Grafana: [Feature request] Elasticsearch Datasource Alerting

Please prefix your title with [Bug] or [Feature request]
For question please check Support Options. Do not open a github issue

Please include this information:

• What Grafana version are you using? v4
• What datasource are you using? Elasticsearch 2.x
• What OS are you running grafana on? debian:jessie
• What did you do? Tried to set up alerts on ES data
• What was the expected result? An alert would be set up
• What happened instead? I got an error

I'm curious if this is a limitation of Elasticsearch itself or the Datasource in Grafana just needs an update to support alerting.

I got the following error:

firing false
timeMs 0.476ms
error tsdb.HandleRequest() error Could not find executor for data source type: elasticsearch