Add support for point_in_time search API

[sothawo]

Spring Data Elasticsearch should support the point in time (PIT) API.

This is needed together with search_after (#1143) to redesign paging through large result sets, which currently is done with the scroll API, but Elasticsearch recommends using search_after and pit.

[mateuszwinnicki]

As search_after is already in repo, can you tell when PIT will be also supported?

[sothawo]

No. I'm currently working on a different issue. This will probably be one of the next issues to address.

Keep in mind that Spring Data Elasticsearch is a community maintained project, I am doing this as well in my private time after work, and so the resources are limited.

[mateuszwinnicki]

Sure, I know that :) thanks

[sothawo]

The Elasticsearch RestHighLevelClient does not yet (version 7.12.1) support the calls to open or close point in time. This was just recently merged into Elasticsearch master (elastic/elasticsearch#70593).
We have to wait for this to be available in the libraries.

[xhaggi]

This is supported since version 7.14 of the Java client.

https://www.elastic.co/guide/en/elasticsearch/client/java-rest/7.14/java-rest-high-point-in-time.html

[mateuszwinnicki]

When 7.14 will be released? I can't find any dates unfortunately

[sothawo]

7.14 is not released yet. When it will be, I don't know, only Elasticsearch knows that.

[xhaggi]

My comment was only meant as an indication of when this problem might be resolved.