MongoDB Recipes: Change mongod’s log level

To view the current log verbosity levels, use the db.getLogComponents() method.
In the below mongod instance, the verbosity is 0 (default informational level). Here we can see that the verbosity of individual components are -1, this means the component inherits the log level of its parent.

We can configure log verbosity levels by

1. Method 1: Using mongod’s startup settings
2. Method 2: Using the logComponentVerbosity parameter
3. Method 3: Using the db.setLogLevel() method.

Method 1:

We can configure global verbosity level using: the systemLog.verbosity settings

Also we can change verbosity level of an individual log component using the systemLog.component.<name>.verbosity setting for that component.

For example we are changing the verbosity level of network component to 0.
systemLog.component.network.verbosity

Method 2:

To change log verbosity level using the logComponentVerbosity parameter, pass a document with the required verbosity settings.
Example, we are going to set the default verbosity level to 2, verbosity level of storage to 1, and the storage.journal to 0
> use admin
> db.runCommand( { setParameter: 1, logComponentVerbosity:
{
verbosity: 2,
storage: {
verbosity: 1,
journal:
{
verbosity: 0
}
}
}
} )

Method 3:

We can use the db.setLogLevel() method to update a single component’s log level.
Example:

• Change the default verbosity level to 0:
  
• Change the storage.journal log level to 4: