To set an alert if a field doesn't exist in log messages in real time

[ssankeneni]

I'm trying to set up a alert If I don't see a log message with in 15 minutes span of time.
I extracted a filed from the log message but I'm not sure how to check for the field in real time .

The query i tired is

index= "metering" host="vm10190" sourcetype="ping" | rex "Ping response: (?.)" | search PingMessage="*OK" | bucket _time span=15m | stats count by _time host | where count<1

Any help would be greatly appreciated .

[richgalloway · Accepted solution]

Create a search that finds your log messages. Then schedule that search and have it send an alert if the event count = 0.

[ssankeneni]

Thanks for your answer

[richgalloway]

Go to the 'Searches and Reports' manager page and click the New button. Enter your search query in the Search box, start time of '-15m' and end time of 'now'. Check the 'Schedule this search' box. Choose "15 minutes" from the 'Run every' box. Under Condition, choose 'if number of events' and 'is equal to' from the respective drop-downs.

Choose the alert action and save the search.

[ssankeneni]

I do get the results now can you please let me know how to use the eventcount in this case

[richgalloway]

Are you sure there were results in the last 15 minutes?

Did you specify the time as 'index= "metering" sourcetype="ping" earliest=-15m | rex "Ping response: (?.)" | search PingMessage=":OK*" ' ?

[ssankeneni]

index= "metering" sourcetype="ping" | rex "Ping response: (?.)" | search PingMessage=":OK*"

this query returns me the results where the ping is ok
but when I add the time it doesn't return any results

[richgalloway]

Include 'earliest=-15m' in your search query.

[ssankeneni]

I am not sure how to create a search query to return the results for just last 15 minutes

[ssankeneni]

Yes, It is a saved search but it is incorrect and it is not returning any results

[richnavis]

For alerting, you need to setup a save search and schedule it. Then, you can alert based on the results of the saved search. Is the search above your saved search?