GroupShardsIterator is used in many places like the search execution
to determin which shards to query. This can hold shards of one index
as well as shards of multiple indices. The iteration order is used
to assigne a per-request shard ID for each shard that is used as a
tie-breaker when scores are the same. Today the iteration order is
soely depending on the HashMap iteration order which is undefined or
rather implementation dependent. This causes search requests to return
inconsistent results across requests if for instance different nodes
are coordinating the requests.
Simple queries like `match_all` may return results in arbitrary order
if pagination is used or may even return different results for the same
request even though there hasn't been a refresh call and preferences are
used.
Today if we run into exception like NumberFormatException or IAE
when we try to open a commit point to retrieve checksums and calculate
store metadata we just bubble them up. Yet, those are very likely index
corruptions. In such a case we should really mark the shard as
corrupted.
In the reduce logic of the top_hits aggregation if the first shard result to process contained has no results then the merging of all the shard results can go wrong resulting in an incorrect sorted hits.
This bug can only manifest with a sort other than score.
Closes#7697
If you have previously corrupted files, this method currently builds an
exception like:
```
failed engine [corrupted preexisting index]
failed to start shard
```
Followed by a CorruptIndexException. This commit writes the entire
stacktrace to provide additional information. It also changes the
failure message from `corrupted preexisting index` to `preexisting
corrupted index` to prevent confusion.
Closes#7596
With #7594 we replaced the static `BaseRestHandler#addUsefulHeaders` by introducing the `RestClientFactory` that can be injected and used to register the relevant headers. To simplify things, we can now register relevant headers through the `RestController` and remove the `RestClientFactory` that was just introduced.
Closes#7675
Returns information about settings, aliases, warmers, and mappings. Basically returns the IndexMetadata. This new endpoint replaces the /{index}/_alias|_aliases|_mapping|_mappings|_settings|_warmer|_warmers and /_alias|_aliases|_mapping|_mappings|_settings|_warmer|_warmers endpoints whilst maintaining the same response formats. The only exception to this is on the /_alias|_aliases|_warmer|_warmers endpoint which will now return a section for 'aliases' or 'warmers' even if no aliases or warmers exist. This backwards compatibility change is documented in the reference docs.
Closes#4069
With the change in #7493, we introduced a pinging round when a master nodes goes down. That pinging round helps validating the current state of the cluster and takes, by default, 3 seconds. It may be that during that window, a new node tries to join the cluster and starts pinging (this is typical when you quickly restart the current master). If this node gets elected as the new master it will force recovery from the gateway (it has no in memory cluster state), which in turn will cause a full cluster shard synchronisation. While this is not a problem on it's own, it's a shame. This commit demotes "new" nodes during master election so the will only be elected if really needed.
Closes#7558
By default the reroute API should return the new cluster state, excluding the metadata. It was however it was wrongly using an old parameter (filter_metadata) and thus failed to do so. This commits restores but wiring it to the correct `metric` parameter. We also add an enum representing the possible metrics, to avoid similar future mistakes.
Closes#7520Closes#7523
The functionality of copying headers in the REST layer (from REST requests to transport requests) remains the same. Made it a bit nicer by introducing a RestClientFactory component that is a singleton and allows to register useful headers without requiring static methods.
Plugins just have to inject the RestClientFactory now, and call its `addRelevantHeaders` method that is not static anymore.
Relates to #6513Closes#7594
Boaz Leskes
Clinton Gormley
Simon Willnauer
Britta Weber
javanna
Martijn van Groningen
Colin Goodheart-Smithe
Honza Král
Lee Hinman
Ulrich Reffle
Nik Everett
Adrien Grand
smayzak
David Pilato
Ryan Ernst