The fcdebug utility can be used to dynamically set the loglevel to debug a library.

The core-site.xml file can be modified to set the loglevel of all modules using the fs.mapr.trace property. However, FUSE must be restarted for the change to take effect. The fcdebug utility allows you to debug a specific library (at runtime) without restarting FUSE.

Note: You may have to run this command once per library (to debug).


/opt/mapr/server/tools/fcdebug [-i] -s <shmid> [-m <module>] [-l <level>]


Parameter Description
-i Lists the current debug level of all modules.
-l Specifies the log level. Value can be one of the following: FATAL, ERROR, WARN, INFO, DEBUG.
Note: If this is not specified, the default level is applied for the module.
-m Refers to the module. The list of modules can be retrieved by running fcdebug -i -s <shmid> command.
Note: If this is not specified, the loglevel is set on all modules.
-s Specifies the process ID of the fileclient or FUSE-based POSIX client. If the process ID is not available, specify the ID of the shared memory segment, which has the size of 1234 bytes.


The following command retrieves the list of modules:
/opt/mapr/server/tools/fcdebug -i -s 196614 
Note: You can run this command after dynamically setting the loglevel to also verify the setting.
The following command dynamically sets the log level to DEBUG on the given module:
/opt/mapr/server/tools/fcdebug -s 196614 -m FuseOps -l DEBUG
Note: It may take up to a minute for the changes to take effect.
The following command sets loglevel to DEBUG on all the modules:
/opt/mapr/server/tools/fcdebug -s 196614 -l DEBUG
The following command resets the log level to the default value on all the modules:
/opt/mapr/server/tools/fcdebug -s 196614