High memory usage by Java process

[hpuxsa]

We have Java 1.3.1.05 installed on HPUX 11.11 servers. We have installed all HP recommended java patches.

We have noticed that the RSS memory reported for one of the java process is very high in glance. Total RSS/VSS :746.9mb/ 1.44gb

Text RSS/VSS: 24kb/ 28kb Data RSS/VSS: 76mb/ 76mb Stack RSS/VSS:1.1mb/2.1mb
Shmem RSS/VSS: 19mb/ 19mb Other RSS/VSS:660mb/1.4gb

Why is Other RSS/VSS value so high. Is this a normal behaviuor ?

Thanks,
Franklin.

[Ravi_8]

Hi

Usually java and java applications consume high resources

[Yogeeraj_1]

hi,

on our systems, it uses both a huge amount of CPU as well as memory too...

Cum Disk
CPU IO Rate RSS
------------------------
154.2 0.1/ 2.1 118.6mb
1247.3 0.1/ 0.0 47.9mb
119.5 0.1/ 0.7 277.9mb


maybe the provider of the Java can explain the why in more details.

regards
yogeeraj

[hpuxsa]

Can someone provide more info on this please.

[Paul Torp]

in java environment, you should always have enough memory..

Java processes should NEVER swap.

A good idea is to use PRM to allocate one cpu for each instance, since the garbage-collector uses lots of cpu, to clean its memory for collected objects.

inside the java code (J2EE), the programmers set there values, about how much memory that should be used..
One also set the limit for when the GC start to clean unused objects..

Talk with the application developers to sort this out.

[Dietmar Konermann]

Franklin,

the regions flagged as "Other" are typically memory mapped files which are used for JVM-internal memory management. Quite usual though that these are the largest ones.

If RSS is large then either the working set of the process is large (means that the process is quite actively using its allocated memory) or your system has plenty of memory free (means that the kernel has no need to reduce the RSS by paging parts of it out).

A good rule of thunb is to simply look at the system's pageout rate. If it's low then you don't have any memory pressure at all.

Best regards...
Dietmar.

[Tony Drake_2]

1.3.1 is an older version of java. 1.4 is the latest. I think 1.4.2 may be the current version.