Finding when difference between servers greater than 50%

[Adacats]

I am using the below query (server names replaced) to find when there is a greater than 50% difference in volume between 2 call routers (servers). For some reason im getting no timechart results, even when setting the difference to 1% which should always return results.

index=OMITTED source=OMITTED host="SERVER1" OR host="SERVER2"
| stats max(Value) as Value by host
| eventstats max(if(host='SERVER1', Value, null)) as server1_value max(if(host='SERVER2', Value, null)) as server2_value
| eval value_difference = abs(server1_value - server2_value)
| eval value_percentage_difference = if(coalesce(server1_value, server2_value) != 0, (value_difference / coalesce(server1_value, server2_value) * 100), 0)
| where value_percentage_difference > 1
| timechart avg(value_percentage_difference)

[yuanliu]

Note you need to place source=OMITTED host="SERVER1" OR host="SERVER2" in parentheses; alternatively use IN operator.  Finding difference should not be that complicated.

index=_internal earliest=-15mindex=OMITTED source=OMITTED host IN ("SERVER1", "SERVER2")
| stats max(Value) as Value by host
| stats max(Value) as max_of_two min(Value) as min_of_two
| where max_of_two / min_of_two > 0.75 

However, your OP says you want timechart.  That's why @richgalloway includes _time in groupby in that first stats.  But you can substitute the first stats with timechart to simplify this, then use the same technique in every row to find percent deviation.

index=_internal earliest=-15mindex=OMITTED source=OMITTED host IN ("SERVER1", "SERVER2")
| timechart span=1d max(Value) as Value by host
| eventstats max(Value) as max_of_two min(Value) as min_of_two
| where max_of_two / min_of_two > 0.75 

[richgalloway]

The query returns no results because the timechart command requires the _time field, but that field was removed by the stats command on line 2.

The fix is to include _time in the stats command, like this

index=OMITTED source=OMITTED host="SERVER1" OR host="SERVER2"
| bin span=1d _time
| stats max(Value) as Value by host, _time
| eventstats ...
| timechart span=1d avg(value_percentage_difference)

 Adjust the span option in the bin and timechart commands to preference.  Make sure they match.

[Adacats]

hmm i might be doing something wrong still as i get the timechart but the results are all zeros and there should be a couple at least above zero