This commit removes the cluster state size field from the cluster state
response, and drops the backwards compatibility layer added in 6.7.0 to
continue to support this field. As calculation of this field was
expensive and had dubious value, we have elected to remove this field.
With #37566 we have introduced the ability to merge multiple search responses into one. That makes it possible to expose a new way of executing cross-cluster search requests, that makes CCS much faster whenever there is network latency between the CCS coordinating node and the remote clusters. The coordinating node can now send a single search request to each remote cluster, which gets reduced by each one of them. from + size results are requested to each cluster, and the reduce phase in each cluster is non final (meaning that buckets are not pruned and pipeline aggs are not executed). The CCS coordinating node performs an additional, final reduction, which produces one search response out of the multiple responses received from the different clusters.
This new execution path will be activated by default for any CCS request unless a scroll is provided or inner hits are requested as part of field collapsing. The search API accepts now a new parameter called ccs_minimize_roundtrips that allows to opt-out of the default behaviour.
Relates to #32125
* Deprecate types in index API
- deprecate type-based constructors of IndexRequest
- update tests to use typeless IndexRequest constructors
- no yaml tests as they have been already added in #35790
Relates to #35190
This commit changes the format of the `hits.total` in the search response to be an object with
a `value` and a `relation`. The `value` indicates the number of hits that match the query and the
`relation` indicates whether the number is accurate (in which case the relation is equals to `eq`)
or a lower bound of the total (in which case it is equals to `gte`).
This change also adds a parameter called `rest_total_hits_as_int` that can be used in the
search APIs to opt out from this change (retrieve the total hits as a number in the rest response).
Note that currently all search responses are accurate (`track_total_hits: true`) or they don't contain
`hits.total` (`track_total_hits: true`). We'll add a way to get a lower bound of the total hits in a
follow up (to allow numbers to be passed to `track_total_hits`).
Relates #33028
The `wait_for_metadata_version` parameter will instruct the cluster state
api to only return a cluster state until the metadata's version is equal or
greater than the version specified in `wait_for_metadata_version`. If
the specified `wait_for_timeout` has expired then a timed out response
is returned. (a response with no cluster state and wait for timed out flag set to true)
In the case metadata's version is equal or higher than `wait_for_metadata_version`
then the api will immediately return.
This feature is useful to avoid external components from constantly
polling the cluster state to whether somethings have changed in the
cluster state's metadata.
Today when checking settings dependencies, we do not check if fallback
settings are present. This means, for example, that if
cluster.remote.*.seeds falls back to search.remote.*.seeds, and
cluster.remote.*.skip_unavailable and search.remote.*.skip_unavailable
depend on cluster.remote.*.seeds, and we have set search.remote.*.seeds
and search.remote.*.skip_unavailable, then validation will fail because
it is expected that cluster.ermote.*.seeds is set here. This commit
addresses this by also checking fallback settings when validating
dependencies. To do this, we adjust the settings exist method to also
check for fallback settings, a case that it was not handling previously.
With features like CCR building on the CCS infrastructure, the settings
prefix search.remote makes less sense as the namespace for these remote
cluster settings than does a more general namespace like
cluster.remote. This commit replaces these settings with cluster.remote
with a fallback to the deprecated settings search.remote.
We have been encountering name mismatches between API defined in our
REST spec and method names that have been added to the high-level REST
client. We should check this automatically to prevent furher mismatches,
and correct all the current ones.
This commit adds a test for this and corrects the issues found by it.
TransportRequestHandler currently contains 2 messageReceived methods,
one which takes a Task, and one that does not. The first just delegates
to the second. This commit changes all existing implementors of
TransportRequestHandler to implement the version which takes Task, thus
allowing the class to be a functional interface, and eliminating the
need to throw exceptions when a task needs to be ensured.
With #30490 we have introduced a new way to provide request options
whenever sending a request using the high-level REST client. Before you
could provide headers as the last argument varargs of each API method,
now you can provide `RequestOptions` that in the future will allow to
provide more options which can be specified per request.
This commit deprecates all of the client methods that accept a `Header`
varargs argument in favour of new methods that accept `RequestOptions`
instead. For some API we don't even go through deprecation given that
they were not released since they were added, hence in that case we can
just move them to the new method.
In #29623 we added `Request` object flavored requests to the low level
REST client and in #30315 we deprecated the the old requests. This
changes many calls in the `qa` projects to use the new version.
* Decouple XContentBuilder from BytesReference
This commit removes all mentions of `BytesReference` from `XContentBuilder`.
This is needed so that we can completely decouple the XContent code and move it
into its own dependency.
While this change appears large, it is due to two main changes, moving
`.bytes()` and `.string()` out of XContentBuilder itself into static methods
`BytesReference.bytes` and `Strings.toString` respectively. The rest of the
change is code reacting to these changes (the majority of it in tests).
Relates to #28504
Today Cross Cluster Search requires at least one node in each remote cluster to be up once the cross cluster search is run. Otherwise the whole search request fails despite some of the data (either local and/or remote) is available. This happens when performing the _search/shards calls to find out which remote shards the query has to be executed on. This scenario is different from shard failures that may happen later on when the query is actually executed, in case e.g. remote shards are missing, which is not going to fail the whole request but rather yield partial results, and the _shards section in the response will indicate that.
This commit introduces a boolean setting per cluster called search.remote.$cluster_alias.skip_if_disconnected, set to false by default, which allows to skip certain clusters if they are down when trying to reach them through a cross cluster search requests. By default all clusters are mandatory.
Scroll requests support such setting too when they are first initiated (first search request with scroll parameter), but subsequent scroll rounds (_search/scroll endpoint) will fail if some of the remote clusters went down meanwhile.
The search API response contains now a new _clusters section, similar to the _shards section, that gets returned whenever one or more clusters were disconnected and got skipped:
"_clusters" : {
"total" : 3,
"successful" : 2,
"skipped" : 1
}
Such section won't be part of the response if no clusters have been skipped.
The per cluster skip_unavailable setting value has also been added to the output of the remote/info API.
Jason Tedor
Luca Cavanna
Mayya Sharipova
Jim Ferenczi
Martijn van Groningen
Ryan Ernst
Nik Everett
Lee Hinman