IndexOperations getMapping fail when using index alias [DATAES-987]

[spring-projects-issues]

edovac opened DATAES-987 and commented

Given an index with at least one alias, when using IndexOperations to retrieve index mapping using the alias instead of the index name the library throws a NullPointerException.

The same code worked fine with version 4.0

It seems that the code in DefaultIndexOperations#doGetMappings(IndexCoordinates) has been changed. It looks up the map using the alias name, but the map contains only index names as keys.  Elasticserach itself allows getting the mappings using an alias, but always returns the mappings for all the indices having the alias.

I know that using an alias to retrieve indices information can be ambiguous, since it there's no guarantee that all indices with the same alias provide a coherent mappings section.

 

Attached you can find a test showing this behaviour

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Affects: 4.1.1 (2020.0.1)

Attachments:

• MappingTest.java (2.53 kB)

Referenced from: pull request #560

Backported to: 4.1.2 (2020.0.2)

[spring-projects-issues]

sothawo commented

thanks for reporting this. I have commented the line that causes this trouble with

??// we only return data for the first index name that was requested (always have done so)??

I think we can change that to just return the first returned mapping without checking the index name. For non-alias request that does not change anything. In the case that ES returns more than one mapping I'd log a warning and return the first returned mapping

[spring-projects-issues]

edovac commented

Thanks. I agree with your proposal.

It's the developer responsability to guarantee that all aliased indices share the same mappings when using this api, otherwhise she should check each index