS Management Console, EB CLI, AWS CLI, and SDKs. The AWS Management Console and EB CLI also applyrecommended values for some options that apply at this level unless overridden.
Saved Configurations–
Settings for any options that are not applied directly to the
environment are loaded from a saved configuration, if specified.
Configuration Files (.ebextensions)– Settings for any options that are not applied directly to the
environment, and also not specified in a saved configuration, are loaded from configuration files in the .ebextensions folder at the root of the application source bundle.
Configuration files are executed in alphabetical order. For example,.ebextensions/01run.configis executed before.ebextensions/02do.config.
Default Values– If a configuration option has a default value, it only applies when the option is not set at any of the above levels.
If the same configuration option is defined in more than one location, the setting with the highest precedence is applied. When a setting is applied from a saved configuration or settings applied directly to the environment, the setting is stored as part of the environment’s configuration. These settings can be removed with the AWS CLI or with the EB CLI
. Settings in configuration files are not applied
directly to the environment and cannot be removed without modifying the configuration files and deploying a new application version.If a setting applied with one of the other methods is removed, the same setting will be loaded from configuration files in the source bundle.
Q26: Which read request in DynamoDB returns a response with the most up-to-date data, reflecting the updates from all prior write operations that were successful?
A. Eventual Consistent Reads
B. Conditional reads for Consistency
C. Strongly Consistent Reads
D. Not possible
C. This is provided very clearly in the AWS documentation as shown below with regards to the read consistency for DynamoDB. Only in Strong Read consistency can you be guaranteed that you get the write read value after all the writes are completed.
Q27: You’ ve been asked to move an existing development environment on the AWS Cloud. This environment consists mainly of Docker based containers. You need to ensure that minimum effort is taken during the migration process. Which of the following step would you consider for this requirement?
A. Create an Opswork stack and deploy the Docker containers
B. Create an application and Environment for the Docker containers in the Elastic Beanstalk service
C. Create an EC2 Instance. Install Docker and deploy the necessary containers.
D. Create an EC2 Instance. Install Docker and deploy the necessary containers. Add an Autoscaling Group for scalability of the containers.
B. The Elastic Beanstalk service is the ideal service to quickly provision development environments. You can also create environments which can be used to host Docker based containers.
Q28: You’ve written an application that uploads objects onto an S3 bucket. The size of the object varies between 200 – 500 MB. You’ve seen that the application sometimes takes a longer than expected time to upload the object. You want to improve the performance of the application. Which of the following would you consider?
A. Create multiple threads and upload the objects in the multiple threads
B. Write the items in batches for better performance
C. Use the Multipart upload API
D. Enable versioning on the Bucket
C. All other options are invalid since the best way to handle large object uploads to the S3 service is to use the Multipart upload API. The Multipart upload API enables you to upload large objects in parts. You can use this API to upload new large objects or make a copy of an existing object. Multipart uploading is a three-step process: You initiate the upload, you upload the object parts, and after you have uploaded all the parts, you complete the multipart upload. Upon receiving the complete multipart upload request, Amazon S3 constructs the object from the uploaded parts, and you can then access the object just as you would any other object in your bucket.
Q29: A security system monitors 600 cameras, saving image metadata every 1 minute to an Amazon DynamoDb table. Each sample involves 1kb of data, and the data writes are evenly distributed over time. How much write throughput is required for the target table?
A. 6000
B. 10
C. 3600
D. 600
B. When you mention the write capacity of a table in Dynamo DB, you mention it as the number of 1KB writes per second. So in the above question, since the write is happening every minute, we need to divide the value of 600 by 60, to get the number of KB writes per second. This gives a value of 10.
You can specify the Write capacity in the Capacity tab of the DynamoDB table.
Q33: You have instances inside private subnets and a properly configured bastion host instance in a public subnet. None of the instances in the private subnets have a public or Elastic IP address. How can you connect an instance in the private subnet to the open internet to download system updates?
A. Create and assign EIP to each instance
B. Create and attach a second IGW to the VPC.
C. Create and utilize a NAT Gateway
D. Connect to a VPN
C. You can use a network address translation (NAT) gateway in a public subnet in your VPC to enable instances in the private subnet to initiate outbound traffic to the Internet, but prevent the instances from receiving inbound traffic initiated by someone on the Internet.
Reference: AWS Network Address Translation Gateway
Q34: What feature of VPC networking should you utilize if you want to create “elasticity” in your application’s architecture?
A. Security Groups
B. Route Tables
C. Elastic Load Balancer
D. Auto Scaling
D. Auto scaling is designed specifically with elasticity in mind. Auto scaling allows for the increase and decrease of compute power based on demand, thus creating elasticity in the architecture.
Reference: AWS Autoscalling
Q31: An organization is using an Amazon ElastiCache cluster in front of their Amazon RDS instance. The organization would like the Developer to implement logic into the code so that the cluster only retrieves data from RDS when there is a cache miss. What strategy can the Developer implement to achieve this?
A. Lazy loading
B. Write-through
C. Error retries
D. Exponential backoff
Answer:
Answer – A
Whenever your application requests data, it first makes the request to the ElastiCache cache. If the data exists in the cache and is current, ElastiCache returns the data to your application. If the data does not exist in the cache, or the data in the cache has expired, your application requests data from your data store which returns the data to your application. Your application then writes the data received from the store to the cache so it can be more quickly retrieved next time it is requested. All other options are incorrect.
Reference: Caching Strategies
Q32: A developer is writing an application that will run on Ec2 instances and read messages from SQS queue. The nessages will arrive every 15-60 seconds. How should the Developer efficiently query the queue for new messages?
A. Use long polling
B. Set a custom visibility timeout
C. Use short polling
D. Implement exponential backoff
Answer – A Long polling will help insure that the applications make less requests for messages in a shorter period of time. This is more cost effective. Since the messages are only going to be available after 15 seconds and we don’t know exacly when they would be available, it is better to use Long Polling.
Reference: Amazon SQS Long Polling
Q33: You are using AWS SAM to define a Lambda function and configure CodeDeploy to manage deployment patterns. With new Lambda function working as per expectation which of the following will shift traffic from original Lambda function to new Lambda function in the shortest time frame?
A. Canary10Percent5Minutes
B. Linear10PercentEvery10Minutes
C. Canary10Percent15Minutes
D. Linear10PercentEvery1Minute
Answer – A
With Canary Deployment Preference type, Traffic is shifted in two intervals. With Canary10Percent5Minutes, 10 percent of traffic is shifted in the first interval while remaining all traffic is shifted after 5 minutes.
Reference: Gradual Code Deployment
Q34: You are using AWS SAM templates to deploy a serverless application. Which of the following resource will embed application from Amazon S3 buckets?
A. AWS::Serverless::Api
B. AWS::Serverless::Application
C. AWS::Serverless::Layerversion
D. AWS::Serverless::Function
Answer – B
AWS::Serverless::Application resource in AWS SAm template is used to embed application frm Amazon S3 buckets.
Reference: Declaring Serverless Resources
Q35: You are using AWS Envelope Encryption for encrypting all sensitive data. Which of the followings is True with regards to Envelope Encryption?
A. Data is encrypted be encrypting Data key which is further encrypted using encrypted Master Key.
B. Data is encrypted by plaintext Data key which is further encrypted using encrypted Master Key.
C. Data is encrypted by encrypted Data key which is further encrypted using plaintext Master Key.
D. Data is encrypted by plaintext Data key which is further encrypted using plaintext Master Key.
Answer – D
With Envelope Encryption, unencrypted data is encrypted using plaintext Data key. This Data is further encrypted using plaintext Master key. This plaintext Master key is securely stored in AWS KMS & known as Customer Master Keys.
Reference: AWS Key Management Service Concepts
Q36: You are developing an application that will be comprised of the following architecture –
A set of Ec2 instances to process the videos.
