BizTalk Throttling

Feb 12, 2009 at 1:01 PM
Hi Clint,

PAL is wonderful tool. It has provided me lot of insight into my production BizTalk server.

Through PAL report only I found that our server is facing rate based throttling. I added publishing inbound and outbound rates to check how imbalanced is publishing rate. But to my surprise both the factors are giving same value. I am wondering what could be the reason of throttling when overdrive factor is 125%.

Please help.

Feb 16, 2009 at 5:07 AM
Rate based throttling means the BizTalk is receiving more messages than it is sending and typically an indicator when BizTalk is saturated, but not always. My first question is what else is busy? Have you done a perf analysis on the backend SQL Server. Almost always the backend SQL Server is bottlenecked by the disk for either the DTADB (tracking database) or the BizTalk Messagebox database.
Feb 16, 2009 at 9:21 AM
I understand that, but I was expectign that to reflect in out-bound publishing rate. If BizTalk is not able to publish messages as fast as it is receiving messages because of any bottleneck, that should have been visible in out-bound publishing rate. In every article it is mentioned that to avoid rate-based throttling, overdrive factor should be adjusted to a value so that incoming rate is less than (outbound rate * overdrive factor). Now, when out-bound rate is equal to incoming rate and overdrive factor is 125, incoming rate is already less.

Till the time I identify throttling, I wanted to setup throttling factors to values so that BizTalk does not throttle messages.

When I mentioned "what could be reason of throttling", I actually menat that by looking at inbound and outbound rates throttling should never had happened!

Feb 25, 2009 at 3:29 AM
Ah, sorry. I misread your initial request.

Correct, we shouldn't see throttling when the receive rate and send rate are the same.
If the log (zipped up) is less than 10MBs, then can you send me the perfmon log? If not, try the new MSN Skydrive for the file transfer. Please do not include customer identifiable information. If this is sensitive or urgent, then please open a support case with Microsoft.

Thank you,
Feb 25, 2009 at 6:10 AM
Actually we have already logged a call with Microsoft. We have shared PerfMon logs and PAL reports, which suggested rate based throttling for couple of hosts. The logs also has inbound and outbound publishing rates.

We have also shared MsgBoxViewer reports with Microsoft.

Thanks for the reply.

Feb 26, 2009 at 4:36 AM
Great. You should be in good hands.