Java process memory grows infinitely Memory leak?

We have a java process running on Solaris 10, serving about 200-300 concurrent users Administrators have reported that the memory used in the process increases significantly over time Reach 2GB in a few days and never stop growing

We have dumped the heap and analyzed it using the eclipse memory analyzer, but we can't see any ordinary memory The heap size is very small

After adding the memory status record, for our application, we found that the memory usage reported by the "top" utility used by the administrator is different from that reported by the memorymxbean and runtime libraries

This is the output of both

Memory usage information 

From the Runtime library
Free memory: 381MB
Allocated memory: 74MB
Max memory: 456MB
Total free memory: 381MB

From the MemoryMXBean library.
Heap Committed: 136MB
Heap Init: 64MB
Heap Used: 74MB
Heap Max: 456MB
Non Heap Committed: 73MB
Non Heap Init: 4MB
Non Heap Used: 72MB

Current idle threads: 4
Current total threads: 13
Current busy threads: 9
Current queue size: 0
Max threads: 200
Min threads: 8
Idle Timeout: 60000

  PID USERNAME NLWP PRI NICE  SIZE   RES STATE    TIME   cpu COMMAND
99802 axuser   115   59    0 2037M 1471M sleep  503:46 0.14% java

How is this possible? The top command reports much more usage I expect res to be close to the heap rather than the heap

PMAP - x, however, reports most of the memory in the heap:

Address     Kbytes       RSS       Anon     Locked Mode   Mapped File
*102000         56         56         56       - rwx----    [ heap ]
*110000       3008       3008       2752       - rwx----    [ heap ]
*400000    1622016    1621056    1167568       - rwx----    [ heap ]
*000000      45056      45056      45056       - rw-----    [ anon ]

Can anyone explain this? I'm completely lost

thank you.

to update

This does not seem to be a problem on Linux

In addition, based on Peter Lawley's response, the "heap" reported by PMAP is a native heap, not a Java heap

Solution

In a garbage collection environment, keeping unused pointers is equivalent to "failed to leak" and prevents the GC from performing its work It's really easy

A common culprit is hash tables The other is array or vector logical cleanup (by setting the reuse index to 0), while the contents of the actual array (above the index) still point to something