These (Ec2 instances) will be spun up by an autoscaling group.
SQS Queues to maintain the processing messages.
There will be 2 pricing tiers.
How will you ensure that the premium customers videos are given more preference?
A. Create 2 Autoscaling Groups, one for normal and one for premium customers
B. Create 2 set of Ec2 Instances, one for normal and one for premium customers
C. Create 2 SQS queus, one for normal and one for premium customers
D. Create 2 Elastic Load Balancers, one for normal and one for premium customers.
Answer – C
The ideal option would be to create 2 SQS queues. Messages can then be processed by the application from the high priority queue first.<br? The other options are not the ideal options. They would lead to extra costs and also extra maintenance.
Reference: SQS
Q37: You are developing an application that will interact with a DynamoDB table. The table is going to take in a lot of read and write operations. Which of the following would be the ideal partition key for the DynamoDB table to ensure ideal performance?
A. CustomerID
B. CustomerName
C. Location
D. Age
Answer- A
Use high-cardinality attributes. These are attributes that have distinct values for each item, like e-mailid, employee_no, customerid, sessionid, orderid, and so on..
Use composite attributes. Try to combine more than one attribute to form a unique key.
Reference: Choosing the right DynamoDB Partition Key
Q38: A developer is making use of AWS services to develop an application. He has been asked to develop the application in a manner to compensate any network delays. Which of the following two mechanisms should he implement in the application?
A. Multiple SQS queues
B. Exponential backoff algorithm
C. Retries in your application code
D. Consider using the Java sdk.
Answer- B. and C.
In addition to simple retries, each AWS SDK implements exponential backoff algorithm for better flow control. The idea behind exponential backoff is to use progressively longer waits between retries for consecutive error responses. You should implement a maximum delay interval, as well as a maximum number of retries. The maximum delay interval and maximum number of retries are not necessarily fixed values, and should be set based on the operation being performed, as well as other local factors, such as network latency.
Reference: Error Retries and Exponential Backoff in AWS
Q39: An application is being developed that is going to write data to a DynamoDB table. You have to setup the read and write throughput for the table. Data is going to be read at the rate of 300 items every 30 seconds. Each item is of size 6KB. The reads can be eventual consistent reads. What should be the read capacity that needs to be set on the table?
A. 10
B. 20
C. 6
D. 30
Answer – A
Since there are 300 items read every 30 seconds , that means there are (300/30) = 10 items read every second.
Since each item is 6KB in size , that means , 2 reads will be required for each item.
So we have total of 2*10 = 20 reads for the number of items per second
Since eventual consistency is required , we can divide the number of reads(20) by 2 , and in the end we get the Read Capacity of 10.
Q40: You are in charge of deploying an application that will be hosted on an EC2 Instance and sit behind an Elastic Load balancer. You have been requested to monitor the incoming connections to the Elastic Load Balancer. Which of the below options can suffice this requirement?
A. Use AWS CloudTrail with your load balancer
B. Enable access logs on the load balancer
C. Use a CloudWatch Logs Agent
D. Create a custom metric CloudWatch lter on your load balancer
Answer – B
Elastic Load Balancing provides access logs that capture detailed information about requests sent to your load balancer. Each log contains information such as the time the request was received, the client’s IP address, latencies, request paths, and server responses. You can use these access logs to analyze traffic patterns and troubleshoot issues.
Reference: Access Logs for Your Application Load Balancer
Q41: A static web site has been hosted on a bucket and is now being accessed by users. One of the web pages javascript section has been changed to access data which is hosted in another S3 bucket. Now that same web page is no longer loading in the browser. Which of the following can help alleviate the error?
A. Enable versioning for the underlying S3 bucket.
B. Enable Replication so that the objects get replicated to the other bucket
C. Enable CORS for the bucket
D. Change the Bucket policy for the bucket to allow access from the other bucket
Answer – C
Cross-origin resource sharing (CORS) defines a way for client web applications that are loaded in one domain to interact with resources in a different domain. With CORS support, you can build rich client-side web applications with Amazon S3 and selectively allow cross-origin access to your Amazon S3 resources.
Cross-Origin Resource Sharing: Use-case Scenarios The following are example scenarios for using CORS:
Scenario 1: Suppose that you are hosting a website in an Amazon S3 bucket named website as described in Hosting a Static Website on Amazon S3. Your users load the website endpoint http://website.s3-website-us-east-1.amazonaws.com. Now you want to use JavaScript on the webpages that are stored in this bucket to be able to make authenticated GET and PUT requests against the same bucket by using the Amazon S3 API endpoint for the bucket, website.s3.amazonaws.com. A browser would normally block JavaScript from allowing those requests, but with CORS you can congure your bucket to explicitly enable cross-origin requests from website.s3-website-us-east-1.amazonaws.com.
Scenario 2: Suppose that you want to host a web font from your S3 bucket. Again, browsers require a CORS check (also called a preight check) for loading web fonts. You would congure the bucket that is hosting the web font to allow any origin to make these requests.
Q42: Your mobile application includes a photo-sharing service that is expecting tens of thousands of users at launch. You will leverage Amazon Simple Storage Service (S3) for storage of the user Images, and you must decide how to authenticate and authorize your users for access to these images. You also need to manage the storage of these images. Which two of the following approaches should you use? Choose two answers from the options below
A. Create an Amazon S3 bucket per user, and use your application to generate the S3 URL for the appropriate content.
B. Use AWS Identity and Access Management (IAM) user accounts as your application-level user database, and offload the burden of authentication from your application code.
C. Authenticate your users at the application level, and use AWS Security Token Service (STS)to grant token-based authorization to S3 objects.
D. Authenticate your users at the application level, and send an SMS token message to the user. Create an Amazon S3 bucket with the same name as the SMS message token, and move the user’s objects to that bucket.
Answer- C
The AWS Security Token Service (STS) is a web service that enables you to request temporary, limited-privilege credentials for AWS Identity and Access Management (IAM) users or for users that you authenticate (federated users). The token can then be used to grant access to the objects in S3.
You can then provides access to the objects based on the key values generated via the user id.
Q43: Your current log analysis application takes more than four hours to generate a report of the top 10 users of your web application. You have been asked to implement a system that can report this information in real time, ensure that the report is always up to date, and handle increases in the number of requests to your web application. Choose the option that is cost-effective and can fulfill the requirements.
A. Publish your data to CloudWatch Logs, and congure your application to Autoscale to handle the load on demand.
B. Publish your log data to an Amazon S3 bucket. Use AWS CloudFormation to create an Auto Scaling group to scale your post-processing application which is congured to pull down your log les stored an Amazon S3
C. Post your log data to an Amazon Kinesis data stream, and subscribe your log-processing application so that is congured to process your logging data.
D. Create a multi-AZ Amazon RDS MySQL cluster, post the logging data to MySQL, and run a map reduce job to retrieve the required information on user counts.
Answer:
Answer – C
Amazon Kinesis makes it easy to collect, process, and analyze real-time, streaming data so you can get timely insights and react quickly to new information. Amazon Kinesis offers key capabilities to cost effectively process streaming data at any scale, along with the flexibility to choose the tools that best suit the requirements of your application. With Amazon Kinesis, you can ingest real-time data such as application logs, website clickstreams, IoT telemetry data, and more into your databases, data lakes and data warehouses, or build your own real-time applications using this data.
Reference: Amazon Kinesis
Q44: You’ve been instructed to develop a mobile application that will make use of AWS services. You need to decide on a data store to store the user sessions. Which of the following would be an ideal data store for session management?
