This commit splits the current ClusterBlockLevel.METADATA into two disctins ClusterBlockLevel.METADATA_READ and ClusterBlockLevel.METADATA_WRITE blocks. It allows to make a distinction between
an operation that modifies the index or cluster metadata and an operation that does not change any metadata.
Before this commit, many operations where blocked when the cluster was read-only: Cluster Stats, Get Mappings, Get Snapshot, Get Index Settings, etc. Now those operations are allowed even when
the cluster or the index is read-only.
Related to #8102, #2833Closes#3703Closes#5855Closes#10521Closes#10522
Added base TransportAction class for master read operations that execute locally or not depending on the request class (local flag).
Added support for local flag where missing, in a backwards compatible manner:
- IndicesExistsRequest
- GetAliasesRequest (get alias api, aliases exist api)
- TypesExistsRequest
- GetIndexTemplatesRequest (get template, template exists)
- GetSettingsRequest
- GetRepositoriesRequest
- PendingClusterTasks
Added parsing of the local flag where missing in Rest*Action.
Updated SPEC adding local flag param where missing and added REST tests that contain use of the local flag where it was just added.
Closes#3345
tlrx
Clinton Gormley
Luca Cavanna
Honza Kral