How to search a exception in splunk which didn't occurred in past

[koushik91]

How to search a exception in splunk which didn't occurred in past

[richgalloway]

Please say more about what you are trying to accomplish.
Understand that searching for something that did not happen is a challenge.

[koushik91]

Hi richgalloway,

Yes, i want to search a exception which was not occurred in past. I am creating a Alert Notification for a exception which was not occurred in past. Please share me search query which you have 

[richgalloway]

Like I said, finding something that has never happened before is a challenge.  The definition of "never" will depend on how far back your indexed data goes.  Because you'll be comparing a given event to all other events in your index(es) you can expect this to be very slow.  A simple example:

index=foo earliest=-1y
| stats count by _raw
| where count = 1
| fields - count

This search will return all unique events from the "foo" index over the past year.  You can speed up the search by being more specific about what you search for.  Perhaps you only want events with "Exception" or "ERROR" in them, for instance.