Description of problem:
In scale environments the sampling process took around 25s.
We want to lower it below 15s in order to run the sampling every 15s.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.Install engine +dwh and set up a scale environment
2.Run dwh in debug mode and with sampling intercal set to 15.
3.Check the sampling time in the dwh log file.
The sampling takes around 25 seconds
Should be under15s.
Created attachment 1189126 [details]
sample query duration values
Tested on 4.0.2-1
DWH (App & DB) on same tier as Engine App
Standard disk used for Database.
Without postgres tuning sample query finishes in 30-39s.
With tuned postgres sample query reduced to 5-6s.
Some sample query degradation occurs during delete jobs but only by a few additional seconds still remaining under 15s for most queries.
While we tune a few settings, in order to see sample query return under 15s please set:
checkpoint_segments = 128
checkpoint_completion_target = 0.9
Further information available: https://mojo.redhat.com/docs/DOC-1089988
Last Sample values parsed, and attached.