Classified as a NoSQL database, MongoDB is an open source, document-oriented database designed with both scalability and developer agility in mind. Instead of storing your data in tables and rows as you would with a relational database, in MongoDB you store JSON-like documents with dynamic schemas; This makes the integration of data in certain types of application easier and faster.
MongoDB can help you make a difference to the business. Tens of thousands of organizations, from startups to the largest companies and government agencies, choose MongoDB because it lets them build applications that weren’t possible before. With MongoDB, these organizations move faster than they could with relational databases at one tenth of the cost. With MongoDB, you can do things you could never do before.
- Install Homebrew
$ /usr/bin/ruby -e “$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)”
Homebrew installs the stuff you need that Apple didn’t.
$ brew install wget
- Install MongoDB
$ brew install mongodb
- Run MongoDB
Create the data directory: $ mkdir -p /data/db
Set permissions for the data directory:$ chown -R you:yourgroup /data/db then chmod -R 775 /data/db
Run MongoDB (as non root): $ mongod
- Begin using MongoDB.(MongoDB will be running as soon as you ran mongod above)
Open another terminal and run: mongo
What is Mac OS X Boot Process:
Firmware. Part of Hardware system
BootROM firmware is activated
Power-On Self Test
initializes some hardware interfaces and verifies that sufficient memory is available and in a good state.
Extensible Firmware Interface
EFI does basic hardware initialization and selects which operating system to use.
boot.efi boot loader
load the kernel environment
The init routine of the kernel is executed
boot loader starts the kernel’s initialization procedure
Various Mach/BSD data structures are initialized by the kernel.
The I/O Kit is initialized.
The kernel starts /sbin/mach_init
mach_init starts /sbin/init
init determines the runlevel, and runs /etc/rc.boot, which sets up the machine enough to run single-user.
rc.boot figures out the type of boot (Multi-User, Safe, CD-ROM, Network etc.)
- Power is turned on.
- Open Firmware code is executed.
- Hardware information is collected and hardware is initialized.
- Something (usually the OS, but also things like the Apple Hardware Test, etc.) is selected to boot. The user may be prompted to select what to boot.
- Control passes to /System/Library/CoreServices/BootX, the boot loader. BootX loads the kernel and also draws the OS badges, if any.
- BootX tries to load a previously cached list of device drivers (created/updated by /usr/sbin/kextcache). Such a cache is of the type mkext and contains the info dictionaries and binary files for multiple kernel extensions. Note that if the mkext cache is corrupt or missing, BootX would look in /System/Library/Extensions for extensions that are needed in the current scenario (as determined by the value of the OSBundleRequired property in the Info.plist file of the extension’s bundle.
- The init routine of the kernel is executed. The root device of the booting system is determined. At this point, Open Firmware is not accessible any more.
- Various Mach/BSD data structures are initialized by the kernel.
- The I/O Kit is initialized.
- The kernel starts /sbin/mach_init, the Mach service naming (bootstrap) daemon. mach_init maintains mappings between service names and the Mach ports that provide access to those services.
From here on, the startup becomes user-level:
- mach_init starts /sbin/init, the traditional BSD init process. init determines the runlevel, and runs /etc/rc.boot, which sets up the machine enough to run single-user.
- rc.boot figures out the type of boot (Multi-User, Safe, CD-ROM, Network etc.). In case of a network boot (the sysctl variable kern.netboot will be set to 1 in which case), it runs /etc/rc.netboot with a start argument.
How to Monitor Macbook with one single command?
$sudo sysdiagnose -f ~/Desktop/
The result is a compressed file named sysdiagnose_YYYY.MM.DD_HH-MM-SS-TTTT.tar.gz and it contains the following: