We are running some quite old versions of Graylog (2.4.6) and Elasticsearch (5.6.14) and are now planning to upgrade.
What is the best path here ?
Can we go directly to the latest versions or is it best to go via older versions (i such case, which versions) ?
In graylog docs there are docs for the upgrade process, and points what you should check before the update (eg. depricated config settings, elastic commands, etc.
There were 2-3 big changes in graylog, so I suggest to
upgrade 2.5
upgrade to Elasticsearch 6.x
up 3.0
3.1 OR 3.2 (check the 3.2, it is unfriendly for some users).
I did our Dev env this week and the big issue was MongoDb.
Fortunately it was fixed by dumping and importing the database (Went from 2.4.10 to 4.0.17)
I still have Elasticsearch left and will upgrade to latest 6 next week