We are using Oracle JDK 12 for our elasticsearch cluster with the following JVM settings
heap=30g
InitiatingHeapOccupancyPercent=30
G1ReservePercent=25
G1HeapRegionSize=16M
G1EagerReclaimHumongousObjects
G1EagerReclaimHumongousObjectsWithStaleRefs
UseStringDeduplication
For the most part, our cluster does totally fine & GC is in an acceptable range (100ms-200ms). But every 2hr, we have a job that takes a snapshot of elasticsearch. My guess is this is a process that involves generating lots of short lived objects (or long lived? unsure). Anyways, we see a spike in the time taken for our young gen GC (goes upto 500ms-1s). We also see number of young GC to shoot up so its more likely that the spike in time is a consequence of the increase in frequency of young GC. I don't think my application is affected because of this, so i'd like to know what all "time" is considered in the calculation of young gen gc. Is only pauses phases considered? or even concurrent phases are considered? Is String deduplication time considered?
Here are my GC logs. The snapshot starts around 08:00 (i had to trim down the gc logs because of character limits, let me know if you need them)
[07:58:28.732][gc,start ] GC(2156) Pause Young (Normal) (G1 Evacuation Pause)
[07:58:28.732][gc,task ] GC(2156) Using 8 workers of 8 for evacuation
[07:58:28.789][gc,ihop ] GC(2156) Basic information (value update), threshold: 6589444172B (20.46), target occupancy: 32212254720B, current occupancy: 7878715904B, recent allocation size: 0B, recent allocation duration: 58516.23ms, recent old gen allocation rate: 0.00B/s, recent marking phase length: 58575.90ms
[07:58:28.789][gc,ihop ] GC(2156) Adaptive IHOP information (value update), threshold: 6589444172B (29.22), internal target occupancy: 22548578304B, occupancy: 7878715904B, additional buffer size: 15955132416B, predicted old gen allocation rate: 62328.84B/s, predicted marking phase length: 64203.29ms, prediction active: true
[07:58:28.789][gc,phases ] GC(2156) Pre Evacuate Collection Set: 0.1ms
[07:58:28.789][gc,phases ] GC(2156) Evacuate Collection Set: 49.0ms
[07:58:28.789][gc,phases ] GC(2156) Post Evacuate Collection Set: 7.6ms
[07:58:28.789][gc,phases ] GC(2156) Other: 0.5ms
[07:58:28.789][gc,heap ] GC(2156) Eden regions: 945->0(945)
[07:58:28.789][gc,heap ] GC(2156) Survivor regions: 5->6(119)
[07:58:28.789][gc,heap ] GC(2156) Old regions: 257->257
[07:58:28.789][gc,heap ] GC(2156) Archive regions: 2->2
[07:58:28.789][gc,heap ] GC(2156) Humongous regions: 206->206
[07:58:28.789][gc,metaspace ] GC(2156) Metaspace: 105348K->105348K(1146880K)
[07:58:28.789][gc ] GC(2156) Pause Young (Normal) (G1 Evacuation Pause) 22614M->7513M(30720M) 57.262ms
[07:58:28.789][gc,cpu ] GC(2156) User=0.40s Sys=0.00s Real=0.05s
[07:59:27.424][gc,start ] GC(2157) Pause Young (Normal) (G1 Evacuation Pause)
[07:59:27.424][gc,task ] GC(2157) Using 8 workers of 8 for evacuation
[07:59:27.478][gc,ihop ] GC(2157) Basic information (value update), threshold: 6572771349B (20.40), target occupancy: 32212254720B, current occupancy: 7895493120B, recent allocation size: 0B, recent allocation duration: 58634.65ms, recent old gen allocation rate: 0.00B/s, recent marking phase length: 58575.90ms
