WebAccelerator slowness

Platform 6900

 

Version 9.4.7

 

 

We enabled WA initially on 6 of our web sites. It ran great at night time when it was enabled, in the morning once the traffic ramped up the performance halted and some web sites even timed out. F5 recommended changing the Prune level, because the default was too low.

 

 

So it was changed to:

 

65

 

75

 

 

Which seemed to function better, then we had another high traffic day and it started to choke. Sites were performing slowly and some timing out.

 

 

Here is a top command I took when i started disabling WA:

 

08:17:42 up 14 days, 14:05, 1 user, load average: 14.08, 14.14, 12.71

 

264 processes: 259 sleeping, 5 running, 0 zombie, 0 stopped

 

CPU states: cpu user nice system irq softirq iowait idle

 

total 38.0% 0.0% 44.0% 0.2% 0.9% 2.8% 13.8%

 

cpu00 20.9% 0.0% 64.7% 0.0% 2.8% 2.8% 8.5%

 

cpu01 18.0% 0.0% 55.2% 0.0% 0.0% 0.9% 25.7%

 

cpu02 14.4% 0.0% 54.8% 0.9% 0.9% 7.6% 21.1%

 

cpu03 99.0% 0.0% 0.9% 0.0% 0.0% 0.0% 0.0%

 

Mem: 8196020k av, 7654160k used, 541860k free, 0k shrd, 654864k buff

 

2759412k actv, 550660k in_d, 134944k in_c

 

Swap: 3521436k av, 432604k used, 3088832k free 1393760k cached

 

 

As soon as I disabled QA, the load averages dropped back down in the 1 range that they normally run in.

 

 

So I opened a ticket, and per SOL9058 they are recommending this still might be too low, and it should be set to 77/83. Has anyone ran into this problem or have any suggestions? We are a bit hesitant to just try changing the setting and trying it again because it will most likely impact orders if it fails again. So I want to research all the options possible.