A. AWS Simple Storage Service
B. AWS DynamoDB
C. AWS RDS
D. AWS Redshift
Answer:
Answer – B
DynamoDB is a alternative solution which can be used for storage of session management. The latency of access to data is less , hence this can be used as a data store for session management
Reference: Scalable Session Handling in PHP Using Amazon DynamoDB
Q45: Your application currently interacts with a DynamoDB table. Records are inserted into the table via the application. There is now a requirement to ensure that whenever items are updated in the DynamoDB primary table , another record is inserted into a secondary table. Which of the below feature should be used when developing such a solution?
A. AWS DynamoDB Encryption
B. AWS DynamoDB Streams
C. AWS DynamoDB Accelerator
D. AWSTable Accelerator
Answer – B
DynamoDB Streams Use Cases and Design Patterns This post describes some common use cases you might encounter, along with their design options and solutions, when migrating data from relational data stores to Amazon DynamoDB. We will consider how to manage the following scenarios:
How do you set up a relationship across multiple tables in which, based on the value of an item from one table, you update the item in a second table?
How do you trigger an event based on a particular transaction?
How do you audit or archive transactions?
How do you replicate data across multiple tables (similar to that of materialized views/streams/replication in relational data stores)?
Relational databases provide native support for transactions, triggers, auditing, and replication. Typically, a transaction in a database refers to performing create, read, update, and delete (CRUD) operations against multiple tables in a block. A transaction can have only two states—success or failure. In other words, there is no partial completion. As a NoSQL database, DynamoDB is not designed to support transactions. Although client-side libraries are available to mimic the transaction capabilities, they are not scalable and cost-effective. For example, the Java Transaction Library for DynamoDB creates 7N+4 additional writes for every write operation. This is partly because the library holds metadata to manage the transactions to ensure that it’s consistent and can be rolled back before commit. You can use DynamoDB Streams to address all these use cases. DynamoDB Streams is a powerful service that you can combine with other AWS services to solve many similar problems. When enabled, DynamoDB Streams captures a time-ordered sequence of item-level modifications in a DynamoDB table and durably stores the information for up to 24 hours. Applications can access a series of stream records, which contain an item change, from a DynamoDB stream in near real time. AWS maintains separate endpoints for DynamoDB and DynamoDB Streams. To work with database tables and indexes, your application must access a DynamoDB endpoint. To read and process DynamoDB Streams records, your application must access a DynamoDB Streams endpoint in the same Region. All of the other options are incorrect since none of these would meet the core requirement.
Reference: DynamoDB Streams Use Cases and Design Patterns
Q46: An application has been making use of AWS DynamoDB for its back-end data store. The size of the table has now grown to 20 GB , and the scans on the table are causing throttling errors. Which of the following should now be implemented to avoid such errors?
A. Large Page size
B. Reduced page size
C. Parallel Scans
D. Sequential scans
Answer – B
When you scan your table in Amazon DynamoDB, you should follow the DynamoDB best practices for avoiding sudden bursts of read activity. You can use the following technique to minimize the impact of a scan on a table’s provisioned throughput. Reduce page size Because a Scan operation reads an entire page (by default, 1 MB), you can reduce the impact of the scan operation by setting a smaller page size. The Scan operation provides a Limit parameter that you can use to set the page size for your request. Each Query or Scan request that has a smaller page size uses fewer read operations and creates a “pause” between each request. For example, suppose that each item is 4 KB and you set the page size to 40 items. A Query request would then consume only 20 eventually consistent read operations or 40 strongly consistent read operations. A larger number of smaller Query or Scan operations would allow your other critical requests to succeed without throttling.
Reference1: Rate-Limited Scans in Amazon DynamoDB
Q47: Which of the following is correct way of passing a stage variable to an HTTP URL ? (Select TWO.)
A. http://example.com/${}/prod
B. http://example.com/${stageVariables.}/prod
C. http://${stageVariables.}.example.com/dev/operation
D. http://${stageVariables}.example.com/dev/operation
E. http://${}.example.com/dev/operation
F. http://example.com/${stageVariables}/prod
Answer – B. and C.
A stage variable can be used as part of HTTP integration URL as in following cases, · A full URI without protocol · A full domain · A subdomain · A path · A query string In the above case , option B & C displays stage variable as a path & sub-domain.
Reference: Amazon API Gateway Stage Variables Reference
Q48: Your company is planning on creating new development environments in AWS. They want to make use of their existing Chef recipes which they use for their on-premise configuration for servers in AWS. Which of the following service would be ideal to use in this regard?
A. AWS Elastic Beanstalk
B. AWS OpsWork
C. AWS Cloudformation
D. AWS SQS
Answer – B
AWS OpsWorks is a configuration management service that provides managed instances of Chef and Puppet. Chef and Puppet are automation platforms that allow you to use code to automate the configurations of your servers. OpsWorks lets you use Chef and Puppet to automate how servers are configured, deployed, and managed across your Amazon EC2 instances or on-premises compute environments All other options are invalid since they cannot be used to work with Chef recipes for configuration management.
Reference: AWS OpsWorks
Q49: Your company has developed a web application and is hosting it in an Amazon S3 bucket configured for static website hosting. The users can log in to this app using their Google/Facebook login accounts. The application is using the AWS SDK for JavaScript in the browser to access data stored in an Amazon DynamoDB table. How can you ensure that API keys for access to your data in DynamoDB are kept secure?
A. Create an Amazon S3 role in IAM with access to the specific DynamoDB tables, and assign it to the bucket hosting your website
B. Configure S3 bucket tags with your AWS access keys for your bucket hosing your website so that the application can query them for access.
C. Configure a web identity federation role within IAM to enable access to the correct DynamoDB resources and retrieve temporary credentials
D. Store AWS keys in global variables within your application and configure the application to use these credentials when making requests.
Answer – C
With web identity federation, you don’t need to create custom sign-in code or manage your own user identities. Instead, users of your app can sign in using a well-known identity provider (IdP) —such as Login with Amazon, Facebook, Google, or any other OpenID Connect (OIDC)-compatible IdP, receive an authentication token, and then exchange that token for temporary security credentials in AWS that map to an IAM role with permissions to use the resources in your AWS account. Using an IdP helps you keep your AWS account secure, because you don’t have to embed and distribute long-term security credentials with your application. Option A is invalid since Roles cannot be assigned to S3 buckets Options B and D are invalid since the AWS Access keys should not be used
Reference: About Web Identity Federation
Q50: Your application currently makes use of AWS Cognito for managing user identities. You want to analyze the information that is stored in AWS Cognito for your application. Which of the following features of AWS Cognito should you use for this purpose?
A. Cognito Data
B. Cognito Events
C. Cognito Streams
D. Cognito Callbacks
Answer – C
Amazon Cognito Streams gives developers control and insight into their data stored in Amazon Cognito. Developers can now configure a Kinesis stream to receive events as data is updated and synchronized. Amazon Cognito can push each dataset change to a Kinesis stream you own in real time. All other options are invalid since you should use Cognito Streams
Reference:
Q51: You’ve developed a set of scripts using AWS Lambda. These scripts need to access EC2 Instances in a VPC. Which of the following needs to be done to ensure that the AWS Lambda function can access the resources in the VPC. Choose 2 answers from the options given below
A. Ensure that the subnet ID’s are mentioned when conguring the Lambda function
B. Ensure that the NACL ID’s are mentioned when conguring the Lambda function
C. Ensure that the Security Group ID’s are mentioned when conguring the Lambda function
D. Ensure that the VPC Flow Log ID’s are mentioned when conguring the Lambda function
Answer: A and C.
AWS Lambda runs your function code securely within a VPC by default. However, to enable your Lambda function to access resources inside your private VPC, you must provide additional VPCspecific configuration information that includes VPC subnet IDs and security group IDs. AWS Lambda uses this information to set up elastic network interfaces (ENIs) that enable your function to connect securely to other resources within your private VPC.