[07:59:27.478][gc,ihop ] GC(2157) Adaptive IHOP information (value update), threshold: 6572771349B (29.15), internal target occupancy: 22548578304B, occupancy: 7895493120B, additional buffer size: 15971909632B, predicted old gen allocation rate: 60702.86B/s, predicted marking phase length: 64203.29ms, prediction active: true
[07:59:27.478][gc,phases ] GC(2157) Pre Evacuate Collection Set: 0.1ms
[07:59:27.478][gc,phases ] GC(2157) Evacuate Collection Set: 46.3ms
[07:59:27.478][gc,phases ] GC(2157) Post Evacuate Collection Set: 7.7ms
[07:59:27.478][gc,phases ] GC(2157) Other: 0.5ms
[07:59:27.478][gc,heap ] GC(2157) Eden regions: 945->0(945)
[07:59:27.478][gc,heap ] GC(2157) Survivor regions: 6->7(119)
[07:59:27.478][gc,heap ] GC(2157) Old regions: 257->257
[07:59:27.478][gc,heap ] GC(2157) Archive regions: 2->2
[07:59:27.478][gc,heap ] GC(2157) Humongous regions: 206->206
[07:59:27.478][gc,metaspace ] GC(2157) Metaspace: 105348K->105348K(1146880K)
[07:59:27.478][gc ] GC(2157) Pause Young (Normal) (G1 Evacuation Pause) 22633M->7529M(30720M) 54.705ms
[07:59:27.478][gc,cpu ] GC(2157) User=0.36s Sys=0.01s Real=0.05s
[07:59:27.479][gc,stringdedup] Concurrent String Deduplication (79018.557s)
[07:59:27.479][gc,stringdedup] Concurrent String Deduplication 65.1K->7040.0B(58.3K) avg 89.7% (79018.557s, 79018.557s) 0.348ms
[08:00:19.850][gc,start ] GC(2158) Pause Young (Concurrent Start) (G1 Evacuation Pause)
[08:00:19.850][gc,task ] GC(2158) Using 8 workers of 8 for evacuation
[08:00:19.914][gc,ihop ] GC(2158) Basic information (value update), threshold: 6623204594B (20.56), target occupancy: 32212254720B, current occupancy: 7945824768B, recent allocation size: 0B, recent allocation duration: 52371.39ms, recent old gen allocation rate: 0.00B/s, recent marking phase length: 58575.90ms
[08:00:19.914][gc,ihop ] GC(2158) Adaptive IHOP information (value update), threshold: 6623204594B (29.37), internal target occupancy: 22548578304B, occupancy: 7945824768B, additional buffer size: 15921577984B, predicted old gen allocation rate: 59120.44B/s, predicted marking phase length: 64203.29ms, prediction active: true
[08:00:19.914][gc,phases ] GC(2158) Pre Evacuate Collection Set: 0.6ms
[08:00:19.914][gc,phases ] GC(2158) Evacuate Collection Set: 55.8ms
[08:00:19.914][gc,phases ] GC(2158) Post Evacuate Collection Set: 7.5ms
[08:00:19.914][gc,phases ] GC(2158) Other: 0.8ms
[08:00:19.914][gc,heap ] GC(2158) Eden regions: 945->0(939)
[08:00:19.914][gc,heap ] GC(2158) Survivor regions: 7->10(119)
[08:00:19.914][gc,heap ] GC(2158) Old regions: 257->257
[08:00:19.914][gc,heap ] GC(2158) Archive regions: 2->2
[08:00:19.914][gc,heap ] GC(2158) Humongous regions: 206->206
[08:00:19.914][gc,metaspace ] GC(2158) Metaspace: 105361K->105361K(1146880K)
[08:00:19.914][gc ] GC(2158) Pause Young (Concurrent Start) (G1 Evacuation Pause) 22649M->7577M(30720M) 64.647ms
[08:00:19.914][gc,cpu ] GC(2158) User=0.48s Sys=0.00s Real=0.07s
[08:00:19.914][gc ] GC(2159) Concurrent Cycle
[08:00:19.914][gc,marking ] GC(2159) Concurrent Clear Claimed Marks
[08:00:19.914][gc,stringdedup] Concurrent String Deduplication (79070.993s)
[08:00:19.915][gc,marking ] GC(2159) Concurrent Clear Claimed Marks 0.492ms
[08:00:19.915][gc,marking ] GC(2159) Concurrent Scan Root Regions
