Difference between revisions of "JVM Performance"
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* Look at the GC logs. Turn on the verbosegc option | * Look at the GC logs. Turn on the verbosegc option | ||
* Look at the Full GC messages : [Full GC $before->$after($total), $time secs] | * Look at the Full GC messages : [Full GC $before->$after($total), $time secs] | ||
| + | * If more memory can be added, add it. | ||
| + | * Do we actually need ALL that data in memory, consider using techniques such as LRU cache & Soft References | ||
Revision as of 11:04, 8 December 2013
Tuning
- Biggest contributor to latency is the Garbage Collector
- Areas of Tuning : Memory, Lock Contention, CPU Usage, I/O
- Areas of Memory Tuning:
- Memory footprint tuning
- Allocation rate tuning
- GC tuning
Memory footprint tuning
- It's all about ensuring that the GC has less work to do
- One of the classic symptoms is the OutOfMemoryError
- Why ? It can be too much data, or the data representation is "fat", or there is a memory leak in the app code
- What is too much data ?
- Look at the GC logs. Turn on the verbosegc option
- Look at the Full GC messages : [Full GC $before->$after($total), $time secs]
- If more memory can be added, add it.
- Do we actually need ALL that data in memory, consider using techniques such as LRU cache & Soft References
