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Joe_Tran's avatar
Joe_Tran
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6 years ago

Alert Tuning for DataSource that has "Automatically Delete Instance" enabled?

I have a version of the "Oracle_DB_BlockedSessions" datasource template deployed and set an alert threshold on a complex datapoint that accounts for WAIT_TIME and SECONDS_IN_WAIT. Here is the complex datapoint expression for those curious---

if( eq(if(un(WAIT_TIME),0,WAIT_TIME), 0), if(un(SECONDS_IN_WAIT_RAW),0,SECONDS_IN_WAIT_RAW), 0)

If the complex datapoint has a value over 300 seconds, an alert triggers with all the enriched instance-level autoProps from the Active Discovery script. All other aspects of this template mirror the gold-standard version--including enabling the "Automatically Delete Instance" option. 

Enter Client X, and they are comfortable with a threshold of 900 seconds. How can I set this custom threshold at a resource group for Client X when they don't currently have any blocking sessions? If I do manage to catch and set this Alert Tuning customization when Client X has a blocking session, will this alert tuning get wiped out when the DSIs are removed automatically?

I suppose the Active Discovery script could be modified to always output a dummy instance... but that leaves an unpleasant taste in my mouth. 

Aside from cloning the datasource just for Client X, are there any other alternatives?

And no, I do not want to alert off of the "Oracle_DB_BlockedSessionOverview" template because a it doesn't do a good job of discerning between one really long blocking session versus sequential and short-lived sessions that happen to exist at the time of the poll. 

 

  • So it looks like while the UI hides datasources without instances and the API will not list the datasource when querying for /device/groups/{groupId}/datasources, the API will still accept PUT/PATCH operations for that datasource id /device/groups/{groupId}/datasources/{datasourceId}/alertsettings

     Hopefully that persists when the datasource finds a blocking session! 

  • I did a quick test with a dummy DataSource. I let it create a dummy instance and setup a custom threshold at the group level's Alert Turning tab. I then modified the DS to have no instances and the entry disappeared from the list. I modified the DS once again to report a different instance and the entry came back and kept the previously set threshold. So it does seem to keep your custom settings even if there are no instances.

    I only tested the difference over a few minutes so you may want to test over a larger period of time (overnight/days). I also don't like how this causes possible hidden settings we might not be aware of. It might show up in a report though (didn't test). Interesting that the API does show it.

     

  • It looks like without instances, the Alert Threshold report does not list the datasource at all.