What should my proxy buffer low be?

Hi all,

 

 

I have a public IIS6 web application behind my 3900 series v10.2.3 LTMs. We currently use the built-in TCP LAN and WAN optimisation profiles with a couple of modifications.

 

 

I'd like to further optimise these profiles if possible to gain some performance improvement for our user base. Reading Jason's article here - https://devcentral.f5.com/Default.aspx?tabid=63&articleType=ArticleView&articleId=287 - the "Proxy Buffer High" and "Proxy Buffer Low" settings have caught my attention.

 

 

I understand that the proxy buffer high value should be set just higher than the maximum object size. This is fine as I can analyse my IIS logs to ascertain the biggest object size and set the value just a little higher than that.

 

 

What I'm not so sure about is the best value for the proxy buffer low setting. The deployment guide for tuning OneConnect (http://www.f5.com/pdf/deployment-guides/oneconnect-tuning-dg.pdf) states that the proxy buffer low value = proxy buffer high - (N x server-side MSS) where N is the desired number of maximum-size packets on the server-side, and should not be lower than 75% of the proxy buffer high value.

 

 

Er, what is my desired number of maximum-size packets on the server side? The deployment guide uses 2x MSS but what drives this multiplier? I mean, I can't see any relationship to the number of nodes, so is it their capability or OS etc?

 

 

Or am I over-thinking all this and should instead just copy the deployment guide above and stick with 2x MSS?

 

 

 

Thanks, Steve