The document discusses troubleshooting JVM outages, presenting case studies from Fortune 500 companies and tools to analyze JVM performance like garbage collection and thread dumps. It highlights issues related to poor response times and automatic garbage collection, along with recommended open-source scripts and analysis methods. Additionally, various success stories of companies optimizing their performance through garbage collection tuning are mentioned, with links to further resources.

1. Troubleshooting JVM Outages
3 Fortune 500
Case Studies
Ram Lakshmanan
Architect GCeasy, FastThread, HeapHero

2. 2
Slowdown
Major Financial Institution in N. America
Analysis Report: https://tinyurl.com/5da3ft8z

3. Open-source script:
https://github.com/ycrash/yc-data-script
1. GC Log
10. netstat
12. vmstat
2. Thread Dump
9. dmesg
3. Heap Dump
6. ps
8. Disk Usage
5. top 13. iostat
11. ping
14. Kernel Params
15. App Logs
16. metadata
4. Heap Substitute
7. top -H
3
360° Troubleshooting artifacts

4. 1 2
3
1
Timestamp at which thread dump was triggered
2 JVM Version info
3
Thread Details - <<details in following slides>>
4

5. 1 2 3 4 5
6
7
1
Thread Name - InvoiceThread-A996
2
Priority - Can have values from 1 to 10
3
Thread Id - 0x00002b7cfc6fb000 – Unique ID assigned by JVM. It's returned by calling the Thread.getId() method.
4
Native Id - 0x4479 - This ID is highly platform dependent. On Linux, it's the pid of the thread. On Windows, it's simply the OS-level thread ID within
a process. On Mac OS X, it is said to be the native pthread_t value.
5
Address space - 0x00002b7d17ab8000 -
6
Thread State - RUNNABLE
7 Stack trace -
5

6. How to analyze Thread dump?
https://www.ibm.com/support/pa
ges/ibm-thread-and-monitor-du
mp-analyzer-java-tmda
IBM TDMA
FastThread
https://fastthread.io/
03
02
https://tinyurl.com/wq95weo
Sample thread
report
yCrash
https://ycrash.io/
01
6

7. 7
Poor Response Time
Major Cloud Service Provider
Blog: https://blog.gceasy.io/garbage-collection-tuning-success-story-reducing-young-gen-size/

8. What is Garbage?
HTTP Request
Objects
Memory
Garbage
8

9. 9
3 - 4 Decades ago
Developer
Writes code to Manually evict Garbage
JVM
Automatically evicts Garbage
Now
How are objects Garbage Collected?
Evolution: Manual -> Automatic

10. 10
Automatic GC sounds good right?
Yes, but for
GC pauses CPU consumption

11. Open-source script:
https://github.com/ycrash/yc-data-script
1. GC Log
10. netstat
12. vmstat
2. Thread Dump
9. dmesg
3. Heap Dump
6. ps
8. Disk Usage
5. top 13. iostat
11. ping
14. Kernel Params
15. App Logs
16. metadata
4. Heap Substitute
7. top -H
11
360° Troubleshooting artifacts

12. 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]
Sample GC Log

13. How to analyze GC Log?
https://developer.ibm.c
om/javasdk/tools/
IBM GC & Memory visualizer
GCeasy
yCrash
https://gceasy.io/
Google Garbage cat (cms)
https://code.google.co
m/archive/a/eclipselabs
.org/p/garbagecat
HP Jmeter
https://h20392.www2.h
pe.com/portal/swdepot
/displayProductInfo.do?
productNumber=HPJME
TER
03
02
01
05
04
https://ycrash.io/
13

14. 14
More GC Tuning case
studies
Uber Saves Millions of $
https://blog.gceasy.io/2022/03/04/garbage-collection-tuning-success-story-reducing-young-gen-size/
Large Automobile Manufacturer Improves Response Time
https://blog.gceasy.io/2022/03/04/garbage-collection-tuning-success-story-reducing-young-gen-size/
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/

15. 15
Large SaaS company CEO’s tweet

16. Intermittent HTTP 502 Errors
16
Major Travel Service Provider

17. EBS Architecture
17

18. Clue: Nginx Error
18

19. 1. GC Log
10. netstat
12. vmstat
2. Thread Dump
9. dmesg
3. Heap Dump
6. ps
8. Disk Usage
5. top 13. iostat
11. ping
14. Kernel Params
15. App Logs
16. metadata
4. Heap Substitute
7. top -H
19
Open-source script:
https://github.com/ycrash/yc-data-script
360° Data

20. 20

21. 21
JVM Performance Master Class
https://ycrash.io/java-performance-training

22. Ram Lakshmanan ram@tier1app.com
@tier1app https://www.linkedin.com/company/ycrash
This deck will be published in:
https://blog.ycrash.io
If you want to learn more …
22
THANK YOU
FRIENDS