[08:00:19.921][gc,stringdedup] Concurrent String Deduplication 521.8K->29.2K(492.6K) avg 89.7% (79070.993s, 79070.999s) 6.278ms
[08:00:19.947][gc,marking ] GC(2159) Concurrent Scan Root Regions 32.108ms
[08:00:19.947][gc,marking ] GC(2159) Concurrent Mark (79071.025s)
[08:00:19.947][gc,marking ] GC(2159) Concurrent Mark From Roots
[08:00:19.947][gc,task ] GC(2159) Using 2 workers of 2 for marking
[08:00:20.206][gc,marking ] GC(2159) Concurrent Mark From Roots 259.199ms
[08:00:20.206][gc,marking ] GC(2159) Concurrent Preclean
[08:00:20.207][gc,marking ] GC(2159) Concurrent Preclean 0.766ms
[08:00:20.207][gc,marking ] GC(2159) Concurrent Mark (79071.025s, 79071.285s) 260.035ms
[08:00:20.207][gc,start ] GC(2159) Pause Remark
[08:00:20.217][gc,stringtable] GC(2159) Cleaned string table, strings: 43384 processed, 10 removed
[08:00:20.217][gc ] GC(2159) Pause Remark 8159M->8159M(30720M) 9.650ms
[08:00:20.217][gc,cpu ] GC(2159) User=0.06s Sys=0.00s Real=0.01s
[08:00:20.217][gc,marking ] GC(2159) Concurrent Rebuild Remembered Sets
[08:00:20.396][gc,marking ] GC(2159) Concurrent Rebuild Remembered Sets 178.818ms
[08:00:20.396][gc,start ] GC(2159) Pause Cleanup
[08:00:20.397][gc ] GC(2159) Pause Cleanup 8453M->8453M(30720M) 0.517ms
[08:00:20.397][gc,cpu ] GC(2159) User=0.01s Sys=0.00s Real=0.00s
[08:00:20.397][gc,marking ] GC(2159) Concurrent Cleanup for Next Mark
[08:00:20.441][gc,marking ] GC(2159) Concurrent Cleanup for Next Mark 43.972ms
[08:00:20.441][gc ] GC(2159) Concurrent Cycle 526.516ms
[08:01:01.561][gc,start ] GC(2160) Pause Young (Prepare Mixed) (G1 Evacuation Pause)
[08:01:01.561][gc,task ] GC(2160) Using 8 workers of 8 for evacuation
[08:01:01.702][gc,ihop ] GC(2160) Basic information (value update), threshold: 22483675846B (69.80), target occupancy: 32212254720B, current occupancy: 8070504336B, recent allocation size: 268435456B, recent allocation duration: 41636.50ms, recent old gen allocation rate: 6447119.35B/s, recent marking phase length: 58575.90ms
[08:01:01.702][gc,ihop ] GC(2160) Adaptive IHOP information (value update), threshold: 22483675846B (99.71), internal target occupancy: 22548578304B, occupancy: 8070504336B, additional buffer size: 0B, predicted old gen allocation rate: 1010889.92B/s, predicted marking phase length: 64203.29ms, prediction active: true
[08:01:01.702][gc,phases ] GC(2160) Pre Evacuate Collection Set: 0.2ms
[08:01:01.702][gc,phases ] GC(2160) Evacuate Collection Set: 132.9ms
[08:01:01.702][gc,phases ] GC(2160) Post Evacuate Collection Set: 8.1ms
[08:01:01.702][gc,phases ] GC(2160) Other: 0.5ms
[08:01:01.702][gc,heap ] GC(2160) Eden regions: 939->0(78)
[08:01:01.702][gc,heap ] GC(2160) Survivor regions: 10->18(119)
[08:01:01.702][gc,heap ] GC(2160) Old regions: 257->257
[08:01:01.702][gc,heap ] GC(2160) Archive regions: 2->2
[08:01:01.702][gc,heap ] GC(2160) Humongous regions: 222->206
[08:01:01.702][gc,metaspace ] GC(2160) Metaspace: 105362K->105362K(1146880K)
[08:01:01.702][gc ] GC(2160) Pause Young (Prepare Mixed) (G1 Evacuation Pause) 22857M->7696M(30720M) 141.749ms
[08:01:01.702][gc,cpu ] GC(2160) User=1.10s Sys=0.00s Real=0.15s
[08:01:01.702][gc,stringdedup] Concurrent String Deduplication (79112.781s)
