Last week, we had the author of TDD for a Shopping Website LiveProject. Friday at 11am Ranch time, Steven Solomon will be hosting a live TDD session just for us. See for the agenda and registration link
Last week, we had the author of TDD for a Shopping Website LiveProject. Friday at 11am Ranch time, Steven Solomon will be hosting a live TDD session just for us. See for the agenda and registration link
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other Pie Elite all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Paul Clapham
  • Ron McLeod
  • Jeanne Boyarsky
  • Tim Cooke
Sheriffs:
  • Liutauras Vilda
  • paul wheaton
  • Henry Wong
Saloon Keepers:
  • Tim Moores
  • Tim Holloway
  • Stephan van Hulst
  • Carey Brown
  • Frits Walraven
Bartenders:
  • Piet Souris
  • Himai Minh

WAS 5 performance problems on Linux (memory leak, processes)

 
Ranch Hand
Posts: 311
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi,

My company used to run websphere 5 server on a unix machine, and it went on quite smoothly.
However, recently we migrated to Linux, and ran into serious performance problems . Would anyone happen to have experience with such phenomena:

1) Memory leak:
Whenever a user requests a JSP's, we see a decrease in free memory. That memory is never reclaimed (as if there's a problem with the garbage collection).
Note our web application is not likely to casue the memory leak (the code is very simple, it has been reviewed, *and* it has been running successfully on Tomcat/unix for months).

2) Stragner still: when we shut down WAS, the memory is still not freed !

3) Processes explosion:
Looking at the OS processes, there appears to be a huge number of java processes launched by WAS (they're not there before WAS starts).
Admittedly, I know very little about linux, but heard that linux would present threads as if they were processes (is that true?). On the other hand, even allowing this, there still appear to be too many processes (we tested about 5 JSP requests, and got about 3 times that many processes).

3) Bad performance (slow responce time), probably due to the above mentioned problems.

Note:
- The machine is strong, and had no trouble handling other app servers that were previously installed on it.


Any hints would be appreciated. Thanks
 
Greenhorn
Posts: 9
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi Sol,

You don't mention the Linux version in question but I worked on a project where just by upgrading Linux, peformance was improved by 60% and the system in general became much more stable. I know it sounds hard to believe but there is not no exageration here. This was due to several improvements and fixes to threading issues, memory optimizations, Asynchronous I/O, network performance, and a much reduced thread size. I believe the versions were Red Hat ES 2.1 going to 3.1. Perhaps you may find something similar in your implementation.

Regarding the process explosion as you call it, what you heard is correct. I think I remember a WAS nodeagent alone kicking off 42 child threads on startup and they are all listed on a "ps" command.

You may be able to find more information through your linux provider and the IBM trouble repository for WebSphere v5.

Hope this helps,

Salomon Zalzman
Versant Corporation
http://www.versant.com
 
Sol Mayer-Orn
Ranch Hand
Posts: 311
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Thank you so much, it's been a great help.
We'll try an upgrade.
 
Don't mess with me you fool! I'm cooking with gas! Here, read this tiny ad:
free, earth-friendly heat - a kickstarter for putting coin in your pocket while saving the earth
https://coderanch.com/t/751654/free-earth-friendly-heat-kickstarter
reply
    Bookmark Topic Watch Topic
  • New Topic