IBM HTTPServer multiple connections problem!!!

Dear Experts!

We are using IBM HTTPServer 1.3.28. In built with Apache 1.3.x running under RHEL3 machine.
All traffic to our application server (WAS6 on other server under RHEL3) are routed via Webserver(IHS 1.3.28).
What happens is when multiple connections (already set to 1000) hits certain range our clients are facing delays in connections.
We have proper load balanced mechanism before choosing web servers, but we provide connecting to existing sessions options for our clients. In this case if a client unfortunately face any n/w prob, still he can connect to his prev session. He will be connected to the same webserver where he was previously.

Almost everyday our clients are reporting that they are facing if maximum connections reach certain limit, say above 600 (but it is set to 1000) they are facing delys in connections.

Can any one help me to move in right direction with this multi-thred issue with web servers(IHS)?

Looking forward for you response!
Who is Participating?
shalomcConnect With a Mentor CTOCommented:
As the IBM HTTP server is just an apache with very few extra modules, you should first optimize your apache environment.
In general, the maximum number of concurrent clients is derived by this siple formula:  
(memory available for Apache / apache child instance size)
Therefore, we want to reduce the size of each child to the bare minimum.
We also want to lighten the CPU and network load.

* have as much RAM as possible on the HTTP server
* If you don't use them, switch off all unnecessary services like nfs, sendmail, printing services etc.
* disable all unnecessary apache modules. You don't need many of the modules that are enabled by default. For example, if you do not serve a lot of static contents, turn OFF ibm_afpa_module
* If you don't need the apache logs - turn them off. If you need them, turn off HostnameLookups and resolve the host names during log file post processing.
* turn off symbolic link support
* AllowOverride None
* Disable KeepAlive

To really tune up your apache server, read this
although it's about PERL, the methodology is relevant to your situation too.

yarabatiAuthor Commented:

Any one there to give guidelines or to point me in right direction!!!
What type of hardware are you running this on?  600 concurrent connections could be to many for the hardware you have.

Have you thought about upgrading to the most recent version?  It is based on Apache 2.0.
Easily Design & Build Your Next Website

Squarespace’s all-in-one platform gives you everything you need to express yourself creatively online, whether it is with a domain, website, or online store. Get started with your free trial today, and when ready, take 10% off your first purchase with offer code 'EXPERTS'.

yarabatiAuthor Commented:
Thanks for your replies.
I came to know IBM IHS 1.3.28 supports upto 4096 connections simultaneously.
We have a fliter in between created by our application if total connections reaches the property maxConnections then we don't allow further connections.
But we see in all situations this filter is working fine. It is now set to 1000 value!!!
But clients reporting IHS failing after 600 threads!

Coming to hardware, all our servers are VMware virtual machines. But highly configured machineds!

Any comments will be highly recieved!
giltjrConnect With a Mentor Commented:
It does not matter how "highly configured" the machines are.  If the box is running at 100% (either the physical host or the virtual host) it still can't do any more.

Technical limitations are typically far different from real world results.

Have you verified that it is IHS that is the problem and not something else (like WebSphere)?
yarabatiAuthor Commented:

Can any one recommend few tools to monitor connections to my web server.
Web server is running under RHEL3 machine, with IBM HTTP 1.3.28 installed.
I had googled before posting this message but most of the tools are of after IHS 2.x release. Didn't find suitable for IBM HTTP Server 1.3.28.
It would be greatly received if I get any comments!!!
IBM's HTTP sever is nothing more than a slightly modified Apache.  So you can look for monitoring tools for release of Apache that IBM is running.  I think that IBM's number matches Apache, so you can look for Apache tools for 1.3.28.  I know that there was a mod_status for Apache 1.3 where you monitor some type of information within Apache.
yarabatiAuthor Commented:

I think I have to close this thread, we found lot bugs in our source implementation... effecting to cause this problem...

Thanks everyone who tried to help me...
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.