[08:01:01.709][gc,stringdedup] Concurrent String Deduplication 699.8K->24.0K(675.9K) avg 89.7% (79112.781s, 79112.788s) 6.964ms
[08:01:07.109][gc,start ] GC(2161) Pause Young (Mixed) (G1 Evacuation Pause)
[08:01:07.109][gc,task ] GC(2161) Using 8 workers of 8 for evacuation
[08:01:07.245][gc,ihop ] GC(2161) Basic information (value update), threshold: 22484181601B (69.80), target occupancy: 32212254720B, current occupancy: 8078195864B, recent allocation size: 268435456B, recent allocation duration: 41636.50ms, recent old gen allocation rate: 6447119.35B/s, recent marking phase length: 47043.07ms
[08:01:07.245][gc,ihop ] GC(2161) Adaptive IHOP information (value update), threshold: 22484181601B (99.71), internal target occupancy: 22548578304B, occupancy: 8078195864B, additional buffer size: 0B, predicted old gen allocation rate: 1010889.92B/s, predicted marking phase length: 63702.98ms, prediction active: true
[08:01:07.245][gc,phases ] GC(2161) Pre Evacuate Collection Set: 0.1ms
[08:01:07.245][gc,phases ] GC(2161) Evacuate Collection Set: 129.4ms
[08:01:07.245][gc,phases ] GC(2161) Post Evacuate Collection Set: 5.8ms
[08:01:07.245][gc,phases ] GC(2161) Other: 0.9ms
[08:01:07.245][gc,heap ] GC(2161) Eden regions: 78->0(89)
[08:01:07.245][gc,heap ] GC(2161) Survivor regions: 18->7(12)
[08:01:07.245][gc,heap ] GC(2161) Old regions: 257->269
[08:01:07.245][gc,heap ] GC(2161) Archive regions: 2->2
[08:01:07.245][gc,heap ] GC(2161) Humongous regions: 206->206
[08:01:07.245][gc,metaspace ] GC(2161) Metaspace: 105362K->105362K(1146880K)
[08:01:07.245][gc ] GC(2161) Pause Young (Mixed) (G1 Evacuation Pause) 8944M->7703M(30720M) 136.242ms
[08:01:07.245][gc,cpu ] GC(2161) User=1.06s Sys=0.01s Real=0.14s
[08:01:07.245][gc,stringdedup] Concurrent String Deduplication (79118.323s)
[08:01:07.899][gc,stringdedup] Concurrent String Deduplication 39.0M->20.9M(18.1M) avg 89.0% (79118.323s, 79118.977s) 653.012ms
[08:01:08.059][gc,start ] GC(2162) Pause Young (Normal) (G1 Evacuation Pause)
[08:01:08.059][gc,task ] GC(2162) Using 8 workers of 8 for evacuation
[08:01:08.128][gc,ihop ] GC(2162) Basic information (value update), threshold: 20875652532B (64.81), target occupancy: 32212254720B, current occupancy: 8044297680B, recent allocation size: 0B, recent allocation duration: 814.49ms, recent old gen allocation rate: 0.00B/s, recent marking phase length: 47043.07ms
[08:01:08.128][gc,ihop ] GC(2162) Adaptive IHOP information (value update), threshold: 20875652532B (92.58), internal target occupancy: 22548578304B, occupancy: 8044297680B, additional buffer size: 1610612736B, predicted old gen allocation rate: 978180.82B/s, predicted marking phase length: 63702.98ms, prediction active: true
[08:01:08.128][gc,phases ] GC(2162) Pre Evacuate Collection Set: 0.2ms
[08:01:08.128][gc,phases ] GC(2162) Evacuate Collection Set: 56.7ms
[08:01:08.128][gc,phases ] GC(2162) Post Evacuate Collection Set: 12.5ms
[08:01:08.128][gc,phases ] GC(2162) Other: 0.4ms
[08:01:08.128][gc,heap ] GC(2162) Eden regions: 89->0(91)
[08:01:08.128][gc,heap ] GC(2162) Survivor regions: 7->5(12)
[08:01:08.128][gc,heap ] GC(2162) Old regions: 269->269
[08:01:08.128][gc,heap ] GC(2162) Archive regions: 2->2
[08:01:08.128][gc,heap ] GC(2162) Humongous regions: 206->206
