Further data points around G1GC - it seems that there was a normal minor GC event, but at the end of that it expanded the Eden space from 8MB to 17GB. On data collection immediately after, we ran into a 17 second object copy.
Blockquote
INFO | jvm 4 | 2019/09/26 13:43:38 | [GC pause (G1 Evacuation Pause) (young), 0.0458696 secs]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Parallel Time: 23.3 ms, GC Workers: 13]
INFO | jvm 4 | 2019/09/26 13:43:38 | [GC Worker Start (ms): Min: 642559943.4, Avg: 642559943.5, Max: 642559943.7, Diff: 0.3]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Ext Root Scanning (ms): Min: 1.7, Avg: 2.0, Max: 3.6, Diff: 1.9, Sum: 26.3]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Update RS (ms): Min: 10.1, Avg: 11.8, Max: 12.0, Diff: 1.9, Sum: 153.0]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Processed Buffers: Min: 18, Avg: 30.3, Max: 54, Diff: 36, Sum: 394]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Scan RS (ms): Min: 0.0, Avg: 0.0, Max: 0.1, Diff: 0.1, Sum: 0.6]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Code Root Scanning (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.0]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Object Copy (ms): Min: 8.9, Avg: 9.0, Max: 9.2, Diff: 0.2, Sum: 117.5]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Termination (ms): Min: 0.0, Avg: 0.1, Max: 0.1, Diff: 0.1, Sum: 0.8]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Termination Attempts: Min: 1, Avg: 65.4, Max: 85, Diff: 84, Sum: 850]
INFO | jvm 4 | 2019/09/26 13:43:38 | [GC Worker Other (ms): Min: 0.0, Avg: 0.1, Max: 0.2, Diff: 0.1, Sum: 0.9]
INFO | jvm 4 | 2019/09/26 13:43:38 | [GC Worker Total (ms): Min: 22.8, Avg: 23.0, Max: 23.1, Diff: 0.3, Sum: 299.2]
INFO | jvm 4 | 2019/09/26 13:43:38 | [GC Worker End (ms): Min: 642559966.5, Avg: 642559966.5, Max: 642559966.6, Diff: 0.1]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Code Root Fixup: 0.0 ms]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Code Root Purge: 0.0 ms]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Clear CT: 0.4 ms]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Other: 22.2 ms]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Choose CSet: 0.0 ms]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Ref Proc: 19.9 ms]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Ref Enq: 0.6 ms]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Redirty Cards: 0.3 ms]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Humongous Register: 0.1 ms]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Humongous Reclaim: 0.1 ms]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Free CSet: 0.6 ms]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Eden: 1704.0M(1704.0M)->0.0B(17.1G) Survivors: 184.0M->72.0M Heap: 12.6G(31.3G)->10.8G(31.3G)]
INFO | jvm 4 | 2019/09/26 13:43:38 | [Times: user=0.42 sys=0.00, real=0.05 secs]
INFO | jvm 4 | 2019/09/26 13:43:38 | Total time for which application threads were stopped: 0.0483955 seconds, Stopping threads took: 0.0001874 seconds
INFO | jvm 4 | 2019/09/26 13:43:46 | Total time for which application threads were stopped: 0.0030136 seconds, Stopping threads took: 0.0002035 seconds
INFO | jvm 4 | 2019/09/26 13:43:46 | Total time for which application threads were stopped: 0.0022161 seconds, Stopping threads took: 0.0001000 seconds
INFO | jvm 4 | 2019/09/26 13:43:46 | Total time for which application threads were stopped: 0.0020475 seconds, Stopping threads took: 0.0000656 seconds
INFO | jvm 4 | 2019/09/26 13:43:46 | Total time for which application threads were stopped: 0.0019047 seconds, Stopping threads took: 0.0000951 seconds
INFO | jvm 4 | 2019/09/26 13:43:46 | Total time for which application threads were stopped: 0.0017944 seconds, Stopping threads took: 0.0000910 seconds
INFO | jvm 4 | 2019/09/26 13:43:46 | Total time for which application threads were stopped: 0.0014950 seconds, Stopping threads took: 0.0000852 seconds
INFO | jvm 4 | 2019/09/26 13:43:46 | Total time for which application threads were stopped: 0.0013441 seconds, Stopping threads took: 0.0000794 seconds
INFO | jvm 4 | 2019/09/26 13:43:46 | Total time for which application threads were stopped: 0.0013973 seconds, Stopping threads took: 0.0001629 seconds
INFO | jvm 4 | 2019/09/26 13:43:50 | Total time for which application threads were stopped: 0.0022608 seconds, Stopping threads took: 0.0002379 seconds
INFO | jvm 4 | 2019/09/26 13:43:56 | I [c.i.i.g.s.g.f.Projects$ProjectChangeMonitor] [11:43:56]: Starting up client project monitor. project=XXXXXXXXXX, uuid=d550e43b-2a35-2a5c-059f-1d1eb70a9975, editCount=3377, scope=4, version=Published request-origin=10.52.212.48, session-user=OP, session-project=XXXXXXXXXX, session-id=8C5248F4
