Hi,
We have 2 biztalk servers in the group. For past few days CPU usage on one server was comparatively very high as compared to other. First server was showing around 60% of CPU usage while second one was reporting 12 %.
Today I just started to stop every host instance on the first server in order to find out the process resulting in high |CPU usage. It came to BizApp.. Host assigned for processing orchestrations.
At first I could'nt understand the reason why first server was taking all the load while second one wsa comparatively free. But to my surprise once I restarted the host instance on first server, CPU usage dropped to 8% for the first one.
I could not understand the reason behind this? It would be really helpful if anybody can give me a clue about it.

Thanks in advance.

Hi Shady,

How is your environment set up? I assume you have multiple hosts setup for receiving, sending and processing. Hosts running the receive handler for the HTTP,
SOAP, and BizTalk Message Queuing (MSMQT) adapters require a load-balancing mechanism such as Network Load Balancing (NLB) to provide high availability. Host cluster support is provided to support high availability for integrated BizTalk adapters that should not be run in multiple host instances simultaneously; such as the FTP receive handler or, under certain circumstances, the POP3 receive handler (http://msdn.microsoft.com/en-us/library/aa560059(BTS.20).aspx). Everything else just do not require any additional clustering or load-balancing mechanism because BizTalk Server automatically distributes workload across multiple computers through host instances, unless you have made changes to hosts themselves (throttling) (http://msdn.microsoft.com/en-us/library/aa559893(BTS.20).aspx).

Regards,

Steef-Jan Wiggers (http://soa-thoughts.blogspot.com/)

If this answers your question please mark it accodingly.

Hi,
Thanks for the reply. We have excatly the same environment setup as you have mentioned. The BiztalkIsolated adapter is balanced using load balancer. FTP host is switched on on the second host. But, the host which is causing CPU usage is processing host and the instances are on both servers. But it seems that first server is taking all/max load? Restrating it pulls it back to normal load but then it again starts climbing slowly.

Hi Shady,

I know from experience that having a software loadbalancer will stress one server more than the other. There was an BizTalkIsolated adapter load balanced software matic (Windows). Having a hardware loadbalancer will result in better load balancing i.e. spread of workload between both processing hosts.

Regards,

Steef-Jan Wiggers (http://soa-thoughts.blogspot.com/)

If this answers your question please mark it accodingly.

Hi Raminder,

BizTalk should load balance your processing host (the one you've assigned the orchestrations to) between the two host instances on your two servers. Can you confirm that the orchestration dlls have been deployed correctly on the second server?

There could also be an issue with your orchestration or some custom DLL that it calls with memory leaks, or the I/O from the server could be impacting the processor usage on server 1.  Were you able to work out what inside that specific processing host instance is causing the high cpu usage? Is it really that there are too many orchestration instances being created on that host or could it be something else?

Completely agree with you. I will do some analysis on it.
Thanks for the suggestion

Thanks for the helpful answer.