[08:01:08.128][gc,metaspace ] GC(2162) Metaspace: 105362K->105362K(1146880K)
[08:01:08.128][gc ] GC(2162) Pause Young (Normal) (G1 Evacuation Pause) 9127M->7671M(30720M) 69.911ms
[08:01:08.128][gc,cpu ] GC(2162) User=0.41s Sys=0.00s Real=0.07s
[08:01:13.212][gc,start ] GC(2163) Pause Young (Normal) (G1 Evacuation Pause)
[08:01:13.212][gc,task ] GC(2163) Using 8 workers of 8 for evacuation
[08:01:13.251][gc,ihop ] GC(2163) Basic information (value update), threshold: 20877662206B (64.81), target occupancy: 32212254720B, current occupancy: 8098476336B, recent allocation size: 0B, recent allocation duration: 5083.41ms, recent old gen allocation rate: 0.00B/s, recent marking phase length: 47043.07ms
[08:01:13.251][gc,ihop ] GC(2163) Adaptive IHOP information (value update), threshold: 20877662206B (92.59), internal target occupancy: 22548578304B, occupancy: 8098476336B, additional buffer size: 1610612736B, predicted old gen allocation rate: 946633.26B/s, predicted marking phase length: 63702.98ms, prediction active: true
[08:01:13.251][gc,phases ] GC(2163) Pre Evacuate Collection Set: 0.1ms
[08:01:13.251][gc,phases ] GC(2163) Evacuate Collection Set: 28.4ms
[08:01:13.251][gc,phases ] GC(2163) Post Evacuate Collection Set: 10.7ms
[08:01:13.251][gc,phases ] GC(2163) Other: 0.4ms
[08:01:13.251][gc,heap ] GC(2163) Eden regions: 91->0(88)
[08:01:13.251][gc,heap ] GC(2163) Survivor regions: 5->8(12)
[08:01:13.251][gc,heap ] GC(2163) Old regions: 269->269
[08:01:13.251][gc,heap ] GC(2163) Archive regions: 2->2
[08:01:13.251][gc,heap ] GC(2163) Humongous regions: 206->206
[08:01:13.251][gc,metaspace ] GC(2163) Metaspace: 105363K->105363K(1146880K)
[08:01:13.251][gc ] GC(2163) Pause Young (Normal) (G1 Evacuation Pause) 9127M->7723M(30720M) 39.714ms
[08:01:13.251][gc,cpu ] GC(2163) User=0.30s Sys=0.00s Real=0.04s
[08:01:13.251][gc,stringdedup] Concurrent String Deduplication (79124.330s)
[08:01:13.261][gc,stringdedup] Concurrent String Deduplication 1332.0K->20.1K(1312.0K) avg 89.0% (79124.330s, 79124.339s) 9.615ms
[08:01:13.940][gc,start ] GC(2164) Pause Young (Normal) (G1 Evacuation Pause)
[08:01:13.940][gc,task ] GC(2164) Using 8 workers of 8 for evacuation
[08:01:13.981][gc,ihop ] GC(2164) Basic information (value update), threshold: 20212961079B (62.75), target occupancy: 32212254720B, current occupancy: 8078222768B, recent allocation size: 19786504B, recent allocation duration: 689.40ms, recent old gen allocation rate: 28700939.91B/s, recent marking phase length: 47043.07ms
[08:01:13.981][gc,ihop ] GC(2164) Adaptive IHOP information (value update), threshold: 20212961079B (89.64), internal target occupancy: 22548578304B, occupancy: 8078222768B, additional buffer size: 2030043136B, predicted old gen allocation rate: 4796856.81B/s, predicted marking phase length: 63702.98ms, prediction active: true
[08:01:13.981][gc,phases ] GC(2164) Pre Evacuate Collection Set: 0.1ms
[08:01:13.981][gc,phases ] GC(2164) Evacuate Collection Set: 30.5ms
[08:01:13.981][gc,phases ] GC(2164) Post Evacuate Collection Set: 9.3ms
[08:01:13.981][gc,phases ] GC(2164) Other: 0.4ms
[08:01:13.981][gc,heap ] GC(2164) Eden regions: 88->0(115)
[08:01:13.981][gc,heap ] GC(2164) Survivor regions: 8->6(12)
