topic Re: multiprocessing load balance in Operating System - HP-UX

multiprocessing load balance

Pedro Sousa — Tue, 14 May 2002 13:54:15 GMT

Hi people.

I have a system L2000, running java 1.3.1, with 2 CPUs.
CPU 0 has always between 2 and 4 times the load of CPU 1.

Do you have any idea that can help me to do some load balancing?

below is the output of top:
System: poru9011 Tue May 14 15:22:42 2002
Load averages: 2.11, 1.80, 2.02
127 processes: 96 sleeping, 31 running
Cpu states:
CPU LOAD USER NICE SYS IDLE BLOCK SWAIT INTR SSYS
0 4.17 0.0% 0.0% 0.0% 100.0% 0.0% 0.0% 0.0% 0.0%
1 0.04 0.0% 0.0% 0.0% 100.0% 0.0% 0.0% 0.0% 0.0%
--- ---- ----- ----- ----- ----- ----- ----- ----- -----
avg 2.11 0.0% 0.0% 0.0% 100.0% 0.0% 0.0% 0.0% 0.0%

Memory: 1391088K (1352704K) real, 5232496K (5171652K) virtual, 239236K free Page# 1/4

CPU TTY PID USERNAME PRI NI SIZE RES STATE TIME %WCPU %CPU COMMAND
0 ? 3692 root 152 20 30780K 52224K run 4:43 0.73 0.73 java
1 ? 2928 root 152 20 30780K 49832K run 5:26 0.53 0.53 java
0 ? 4061 root 152 20 43068K 59192K run 0:48 0.51 0.51 java
0 ? 3613 root 152 20 43068K 65568K run 4:53 0.47 0.47 java
0 ? 3748 root 152 20 43068K 62444K run 4:28 0.46 0.46 java
0 ? 6505 root 152 20 43068K 61896K run 2:25 0.45 0.45 java
1 ? 13758 root 152 20 43068K 62140K run 2:20 0.44 0.44 java
0 ? 1235 root 152 20 30780K 49052K run 4:40 0.44 0.44 java
0 ? 3720 root 152 20 30780K 50248K run 5:27 0.43 0.43 java

tia,
Pedro

Re: multiprocessing load balance

Pedro Sousa — Tue, 14 May 2002 13:55:53 GMT

I forgot to say that the system is running HPUX 11i

Re: multiprocessing load balance

Sandip Ghosh — Tue, 14 May 2002 14:04:25 GMT

Have you checked with Glance? I think the application has not been written properly for multi-threading. If it has benn written as mut-threaded operation , it would have shared the load between 2 CPU.

Sandip

Re: multiprocessing load balance

harry d brown jr — Tue, 14 May 2002 14:06:22 GMT

You don't appear to be using threads for your java, is there a reason for this?

live free or die
harry

Re: multiprocessing load balance

Pedro Sousa — Tue, 14 May 2002 14:06:50 GMT

this system doesn't have a license for glance. And the trial one, has already expired.

Re: multiprocessing load balance

John Bolene — Tue, 14 May 2002 14:07:17 GMT

Curious, looks pretty balanced with no load.

Both processors are 100% idle.

It takes busy processors before HPUX will do anything with moving processes between processors.

If you are not having any performance problems, there is nothing to balance.

Re: multiprocessing load balance

Bill Hassell — Tue, 14 May 2002 15:26:13 GMT

HP-UX will assign processes to different processors when there is something to do. Since you have a lot of java programs, this will occur automatically. If the java code is in response to web queries, most likely none of the code will run for more than a few seconds so it will be hard to see two processes running at the same time on different processors.

To prove that HP-UX can indeed assign a busy process to the next available processor, try typing this in two different sessions:

while :
do
:
done

This is an endless loop which will use 100% of one CPU. Start another copy and it will run on the second processor. Use CTRL-C to terminate the shell loop.

Re: multiprocessing load balance

Pedro Sousa — Tue, 10 Sep 2002 11:05:04 GMT

Sorry guys, I've been out for a while...

Can you still help me ;)?

Harry, I can't tell you the the app is configured to use threads. But it seems to me it does.

John, I'm not having performance problems. though I would like to understand the LOAD diference between the processors.

Bill, good test. it worked fine. so, I assume the balancing is OK.

The main question is:
both CPUs show different LOADs, why?

many thanks for the previous answers.

Re: multiprocessing load balance

harry d brown jr — Tue, 10 Sep 2002 11:11:29 GMT

They will always show different loads unless you have two identical applications running, that start at the same time, and perform the same things at the same time.

Now, bing that you originally posted this in MAY, I'd suggest you first bring your system up to date with the latest patch bundles, then let us know what's going on.

BTW, you are not running a threaded java application. If you where, you wouldn't have a gillion java processes running.

live free or die
harry