![2019-08-31T01:09:19.397+0000: 1.606: [GC (Metadata GC Threshold) [PSYoungGen: 545393K->18495K(2446848K)] 545393K->18519K(8039424K),
0.0189376 secs] [Times: user=0.15 sys=0.01, real=0.02 secs]
2019-08-31T01:09:19.416+0000: 1.625: [Full GC (Metadata GC Threshold) [PSYoungGen: 18495K->0K(2446848K)] [ParOldGen: 24K->17366K(5592576K)]
18519K->17366K(8039424K), [Metaspace: 20781K->20781K(1067008K)], 0.0416162 secs] [Times: user=0.38 sys=0.03, real=0.04 secs]
2019-08-31T01:18:19.288+0000: 541.497: [GC (Metadata GC Threshold) [PSYoungGen: 1391495K->18847K(2446848K)] 1408861K->36230K(8039424K),
0.0568365 secs] [Times: user=0.31 sys=0.75, real=0.06 secs]
2019-08-31T01:18:19.345+0000: 541.554: [Full GC (Metadata GC Threshold) [PSYoungGen: 18847K->0K(2446848K)] [ParOldGen: 17382K-
>25397K(5592576K)] 36230K->25397K(8039424K), [Metaspace: 34865K->34865K(1079296K)], 0.0467640 secs] [Times: user=0.31 sys=0.08, real=0.04
secs]
2019-08-31T02:33:20.326+0000: 5042.536: [GC (Allocation Failure) [PSYoungGen: 2097664K->11337K(2446848K)] 2123061K->36742K(8039424K),
0.3298985 secs] [Times: user=0.00 sys=9.20, real=0.33 secs]
2019-08-31T03:40:11.749+0000: 9053.959: [GC (Allocation Failure) [PSYoungGen: 2109001K->15776K(2446848K)] 2134406K->41189K(8039424K),
0.0517517 secs] [Times: user=0.00 sys=1.22, real=0.05 secs]
2019-08-31T05:11:46.869+0000: 14549.079: [GC (Allocation Failure) [PSYoungGen: 2113440K->24832K(2446848K)] 2138853K->50253K(8039424K),
0.0392831 secs] [Times: user=0.02 sys=0.79, real=0.04 secs]
2019-08-31T06:26:10.376+0000: 19012.586: [GC (Allocation Failure) [PSYoungGen: 2122496K->25600K(2756096K)] 2147917K->58149K(8348672K),
0.0371416 secs] [Times: user=0.01 sys=0.75, real=0.04 secs]
2019-08-31T07:50:03.442+0000: 24045.652: [GC (Allocation Failure) [PSYoungGen: 2756096K->32768K(2763264K)] 2788645K->72397K(8355840K),
0.0709641 secs] [Times: user=0.16 sys=1.39, real=0.07 secs]
2019-08-31T09:04:21.406+0000: 28503.616: [GC (Allocation Failure) [PSYoungGen: 2763264K->32768K(2733568K)] 2802893K->83469K(8326144K),
0.0789178 secs] [Times: user=0.12 sys=1.59, real=0.08 secs]
Vanilla Format](https://image.slidesharecdn.com/jvm-match-making-gc-250820150345-41863f67/85/Matchmaking-for-JVMs-How-to-Pick-the-Perfect-GC-Partner-18-320.jpg)
Matchmaking for JVMs: How to Pick the Perfect GC Partner
- 2. Choosing a GC Algorithm = Choosing a Life Partner Coexist In The Same Roof (JVM) GC Cleans Up The Mess Your App Creates Aggressive App, Aggressive GC Competing For The Same Resources (CPU Cycles)
- 3. What is Garbage? HTTP Request Objects Memory Garbage
- 4. 3 - 4 Decades ago Developer Writes code to Manually evict Garbage JVM Automatically evicts Garbage Now How are objects Garbage Collected? Evolution: Manual -> Automatic
- 5. Automatic GC sounds good right? Yes, but for GC pauses CPU consumption
- 6. Key Performance Indicators GC Event’s Pause Time 1. Latency Percentage of time spent in processing customer transactions vs time spent in GC activity. i.e. productive work vs non-productive work 2. Throughput Memory, CPU, Response Time 3. Foot Print 99.994 % Memory: 2GB CPU Time: 1 hr 9min You can't optimize, what you can't measure 1.2 secs 4. Key Metric Key Metrics in any Performance Exercise
- 7. What is your Goal? 2. High Throughput 1. Low Pause Time 3. Footprint Example: Online trading application - A 100 ms GC pause could delay stock trades, leading to financial loss. Here the priority is predictability & ultra-low latency. Example: Batch data processing system – A Hadoop/Spark job crunching terabytes overnight. Occasional pauses don’t matter, but finishing the job faster (higher throughput) reduces infrastructure cost. Example: Microservice running in Kubernetes – Each pod is allocated a tight memory budget (say 512 MB). Optimizing GC for low memory footprint allows higher pod density and lowers the overall cloud bill.