[08:01:13.981][gc,heap ] GC(2164) Old regions: 269->270
[08:01:13.981][gc,heap ] GC(2164) Archive regions: 2->2
[08:01:13.981][gc,heap ] GC(2164) Humongous regions: 206->206
[08:01:13.981][gc,metaspace ] GC(2164) Metaspace: 105363K->105363K(1146880K)
[08:01:13.981][gc ] GC(2164) Pause Young (Normal) (G1 Evacuation Pause) 9131M->7703M(30720M) 40.298ms
[08:01:13.981][gc,cpu ] GC(2164) User=0.30s Sys=0.00s Real=0.04s
[08:01:13.981][gc,stringdedup] Concurrent String Deduplication (79125.059s)
[08:01:13.992][gc,stringdedup] Concurrent String Deduplication 2402.6K->32.9K(2369.6K) avg 89.0% (79125.059s, 79125.070s) 11.023ms
[08:01:19.482][gc,start ] GC(2165) Pause Young (Normal) (G1 Evacuation Pause)
[08:01:19.482][gc,task ] GC(2165) Using 8 workers of 8 for evacuation
[08:01:19.556][gc,ihop ] GC(2165) Basic information (value update), threshold: 19776268143B (61.39), target occupancy: 32212254720B, current occupancy: 8119539992B, recent allocation size: 201326592B, recent allocation duration: 5501.13ms, recent old gen allocation rate: 36597302.91B/s, recent marking phase length: 47043.07ms
[08:01:19.556][gc,ihop ] GC(2165) Adaptive IHOP information (value update), threshold: 19776268143B (87.71), internal target occupancy: 22548578304B, occupancy: 8119539992B, additional buffer size: 2248146944B, predicted old gen allocation rate: 8228236.57B/s, predicted marking phase length: 63702.98ms, prediction active: true
[08:01:19.556][gc,phases ] GC(2165) Pre Evacuate Collection Set: 0.1ms
[08:01:19.556][gc,phases ] GC(2165) Evacuate Collection Set: 63.7ms
[08:01:19.556][gc,phases ] GC(2165) Post Evacuate Collection Set: 10.5ms
[08:01:19.556][gc,phases ] GC(2165) Other: 0.4ms
[08:01:19.556][gc,heap ] GC(2165) Eden regions: 115->0(126)
[08:01:19.556][gc,heap ] GC(2165) Survivor regions: 6->8(16)
[08:01:19.556][gc,heap ] GC(2165) Old regions: 270->270
[08:01:19.556][gc,heap ] GC(2165) Archive regions: 2->2
[08:01:19.556][gc,heap ] GC(2165) Humongous regions: 218->206
[08:01:19.556][gc,metaspace ] GC(2165) Metaspace: 105386K->105386K(1146880K)
[08:01:19.556][gc ] GC(2165) Pause Young (Normal) (G1 Evacuation Pause) 9735M->7743M(30720M) 74.803ms
[08:01:19.556][gc,cpu ] GC(2165) User=0.50s Sys=0.01s Real=0.08s
[08:01:19.556][gc,stringdedup] Concurrent String Deduplication (79130.635s)
[08:01:19.559][gc,stringdedup] Concurrent String Deduplication 348.8K->11.9K(336.9K) avg 89.0% (79130.635s, 79130.637s) 2.368ms
[08:01:24.287][gc,start ] GC(2166) Pause Young (Normal) (G1 Evacuation Pause)
[08:01:24.287][gc,task ] GC(2166) Using 8 workers of 8 for evacuation
[08:01:24.326][gc,ihop ] GC(2166) Basic information (value update), threshold: 19120266533B (59.36), target occupancy: 32212254720B, current occupancy: 8114407056B, recent allocation size: 67108864B, recent allocation duration: 4730.46ms, recent old gen allocation rate: 14186539.53B/s, recent marking phase length: 47043.07ms
[08:01:24.326][gc,ihop ] GC(2166) Adaptive IHOP information (value update), threshold: 19120266533B (84.80), internal target occupancy: 22548578304B, occupancy: 8114407056B, additional buffer size: 2868903936B, predicted old gen allocation rate: 8781501.37B/s, predicted marking phase length: 63702.98ms, prediction active: true
