The following table shows the various publish message throttling states, trigger conditions and what actions BizTalk server takes to mitigate the risk. This data is important to understand the throttling analyser user interface Understand user interaction with Publish and Delivery Throttling Graph 


State

Trigger for Throttling Condition

Throttling Actions Taken

2

Message publishing incoming rate for the host instance exceeds theMessage publishing outgoing rate * the specifiedRate overdrive factor (percent) value. The database cannot keep up with the publishing rate.

Block the publishing thread for a dynamically computed time period until theMessage Publishing Incoming Rate is at par with the Message Publishing Outgoing Rate * the specified Rate overdrive factor (percent) value.

4

Process memory exceeds the specified threshold.

This can occur if the batch to be published has steep memory requirements or too many threads are processing messages

Reduce the size of the thread pool used by EPM.

Block the EPM threads to prevent processing of new messages batches.

If there is a steep memory requirement to persist the messages in a batch to the database, the publishing thread is also subject to a progressive delay before the messages are persisted to the database.

Whether the publishing batch will be blocked or not due to process memory pressure depends on several factors including the number of messages in the batch or if there are dehydration or message deletion commands in the batch.

6

Host message queue size, the spool table size or the tracking table size exceed the specified threshold.

Possible reasons for this condition include:

· The SQL Server Agent jobs used by BizTalk Server to maintain the BizTalk Server databases not running or are running slowly.

· Down-stream components are not processing messages from the in-memory queue in a timely manner.

· Number of suspended messages is high.

· Maximum sustainable load for the system has been reached.

Reduce the size of the thread pool used by EPM.

Block the EPM threads to prevent processing of new messages batches.

The publishing thread is also subject to a progressive delay before the messages are persisted to the database.

8

Database sessions being used by the host instance exceed the specified threshold.

Reduce the size of the thread pool used by EPM.

Block the EPM threads to prevent processing of new messages batches.

The publishing thread is also subject to a progressive delay before the messages are persisted to the database.

9

Process thread count exceeds the specified threshold.

Reduce the size of the thread pool used by EPM.

Block the EPM threads to prevent processing of new messages batches.

The publishing thread is also subject to a progressive delay before the messages are persisted to the database.

5

System memory exceeds the specified threshold.

Reduce the size of the thread pool used by EPM.

Block the EPM threads to prevent processing of new messages batches.

If there is a steep memory requirement to persist the messages in a batch to the database, the publishing thread is also subject to a progressive delay before the messages are persisted to the database.

Whether the publishing batch will be blocked or not due to process memory pressure depends on several factors including the number of messages in the batch or if there are dehydration or message deletion commands in the batch.

 


For more information about Message Publishing Throttling, please read Inbound Host Throttling