- 8. CMS Parallel Serial Shenandoa h G1 03 02 01 05 04 Z GC 06 Epsilo n 0 7 How many GC algorithms in Java 11?
- 9. GC Algorithm Performance Comparison Stefan Johanson, Oracle Stefan’s Blog: https://kstefanj.github.io/
- 10. Test Setup 2. Heap Size 16GB 1. SPECjbb® 2015 – Well-Known Standard Benchmark 3. Enable Large Pages
- 15. How to find Right GC Algorithm for your Application? Tools, Tips & Tricks
- 16. Key Performance Indicators GC Event’s Pause Time 1. Latency Percentage of time spent in processing customer transactions vs time spent in GC activity. i.e. productive work vs non-productive work 2. Throughput Memory, CPU, Response Time 3. Foot Print 99.994 % Memory: 2GB CPU Time: 1 hr 9min You can't optimize, what you can't measure 1.2 secs 4. Key Metric Key Metrics in any Performance Exercise
- 17. 17 Step 1: Enable GC Logging -XX:+PrintGCDetails -XX:+PrintGCDateStamps -Xloggc:<file-path> Till Java 8 -Xlog:gc*:file=<file-path> From Java 9 Enable GC logs (always) Almost zero overhead. https://blog.gceasy.io/overhead-added-by-garbage-collection ging/
- 18. 2019-08-31T01:09:19.397+0000: 1.606: [GC (Metadata GC Threshold) [PSYoungGen: 545393K->18495K(2446848K)] 545393K->18519K(8039424K), 0.0189376 secs] [Times: user=0.15 sys=0.01, real=0.02 secs] 2019-08-31T01:09:19.416+0000: 1.625: [Full GC (Metadata GC Threshold) [PSYoungGen: 18495K->0K(2446848K)] [ParOldGen: 24K->17366K(5592576K)] 18519K->17366K(8039424K), [Metaspace: 20781K->20781K(1067008K)], 0.0416162 secs] [Times: user=0.38 sys=0.03, real=0.04 secs] 2019-08-31T01:18:19.288+0000: 541.497: [GC (Metadata GC Threshold) [PSYoungGen: 1391495K->18847K(2446848K)] 1408861K->36230K(8039424K), 0.0568365 secs] [Times: user=0.31 sys=0.75, real=0.06 secs] 2019-08-31T01:18:19.345+0000: 541.554: [Full GC (Metadata GC Threshold) [PSYoungGen: 18847K->0K(2446848K)] [ParOldGen: 17382K- >25397K(5592576K)] 36230K->25397K(8039424K), [Metaspace: 34865K->34865K(1079296K)], 0.0467640 secs] [Times: user=0.31 sys=0.08, real=0.04 secs] 2019-08-31T02:33:20.326+0000: 5042.536: [GC (Allocation Failure) [PSYoungGen: 2097664K->11337K(2446848K)] 2123061K->36742K(8039424K), 0.3298985 secs] [Times: user=0.00 sys=9.20, real=0.33 secs] 2019-08-31T03:40:11.749+0000: 9053.959: [GC (Allocation Failure) [PSYoungGen: 2109001K->15776K(2446848K)] 2134406K->41189K(8039424K), 0.0517517 secs] [Times: user=0.00 sys=1.22, real=0.05 secs] 2019-08-31T05:11:46.869+0000: 14549.079: [GC (Allocation Failure) [PSYoungGen: 2113440K->24832K(2446848K)] 2138853K->50253K(8039424K), 0.0392831 secs] [Times: user=0.02 sys=0.79, real=0.04 secs] 2019-08-31T06:26:10.376+0000: 19012.586: [GC (Allocation Failure) [PSYoungGen: 2122496K->25600K(2756096K)] 2147917K->58149K(8348672K), 0.0371416 secs] [Times: user=0.01 sys=0.75, real=0.04 secs] 2019-08-31T07:50:03.442+0000: 24045.652: [GC (Allocation Failure) [PSYoungGen: 2756096K->32768K(2763264K)] 2788645K->72397K(8355840K), 0.0709641 secs] [Times: user=0.16 sys=1.39, real=0.07 secs] 2019-08-31T09:04:21.406+0000: 28503.616: [GC (Allocation Failure) [PSYoungGen: 2763264K->32768K(2733568K)] 2802893K->83469K(8326144K), 0.0789178 secs] [Times: user=0.12 sys=1.59, real=0.08 secs] Vanilla Format