[08:01:24.326][gc,phases ] GC(2166) Pre Evacuate Collection Set: 0.1ms
[08:01:24.326][gc,phases ] GC(2166) Evacuate Collection Set: 28.8ms
[08:01:24.326][gc,phases ] GC(2166) Post Evacuate Collection Set: 9.9ms
[08:01:24.326][gc,phases ] GC(2166) Other: 0.4ms
[08:01:24.326][gc,heap ] GC(2166) Eden regions: 126->0(163)
[08:01:24.326][gc,heap ] GC(2166) Survivor regions: 8->8(17)
[08:01:24.326][gc,heap ] GC(2166) Old regions: 270->270
[08:01:24.326][gc,heap ] GC(2166) Archive regions: 2->2
[08:01:24.326][gc,heap ] GC(2166) Humongous regions: 210->206
[08:01:24.326][gc,metaspace ] GC(2166) Metaspace: 105386K->105386K(1146880K)
[08:01:24.326][gc ] GC(2166) Pause Young (Normal) (G1 Evacuation Pause) 9823M->7738M(30720M) 39.317ms
[08:01:24.326][gc,cpu ] GC(2166) User=0.29s Sys=0.00s Real=0.04s
[08:01:24.326][gc,stringdedup] Concurrent String Deduplication (79135.404s)
[08:01:24.329][gc,stringdedup] Concurrent String Deduplication 698.8K->27.3K(671.6K) avg 89.0% (79135.404s, 79135.408s) 3.269ms
[08:01:30.866][gc,start ] GC(2167) Pause Young (Normal) (G1 Evacuation Pause)
[08:01:30.866][gc,task ] GC(2167) Using 8 workers of 8 for evacuation
[08:01:30.911][gc,ihop ] GC(2167) Basic information (value update), threshold: 18015410601B (55.93), target occupancy: 32212254720B, current occupancy: 8139550208B, recent allocation size: 0B, recent allocation duration: 6539.92ms, recent old gen allocation rate: 0.00B/s, recent marking phase length: 47043.07ms
[08:01:30.911][gc,ihop ] GC(2167) Adaptive IHOP information (value update), threshold: 18015410601B (79.90), internal target occupancy: 22548578304B, occupancy: 8139550208B, additional buffer size: 3992977408B, predicted old gen allocation rate: 8479827.28B/s, predicted marking phase length: 63702.98ms, prediction active: true
[08:01:30.911][gc,phases ] GC(2167) Pre Evacuate Collection Set: 0.1ms
[08:01:30.911][gc,phases ] GC(2167) Evacuate Collection Set: 34.9ms
[08:01:30.911][gc,phases ] GC(2167) Post Evacuate Collection Set: 10.6ms
[08:01:30.911][gc,phases ] GC(2167) Other: 0.4ms
[08:01:30.911][gc,heap ] GC(2167) Eden regions: 163->0(229)
[08:01:30.912][gc,heap ] GC(2167) Survivor regions: 8->9(22)
[08:01:30.912][gc,heap ] GC(2167) Old regions: 270->270
[08:01:30.912][gc,heap ] GC(2167) Archive regions: 2->2
[08:01:30.912][gc,heap ] GC(2167) Humongous regions: 206->206
[08:01:30.912][gc,metaspace ] GC(2167) Metaspace: 105386K->105386K(1146880K)
[08:01:30.912][gc ] GC(2167) Pause Young (Normal) (G1 Evacuation Pause) 10346M->7762M(30720M) 46.040ms
[08:01:30.912][gc,cpu ] GC(2167) User=0.33s Sys=0.00s Real=0.05s
[08:01:30.912][gc,stringdedup] Concurrent String Deduplication (79141.990s)
[08:01:30.920][gc,stringdedup] Concurrent String Deduplication 844.3K->299.4K(544.9K) avg 89.0% (79141.990s, 79141.998s) 7.908ms
[08:01:42.598][gc,start ] GC(2168) Pause Young (Normal) (G1 Evacuation Pause)
[08:01:42.598][gc,task ] GC(2168) Using 8 workers of 8 for evacuation
[08:01:42.650][gc,ihop ] GC(2168) Basic information (value update), threshold: 16591082317B (51.51), target occupancy: 32212254720B, current occupancy: 8169059536B, recent allocation size: 0B, recent allocation duration: 11686.27ms, recent old gen allocation rate: 0.00B/s, recent marking phase length: 47043.07ms
