Upgrade ES to 6.8 and Graylog to 4.0

I’m currently using graylog 3.3 and I’d like to upgrade to version 4.0.
It looks like I need to upgrade Elasticsearch first ( currently using version 5.6).
I’ve done research online but I can’t seem to find how to re-index my indices. Any help is appreciated.

Welcome to our community! :smiley:

You might be better off running up a newer cluster and then doing a remote reindex into it. Is that possible?

If you upgrade from Elasticsearch 5.6 to 6.8 and do not have indices created in earlier versions you should not need to reindex your data.

Thank for your reply, this is my problem I've version 2.4 indices.

java.lang.IllegalStateException: The index [[graylog_644/cp172I2ERtexC-UVsEEKsg]] was created with version [2.4.6] but the minimum compatible version is [5.0.0]. It should be re-indexed in Elasticsearch 5.x before upgrading to 6.8.19

Thank for your reply, this is my problem I've version 2.4 indices.

java.lang.IllegalStateException: The index [[graylog_644/cp172I2ERtexC-UVsEEKsg]] was created with version [2.4.6] but the minimum compatible version is [5.0.0]. It should be re-indexed in Elasticsearch 5.x before upgrading to 6.8.19.

Then you need to reindex them in the current version prior to upgrading. How to best do that probably depends on GrayLog, which I am not familiar with.