What are "Queued events"?

What are "Queued events"?

  

Hi,

Let's have a look at the page Service Center -> Monitoring -> Environment Health. We can find here, in the section "Processes", a table with a column "Events": Queued / With Errors. It is said (above this table), that all the numbers (except Process Instances: Active) should be zero. But in my case it is not zero, it is ca. 420,000 (maybe they are remnants after about 370,000 process instances that were killed about 2 weeks ago). 

My main question is: what are these events (and how dangerous :-) )? I've tried to find it in somewhere in the documentation but I've failed. The second one: how can I get rid of them?

Regards

Tomasz

Solution

Hi Tomasz,


Do you have the Processes running in your front end?


Basically, Queued Activities and Events are the next activities/events to be processed by the BPT engine:



Events queue are the next events to be handled regarding the transactions of “insert” and “update” events for specific database entities built on BPT flow.

You may have BPT implemented on your factory but your BPT processes are not running.

More in detail:

https://www.outsystems.com/blog/posts/pump-up-the-volume_scalable_database_queueing/


Hope it helps you.

Best regards.

Solution

Hi,

OK, it makes sense. Indeed, I have a process that is based on inserts to some table. This process has been just locked. This process is at the moment useless but we didn't want to change anything in the production application and we have only locked it. Therefore the events are getting queued.

So, the question now is: can the constantly growing numer of queued events slow down the whole application? 

Regards

Tomasz



Hi Tomasz,

The constantly growing number of queued events will definitely contribute for the degradation your entire BPT Events process performance.

A good measure will be checking the SLOW SQL warnings related with ossys_BPM_Event_Queue.


Best regards.