We encounter a big number of SLOWSQL warnings in the General Log of Service Center on our on-premises OutSystems production environment. The message we get is:

OS: outsystems.hubedition.runtimeplatform.DBRuntimePlatform.dequeueNormalEvent took 2219 ms

We are trying to figure out what is going wrong, but we don't have any context provided by the general other than the message above.

Has anyone encountered this before? 

What was the cause for you?

Very first, I would like you to point to the OutSystems post which describes the reasons and tip off for SLOWSQL

https://www.outsystems.com/forums/discussion/15702/tip-performance-of-query-in-outsystems-platform-slower-than-running-in-database/


Then if you know what and why, try checking the execution plan of the queries.

Hi Roel,

In parallel to this forum question, I'd contact OutSystems Support. DBRuntimePlatform is a system component, so if it's generating SLOWSQL warnings, perhaps some configuration is off.

Solution

We investigated the issue further on our own. For future reference, in case someone else encounters the exact same issue, I am mentioning it here.

dequeueNormalEvent implicitely fires a SQL that uses tables OSSYS_BPM_PROCESS and OSSYS_BPM_ACTIVITY. These tables contained a high number of records, that causes the query to be slow.

We have cleaned the tables, removing records via BPTUtils forge component.

Also see: https://www.outsystems.com/forums/discussion/39611/ossys-bpm-activity/

Solution

Hi Roel,

Thanks for the feedback!

Roel Oomens wrote:

We investigated the issue further on our own. For future reference, in case someone else encounters the exact same issue, I am mentioning it here.

dequeueNormalEvent implicitely fires a SQL that uses tables OSSYS_BPM_PROCESS and OSSYS_BPM_ACTIVITY. These tables contained a high number of records, that causes the query to be slow.

We have cleaned the tables, removing records via BPTUtils forge component.

Also see: https://www.outsystems.com/forums/discussion/39611/ossys-bpm-activity/


Thanks for adding your finding as reference.