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javagarbage-collectiong1gc

SerialOld GC with G1GC

I am using G1GC and in the java mission control I found the following:

enter image description here

Why it shows SerialOld? In the config it shows the following: enter image description here

Solution

  • I believe this is Full GC operation in G1. It used to be serial before JDK 10, it is now parallel after JEP 307 was integrated. This is also evident from the duration of those phases: almost 4 seconds, comparing to regular G1 cycles.

    See the source: G1 Full GC used the SerialOldTracer for reporting, now it uses G1FullTracer. So, before JDK 10 it would have reported "SerialOld" for Full GC, it should now report "G1Full".