Reference: Configuring a Lambda Function to Access Resources in an Amazon VPC
Q52: You’ve currently been tasked to migrate an existing on-premise environment into Elastic Beanstalk. The application does not make use of Docker containers. You also can’t see any relevant environments in the beanstalk service that would be suitable to host your application. What should you consider doing in this case?
A. Migrate your application to using Docker containers and then migrate the app to the Elastic Beanstalk environment.
B. Consider using Cloudformation to deploy your environment to Elastic Beanstalk
C. Consider using Packer to create a custom platform
D. Consider deploying your application using the Elastic Container Service
Answer – C
Elastic Beanstalk supports custom platforms. A custom platform is a more advanced customization than a Custom Image in several ways. A custom platform lets you develop an entire new platform from scratch, customizing the operating system, additional software, and scripts that Elastic Beanstalk runs on platform instances. This flexibility allows you to build a platform for an application that uses a language or other infrastructure software, for which Elastic Beanstalk doesn’t provide a platform out of the box. Compare that to custom images, where you modify an AMI for use with an existing Elastic Beanstalk platform, and Elastic Beanstalk still provides the platform scripts and controls the platform’s software stack. In addition, with custom platforms you use an automated, scripted way to create and maintain your customization, whereas with custom images you make the changes manually over a running instance. To create a custom platform, you build an Amazon Machine Image (AMI) from one of the supported operating systems—Ubuntu, RHEL, or Amazon Linux (see the flavor entry in Platform.yaml File Format for the exact version numbers)—and add further customizations. You create your own Elastic Beanstalk platform using Packer, which is an open-source tool for creating machine images for many platforms, including AMIs for use with Amazon EC2. An Elastic Beanstalk platform comprises an AMI configured to run a set of software that supports an application, and metadata that can include custom configuration options and default configuration option settings.
Reference: AWS Elastic Beanstalk Custom Platforms
Q53: Company B is writing 10 items to the Dynamo DB table every second. Each item is 15.5Kb in size. What would be the required provisioned write throughput for best performance? Choose the correct answer from the options below.
A. 10
B. 160
C. 155
D. 16
Answer – B.
Company B is writing 10 items to the Dynamo DB table every second. Each item is 15.5Kb in size. What would be the required provisioned write throughput for best performance? Choose the correct answer from the options below.
Reference: Read/Write Capacity Mode
Q57: Which of the following practices allows multiple developers working on the same application to merge code changes frequently, without impacting each other and enables the identification of bugs early on in the release process?
Q60: You want to receive an email whenever a user pushes code to CodeCommit repository, how can you configure this?
A. Create a new SNS topic and configure it to poll for CodeCommit eveents. Ask all users to subscribe to the topic to receive notifications
B. Configure a CloudWatch Events rule to send a message to SES which will trigger an email to be sent whenever a user pushes code to the repository.
C. Configure Notifications in the console, this will create a CloudWatch events rule to send a notification to a SNS topic which will trigger an email to be sent to the user.
D. Configure a CloudWatch Events rule to send a message to SQS which will trigger an email to be sent whenever a user pushes code to the repository.
Q63: You are deploying a number of EC2 and RDS instances using CloudFormation. Which section of the CloudFormation template would you use to define these?
A. Transforms
B. Outputs
C. Resources
D. Instances
Answer: C.
The Resources section defines your resources you are provisioning. Outputs is used to output user defines data relating to the reources you have built and can also used as input to another CloudFormation stack. Transforms is used to reference code located in S3.
Reference: Resources
Q64: Which AWS service can be used to fully automate your entire release process?
A. CodeDeploy
B. CodePipeline
C. CodeCommit
D. CodeBuild
Answer: B.
AWS CodePipeline is a fully managed continuous delivery service that helps you automate your release pipelines for fast and reliable application and infrastructure updates
Q65: You want to use the output of your CloudFormation stack as input to another CloudFormation stack. Which sections of the CloudFormation template would you use to help you configure this?
A. Outputs
B. Transforms
C. Resources
D. Exports
Answer: A.
Outputs is used to output user defines data relating to the reources you have built and can also used as input to another CloudFormation stack.
Reference: CloudFormation Outputs
Q66: You have some code located in an S3 bucket that you want to reference in your CloudFormation template. Which section of the template can you use to define this?
A. Inputs
B. Resources
C. Transforms
D. Files
Answer: C.
Transforms is used to reference code located in S3 and also specififying the use of the Serverless Application Model (SAM) for Lambda deployments.
Reference: Transforms
Q67: You are deploying an application to a number of Ec2 instances using CodeDeploy. What is the name of the file
used to specify source files and lifecycle hooks?
Q68: Which of the following approaches allows you to re-use pieces of CloudFormation code in multiple templates, for common use cases like provisioning a load balancer or web server?
A. Share the code using an EBS volume
B. Copy and paste the code into the template each time you need to use it
C. Use a cloudformation nested stack
D. Store the code you want to re-use in an AMI and reference the AMI from within your CloudFormation template.
Q72: Which of the following is an encrypted key used by KMS to encrypt your data
A. Custmoer Mamaged Key
B. Encryption Key
C. Envelope Key
D. Customer Master Key
Answer: C.
Your Data key also known as the Enveloppe key is encrypted using the master key.This approach is known as Envelope encryption.
Envelope encryption is the practice of encrypting plaintext data with a data key, and then encrypting the data key under another key.
AWS has provided whitepapers to help you understand the technical concepts. Below are the recommended whitepapers for the AWS Certified Developer – Associate Exam.
The AWS Certified Developer-Associate Examination (DVA-C01) is a pass or fail exam. The examination is scored against a minimum standard established by AWS professionals guided by certification industry best practices and guidelines.
Your results for the examination are reported as a score from 100 – 1000, with a minimum passing score of 720.
Domain 1: Deployment (22%)
1.1 Deploy written code in AWS using existing CI/CD pipelines, processes, and patterns.
1.2 Deploy applications using Elastic Beanstalk.
1.3 Prepare the application deployment package to be deployed to AWS.
1.4 Deploy serverless applications
22%
Domain 2: Security (26%)
2.1 Make authenticated calls to AWS services.
2.2 Implement encryption using AWS services.
2.3 Implement application authentication and authorization.
26%
Domain 3: Development with AWS Services (30%)
3.1 Write code for serverless applications.
3.2 Translate functional requirements into application design.
3.3 Implement application design into application code.
3.4 Write code that interacts with AWS services by using APIs, SDKs, and AWS CLI.
30%
Domain 4: Refactoring
4.1 Optimize application to best use AWS services and features.
4.2 Migrate existing application code to run on AWS.
10%
Domain 5: Monitoring and Troubleshooting (10%)
5.1 Write code that can be monitored.
5.2 Perform root cause analysis on faults found in testing or production.
What is the AWS Certified Cloud Practitioner Exam?
The AWS Certified Cloud Practitioner Exam is an introduction to AWS services and the intention is to examine the candidates ability to define what the AWS cloud is and its global infrastructure. It provides an overview of AWS core services security aspects, pricing and support services. The main objective is to provide an overall understanding about the Amazon Web Services Cloud platform. The course helps you get the conceptual understanding of the AWS and can help you know about the basics of AWS and cloud computing, including the services, cases and benefits.
To succeed with the real exam, do not memorize the answers below. It is very important that you understand why a question is right or wrong and the concepts behind it by carefully reading the reference documents in the answers.
aws cloud practitioner practice questions and answers
aws cloud practitioner practice exam questions and references
For auditing purposes, your company now wants to monitor all API activity for all regions in your AWS environment. What can you use to fulfill this new requirement?
