You can now track garbage collection for each generation of the G1, CMS and Serial collectors in your Java applications, with the number of collections and the time spent collecting. Until now the JVM Metrics view in Atatus Java APM had a single GC chart, G1 Old Gen Heap Usage, which counted G1 old generation collections.
Open a Java project, go to JVM Metrics and click a host. The charts are on the Memory tab of the JVM Metrics panel. They use the JVM metrics the Java agent already sends, so there is nothing to install. JVM metrics need Java agent 2.1.0 or later.
What the new charts show
- G1: G1 Young Gen GC Count and G1 Young Gen GC Cpu Time for the young generation. For the old generation, G1 Old Gen GC Cpu Time and the G1 Old Gen Heap Count chart, which counts old generation collections.
- CMS: GC Count and GC Cpu Time charts for ParNew and ConcurrentMarkSweep.
- Serial: GC Count and GC Cpu Time charts for Copy and MarkSweepCompact.
- One chart per collector: Each collector and generation has its own count chart and its own time chart, so one busy collector does not hide the others. Charts for collectors your JVM does not use show no data.
- Parallel collector: GC count and time for PS Scavenge and PS MarkSweep stay on the Runtime Metrics page, as before.