Change the "Master" nomenclature

[tlfeng]

Is your feature request related to a problem? Please describe.
OpenSearch repository is going to replace the terminology "master"with "cluster manager".
issue: opensearch-project/OpenSearch#472, with the plan for its terminology replacement.

Although the existing usages with "master" will be supported in OpenSearch version 2.x to keep the backwards compatibility, please prepare for the nomenclature change in advance, and replace all the usages with "master" terminology in the code base.
All the OpenSearch REST APIs and settings that contain "master" terminology will be deprecated in 2.0, and alternative usages will be added.

Describe the solution you'd like
Replace the terminology "master" with "cluster manager".

When being compatible with OpenSearch 2.0:

• Deprecate REST API (request parameter) that contains "master" and provide alternative inclusive usage:
  deprecate parameter "master_timeout" and add new parameter "cluster_manager_timeout" in RestQuerySettingsAction (updated after the below comment)

When being compatible with OpenSearch 3.0:

• Replace "master" in the reference to OpenSearch Java API
  • clusterUpdateSettingsRequest.masterNodeTimeout -> clusterUpdateSettingsRequest.clusterManagerNodeTimeout (new API is available in version 2.2)

Describe alternatives you've considered
None.

Additional context

[dblock]

I am still seeing

sql/plugin/src/main/java/org/opensearch/sql/plugin/rest/RestQuerySettingsAction.java

Line 82 in 907019c

clusterUpdateSettingsRequest.masterNodeTimeout(request.paramAsTime(

reopening

[dai-chen]

I am still seeing

sql/plugin/src/main/java/org/opensearch/sql/plugin/rest/RestQuerySettingsAction.java

Line 82 in 907019c

clusterUpdateSettingsRequest.masterNodeTimeout(request.paramAsTime(

reopening

I didn't see the new API for this. Do we have a doc for this?

[tlfeng]

@dai-chen Thanks for taking care of the issue.
Looks like it's a REST API of SQL plugin to update setting, which using a request parameter master_timeout which contains "master" word. Sorry I didn't understand this usage in SQL plugin correctly and didn't mention correctly in above.

I suggest to deprecate the request parameter master_timeout, and add a new request parameter cluster_manager_timeout. Then remove the support of parameter master_timeout in the future.

How OpenSearch deal with the API request parameter master_timeout:
In OpenSearch, the parameter master_timeout is deprecated and will be replaced by parameter cluster_manager_timeout.
The timeline for deprecating the parameter master_timeout is special in OpenSearch (core):

1. In version 2.0: new parameter cluster_manager_timeout is added, while no warning for using master_timeout.
2. In version 3.0: deprecation warning will be emitted if using the parameter master_timeout.
3. In version 4.0: the support of master_timeout will be removed.

Technically it is fine to keep using the parameter master_timeout when being compatible with OpenSearch 2.0, but deprecation warning will be shown in 3.0 .

I described all the deprecated non-inclusive REST API / Settings and the alternatives in issue opensearch-project/documentation-website#450.
The code change was tracked in the issue opensearch-project/OpenSearch#2511
You could take them as reference.

Note that the method masterNodeTimeout() will be replaced in OpenSearch 3.0, so there is no action for being compatible with version 2.0 . The work to replace "master" in OpenSearch public Java API is tracked in the issue opensearch-project/OpenSearch#1684, and the work hasn't been started yet.

[dai-chen]

@tlfeng Thanks for the very detailed info! Will refresh OpenSearch dependency and check the latest API. Thanks