A. For each region, enable CloudTrail and send all logs to a bucket in each region.
B. Enable CloudTrail for all regions.
C. Ensure one CloudTrail is enabled for all regions.
D. Use AWS Config to enable the trail for all regions.
Answer:
C. Ensure one CloudTrail is enabled for all regions.
Turn on CloudTrail for all regions in your environment and CloudTrail will deliver log files from all regions to one S3 bucket.
AWS CloudTrail is a service that enables governance, compliance, operational auditing, and risk auditing of your AWS account. With CloudTrail, you can log, continuously monitor, and retain account activity related to actions across your AWS infrastructure. CloudTrail provides event history of your AWS account activity, including actions taken through the AWS Management Console, AWS SDKs, command line tools, and other AWS services. This event history simplifies security analysis, resource change tracking, and troubleshooting.
What is the best solution to provide secure access to an S3 bucket not using the internet?
A. Use a VPN connection.
B. Use an Internet Gateway.
C. Use a VPC Endpoint to access S3.
D. Use a NAT Gateway.
Answer:
C. Use a VPC Endpoint to access S3.
A VPC endpoint enables you to privately connect your VPC to supported AWS services and VPC endpoint services powered by PrivateLink without requiring an internet gateway, NAT device, VPN connection, or AWS Direct Connect connection. Instances in your VPC do not require public IP addresses to communicate with resources in the service. Traffic between your VPC and the other service does not leave the Amazon network.
AWS PrivateLink simplifies the security of data shared with cloud-based applications by eliminating the exposure of data to the public Internet.
A. and D.
It is AWS responsibility to secure Edge locations and decommission the data.
AWS responsibility “Security of the Cloud” – AWS is responsible for protecting the infrastructure that runs all of the services offered in the AWS Cloud. This infrastructure is composed of the hardware, software, networking, and facilities that run AWS Cloud services.
You have EC2 instances running at 90% utilization and you expect this to continue for at least a year. What type of EC2 instance would you choose to ensure your cost stay at a minimum?
A. Dedicated host instances
B. On-demand instances
C. Spot instances
D. Reserved instances
Answer:
D. Reserved instances:
Reserved instances are the best choice for instances with continuous usage and offer a reduced cost because you purchase the instance for the entire year.
Amazon EC2 Reserved Instances (RI) provide a significant discount (up to 75%) compared to On-Demand pricing and provide a capacity reservation when used in a specific Availability Zone.
What tool would you use to get an estimated monthly cost for your environment?
A. TCO Calculator
B. Simply Monthly Calculator
C. Cost Explorer
D. Consolidated Billing
Answer:
B. Simply Monthly Calculator:
The AWS Simple Monthly Calculator helps customers and prospects estimate their monthly AWS bill more efficiently. Using this tool, they can add, modify and remove services from their ‘bill’ and it will recalculate their estimated monthly charges automatically.
How do you make sure your organization does not exceed its monthly budget?
A. Sign up for the free alert under filing preferences in the AWS Management Console.
B. Set a schedule to regularly review the Billing an Cost Management dashboard each month.
C. Create an email alert in AWS Budget
D. In CloudWatch, create an alarm that triggers each time the limit is exceeded.
Answer:
C. Create an email alert in AWS Budget.
AWS Budgets gives you the ability to set custom budgets that alert you when your costs or usage exceed (or are forecasted to exceed) your budgeted amount.
You can also use AWS Budgets to set reservation utilization or coverage targets and receive alerts when your utilization drops below the threshold you define. Reservation alerts are supported for Amazon EC2, Amazon RDS, Amazon Redshift, Amazon ElastiCache, and Amazon Elasticsearch reservations.
An Edge Location is a specialization AWS data centre that works with which services?
A. Lambda
B. CloudWatch
C. CloudFront
D. Route 53
Answer:
A. C. D. : Lambda, CloudFront and Route 53
Lambda@Edge lets you run Lambda functions to customize the content that CloudFront delivers, executing the functions in AWS locations closer to the viewer.
Amazon CloudFront is a web service that speeds up distribution of your static and dynamic web content, such as .html, .css, .js, and image files, to your users. CloudFront delivers your content through a worldwide network of data centers called edge locations. When a user requests content that you’re serving with CloudFront, the user is routed to the edge location that provides the lowest latency (time delay), so that content is delivered with the best possible performance.
CloudFront speeds up the distribution of your content by routing each user request through the AWS backbone network to the edge location that can best serve your content. Typically, this is a CloudFront edge server that provides the fastest delivery to the viewer. Using the AWS network dramatically reduces the number of networks that your users’ requests must pass through, which improves performance. Users get lower latency—the time it takes to load the first byte of the file—and higher data transfer rates.
You also get increased reliability and availability because copies of your files (also known as objects) are now held (or cached) in multiple edge locations around the world.
What is the preferred method of linking 2 AWS accounts?
A. AWS Organizations
B. Cost Explorer
C. VPC Peering
D. Consolidated billing
Answer:
A. AWS Organizations
AWS Organizations is an account management service that enables you to consolidate multiple AWS accounts into an organization that you create and centrally manage. AWSOrganizations includes account management and consolidated billing capabilities that enable you to better meet the budgetary, security, and compliance needs of your business.
Which of the following service is most useful when a Disaster Recovery method is triggered in AWS.
A. Amazon Route 53
B. Amazon SNS
C. Amazon SQS
D. Amazon Inspector
Answer:
A. Route 53 is a domain name system service by AWS. When a Disaster does occur , it can be easy to switch to secondary sites using the Route53 service.
Amazon Route 53 is a highly available and scalable cloud Domain Name System (DNS) web service. It is designed to give developers and businesses an extremely reliable and cost effective way to route end users to Internet applications by translating names like www.example.com into the numeric IP addresses like 192.0.2.1 that
computers use to connect to each other. Amazon Route 53 is fully compliant with IPv6 as well.
Which of the following disaster recovery deployment mechanisms that has the highest downtime
A. Pilot light
B. Warm standby
C. Multi Site
D. Backup and Restore
Answer:
D. The below snapshot from the AWS Documentation shows the spectrum of the Disaster recovery methods. If you go to the further end of the spectrum you have the least time for downtime for the users.
Your company is planning to host resources in the AWS Cloud. They want to use services which can be used to decouple resources hosted on the cloud. Which of the following services can help fulfil this requirement?
A. AWS EBS Volumes
B. AWS EBS Snapshots
C. AWS Glacier
D. AWS SQS
Answer:
D. AWS SQS: Amazon Simple Queue Service (Amazon SQS) offers a reliable, highly-scalable hosted queue for storing messages as they travel between applications or microservices. It moves data between distributed application components and helps you decouple these components.
What is the availability and durability rating of S3 Standard Storage Class?
Choose the correct answer:
A. 99.999999999% Durability and 99.99% Availability
B. 99.999999999% Availability and 99.90% Durability
C. 99.999999999% Durability and 99.00% Availability
D. 99.999999999% Availability and 99.99% Durability
Answer:
A. 99.999999999% Durability and 99.99% Availability
S3 Standard Storage class has a rating of 99.999999999% durability (referred to as 11 nines) and 99.99% availability.
What AWS database is primarily used to analyze data using standard SQL formatting with compatibility for your existing business intelligence tools
A. Redshift
B. RDS
C. DynamoDB
D. ElastiCache
Answer:
A. Redshift is a database offering that is fully-managed and used for data warehousing and analytics, including compatibility with existing business intelligence tools.
Which of the following are the benefits of AWS Organizations?
Choose the 2 correct answers:
A. Analyze cost before migrating to AWS.
B. Centrally manage access polices across multiple AWS accounts.
C. Automate AWS account creation and management.
D. Provide technical help (by AWS) for issues in your AWS account.
Answer:
B. and C.:
CENTRALLY MANAGE POLICIES ACROSS MULTIPLE AWS ACCOUNTS
AUTOMATE AWS ACCOUNT CREATION AND MANAGEMENT
CONTROL ACCESS TO AWS SERVICES
CONSOLIDATE BILLING ACROSS MULTIPLE AWS ACCOUNTS
There is a requirement hosting a set of servers in the Cloud for a short period of 3 months. Which of the following types of instances should be chosen to be cost effective.
A. Spot Instances
B. On-Demand
C. No Upfront costs Reserved
D. Partial Upfront costs Reserved
Answer:
B. Since the requirement is just for 3 months, then the best cost effective option is to use On-Demand Instances.
What service helps you to aggregate logs from your EC2 instance? Choose one answer from the options below:
A. SQS
B. S3
C. Cloudtrail
D. Cloudwatch Logs
Answer:
D. You can use Amazon CloudWatch Logs to monitor, store, and access your log files from Amazon Elastic Compute Cloud (Amazon EC2) instances, AWS CloudTrail, and other sources. You can then retrieve the associated log data from CloudWatch Log.
A company is deploying a new two-tier web application in AWS. The company wants to store their most frequently used data so that the response time for the application is improved. Which AWS service provides the solution for the company’s requirements?
A. MySQL Installed on two Amazon EC2 Instances in a single Availability Zone
B. Amazon RDS for MySQL with Multi-AZ
C. Amazon ElastiCache
D. Amazon DynamoDB
Answer:
C. Amazon ElastiCache is a web service that makes it easy to deploy, operate, and scale an in-memory data store or cache in the cloud. The service improves the performance of web applications by allowing you to retrieve information from fast, managed, in-memory data stores, instead of relying entirely on slower disk-based databases.
You have a distributed application that periodically processes large volumes of data across multiple Amazon EC2 Instances. The application is designed to recover gracefully from Amazon EC2 instance failures. You are required to accomplish this task in the most cost-effective way. Which of the following will meet your requirements?
A. Spot Instances
B. Reserved Instances
C. Dedicated Instances
On-Demand Instances
Answer:
A. When you think of cost effectiveness, you can either have to choose Spot or Reserved instances. Now when you have a regular processing job, the best is to use spot instances and since your application is designed recover gracefully from Amazon EC2 instance failures, then even if you lose the Spot instance , there is no issue because your application can recover.
Which of the following features is associated with a Subnet in a VPC to protect against Incoming traffic requests?
A. AWS Inspector
B. Subnet Groups
C. Security Groups
D. NACL
Answer:
D. A network access control list (ACL) is an optional layer of security for your VPC that acts as a firewall for controlling traffic in and out of one or more subnets. You might set up network ACLs with rules similar to your security groups in order to add an additional layer of security to your VPC.
A company is deploying a two-tier, highly available web application to AWS. Which service provides durable storage for static content while utilizing Overall CPU resources for the web tier?
A. Amazon EBC volume.
B. Amazon S3
C. Amazon EC2 instance store
D. Amazon RDS instance
Answer:
B. Amazon S3 is the default storage service that should be considered for companies. It provides durable storage for all static content.
What are characteristics of Amazon S3? Choose 2 answers from the options given below.
A. S3 allows you to store objects of virtually unlimited size.
B. S3 allows you to store unlimited amounts of data.
C. S3 should be used to host relational database.
D. Objects are directly accessible via a URL.
Answer:
B. and D.: Each object does have a limitation in S3, but you can store virtually unlimited amounts of data. Also each object gets a directly accessible URL
When working on the costing for on-demand EC2 instances , which are the following are attributes which determine the costing of the EC2 Instance. Choose 3 answers from the options given below
A. Instance Type
B. AMI Type
C. Region
D. Edge location
Answer:
A. B. C. : See components making up the pricing below.
You have a mission-critical application which must be globally available at all times. If this is the case, which of the below deployment mechanisms would you employ
A. Deployment to multiple edge locations
B. Deployment to multiple Availability Zones
D. Deployment to multiple Data Centers
D. Deployment to multiple Regions
Answer:
D. Regions represent different geographic locations and it is best to host your application across multiple regions for disaster recovery.
Which of the following are right principles when designing cloud based systems. Choose 2 answers from the options below
A. Build Tightly-coupled components
B. Build loosely-coupled components
C. Assume everything will fail
D. Use as many services as possible
Answer:
B. and C. Always build components which are loosely coupled. This is so that even if one component does fail, the entire system does not fail. Also if you build with the assumption that everything will fail, then you will ensure that the right measures are taken to build a highly available and fault tolerant system.
You have 2 accounts in your AWS account. One for the Dev and the other for QA. All are part of consolidated billing. The master account has purchase 3 reserved instances. The Dev department is currently using 2 reserved instances. The QA team is planning on using 3 instances which of the same instance type. What is the pricing tier of the instances that can be used by the QA Team?
A. No Reserved and 3 on-demand
B. One Reserved and 2 on-demand
C. Two Reserved and 1 on-demand
D. Three Reserved and no on-demand
Answer:
B. Since all are a part of consolidating billing, the pricing of reserved instances can be shared by All. And since 2 are already used by the Dev team , another one can be used by the QA team. The rest of the instances can be on-demand instances.
Which of the following storage mechanisms can be used to store messages effectively which can be used across distributed systems?
A. Amazon Glacier
B. Amazon EBS Volumes
C. Amazon EBS Snapshots
D. Amazon SQS
Answer:
D. Amazon Simple Queue Service (Amazon SQS) offers a reliable, highly-scalable hosted queue for storing messages as they travel between applications or microservices. It moves data between distributed application components and helps you decouple these components.
You are exploring what services AWS has off-hand. You have a large number of data sets that need to be processed. Which of the following services can help fulfil this requirement.
A. EMR
B. S3
C. Glacier
D. Storage Gateway
Answer:
A. Amazon EMR helps you analyze and process vast amounts of data by distributing the computational work across a cluster of virtual servers running in the AWS Cloud. The cluster is managed using an open-source framework called Hadoop. Amazon EMR lets you focus on crunching or analyzing your data without having to worry about time-consuming setup, management, and tuning of Hadoop clusters or the compute capacity they rely on.
Which of the following services allows you to analyze EC2 Instances against pre-defined security templates to check for vulnerabilities
A. AWS Trusted Advisor
B. AWS Inspector
C. AWS WAF
D. AWS Shield
Answer:
B. Amazon Inspector enables you to analyze the behaviour of your AWS resources and helps you to identify potential security issues. Using Amazon Inspector, you can define a collection of AWS resources that you want to include in an assessment target. You can then create an assessment template and launch a security assessment run of this target.
Your company is planning to offload some of the batch processing workloads on to AWS. These jobs can be interrupted and resumed at any time. Which of the following instance types would be the most cost effective to use for this purpose.
A. On-Demand
B. Spot
C. Full Upfront Reserved
D. Partial Upfront Reserved
Answer:
B. Spot Instances are a cost-effective choice if you can be flexible about when your applications run and if your applications can be interrupted. For example, Spot Instances are well-suited for data analysis, batch jobs, background processing, and optional tasks
Which of the below cannot be used to get data onto Amazon Glacier.
A. AWS Glacier API
B. AWS Console
C. AWS Glacier SDK
D. AWS S3 Lifecycle policies
Answer:
B. Note that the AWS Console cannot be used to upload data onto Glacier. The console can only be used to create a Glacier vault which can be used to upload the data.
Which of the following from AWS can be used to transfer petabytes of data from on-premise locations to the AWS Cloud.
A. AWS Import/Export
B. AWS EC2
C. AWS Snowball
D. AWS Transfer
Answer:
C. Snowball is a petabyte-scale data transport solution that uses secure appliances to transfer large amounts of data& into and out of the AWS cloud. Using Snowball addresses common challenges with large-scale data transfers including high network costs, long transfer times, and security concerns. Transferring data with Snowball is simple, fast, secure, and can be as little as one-fifth the cost of high-speed Internet.
