Rollup index not recognized as such

[kandelon]

Elasticsearch version (bin/elasticsearch --version): 7.3.0

Plugins installed: []

JVM version (java -version): cloud

OS version (uname -a if on a Unix-like system): cloud

Description of the problem including expected versus actual behavior:
In working around a different issue I have spun up a fresh cluster, put in some data and templates and created a rollup job via kibana. The job was successfully created and the rollup index started filling with data. However, _rollup_search returns no data (sum/max/etc all come back as null) and on investigation the rollup index has no rollup meta data and GET /*/_rollup/data returns an empty object. I've created other simple indexes and rollup jobs on the cluster and they all come out the same. It seem like the rollup indexes is not being recognized as such, even though the task is running and adding rollup data.

[elasticmachine]

Pinging @elastic/es-analytics-geo

[polyfractal]

Do you happen to have index templates in the cluster that might match the rollup_index itself?

There was a bug (just fixed in #43943) which doesn't merge existing index templates into the rollup settings/mappings correctly. The side-effect is that the existing index template "wins" and the _meta._rollup fields aren't added to the new index. The job itself works fine, but anything relying on the _meta field (like index caps API, or _rollup_search which needs the config for validation)

[kandelon]

Ah, I do indeed! Thanks. I think I can get by without the template for now.

[polyfractal]

👍 That bugfix should be part of the next release (7.4), and at least in the mean time you can add important settings/mappings into the rollup index manually after creation. A pain, but should work until 7.4 is released :)