How to use the command 'mongod' (with examples)
The ‘mongod’ command is the MongoDB database server, which is responsible for hosting database instances and handling client requests. It allows users to manage and configure MongoDB servers.
Use case 1: Specify the storage directory
Code:
mongod --dbpath path/to/directory
Motivation: This example allows you to specify a custom storage directory for the MongoDB database. By default, on Linux and macOS, the storage directory is set to /data/db, and on Windows, it is set to C:\data\db. However, sometimes you may want to store the database in a different directory for organizational or storage capacity reasons.
Explanation: The --dbpath option is used to specify the path to the directory where the MongoDB database files are stored. “path/to/directory” should be replaced with the desired location of the database storage directory.
Example output:
2021-12-10T15:00:00.000+00:00 I NETWORK [initandlisten] waiting for connections on port 27017
Use case 2: Specify a config file
Code:
mongod --config path/to/file
Motivation: With this example, you can specify a configuration file to customize the MongoDB server settings. This is useful when you want to manage various server options easily in a single file.
Explanation: The --config option is used to specify the path to a configuration file. “path/to/file” should be replaced with the location of the desired configuration file.
Example output:
2021-12-10T15:00:00.000+00:00 I NETWORK [initandlisten] waiting for connections on port 27017
Use case 3: Specify the port to listen on
Code:
mongod --port port
Motivation: In this example, you can change the default port (27017) to a specific port of your choice. This can be helpful when you want to run multiple MongoDB instances on the same server or avoid conflicts with other services using the default port.
Explanation: The --port option is used to specify the port number on which the MongoDB server should listen for incoming client connections. “port” should be replaced with the desired port number.
Example output:
2021-12-10T15:00:00.000+00:00 I NETWORK [initandlisten] waiting for connections on port 27018
Use case 4: Specify the database profiling level
Code:
mongod --profile 0|1|2
Motivation: This example allows you to adjust the level of detailed performance profiling information logged by the MongoDB server. Depending on your needs, you can choose to turn off profiling or log only slow operations or log all operations.
Explanation: The --profile option is used to specify the profiling level for the MongoDB server. It accepts three values: 0 (profiling off), 1 (log slow operations), and 2 (log all operations).
Example output:
2021-12-10T15:00:00.000+00:00 I NETWORK [initandlisten] waiting for connections on port 27017
Conclusion
In this article, we explored various use cases of the ‘mongod’ command, which allows you to manage and configure MongoDB servers. By specifying the storage directory, config file, port, and database profiling level, you can customize the MongoDB server to suit your specific requirements.