Which of the following services allows you to analyze EC2 Instances against pre-defined security templates to check for vulnerabilities
A. AWS Trusted Advisor
B. AWS Inspector
C. AWS WAF
D. AWS Shield
Answer:
B. Amazon Inspector enables you to analyze the behavior of your AWS resources and helps you to identify potential security issues. Using Amazon Inspector, you can define a collection of AWS resources that you want to include in an assessment target. You can then create an assessment template and launch a security assessment run of this target.
Your company wants to move an existing Oracle database to the AWS Cloud. Which of the following services can help facilitate this move.
A. AWS Database Migration Service
B. AWS VM Migration Service
C. AWS Inspector
D. AWS Trusted Advisor
Answer:
A. AWS Database Migration Service helps you migrate databases to AWS quickly and securely. The source database remains fully operational during the migration, minimizing downtime to applications that rely on the database. The AWS Database Migration Service can migrate your data to and from most widely used commercial and open source databases.
Which of the following features of AWS RDS allows for offloading reads of the database.
A. Cross region replication
B. Creating Read Replica’s
C. Using snapshots
D. Using Multi-AZ feature
Answer:
B. You can reduce the load on your source DB Instance by routing read queries from your applications to the read replica. Read replicas allow you to elastically scale out beyond the capacity constraints of a single DB instance for read-heavy database workloads.
Which of the following does AWS perform on its behalf for EBS volumes to make it less prone to failure?
A. Replication of the volume across Availability Zones
B. Replication of the volume in the same Availability Zone
C. Replication of the volume across Regions
D. Replication of the volume across Edge locations
Answer:
B. When you create an EBS volume in an Availability Zone, it is automatically replicated within that zone to prevent data loss due to failure of any single hardware component
Your company is planning to host a large e-commerce application on the AWS Cloud. One of their major concerns is Internet attacks such as DDos attacks. Which of the following services can help mitigate this concern. Choose 2 answers from the options given below
A. A. Cloudfront
B. AWS Shield
C. C. AWS EC2
D. AWS Config
Answer:
A. and B. : One of the first techniques to mitigate DDoS attacks is to minimize the surface area that can be attacked thereby limiting the options for attackers and allowing you to build protections in a single place. We want to ensure that we do not expose our application or resources to ports, protocols or applications from where they do not expect any communication. Thus, minimizing the possible points of attack and letting us concentrate our mitigation efforts. In some cases, you can do this by placing your computation resources behind Content Distribution
Networks (CDNs), Load Balancers and restricting direct Internet traffic to certain parts of your infrastructure
like your database servers. In other cases, you can use firewalls or Access Control Lists (ACLs) to control what traffic reaches your applications.
Which of the following are 2 ways that AWS allows to link accounts
A. Consolidating billing
B. AWS Organizations
C. Cost Explorer
D. IAM
Answer:
A. and B. : You can use the consolidated billing feature in AWS Organizations to consolidate payment for multiple AWS accounts or multiple AISPL accounts. With consolidated billing, you can see a combined view of AWS charges incurred by all of your accounts. You also can get a cost report for each member account that is associated with your master account. Consolidated billing is offered at no additional charge.
Which of the following helps in DDos protection. Choose 2 answers from the options given below
A. Cloudfront
B. AWS Shield
C. AWS EC2
D. AWS Config
Answer:
A. and B. : One of the first techniques to mitigate DDoS attacks is to minimize the surface area that can be attacked thereby limiting the options for attackers and allowing you to build protections in a single place. We want to ensure that we do not expose our application or resources to ports, protocols or applications from where they do not expect any communication. Thus, minimizing the possible points of attack and letting us concentrate our mitigation efforts. In some cases, you can do this by placing your computation resources behind; Content Distribution Networks (CDNs), Load Balancers and restricting direct Internet traffic to certain parts of your infrastructure like your database servers. In other cases, you can use firewalls or Access Control Lists (ACLs) to control what traffic reaches your applications.
A company wants to host a self-managed database in AWS. How would you ideally implement this solution?
A. Using the AWS DynamoDB service
B. Using the AWS RDS service
C. Hosting a database on an EC2 Instance
D. Using the Amazon Aurora service
Answer:
C. If you want a self-managed database, that means you want complete control over the database engine and the underlying infrastructure. In such a case you need to host the database on an EC2 Instance
There is a requirement to host a database server for a minimum period of one year. Which of the following would result in the least cost?
A. Spot Instances
B. On-Demand
C. No Upfront costs Reserved
D. Partial Upfront costs Reserved
Answer:
D. : If the database is going to be used for a minimum of one year at least , then it is better to get Reserved Instances. You can save on costs , and if you use a partial upfront options , you can get a better discount
which of the below can be used to import data into Amazon Glacier? Choose 3 answers from the options given below:
A. AWS Glacier API
B. AWS Console
C. AWS Glacier SDK
D. AWS S3 Lifecycle policies
Answer:
A. C. and D. : The AWS Console cannot be used to upload data onto Glacier. The console can only be used to create a Glacier vault which can be used to upload the data.
Which of the following can be used to secure EC2 Instances hosted in AWS. Choose 2 answers
A. Usage of Security Groups
B. Usage of AMI’s
C. Usage of Network Access Control Lists
D. Usage of the Internet gateway
Answer:
A and C: Security groups acts as a virtual firewall for your instance to control inbound and outbound traffic. Network access control list (ACL) is an optional layer of security for your VPC that acts as a firewall for
controlling traffic in and out of one or more subnets.
You plan to deploy an application on AWS. This application needs to be PCI Compliant. Which of the below steps are needed to ensure the compliance? Choose 2 answers from the below list:
A. Choose AWS services which are PCI Compliant
B. Ensure the right steps are taken during application development for PCI Compliance
C. Encure the AWS Services are made PCI Compliant
D. Do an audit after the deployment of the application for PCI Compliance.
Question: Which of the following is a factor when calculating Total Cost of Ownership (TCO) for the AWS Cloud?
A. The number of servers migrated to AWS
B. The number of users migrated to AWS
C. The number of passwords migrated to AWS
D. The number of keys migrated to AWS
Answer:
A. Running servers will incur costs. The number of running servers is one factor of Server Costs; a key component of AWS’s Total Cost of Ownership (TCO). Reference: AWS cost calculator
Which AWS Services can be used to store files? Choose 2 answers from the options given below:
A. Amazon CloudWatch
B. Amazon Simple Storage Service (Amazon S3)
C. Amazon Elastic Block Store (Amazon EBS)
D. AWS COnfig
D. AWS Amazon Athena
Answer:
B. and C. Amazon S3 is a Object storage built to store and retrieve any amount of data from anywhere. Amazon Elastic Block Store is a Persistent block storage for Amazon EC2.
Question: What best describes Amazon Web Services (AWS)?
Choose the correct answer:
A. AWS is the cloud.
B. AWS only provides compute and storage services.
C. AWS is a cloud services provider.
D. None of the above.
Answer:
C: AWS is defined as a cloud services provider. They provide hundreds of services of which compute and storage are included (not not limited to).
Reference: AWS
Question: Which AWS service can be used as a global content delivery network (CDN) service?
A. Amazon SES
B. Amazon CouldTrail
C. Amazon CloudFront
D. Amazon S3
Answer:
C: Amazon CloudFront is a web service that gives businesses and web application developers an easy
and cost effective way to distribute content with low latency and high data transfer speeds. Like other AWS services, Amazon CloudFront is a self-service, pay-per-use offering, requiring no long term commitments or minimum fees. With CloudFront, your files are delivered to end-users using a global network of edge locations.Reference: AWS cloudfront
What best describes the concept of fault tolerance?
