Elasticsearch 2.2.x vs Grafana 2.6.x

Hi All,
we have installed on our staging environment a stack composed by Logstash 2.2.x, Elasticsearch 2.2.x and we tried to add as monitoring dashboard a new version of Grafana 2.6.0 in parallel with Kibana 4.4.3.

The dashboards on Kibana 4.4.3 works fine but on Grafana we noticed some strage behavior. We added the source ad Elasticsearch 2.x and when we tried to require some terms we received an error reported below

indent preformatted text by 4 spaces
[2016-03-16 15:18:35,861][DEBUG][action.search.type ]
[cw-stms-ebe01] [logstash-apache-it-2016.03.16][0],
node[aZHu4TEORJ6gLY-avVDrVQ], [P], v[2], s[STARTED],
a[id=ZMvdL6ToQcSJiTQHC4wcjQ]: Failed to execute [org.elasticsearch.action.search.SearchRequest@482439b]

RemoteTransportException[[cw-stms-ebe01][10.175.241.191:9300][indices:data/read/search[phase/query]]];
nested: QueryPhaseExecutionException[Query Failed [Failed to execute
main query]]; nested:
ElasticsearchException[java.lang.IllegalStateException: Field data
loading is forbidden on response]; nested:
UncheckedExecutionException[java.lang.IllegalStateException: Field data
loading is forbidden on response]; nested: IllegalStateException[Field
data loading is forbidden on response];

Caused by: QueryPhaseExecutionException[Query Failed [Failed to execute
main query]]; nested:
ElasticsearchException[java.lang.IllegalStateException: Field data
loading is forbidden on response]; nested:
UncheckedExecutionException[java.lang.IllegalStateException: Field data
loading is forbidden on response]; nested: IllegalStateException[Field
data loading is forbidden on response];

    at org.elasticsearch.search.query.QueryPhase.execute(QueryPhase.java:409)

    at org.elasticsearch.search.query.QueryPhase.execute(QueryPhase.java:113)

    at org.elasticsearch.search.SearchService.loadOrExecuteQueryPhase(SearchService.java:364)

    at org.elasticsearch.search.SearchService.executeQueryPhase(SearchService.java:376)

    at 

org.elasticsearch.search.action.SearchServiceTransportAction$SearchQueryTransportHandler.messageReceived(SearchServiceTransportAction.java:368)

    at 

org.elasticsearch.search.action.SearchServiceTransportAction$SearchQueryTransportHandler.messageReceived(SearchServiceTransportAction.java:365)

    at org.elasticsearch.transport.TransportService$4.doRun(TransportService.java:350)

    at org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37)

    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)

    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)

    at java.lang.Thread.run(Thread.java:745)

Could someone help us to identify the issue?

Thanks,
Marcello

Field data loading is forbidden on [FIELDNAME] · Issue #15267 · elastic/elasticsearch · GitHub may be of assistance.

From that issue;

The problem happens when "fielddata" : { "format" : "disabled" } is set in a field's mapping, which is the default as of Logstash 2.1, due to this issue.