Document elasticsearch_exporter supported versions (matrix?)

[oldthreefeng]

I dont even found an support version of es.

I have several es clusters . 6.8.8 and 7.4.2 . what version of elasticsearch_exporter i can use ?
can any one helps me out?

$ k get es -A             
NAMESPACE            NAME      HEALTH    NODES   VERSION   PHASE             AGE
deps-prod            elastic   green     3       7.4.0     Ready             23h
elastic-system       elastic   green     3       7.4.2     Ready             362d
prod                 elastic   green     3       7.4.2     Ready             346d
rasp-prod            elastic   green     3       6.8.8     Ready             377d
skywalking-prod-v8   elastic   green     3       7.4.2     Ready             151d
sls-prod             elastic   green     3       6.8.8     Ready             350d

[caarlos0]

what version of elasticsearch_exporter i can use ?

I think the latest should work with all of them 🤔

[sysadmind]

I think that 7.13 does not currently work due to a breaking change in Elasticsearch, but otherwise yes, it should work with all versions to my knowledge.

I think a compatibility matrix or a statement on the README would probably be a good enhancement.

[hartfordfive]

@sysadmind any news on when you'll support v7.13? I've recently upgraded my clusters and I've now notice the exporter is failing with errors.

[sysadmind]

There's no exact timeline. We're working on cutting a 1.2.0 stable release in the next few days before we do larger refactoring like this. After we work through all the breaking changes, we will cut a 2.0 release which should support 7.13

[Skunnyk]

Thank you for taking care of this exporter !
As the fix for ES 7.13 is now merged on master and does not seems to be too invasive, you should cut a fix release (1.2.1 ?) with ES 7.13 support, otherwise people will start to use master and/or fork (and may be afraid of using a "breaking change 2.0" version ?) :)

[frittentheke]

@sysadmind ... thanks again for maintaining this exporter. It's been of great help in running ES clusters for years!

May I point to a rather drastic incoming change in the ES client ecosystem:

• https://aws.amazon.com/blogs/opensource/keeping-clients-of-opensearch-and-elasticsearch-compatible-with-open-source/

and commits / PRs like elastic/go-elasticsearch#324 and the others around it updating the documenation accordingly. In essence ES clients are being updated to only work with ElasticSearch clusters and not i.e. https://www.opensearch.org anymore.

[sysadmind]

@frittentheke Thanks for the kind words, but the credit must really go to the JustWatch team and @zwopir who were the creators and did all the heavy lifting.

Thanks for the note about the clients. I have been following the news to some extent. The good news for this exporter is that it is only using the native go net/http client and libraries, so it is not dependent on any official client libraries. That should prevent any collateral damage to this exporter. I do hope to start a compatibility matrix, especially since there are so many versions of Elasticsearch that users may be running.

[zwopir]

indeed, the exporter only uses the ES API via the stdlib http client. So to create a version matrix, a comparison between the different ES version json output of all the used endpoints must be created.
I'm currently not working on any projects that use ES+prometheus and don't have the time and resources to do this.
As a note aside: IIRC the exporter was developed on a 5.x cluster (now EOL) and no major efforts were taken to migrate/test it with versions higher than that.

Incompatibilities between the 2.x and 5.x versions are handled on a case by case basis and I remember not being happy about this. So to minimize the maintenance effort I'd suggest to freeze the exporter for 2.x and 5.x only support (and fix) non EOL versions

[sysadmind]

Thanks for the feedback @zwopir. I think the plan is to refactor a lot of the code and like you suggest, the next release will likely be a major version change and will not support EOL versions. I have started adding test cases for newer Elasticsearch versions and I hope to include a full set of test fixtures for compatible Elasticsearch versions as I work through the refactors. Thanks again.