Poonam Parhar, currently a JVM Sustaining Engineer at Oracle where her primary responsibility is to resolve customer escalated problems against JRockit and HotSpot JVMs. She loves debugging and troubleshooting problems, and is always focused on improving the serviceability and supportability of the JVM. She has nailed down many complex Garbage Collection issues in the HotSpot JVM, and is passionate about improving the debugging tools and the serviceability of the product so as to make it easier to troubleshoot and fix Garbage Collector related issues in the JVM. In an attempt to help the customers and the Java community, she shares her work experiences and knowledge through the blog she maintains here: https://blogs.oracle.com/poonam/.
With JEP 271, GC logging has been re-implemented to use the Unified JVM Logging Framework introduced with JEP 158. Unified JVM logging introduced a new JVM option -Xlog, and also defined the category tags for all the different components of the JVM. With 'gc' tag specified for the GC logging, -Xlog:gc option along with the other granular tag-sets, levels and decorations can be used to enable the GC logging for different parts of the GC system at various levels of detail.
This talk discusses the GC logging JVM options that are going to be removed in Java 9, and covers in detail the parameters that can be used with Xlog:gc option to get the GC logging equivalent to what we could produce with the now removed JVM options.
This session will also take a deep dive into looking at the sample GC logs generated with the new logging mechanism, and will throw light on how those logs can be read and interpreted.