I've been using the A4Swift (v2.1) accelerator a lot recently, which I have to say is extremely good. Around this I though it worth sharing a tip with you all that has caused me some pain on two occasions recently!! Depending on your scenario, the issue can cause a significant performance degradation on the receive side, the CPU utilization is pegged at close to 100% but the inbound processing rate is very slow.
The issue is caused by some of the QFE's for the Rule Engine and possibly even the A4Swift accelerator, to be honest I don't want to waste time digging thru the dependencies and which QFE cause it. The bottom line is that the following registry key needs to be checked after applying any of the QFE's for the Rule engine and to be safe the A4Swift accelerator:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\BusinessRules\3.0\CacheEntries = 512
A couple of the QFE's that I have applied reset the Cache entries back to 32 which is the default for the Rule Engine, the problem is that A4Swift accelerator uses a large number of rules so the cache size needs to be bumped up to 512 otherwise the Rule engine will spend all of it’s time loading rules. So the bottom line is to check this registry key if you are using the Rule engine.