Starting and Stopping MongoDB

Starting the MongoDB

MongoDB is started with a mongod executable file, it has many configurable options which can be viewed with mongod--help on the command line

We will discuss a few important of them below 

--dbpath

Each mongod process needs its own data directory. if you are running multiple instances of mongod on the same machine then you need a separate directory for each instance

When mongod starts up, it creates mongod.lock in the data directory, which prevents any other mongod process from using the same directory.

--port

By default, mongod uses a 27017 port for the server to listen. In case another instance is required to be run on same machine then different port needs to be assigned.

--fork

Fork the server process, running MongoDB as daemon

--logpath

This will create a logfile in the directory specified instead of writing everything on the command line, it will overwrite the existing logfile if --logappend option is not specified in addition to --logpath. Before overwriting it take a backup of the existing logfile with the timestamp

--config

Use configuration file for additional options not specified on the command line such as mongo --config ~/.mongodb.conf to read the configuration file

So if we want to run mongo on port 27027 with data directory D:\mongodb\data\db\logs and logfile directory D:\mongodb\data\db\logs we will use the below command

mongod --dbpath=D:\mongodb\data\db --port 27027 --logpath D:\mongodb\data\db\logs\mongodblog.log

Below are commands executed and their output on the command line

Once we start mongod with options as mentioned above, it creates lock file and log file

mongod.lock file in dbpath location

Logfile

Stopping the MongoDB

There are a couple of ways of stopping MongoDB

• First and basic way to press Ctrl-C, It will send SIGINT or SIGTERM signal. 
• Another way is to use the kill command 

if PID of the mongod process is xyz then kill -2 xyz will do the same Ctrl-C. (never use kill -9 as you will need to repair the database on the next startup as there are chances of corruption on datafiles)

Another way to cleanly shut down a running server is to use the shutdown command. This should be run admin database shown below

Comment below if you need any additional information