Upgraded, existing indices unavailable

Elastic Stack Elasticsearch
1

Greetings, everyone.

I have an issue where I upgraded my ElasticSearch cluster (3 masters, 5 data) from 0.90.10 to 1.4.5. All the existing indices are missing when I look in kopf. They are present on disk, but not in kopf.

Can I get them back directly, or do I have to regenerate all the data?

I attended the upgrade webinar and it seems the Lucene in 1.4.5 should be able to read the indices from 0.90.10, so that's not the problem.

Perhaps a bug or a split-brain issue?

Any help is greatly appreciated.

2

Any errors in the log files?

3

I forgot to mention that. I don't see any error messages in the log files related to the indices.

4

Any errors or warnings that are not related to the indices but related to the cluster as a whole?