Opensearch rollback(downgrade) to lower version

Versions (relevant - OpenSearch): Opensearch 2.6.0

Describe the issue: I was trying to upgrade the OpenSearch from Version 1.3.x to Opensearch 2.6.0 version

As part of our organization use case, we need to deliver the Install/upgrade/rollback feature. but when we try to downgrade the opensearch from higher version to lower version then we could nt restore the snapshot which has been taken from higher version to lower version

We are getting the below exception when we try to restore the snapshot

> POST "/_snapshot/repository/1/_restore?pretty"
> {
>   "error" : {
>     "root_cause" : [
>       {
>         "type" : "snapshot_restore_exception",
>         "reason" : "[repository:1/KJHRb6oFRjqlulc5Q_0yOQ] the snapshot was created with OpenSearch version [2.6.0] which is higher than the version of this node [1.3.8]"
>       }
>     ],
>     "type" : "snapshot_restore_exception",
>     "reason" : "[repository:1/KJHRb6oFRjqlulc5Q_0yOQ] the snapshot was created with OpenSearch version [2.6.0] which is higher than the version of this node [1.3.8]"
>   },
>   "status" : 500
> }

Could you please help us to solve this problem. is there any way to avoid this exception.

Configuration:

Relevant Logs or Screenshots:

Hi @RAGURAMAN

As per the documentation below, snapshots are only forward-compatible by one major version:

In order to copy your data from the OpenSearch version 2.6.0 to the OpenSearch version 1.3.x, you can use reindex API: