How to restore index data if I remove all my master nodes accidentally!

There are 3 master nodes and 6 data nodes in my ES Cluster. ES version is 6.7.x.
I delete virtual machines accidentally, so 3 master nodes are disappeared forever!
But my 6 data nodes are still on.
Is any possible to restore old data from the data nodes?
BTW: I have no snapshots, no backups @_@

Which version of Elasticsearch are you using? Do you have a snapshot taken using the Elasticsearch APIs to restore from?

:tired_face: version is 6.7. I don't have any snapshot.
And i have already read Elasticsearch Reference, but it does not help.

Welcome to our community! :smiley:

You might be able to convert a data node to a master and see if that bootstraps the cluster back. But without backups there's no guarantee.

1 Like

Thanks for your help!
I'm trying to solve the matter in other ways.
Can I just write a application with JAVA Lucene to read the files from ES data nodes:

  1. Fields: *.fnm
  2. Field Index: *.fdx
  3. Field Data: *.fdt

Is it possible to read the Key/Value from these files?
Or anything else I missed?

Why would you start with such a custom and unsupported approach?

1 Like

Because the approach (convert a data node to a master) might not work
If this happens, my final choice is and only is Reading the files :skull:

I would recommend trying to make the data nodes master eligible first though as it would save you a lot of work if it was successful. I believe Elasticsearch 6.x is more forgiving than 7.x so would not rule out that it could work.

1 Like

Thanks a lot!
convert a data node to a master finally it works :smiley:

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