Choose the correct answer:
A. The ability for a system to withstand a certain amount of failure and still remain functional.
B. The ability for a system to grow in size, capacity, and/or scope.
C. The ability for a system to be accessible when you attempt to access it.
D. The ability for a system to grow and shrink based on demand.
Answer:
A: Fault tolerance describes the concept of a system (in our case a web application) to have failure in some of its components and still remain accessible (highly available). Fault tolerant web applications will have at least two web servers (in case one fails).
Question: The firm you work for is considering migrating to AWS. They are concerned about cost and the initial investment needed. Which of the following features of AWS pricing helps lower the initial investment amount needed? Choose 2 answers from the options given below:
A. The ability to choose the lowest cost vendor.
B. The ability to pay as you go
C. No upfront costs
D. Discounts for upfront payments
Answer:
B and C: The best features of moving to the AWS Cloud is: No upfront cost and The ability to pay as you go where the customer only pays for the resources needed. Reference: AWS pricing
Question: Your company has
started using AWS. Your IT Security team is concerned with the
security of hosting resources in the Cloud. Which AWS service provides security optimization recommendations that could help the IT Security team secure resources using AWS?
A. AWS API Gateway
B. Reserved Instances
C. AWS Trusted Advisor
D. AWS Spot Instances
Answer:
C: An online resource to help you reduce cost, increase performance, and improve security by optimizing your AWS environment, Trusted Advisor provides real time guidance to help you provision your resources following AWS best practices. Reference: AWS trusted advisor
What is the relationship between AWS global infrastructure and the concept of high availability?
Choose the correct answer:
A. AWS is centrally located in one location and is subject to widespread outages if something happens at that one location.
B. AWS regions and Availability Zones allow for redundant architecture to be placed in isolated parts of the world.
C. Each AWS region handles a different AWS services, and you must use all regions to fully use AWS.
D. None of the above
Answer
B: As an AWS user, you can create your applications infrastructure and duplicate it. By placing duplicate infrastructure in multiple regions, high availability is created because if one region fails you have a backup (in a another region) to use.
Question: You are hosting a number of EC2 Instances on AWS. You are looking to monitor CPU Utilization on the Instance. Which service would you use to collect and track performance metrics for AWS services?
C: Amazon CloudWatch is a monitoring service for AWS cloud resources and the applications you run on AWS. You can use Amazon CloudWatch to collect and track metrics, collect and monitor log files, set alarms, and automatically react to changes in your AWS resources. Reference: AWS cloudwatch/
Question: Which of the following support plans give access to all the checks in the Trusted Advisor service. Choose 2 answers from the options given below:
Question: Which of the following in AWS maps to a separate geographic location?
A. AWS Region
B. AWS Data Centers
C. AWS Availability Zone
Answer:
A: Amazon cloud computing resources are hosted in multiple locations world-wide. These locations are composed of AWS Regions and Availability Zones. Each AWS Region is a separate geographic area. Reference: AWS Regions And Availability Zone
A. The ability for a system to grow and shrink based on demand.
B. The ability for a system to grow in size, capacity, and/or scope.
C. The ability for a system be be accessible when you attempt to access it.
D. The ability for a system to withstand a certain amount of failure and still remain functional.
Answer
B: Scalability refers to the concept of a system being able to easily (and cost-effectively) scale UP. For web applications, this means the ability to easily add server capacity when demand requires.
Question: If you wanted to monitor all events in your AWS account, which of the below services would you use?
A. AWS CloudWatch
B. AWS CloudWatch logs
C. AWS Config
D. AWS CloudTrail
Answer:
D: AWS CloudTrail is a service that enables governance, compliance, operational auditing, and risk
auditing of your AWS account. With CloudTrail, you can log, continuously monitor, and retain account activity related to actions across your AWS infrastructure. CloudTrail provides event history of your AWS account activity, including actions taken through the AWS Management Console, AWS SDKs, command line tools, and other AWS services. This event history simplifies security analysis, resource change tracking, and troubleshooting. Reference: Cloudtrail
What are the four primary benefits of using the cloud/AWS?
Choose the correct answer:
A. Fault tolerance, scalability, elasticity, and high availability.
B. Elasticity, scalability, easy access, limited storage.
C. Fault tolerance, scalability, sometimes available, unlimited storage
D. Unlimited storage, limited compute capacity, fault tolerance, and high availability.
Answer:
A: Fault tolerance, scalability, elasticity, and high availability are the four primary benefits of AWS/the cloud.
What best describes a simplified definition of the “cloud”?
Choose the correct answer:
A. All the computers in your local home network.
B. Your internet service provider
C. A computer located somewhere else that you are utilizing in some capacity.
D. An on-premise data center that your company owns.
Answer
D: The simplest definition of the cloud is a computer that is located somewhere else that you are utilizing in some capacity. AWS is a cloud services provider, as the provide access to computers they own (located at AWS data centers), that you use for various purposes.
Question: Your development team is planning to host a development environment on the cloud. This consists of EC2 and RDS instances. This environment will probably only be required for 2 months. Which types of instances would you use for this purpose?
A. On-Demand
B. Spot
C. Reserved
D. Dedicated
Answer:
A: The best and cost effective option would be to use On-Demand Instances. The AWS documentation gives the following additional information on On-Demand EC2 Instances. With On-Demand instances you only pay for
EC2 instances you use. The use of On-Demand instances frees you from the costs and complexities of planning, purchasing, and maintaining hardware and transforms what are commonly large fixed costs into much smaller variable costs. Reference: AWS ec2 pricing on-demand
Question: Which of the following can be used to secure EC2 Instances?
A. Security Groups
B. EC2 Lists
C. AWS Configs
D. AWS CloudWatch
Answer:
A: security group< acts as a virtual firewall for your instance to control inbound and outbound traffic. When you launch an instance in a VPC, you can assign up to five security groups to the instance. Security groups act at the instance level, not the subnet level. Therefore, each instance in a subnet in your VPC could be assigned to a different set of security groups. If you don’t specify a particular group at launch time, the instance is automatically assigned to the default security group for the VPC. Reference: VPC Security Groups
Exam Topics:
The AWS Cloud Practitioner exam is broken down into 4 domains
Cloud Concepts
Security
Technology
Billing and Pricing.
What is the purpose of a DNS server?
Choose the correct answer:
A. To act as an internet search engine.
B. To protect you from hacking attacks.
C. To convert common language domain names to IP addresses.
D. To serve web application content.
Answer:
C: Domain name system servers act as a “third party” that provides the service of converting common language domain names to IP addresses (which are required for a web browser to properly make a request for web content).
What best describes the concept of high availability?
Choose the correct answer:
A. The ability for a system to grow in size, capacity, and/or scope.
B. The ability for a system to withstand a certain amount of failure and still remain functional.
C. The ability for a system to grow and shrink based on demand.
D. The ability for a system to be accessible when you attempt to access it.
Answer:
D: High availability refers to the concept that something will be accessible when you try to access it. An object or web application is “highly available” when it is accessible a vast majority of the time.
What is the major difference between AWS’s RDS and DynamoDB database services?
Choose the correct answer:
A. RDS offers NoSQL database options, and DynamoDB offers SQL database options.
B. RDS offers one SQL database option, and DynamoDB offers many NoSQL database options.
C. RDS offers SQL database options, and DynamoDB offers a NoSQL database option.
D. None of the above
Answer:
C. RDS is a SQL database service (that offers several database engine options), and DynamoDB is a NoSQL database option that only offers one NoSQL engine.
Reference:
What are two open source in-memory engines supported by ElastiCache?
If you want to have SMS or email notifications sent to various members of your department with status updates on resources in your AWS account, what service should you choose?
Choose the correct answer:
A. SNS
B. GetSMS
C. RDS
D. STS
Answer:
A. Simple Notification Service (SNS) is what publishes messages to SMS and/or email endpoints.
