I have set the number of maxiothread and other settings in the machine.config as MS has suggested for heavy loads. I am running on Dual CPU's Dual Core servers with 16 GB of RAM. I am running load test using 3 sites going to different application pools - load balanced. I get up to around 250 users and I start to see response delays but can't figure out what is causing them. All 3 servers, web/app and db are running under 30% cpu and under 10% memory.
I am loading the system to 500 concurrent users and have tried adjusting the settings for better CPU utilization on the web server with no luck.
I am reading all the Tuning .NET Application Performance (pattern & practices) chapters on this subject.
I am running Windows 2003 x64 OS on all 3 servers. With .Net 1.1 being x32 is that a problem I am using the /3GB switch.
I ran test using 3 VS's(Virtual Servers) on the web server with 1 site each and was able to push to around 600 users before I started to see the delays so I know my app and db can handle the load.
Can I config my web server to perform like it does using VS's I really want to see how much I can push this server using IIS.
Thanks,
Paul
Trying to figure out the max. number of concurrent users/requests for a single server.
wirwin
I agree with Pranshu - this looks like an IO resource problem - disk IO, locks on the DB , network etc.
Arnon
AVVIT
Hi Paul,
Try to see the Disk IO queue to see if reading/writing to disk is a bottleneck.
Try to figure out if the network IO Queue.
Check our the CPU/Memory/Disk IO and network IO for your Load Test Client as well - it is possible that the load test setup / or the network in between - is maxed out resulting in the slowness.
If none of them point out anything, it may point to some kind of locking or similar resource contention - like all three app pools trying to write to the same Log file or some other form of locking.
If that is the case, you can determine that by loading a 4th completely unrelated application and loading that, while the first 3 webapps are running at full load. If the 4th application works without any delays, then you know that server resource contention is definitely not an issue.
Pranshu