The asynchronous processing functionality is implemented by using Pega queue processors that process cases according to certain parameters. Customers might need to change the default configuration to meet the needs of their specific implementations.
The application contains the following queue processors:
- AsyncProcessing – manages all cases that are queued for asynchronous processing that require immediate execution. With the default configuration, this queue is used for all cases.
- AsyncProcessingDelayed – manages cases that are queued for asynchronous processing with a delayed start. Most of the time, this working mode is not needed but, if required, it checks the AsyncProcessing flow and, where the AsyncProcessingQueue activity is invoked, sets the parameter Deferred to true.
Both queue processors come with the following configuration (available under Records > SysAdmin > Queue Processors):
- Number of threads per node: 3 – This is the number of concurrent threads that the system can process per node in the cluster. One thread equals one case being processed. For example, a configuration of three threads in a cluster of four nodes, configured for background processing, would provide 12 simultaneous cases. This number might need to be adjusted based on your volume and the size and performance of your system.
- Max Attempts: 3 – In some situations, the system can find errors while processing a case. For example, an external system might be down or there is an unexpected situation that prevents the process from finishing. Retying three times is usually enough to resolve those situations. After the maximum number of retries is reached, the case goes to the broken-process status and an administrator needs to take action.
- Initial delay (in minutes): 1 – This is the time that the system waits between a first failed execution attempt and a second attempt.
- Delay factor: 2 – This is a correction factor applied to the initial delay between subsequent retries. For example, if the initial delay was 1 and the delay factor is 2, the system waits one minute between the first attempt and the second, two minutes between second and third, four minutes between third and fourth, and so on.
Most of the time, the default parameters are sufficient. If you need to make changes to these parameters, see the Pega Client Lifecycle Management for Financial Services Implementation Guide.