Upgrading elasticsearch from 5.6 to 6.7 error: The Upgrade API must be run for 6.x nodes to join the cluster


I'm following the instructions to run an rolling update from a 3-node cluster (elasticsearch, logstash & kibana) as described here.
I had just 1 index that was in version 2.3.3 and I have reindexed that one before updating the RPM package in one of the nodes.
Now the upgraded node starts up seemingly fine but it's unable to join the cluster. After the startup it gets stuck in a loop stating this message again and again:

[2022-07-14T15:57:33,648][INFO ][o.e.d.z.ZenDiscovery     ] [<my_hostname>] failed to send join request to master [{<master_node_hostname>}{o4u1Wip3TmyokMzNPDXeNA}{NyNlaqM6RzGHHAdQn4qhHA}{<my_ip>}{<my_ip>:9300}], reason [RemoteTransportException[[icelkgvap1][<my_ip>:9300][internal:discovery/zen/join]]; nested: IllegalStateException[failure when sending a validation request to node]; nested: RemoteTransportException[[<my_hostname>][<my_ip>:9300][internal:discovery/zen/join/validate]]; nested: IllegalStateException[Security index is not on the current version [6] - The Upgrade API must be run for 6.x nodes to join the cluster]; ]

I can't find but one post related to the "The Upgrade API must be run for 6.x nodes to join the cluster" statement, this one and according to the poster, the .security index needs to be updated before the upgrade from 5.6.x to 6.x. In my case this index is already in version 5. And I don't know if it can be re-indexed to version 6 issuing the reindex in a version 5.6 elasticsearch, is this possible? (I've tried unsuccessfully).

Anybody can give a hint on how to run the upgrade API?

Thanks a lot in advance.

Welcome to our community! :smiley:

Do you have Security setup on the cluster?

Hi Mark,
Thanks for the reply.
I don't really know how to check if Security has been set up on the cluster (I kind of have inherited this environment and don't really know much about how it was set up).
Would you mind give me a hint on how to check this? Would be very appreciated.
Anyway, I'll check if I can find some info online on how to check it.


This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.