The document discusses basic JVM troubleshooting using JMX, highlighting issues such as high CPU consumption due to inefficient data structures, thread contention, and excessive memory allocation. It provides insights into monitoring high load scenarios, including the use of tools like 'java-threadtop' for observing thread performance and memory allocation. Key metrics and MBeans are mentioned for identifying and addressing JVM performance issues.

1. Basic JVM Troubleshooting
with JMX
Haim Yadid

4. VisualVM

5. CPU Bound Code
• Number crunching code usually due to wrong data
structure and algorithms
• High CPU consumption
• No GC activity
• MBean : java.lang.Threading::getThreadCpuTime

6. ThreadContentionMonitoringEnabled

7. Lock Contention
• High latency on high load
• Cannot max out CPU with increasing load on system
• Thread stacks have locked threads
• java.lang.Threading :: getThreadInfo

8. Excessive Memory Allocation
• High CPU consumption
• High rate of memory allocation
• MBean : java.lang.Threading::GetThreadAllocatedBytes

9. Heap Exhaustion
• High CPU consumption
• Frequent GC triggering
• Heap usage after GC is higher than old generation
• MBean: java.lang.GarbageCollector
• CollectionTime

10. Java Thread Top
• Open source project
• https://github.com/lifey/Java-threadTop
• connects to a process via JMX
• Collects data over an interval of 5 seconds

11. Java Thread Top - CPU

12. Java Thread Top - Contention
• Open source project
• https://github.com/lifey/Java-threadTop
• connects to a process via JMX
• Collects data over an interval of 5 seconds

13. Java Thread Top Memory
Allocation

14. Thanks
Q&A