Math in watcher condition part

[Izek (IzekChen)]

I am try to do the calculate of the condition part in watcher.
But I have no idea how to do it .

For logstash monitoring index, there have a doc.logstash_stats.events.in and doc.logstash_stats.events.out.
How could I do subtraction between this to value and that is the value is less than 1000 or something, then return true?

[Izek (IzekChen)]

Finally, I solved the problem.
use script field to create a new field

than just use compare in the condition

[spinscale (Alexander Reelsen)]

hey,

so script fields will have a considerable performance difference compared to a script condition - and they also solve a different problem.

If you dont spent some time on explaining your use-case, it will be hard to help.

Also, please refrain from using screenshots, as many people cannot see them (and you cannot paste it into a kibana instance and test it out yourself).

Thanks!

--Alex

[Izek (IzekChen)]

Hi @spinscale ,

There have two field named "logstash_stats.events.in" and "logstash_stats.events.out" in the .monitoring-logstash index.
I would like to calculate the gap of in and out to make there have no data missing.

But actually I tried to do the subtraction in the condition, but still cannot get it done.
So I try to use script field, also cannot get it.

Here is my code:

{
"trigger": {
"schedule": {
"interval": "10s"
}
},
"input": {
"http": {
"request": {
"host": "localhost",
"port": 9200,
"path": "/<.monitoring-logstash-6-{now%2Fd}>/_search",
"body" : "{"query":{"match_all":{}},"script_fields":{"logstash_stats.events.gap":{"script":"doc['logstash_stats.events.in'].value - doc['logstash_stats.events.out'].value"}},"size":1,"sort":[{"logstash_stats.timestamp":{"order":"desc"}}]}"
}
}
},
"condition": {
"compare" : {
"ctx.payload.hits.hits.0._source.logstash_stats.events.gap" : {
"gt" : "1000"
}
}
},
"actions": {
"email_administrator" : {
"email" : {
"to" : "test@mail.com",
"subject" : "test",
"body" : "test",
"priority" : "high"
}
}
}
}

But the result of gap is null

  "condition": {
    "type": "compare",
    "status": "success",
    "met": false,
    "compare": {
      "resolved_values": {
        "ctx.payload.hits.hits.0._source.logstash_stats.events.gap": null
      }
    }
  }

Do you have any idea or suggestion about this?

[spinscale (Alexander Reelsen)]

If you want to access a scripted field in the condition, you need to use the correct path.

A reply of a script fields looks a bit different

"hits": [
      {
        "_index": ".watcher-history-3-2017.10.23",
        "_type": "watch_record",
        "_id": "e4ZR1JpWQUCr7cFWH8l77Q_kibana_version_mismatch_41b24cc8-6269-45de-8252-6ecb593dcf29-2017-10-23T00:00:44.952Z",
        "_score": 1,
        "fields": {
          "foo": [
            "e4ZR1JpWQUCr7cFWH8l77Q_kibana_version_mismatch"
          ]
        }
      },
      {
...

so you would need to use ctx.payload.hits.hits.0.fields.foo.0 in this example.

--Alex

[Izek (IzekChen)]

Already solved the problem

Thanks.