Logging GC information in the application

Question

Is there a way to forward the garbage collection information (for example the output of -XX:+PrintGCDetails or -verbose:gc) to a logger within the Java application (sl4j + logback in my case)?

Answer 1

Those messages are generated by the JVM native process and not from Java code, so you just can

1. Redirect output to file using -Xloggc (no rotation)
   • How to redirect verbose garbage collection output to a file?
2. Pipe stdout directly (several rotation options)
   • Log rotation of stdout?
   • Rolling garbage collector logs in java
   • Garbage collector log (loggc) file rotation with logrotate does not work properly

Answer 2

An interesting approach would be to redirect gc.log to a named pipe -Xloggc:/my/named/pipe How to write GC log to named pipe

then read that pipe form the application itself: How to open a Windows named pipe from Java?

and log to an arbitrary (e.g. async rolling) logback logger from the code.

Tried that on a Windows machine. Unfortunately, it is trickier to setup on Windows than on Linux.

On Windows it works basically with help of an additional Powershell script (can be a dedicated application as well). This sample project also contains a demo application that can be used right away to test the GC logs redirection to Logback via SLF4J.