How to Check and Optimize Memory Size for Better Application Performance
- 1. Is Your Memory Correctly Sized? I am doubtful Ram Lakshmanan Architect GCeasy, FastThread, HeapHero
- 2. 2 What is the Impact of Wrong Memory Size? When Memory is Under Allocated You are going to disappoint Customers with poor response time When Memory is Over Allocated You are going to make already rich Cloud Providers AWS, Azure, GCP… richer
- 3. 3 Do Garbage Collection Study How to know whether memory is correctly sized?
- 4. 4 How to do Garbage Collection Study?
- 5. 5 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-logging/
- 6. 6 Step 2: Analyze using 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
- 7. 7 When Memory is Under Allocated
- 8. 8 Memory Under Allocation GC Behavior-1 - Full Garbage Collection Event Real World GC Report: https://tinyurl.com/5ezmmjyb
- 9. 9 Memory Under Allocation GC Behavior-2 - Full Garbage Collection Event Real World GC Report: https://tinyurl.com/2an5j4fp
- 10. 10 GCeasy will generate following warnings
- 11. Insurance Provider Application Improves Throughput by 25% GC Behavior due to Memory under Allocation: https://tinyurl.com/2wfj3p7v GC Behavior upon increasing Memory Allocation: https://tinyurl.com/42fbp8sm
- 12. GC Throughput 96% GC Throughput means Application is spending 96% of it’s time in processing customer transactions. Remaining 4% of time in processing GC activities. What is 96% GC Throughput? 1 day has 1440 minutes (i.e. 24 hours x 60 minutes) 4% = 57.6 minutes/day/JVM is stopping
- 13. Large Automobile Manufacturer reduces response time by 50% https://blog.gceasy.io/automobile-company-optimizes-performance-using-gceasy GC Behavior due to MetaSpace Under Allocation: https://tinyurl.com/2p2mmse9
- 14. JVM Memory Regions 14 –XX:MaxMetaspaceSize -Xmx Young Old Metaspac e Threads JNI misc GC Direc t Buff Code Cach e Heap Memory Native Memory Java Process Memory -XX:MaxDirectMemorySize
- 15. 15 Memory Under Allocation Recap Impact 1. Response Time Degrades, leading to unpleasant customer experience Symptoms 1. Application will become unresponsive 2. CPU consumption will spike up Solutions 1. Increase Heap Size 2. Increase Region Size 3. Add More JVM Instances 4. Quarantine Unusual Traffic (if possible)
- 16. 16 When Memory is Over Allocated
- 17. 17 GC Behavior when there is Memory Over Allocation Can you Guess? It will look Normal. A True Silent Killer!
- 18. 18 GCeasy Mathematical Models Will Generate Following Warning
- 19. Security Service Provider Reduces Memory by 75% GC Behavior due to Memory under Allocation: https://tinyurl.com/r7nveb7z GC Behavior upon increasing Memory Allocation: https://tinyurl.com/tvvvx8bx
- 20. 20 Sometimes Mathematical Models Will Not Detect, Due to 02 01 Interim Traffic Spike. Examples: a. Batch Jobs Running b. Special Transactions (like Report Generation, Girls Scout Account…) Model needs at least 24 hours of GC log data to diagnose properly 03 Sometimes it can do premature detection. What if you upload a weekend traffic data
- 21. 21 GC Log Analysis Best Practices 02 01 Use GC Log from Production JVM Take at least 24 hours of data More Best Practices: https://blog.gceasy.io/java-garbage-collection-best-practices 03 Take GC Log during a weekday
- 22. 22 How much memory can I Reduce? 02 01 You can reduce as long as your GC KPIs don’t degrade i.e. a. GC Throughput % b. GC Pause Time More Importantly your Response Time shouldn’t degrade
- 23. 23 Memory Over Allocation Recap Impact 1. You are going to end up paying more to cloud providers. Heavy cash drain Symptoms 1. None Solutions 1. Reduce Heap Size 2. Reduce JVM Instances 3. Plan diligently for occasional spikes
- 24. Ram Lakshmanan [email protected] @tier1app https://www.linkedin.com/company/ycrash This deck will be published in: https://blog.heaphero.io If you want to learn more … 24 THANK YOU FRIENDS
Editor's Notes
- #6: Demo: GCeasy - C:\workspace\ycrash\speeches\9-types-oom\gc-memory-leak.zip