Recover all translogs during relocation handoff for remote-backed indexes

[ashking94]

Signed-off-by: Ashish Singh ssashish@amazon.com

Description

As discussed in #6214, during relocation certain documents indexed on the older primary were not seen on the new primary upon search. This was happening as recoverFromTranslog was recovering upto last known global checkpoint while it should be done upto Long.Max for cases where remote translog store is enabled.

OpenSearch/server/src/main/java/org/opensearch/index/shard/IndexShard.java

Lines 4314 to 4317 in 49d9a90

	newEngineReference.get()
	.translogManager()
	.recoverFromTranslog(translogRunner, newEngineReference.get().getProcessedLocalCheckpoint(), globalCheckpoint);
	newEngineReference.get().refresh("reset_engine");

When remote translog is enabled, then remote store acts as the source of truth for storing translogs. During relocation we reset engine to writeable engine. When this happens, we initialise the RemoteFsTranslog which downloads all the translogs from remote store. The fix is to replay all the translogs here.

Issues Resolved

This fixes #6214.

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Commits are signed per the DCO using --signoff
• Commit changes are listed out in CHANGELOG.md file (See: Changelog)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: SUCCESS ✅
• URL: https://build.ci.opensearch.org/job/gradle-check/11113/
• CommitID: 7ae0c9c

[opensearch-trigger-bot]

The backport to 2.x failed:

The process '/usr/bin/git' failed with exit code 128

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/backport-2.x 2.x
# Navigate to the new working tree
pushd ../.worktrees/backport-2.x
# Create a new branch
git switch --create backport/backport-6314-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 ac322595eb1838b68e4d9a46cf97cbe56b811aed
# Push it to GitHub
git push --set-upstream origin backport/backport-6314-to-2.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/backport-2.x

Then, create a pull request where the base branch is 2.x and the compare/head branch is backport/backport-6314-to-2.x.

[ashking94]

Created manual PR - #6318