[Backport to 2.x] Enhance search preference based routing for WRR (#6834)

[linuxpi]

Signed-off-by: Varun Bansal [email protected]
(cherry picked from commit d8d6e73)

Description

Backport of #6834

Issues Resolved

NA

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.
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[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/13097/
• CommitID: d7b2b33
  Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green.
  Is the failure a flaky test unrelated to your change?

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/13250/
• CommitID: 5b19d0c
  Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green.
  Is the failure a flaky test unrelated to your change?

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: UNSTABLE ❕
• TEST FAILURES:

      3 org.opensearch.search.SearchWeightedRoutingIT.testStrictWeightedRoutingWithCustomString
      1 org.opensearch.backwards.MixedClusterClientYamlTestSuiteIT.test {p0=indices.shrink/30_copy_settings/Copy settings during shrink index}

• URL: https://build.ci.opensearch.org/job/gradle-check/13262/
• CommitID: a9ba98f
  Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: UNSTABLE ❕
• TEST FAILURES:

      1 org.opensearch.snapshots.DedicatedClusterSnapshotRestoreIT.testIndexDeletionDuringSnapshotCreationInQueue
      1 org.opensearch.backwards.MixedClusterClientYamlTestSuiteIT.test {p0=indices.split/30_copy_settings/Copy settings during split index}
      1 org.opensearch.backwards.MixedClusterClientYamlTestSuiteIT.test {p0=indices.shrink/30_copy_settings/Copy settings during shrink index}

• URL: https://build.ci.opensearch.org/job/gradle-check/13270/
• CommitID: 267bf4a
  Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.