Azure BizTalk Services implements service throttling based on two conditions: memory usage and the number of simultaneous messages processing. This topic lists the throttling thresholds and describes the Runtime behavior when a throttling condition occurs.
The following table lists the throttling source and thresholds:
|Description||Low Threshold||High Threshold|
|Memory||% of total system memory available/PageFileBytes.
Total available PageFileBytes is approximately 2 times the RAM of the system.
|Message Processing||Number of messages processing simultaneously||40 * number of cores||100 * number of cores|
When a high threshold is reached, Azure BizTalk Services starts to throttle. Throttling stops when the low threshold is reached. For example, your service is using 65% system memory. In this situation, the service does not throttle. Your service starts using 70% system memory. In this situation, the service throttles and continues to throttle until the service uses 60% (low threshold) system memory.
Azure BizTalk Services tracks the throttling status (normal state vs. throttled state) and the throttling duration.
When Azure BizTalk Services enters a throttling state, the following occurs: