Professional BizTalk® Server 2006

10.4. Tuning BizTalk for Low Latency

As previously mentioned, BizTalk is tuned for high throughput out of the box. It usually needs to be explicitly tuned for low latency. For the most part, this tuning is relatively straightforward, although it is important to understand what effects other factors, besides tuning, can have on latency.

The best approach to tuning for low latency is to change the configuration parameters that affect latency one at a time, measuring the difference after each time to evaluate the effect. The first parameters that you must tune are stored in the BizTalkMgmtDB database in the adm_ServiceClass table. This table has a row for each service class. You should think of a service class as a BizTalk subservice.

There are four types of service classes, as shown in Figure 10-3. The first two should be self-explanatory: XLANG/s is the Orchestration Engine, and Messaging InProcess is the Messaging Engine. You might be surprised to see MSMQT as the third entry. Although MSMQT appears as an adapter, it is actually another service class. The reason for this is its requirements regarding in-order delivery of messages. At this point, you might be thinking that you wouldn't mind writing your own service class. With BizTalk Server 2006, however, you would gain little advantage by doing so. The interfaces that you need to interact with are low level and designed only for internal usage. In addition, they are not tested in the same way that public interfaces are, which ...