INFO | jvm 4 | 2019/09/26 13:43:56 | Total time for which application threads were stopped: 0.0028659 seconds, Stopping threads took: 0.0001919 seconds
INFO | jvm 4 | 2019/09/26 13:43:56 | Total time for which application threads were stopped: 0.0019966 seconds, Stopping threads took: 0.0001740 seconds
INFO | jvm 4 | 2019/09/26 13:43:56 | Total time for which application threads were stopped: 0.0017132 seconds, Stopping threads took: 0.0001392 seconds
INFO | jvm 4 | 2019/09/26 13:43:56 | Total time for which application threads were stopped: 0.0023148 seconds, Stopping threads took: 0.0002129 seconds
INFO | jvm 4 | 2019/09/26 13:43:56 | Total time for which application threads were stopped: 0.0023299 seconds, Stopping threads took: 0.0002030 seconds
INFO | jvm 4 | 2019/09/26 13:43:56 | Total time for which application threads were stopped: 0.0015708 seconds, Stopping threads took: 0.0001941 seconds
INFO | jvm 4 | 2019/09/26 13:43:56 | Total time for which application threads were stopped: 0.0015231 seconds, Stopping threads took: 0.0001709 seconds
INFO | jvm 4 | 2019/09/26 13:43:57 | I [T.ClientInterface ] [11:43:56]: Removing Tags due to switching user. request-origin=10.52.212.48, session-user=OP, session-project=XXXXXXXXXX, session-id=8C5248F4
INFO | jvm 4 | 2019/09/26 13:43:59 | Total time for which application threads were stopped: 0.0028913 seconds, Stopping threads took: 0.0002459 seconds
INFO | jvm 4 | 2019/09/26 13:44:00 | Total time for which application threads were stopped: 0.0026298 seconds, Stopping threads took: 0.0002736 seconds
INFO | jvm 4 | 2019/09/26 13:44:00 | Total time for which application threads were stopped: 0.0032073 seconds, Stopping threads took: 0.0003124 seconds
INFO | jvm 4 | 2019/09/26 13:44:02 | Total time for which application threads were stopped: 0.0036977 seconds, Stopping threads took: 0.0002486 seconds
INFO | jvm 4 | 2019/09/26 13:44:06 | [GC pause (G1 Evacuation Pause) (young)
INFO | jvm 4 | 2019/09/26 13:44:23 | , 17.5622303 secs]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Parallel Time: 17498.2 ms, GC Workers: 13]
INFO | jvm 4 | 2019/09/26 13:44:23 | [GC Worker Start (ms): Min: 642586730.4, Avg: 642586730.5, Max: 642586730.6, Diff: 0.3]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Ext Root Scanning (ms): Min: 2.0, Avg: 2.5, Max: 5.6, Diff: 3.6, Sum: 31.9]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Update RS (ms): Min: 14.4, Avg: 17.5, Max: 18.1, Diff: 3.7, Sum: 227.7]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Processed Buffers: Min: 25, Avg: 39.3, Max: 58, Diff: 33, Sum: 511]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Scan RS (ms): Min: 0.2, Avg: 0.5, Max: 0.7, Diff: 0.5, Sum: 6.7]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Code Root Scanning (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.2]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Object Copy (ms): Min: 17092.4, Avg: 17122.5, Max: 17157.8, Diff: 65.4, Sum: 222592.0]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Termination (ms): Min: 319.4, Avg: 354.7, Max: 384.7, Diff: 65.3, Sum: 4611.3]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Termination Attempts: Min: 366042, Avg: 401317.8, Max: 429641, Diff: 63599, Sum: 5217131]
INFO | jvm 4 | 2019/09/26 13:44:23 | [GC Worker Other (ms): Min: 0.0, Avg: 0.1, Max: 0.2, Diff: 0.2, Sum: 1.9]
INFO | jvm 4 | 2019/09/26 13:44:23 | [GC Worker Total (ms): Min: 17497.7, Avg: 17497.8, Max: 17498.0, Diff: 0.4, Sum: 227471.8]
INFO | jvm 4 | 2019/09/26 13:44:23 | [GC Worker End (ms): Min: 642604228.2, Avg: 642604228.3, Max: 642604228.4, Diff: 0.2]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Code Root Fixup: 0.0 ms]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Code Root Purge: 0.0 ms]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Clear CT: 2.1 ms]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Other: 61.9 ms]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Choose CSet: 0.0 ms]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Ref Proc: 53.9 ms]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Ref Enq: 1.9 ms]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Redirty Cards: 0.7 ms]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Humongous Register: 0.2 ms]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Humongous Reclaim: 0.1 ms]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Free CSet: 4.0 ms]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Eden: 17.1G(17.1G)->0.0B(8192.0K) Survivors: 72.0M->1688.0M Heap: 28.0G(31.3G)->12.4G(31.3G)]
INFO | jvm 4 | 2019/09/26 13:44:23 | [Times: user=227.24 sys=0.05, real=17.56 secs]