Changes to the indices stats API

[clintongormley]

Recommendations:

Remove the all and clear flags. Default to return all by default, unless specific metrics specified.

Change the path format to:

/{index}/_stats/{metric}

where:

• {index}: comma-delimited list of indices, _all, or blank
• {metric} is blank or comma-delimited list of metrics

Metrics can be any of:

• completion
• docs
• fielddata
• filter_cache
• flush
• get
• id_cache
• indexing
• merge
• refresh
• search
• store
• warmer

Four metrics take optional parameters, which can be specified in the query string. These are:

• completion: fields or completion_fields
• fielddata: fields or fielddata_fields
• indexing: types
• search: groups

Change level to accept cluster, indices and shards, as per the cluster health API. Default to indices. If set to cluster, only return the _all stats.

Add the translog info from the index status API into the shard-level info of the indices stats API.

[spinscale]

Started working on this.

It seems, that the level parameter is only mentioned in the documentation, but actually nowhere in the REST action. Maybe I am missing something?

[spinscale]

Forget my previous comment, it is hidden in the stats response in the toXContent serialization, not in the request...