configuring log4j in a clustered environment

Question

We are using log4j for the logging functionality. The application is running in a Clustered environment. How can I configure log4j properties such that all the instances log to the same log file?

Answer 1

Mithun - I have same dilemma with Weblogic Need to allow 2 different instances (JVMs) to write to the same .log file.

Answer 2

One solution is to have a directory dedicated for logging. That directory can be on a network share (NFS, etc.) that is mounted to a location that is the same for both processes. This could be as simple as mounting to the identical spot in the file structure or it could be done using environment variables ($LOGDIR) so each host could point to a different location in their local file structure.

The important thing is that the folder be shared so that multiple processes are writing to the same file. The normal shared-resource restrictions apply though; make sure the file isn't locked by one host while preventing the other from writing, etc. Also, use an output pattern that includes hostname/process name/thread id.

Another approach I've used is a database appender that writes to a log table. No share needed but you still need to design the table considering the issues with multi-process logging.