Process becomes slower as it runs, why?

[rzc7]

We are running a process that processes 20% fewer transactions every hour it runs. For example:

hour 1 - 60,000
hour 2 - 48,000
hour 3 - 38,400
etc

As a workaround, we are bouncing the process every two hours.

We immediately suspected a memory leak. We tested the process very throughly under Great Circle and have not found a memory leak. The process does not consume a large amount of memory. It is only taking up 0.3% - 0.5% of the total system memory. It is not consuming a large amount of the CPU. The machine is running at approximately 90% CPU idle.

We are running:

Machine hardware: sun4u
OS version: 5.8
Processor type: sparc
Hardware: SUNW,Sun-Fire-880

What other causes can there be for a process to run more slowly over time (besides a memory leak)? As soon as we bounce the process it immediately starts back processing at full capacity.

Any ideas would be greatly appreciated!

 

[guggach]

strange, what does the proc, language ?

are you speaking about speed or trans quantity ?
by 2.nd loop, after 1 hour, are there enough
trans to process ?


don't forget, RTFMP guggach

 

[z28sarefun]

Not knowing anything about the process I'd say look at if it is writing any log files or if it is searching any files that are growing. These files would probably be reset when the process restarts and that might explain the performance change.

Just a WAG
Brian

 

[mrn]

I'd check I/O

Mike

"A foolproof method for sculpting an elephant: first, get a huge block of marble, then you chip away everything that doesn't look like an elephant."

 

[nawlej]

As the process gets older, it starts to become less of a priority, and reside more in swap than in memory. You can, tell it not to run in swap, and continue to run in RAM. My guess is that its being traded off into swap for higher priority processes. I would initially try to "nice" the process every so often instead of bouncing it. I remember theres a way to get the process to stay in physical memory instead of swap, but fgor the life of me cannot remember how...its in one of my books at home.

___________________________________
[morse]--... ...--[/morse], Eric.