Deprecation Note

Gcviz is no longer maintained and should be considered archived.

Note that gcviz code is not intended to be deployed on untrusted networks, or without external authentication and authorization. Specifically, it has functionality that can allow execution of system commands by remote users.

Original README

This is gcviz, a set of programs that help generate visualizations from gc.log, a log file that the HotSpot, a Java Virual Machine, writes when configured with the following flags: -verbose:gc -verbose:sizes -Xloggc:/apps/tomcat/logs/gc.log -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintTenuringDistribution

gcviz is intended to be used as a webapp when installed on the same host as tomcat, or any other Java web container. The gcviz program itself is served by apache httpd inside netflix, but could be served by any webserver that supports CGI. gcviz implicitly assumes to be running in a linux environment.

By default gcviz is available at: http://127.0.0.1:8080/AdminGCViz/index

Internally, gcviz is a bundle of four sorts of things:

• python programs that require matplotlib, numpy, pylab, etc.
• cgi scripts that invoke these python programs
• some minor assistive perl scripts
• very minor rpm infrastructure to package the previous things.

I wrote gcviz to address challenges we face inside Netflix. If you feel that any changes you might propose could be helpful for Netflix or for the community at large, please write.

Brian Moore