TCP Tuning: How to test web application performance

I certainly agree with the other comments. This really can be a complex question to answer - it all depends on how far you want to get into it. I second the recommendation by L4L7. If you really want to do this correctly and completely, you're going to need some type of external appliance to do the calculations on a spanned port. If you are just looking to do thumbnail calculations, you can use something like HTTP Analyzer. Wireshark also has basic charting capabilites. I've also exported data from Wireshark and done calculations in Excel before too. It's really a matter of how detailed you want to get.

 

 

Just to give you a more practical perspective, we had very poor application performance on our LTM-hosted web applications too when I first started managing LTMs. And I didn't know anything about TCP at the time. Having studied TCP for several years now and knowing what I know now about the LTMs, I would immediately do the following:

 

 

Increase the Send Buffer and Receive Buffer to 65535

 

Increase the Proxy Buffer Low to 98304

 

Increase the Proxy Buffer High to 131072

 

Disable Nagle's Algorithm

 

 

These settings might be part of the tcp-lan-optimized profile that Chris suggested. If your settings aren't already at this level, you should see an immediate, significant performance improvement. Beyond this, I have seen huge performance gains by disabling Slow Start, though not in all cases - in certain situations it has caused problems. This particular setting takes a bit more study.