[08:01:42.650][gc,ihop ] GC(2168) Adaptive IHOP information (value update), threshold: 16591082317B (73.58), internal target occupancy: 22548578304B, occupancy: 8169059536B, additional buffer size: 5435817984B, predicted old gen allocation rate: 8189224.05B/s, predicted marking phase length: 63702.98ms, prediction active: true
[08:01:42.650][gc,phases ] GC(2168) Pre Evacuate Collection Set: 0.1ms
[08:01:42.650][gc,phases ] GC(2168) Evacuate Collection Set: 41.6ms
[08:01:42.650][gc,phases ] GC(2168) Post Evacuate Collection Set: 10.1ms
[08:01:42.650][gc,phases ] GC(2168) Other: 0.4ms
[08:01:42.650][gc,heap ] GC(2168) Eden regions: 229->0(313)
[08:01:42.650][gc,heap ] GC(2168) Survivor regions: 9->11(30)
[08:01:42.650][gc,heap ] GC(2168) Old regions: 270->270
[08:01:42.650][gc,heap ] GC(2168) Archive regions: 2->2
[08:01:42.650][gc,heap ] GC(2168) Humongous regions: 206->206
[08:01:42.650][gc,metaspace ] GC(2168) Metaspace: 105386K->105386K(1146880K)
[08:01:42.650][gc ] GC(2168) Pause Young (Normal) (G1 Evacuation Pause) 11426M->7790M(30720M) 52.271ms
[08:01:42.650][gc,cpu ] GC(2168) User=0.38s Sys=0.00s Real=0.05s
[08:01:42.650][gc,stringdedup] Concurrent String Deduplication (79153.728s)
[08:01:42.655][gc,stringdedup] Concurrent String Deduplication 690.2K->374.5K(315.8K) avg 89.0% (79153.728s, 79153.733s) 4.859ms
[08:01:54.760][gc,start ] GC(2169) Pause Young (Normal) (G1 Evacuation Pause)
[08:01:54.760][gc,task ] GC(2169) Using 8 workers of 8 for evacuation
[08:01:54.832][gc,ihop ] GC(2169) Basic information (value update), threshold: 15971249571B (49.58), target occupancy: 32212254720B, current occupancy: 8200702272B, recent allocation size: 67108864B, recent allocation duration: 12110.77ms, recent old gen allocation rate: 5541256.23B/s, recent marking phase length: 47043.07ms
[08:01:54.832][gc,ihop ] GC(2169) Adaptive IHOP information (value update), threshold: 15971249571B (70.83), internal target occupancy: 22548578304B, occupancy: 8200702272B, additional buffer size: 6056574976B, predicted old gen allocation rate: 8174715.37B/s, predicted marking phase length: 63702.98ms, prediction active: true
[08:01:54.832][gc,phases ] GC(2169) Pre Evacuate Collection Set: 0.1ms
[08:01:54.832][gc,phases ] GC(2169) Evacuate Collection Set: 60.1ms
[08:01:54.832][gc,phases ] GC(2169) Post Evacuate Collection Set: 11.4ms
[08:01:54.832][gc,phases ] GC(2169) Other: 0.4ms
[08:01:54.832][gc,heap ] GC(2169) Eden regions: 313->0(348)
[08:01:54.832][gc,heap ] GC(2169) Survivor regions: 11->13(41)
[08:01:54.832][gc,heap ] GC(2169) Old regions: 270->270
[08:01:54.832][gc,heap ] GC(2169) Archive regions: 2->2
[08:01:54.832][gc,heap ] GC(2169) Humongous regions: 210->206
[08:01:54.832][gc,metaspace ] GC(2169) Metaspace: 105386K->105386K(1146880K)
[08:01:54.833][gc ] GC(2169) Pause Young (Normal) (G1 Evacuation Pause) 12862M->7820M(30720M) 72.189ms
[08:01:54.833][gc,cpu ] GC(2169) User=0.55s Sys=0.00s Real=0.08s
[08:01:54.833][gc,stringdedup] Concurrent String Deduplication (79165.911s)
[08:01:54.841][gc,stringdedup] Concurrent String Deduplication 892.8K->535.8K(356.9K) avg 89.0% (79165.911s, 79165.919s) 8.111ms
I truly suspect an increase in young gc to affect our gc time graphs. how do i avoid frequent young gc?
