Java RMI tcp connect memory issue

Question

I have an issue I can locate in the profiler but I have no clue how to fix it. After I load the application I get this sawtooth wave pattern, the program is idle but consume memory, as you may see here.

When I checked the sampler thread memory allocations I saw that RMI TCP Connection to my eth0 (172.16.20.51) consumes memory at half a megabyte per second (413,213) which results in production to log 'stop the world' GC :-( I could not track the reason of this issue as I don't know which port it is of which thread it is, on the other hand I tried to run my jar with -com.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false flags but it was not helpful. Any idea will be appreciated.

Kesley

in your snapshot it is pool-6-thread-1 that consumes everything – Meadors

what about your heap histogram? Can we have a snapshot of it? – Meadors

a heap dump will also help in this case – Meadors

Is this an RMI server? Or client? Is it really idle or does it have an outbound or inbound RMI connection? – Flabellum

Its client RMI, I don't know its originator, it's part of huge code base. how do I do heap dump and how I can read it? – Kesley

the issue is not pool-6 since its stays the same, the issue is with this rmi tcp consuming 413K bytes per second – Kesley

Answer 1

I know this is an old post, but since I stumbled across it with the same problem, an answer might help others too..

The RMI TCP Connection thread is how Virtual VM samples your memory usage. So a high Allocated Bytes/sec is what you expect to see when profiling, and doesn't (necessarily) indicate any problem with your application. See for example this SO question.

Regarding heap dumps, Visual VM has a 'Heap Dump' button in the Monitor and Sampler tabs, which will save a heap dump file. You can load this into, for example, the free Eclipse Memory Analyzer (MAT) to examine for memory leaks etc.

Weldon