Elasticsearch 8.19.0-preview feedback

[Ramstad]

The version 8.19 preview is described as such: This release backports all improvements of the 9.0 client to the 8.x major version of the client.
I've noticed some changes that hasn't been backported:

1. GetAliasResponse has a Values property (8.19) instead of an Aliases property (9.0).
2. GetMappingResponse has a Values property (8.19) instead of an Mappings property (9.0).

I guess there are also other response types with the same "issue".

[flobernd]

Hi @Ramstad ,

thanks for the feedback!

Large parts of the client are generated from a shared specification. We maintain different branches of the specification for each Elasticsearch version. In some cases, we provide name hints for the code generators. In the 8.x branch, we do not have these hints for the above properties, which leads to the default name Values being generated. In the 9.x branch we specified custom codegen hints.

Sadly we can not backport these changes in the specification since they would introduce breaking changes for the other clients.

I'm considering to hardcode these cases in the .NET code generator, but have not made a final decision.

[Ramstad]

Thanks for the clarification!

[gpetrou]

@flobernd in 8.17.4 and previous versions we have:

So, it seems that this changed now for 8.19 and then it will change back again in 9.0.

[pquentin]

@gpetrou I can't discuss the .NET client itself, but note that 8.19 -> 9.0 won't be a supported upgrade path for the Elasticsearch server. 8.18 -> 9.1 will be doable with 8.18 -> 8.19 -> 9.1 or 8.18 -> 9.0 -> 9.1. For this reason, and to avoid the scenario you mention, it would not be a good idea to use an 8.19 client on a 9.0 server.