A more descriptive warning message instead of the vague and not useful "Courier Fetch: 1 of 5 shards failed"

[astefan]

Kibana version: 5.3.0/5.2.0

Elasticsearch version: 5.3.0/5.2.0

Description of the problem including expected versus actual behavior:

Kibana seems to report a vague and incorrect message for a mapping problem in the Elasticsearch index. It would be better if the message displayed would be more descriptive. The Elasticsearch one is definitely more helpful.

Steps to reproduce:

1. create a simple index like the following gist
2. in Kibana, define an Index Pattern to cover the test index that was just created
3. go to the Discover tab and choose the freshly created pattern

Errors in browser (if relevant): Courier Fetch: 1 of 5 shards failed.

Provide logs and/or server output (if relevant):

[2017-04-12T05:44:00,350][DEBUG][o.e.a.s.TransportSearchAction] [main_node_5_3_0] [45] Failed to execute fetch phase
org.elasticsearch.transport.RemoteTransportException: [main_node_5_3_0][127.0.0.1:9300][indices:data/read/search[phase/fetch/id]]
Caused by: java.lang.IllegalArgumentException: Can't load fielddata on [my_date] because fielddata is unsupported on fields of type [date]. Use doc values instead.
	at org.elasticsearch.index.mapper.MappedFieldType.failIfNoDocValues(MappedFieldType.java:428) ~[elasticsearch-5.3.0.jar:5.3.0]
	at org.elasticsearch.index.mapper.DateFieldMapper$DateFieldType.fielddataBuilder(DateFieldMapper.java:379) ~[elasticsearch-5.3.0.jar:5.3.0]
	at org.elasticsearch.index.fielddata.IndexFieldDataService.getForField(IndexFieldDataService.java:111) ~[elasticsearch-5.3.0.jar:5.3.0]
	at org.elasticsearch.search.fetch.subphase.DocValueFieldsFetchSubPhase.hitExecute(DocValueFieldsFetchSubPhase.java:65) ~[elasticsearch-5.3.0.jar:5.3.0]

[Bargs]

I believe we're just passing through the message that came back from ES. Was there a "more info" button on the right side of the notification banner? Usually we'll include the full ES error there.

The message we get in master seems to be improved:

[truebit]

@Bargs this is a warning message, It only displays as follows:

@astefan could you tell me how could I locate the exception? I could not found such log in elasticsearch log file.

I finally found that it's due to scripted fields issue.

[alexfrancoeur]

@epixa what team would own this, would it be platform? Seems like this is a common pain point and wasted time for debugging issues in support. If we could provide any additional context for errors like this it'd be fantastic.

[epixa]

Discovery

[mauriziod]

This will be really helpful to have. I had the same problem and I managed to fix it by resolving the field type conflicts reported in the Management section on the left hand side menu. Hope that helps.

[cjcenizal]

This is a very valid problem, but this issue is a dupe of #5957. I'm closing this in favor of that one.

[u007]

in my case, changing data structure seems to be the problem. i did a quick resolution by removing elasticsearch database. not recommended for others, but mine is just statistic, isnt important to keep history of data.