Allows users of the Low Level REST client to specify which hosts a
request should be run on. They implement the `NodeSelector` interface
or reuse a built in selector like `NOT_MASTER_ONLY` to chose which nodes
are valid. Using it looks like:
```
Request request = new Request("POST", "/foo/_search");
RequestOptions options = request.getOptions().toBuilder();
options.setNodeSelector(NodeSelector.NOT_MASTER_ONLY);
request.setOptions(options);
...
```
This introduces a new `Node` object which contains a `HttpHost` and the
metadata about the host. At this point that metadata is just `version`
and `roles` but I plan to add node attributes in a followup. The
canonical way to **get** this metadata is to use the `Sniffer` to pull
the information from the Elasticsearch cluster.
I've marked this as "breaking-java" because it breaks custom
implementations of `HostsSniffer` by renaming the interface to
`NodesSniffer` and by changing it from returning a `List<HttpHost>` to a
`List<Node>`. It *shouldn't* break anyone else though.
Because we expect to find it useful, this also implements `host_selector`
support to `do` statements in the yaml tests. Using it looks a little
like:
```
---
"example test":
- skip:
features: host_selector
- do:
host_selector:
version: " - 7.0.0" # same syntax as skip
apiname:
something: true
```
The `do` section parses the `version` string into a host selector that
uses the same version comparison logic as the `skip` section. When the
`do` section is executed it passed the off to the `RestClient`, using
the `ElasticsearchHostsSniffer` to sniff the required metadata.
The idea is to use this in mixed version tests to target a specific
version of Elasticsearch so we can be sure about the deprecation
logging though we don't currently have any examples that need it. We do,
however, have at least one open pull request that requires something
like this to properly test it.
Closes#21888
This commit reworks the Sniffer component to simplify it and make it possible to test it.
In particular, it no longer takes out the host that failed when sniffing on failure, but rather relies on whatever the cluster returns. This is the result of some valid comments from #27985. Taking out one single host is too naive, hard to test and debug.
A new Scheduler abstraction is introduced to abstract the tasks scheduling away and make it possible to plug in any test implementation and take out timing aspects when testing.
Concurrency aspects have also been improved, synchronized methods are no longer required. At the same time, we were able to take #27697 and #25701 into account and fix them, especially now that we can more easily add tests.
Last but not least, unit tests are added for the Sniffer component, long overdue.
Closes#27697Closes#25701
This commit removes the http.enabled setting. While all real nodes (started with bin/elasticsearch) will always have an http binding, there are many tests that rely on the quickness of not actually needing to bind to 2 ports. For this case, the MockHttpTransport.TestPlugin provides a dummy http transport implementation which is used by default in ESIntegTestCase.
closes#12792
Currently, the only way to get the REST response for the `/_cluster/state`
call to return the `cluster_uuid` is to request the `metadata` metrics,
which is one of the most expensive response structures. However, external
monitoring agents will likely want the `cluster_uuid` to correlate the
response with other API responses whether or not they want cluster
metadata.
We had a number of awaitsFix links that weren't updated after the xpack
merge.
Where possible I changed the links to the new locations, but in some
circumstances the original ticket was closed (suggesting the awaitsfix
should be removed) or was otherwise unclear the status.
Nik Everett
Tanguy Leroux
Luca Cavanna
Ryan Ernst
Chris Earle
Zachary Tong