- 19. GC Log analysis tools https://developer.ibm.com/ja vasdk/tools/ IBM GC & Memory visualizer GC Viewer https://github.com/chewiebu g/GCViewer GCeasy https://gceasy.io/ Google Garbage cat (cms) https://code.google.com/arch ive/a/eclipselabs.org/p/garba gecat HP Jmeter https://h20392.www2.hpe.co m/portal/swdepot/displayPro ductInfo.do?productNumber =HPJMETER 03 02 01 05 04
- 21. 9 GC Tuning Tips & Tricks https://blog.gceasy.io/reduce-long-garbage-collection-pauses/
- 22. https://blog.gceasy.io/automobile-company-optimizes-performance-using-gceasy/ Real case study: GC Performance of a one of the Largest Car Maker
- 23. Large Car Maker Reduces Response time by 50% https://blog.gceasy.io/automobile-company-optimizes-performance-using-gceasy/
- 24. Real case study: Warehouse Robotics App Poor Performance https://blog.gceasy.io/2024/02/21/optimizing-robotics-applications-performance/
- 25. GC Tuning How We Saved 70K Cores Across 30 Mission-Critical Services? https://www.uber.com/en-IN/blog/how-we-saved-70k-cores-across-30-mission-critical-services/
- 26. More GC Tuning case studies Uber Saves Millions of $ https://blog.gceasy.io/2022/03/04/garbage-collection-tuning-success-story-reducing-young-gen-siz e/ Large Automobile Manufacturer Improves Response Time https://blog.gceasy.io/2022/03/04/garbage-collection-tuning-success-story-reducing-young-gen-siz e/ CloudBees (Jenkins Parent company) optimizes https://blog.gceasy.io/2019/08/01/cloudbees-gc-performance-optimized-with-gceasy/ Oracle optimizes App performance by tuning GC https://blog.gceasy.io/2022/12/06/oracle-architect-optimizes-performance-using-gceasy/
- 27. 27
- 28. Thank you my friends! Ram Lakshmanan @ycrash_rca This deck will be published in: https://blog.gceasy.io https://www.linkedin.com/company/ycrash
Editor's Notes
- #19: Demo: GCeasy - C:\workspace\speeches\9-types-oom\gc-memory-leak.zip
- #20: https://docs.google.com/spreadsheets/d/1EEfqs0rfEQR2MsfwpX_f_1vgyx75HKdm/edit?gid=540467667#gid=540467667
- #22: https://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMjEvMDQvOC8tLWdjLTIwMjEtMDQtMDZfMjAtMTgtNTRfbm9kZTYxLmxvZy0tMTUtMjgtMw==&s=t&channel=WEB&s=t Baseline: http://localhost:8080/yc-report.jsp?ou=SAP&de=192.168.56.170&app=yc&ts=2024-04-21T11-43-54 Benchmark: http://localhost:8080/yc-report.jsp?ou=SAP&de=192.168.56.170&app=yc&ts=2024-04-21T11-45-24
- #24: CMS GC: https://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMjQvMDIvNi9nYy4yMDIzMTIxNC5sb2ctLTIzLTU5LTY=&channel=WEB&s=t G1 GC: https://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMjMvMTIvMjEvZ2MubG9nLS01LTIxLTU0&channel=WEB&s=t