Abstract AsyncShardFetch cache to allow restructuring for other caching strategies

[amkhar]

Description

Abstract AsyncShardFetch cache to allow restructuring for other caching strategies.
Currently cache is like private final Map<String, NodeEntry<T>> cache = new HashMap<>();
This is can not support other strategies. So abstracting out this implementation in a separate class will help other caching strategies to be implemented easily.

Related Issues

Resolves ##12440

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Failing checks are inspected and point to the corresponding known issue(s) (See: Troubleshooting Failing Builds)
• Commits are signed per the DCO using --signoff
  - [ ] Commit changes are listed out in CHANGELOG.md file (See: Changelog)
  - [ ] Public documentation issue/PR created

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 result for c26c6c1: FAILURE

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]

Compatibility status:

Checks if related components are compatible with change d7903f7

Incompatible components

Skipped components

Compatible components

Compatible components: [https://github.com/opensearch-project/custom-codecs.git, https://github.com/opensearch-project/asynchronous-search.git, https://github.com/opensearch-project/performance-analyzer-rca.git, https://github.com/opensearch-project/flow-framework.git, https://github.com/opensearch-project/cross-cluster-replication.git, https://github.com/opensearch-project/job-scheduler.git, https://github.com/opensearch-project/reporting.git, https://github.com/opensearch-project/security.git, https://github.com/opensearch-project/opensearch-oci-object-storage.git, https://github.com/opensearch-project/geospatial.git, https://github.com/opensearch-project/k-nn.git, https://github.com/opensearch-project/neural-search.git, https://github.com/opensearch-project/common-utils.git, https://github.com/opensearch-project/security-analytics.git, https://github.com/opensearch-project/anomaly-detection.git, https://github.com/opensearch-project/performance-analyzer.git, https://github.com/opensearch-project/notifications.git, https://github.com/opensearch-project/ml-commons.git, https://github.com/opensearch-project/observability.git, https://github.com/opensearch-project/index-management.git, https://github.com/opensearch-project/alerting.git, https://github.com/opensearch-project/sql.git]

[github-actions]

❌ Gradle check result for 608c8ae: FAILURE

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 result for a6921f0: FAILURE

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 result for 0daa63e: FAILURE

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 result for 8383c63: UNSTABLE

• TEST FAILURES:

      1 org.opensearch.remotestore.RemoteStoreStatsIT.testDownloadStatsCorrectnessSinglePrimaryMultipleReplicaShards

Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

[codecov]

Codecov Report

Attention: Patch coverage is 81.33333% with 28 lines in your changes are missing coverage. Please review.

Project coverage is 71.35%. Comparing base (2b17902) to head (d7903f7).

Files	Patch %	Lines
...a/org/opensearch/gateway/AsyncShardFetchCache.java	78.33%	10 Missing and 16 partials ⚠️
...n/java/org/opensearch/gateway/AsyncShardFetch.java	93.33%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #12441      +/-   ##
============================================
- Coverage     71.43%   71.35%   -0.08%     
- Complexity    59960    59982      +22     
============================================
  Files          4984     4985       +1     
  Lines        282247   282275      +28     
  Branches      40952    40946       -6     
============================================
- Hits         201617   201415     -202     
- Misses        63954    64198     +244     
+ Partials      16676    16662      -14     

☔ View full report in Codecov by Sentry.
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[amkhar]

❕ Gradle check result for 8383c63: UNSTABLE

• TEST FAILURES:

      1 org.opensearch.remotestore.RemoteStoreStatsIT.testDownloadStatsCorrectnessSinglePrimaryMultipleReplicaShards

Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

Flaky test link : #10152

[github-actions]

❕ Gradle check result for 91e094a: UNSTABLE

• TEST FAILURES:

      1 org.opensearch.search.SearchWeightedRoutingIT.testMultiGetWithNetworkDisruption_FailOpenEnabled

Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

[sachinpkale]

Changes LGTM but there are no tests added for changes in this PR. Are they already covered?

[amkhar]

Changes LGTM but there are no tests added for changes in this PR. Are they already covered?

Thanks @sachinpkale !
Yes, AsyncShardFetchTests class already covers all the tests for existing implementation. For new implementations, tests are being added in https://github.com/opensearch-project/OpenSearch/pull/12504/files#diff-4c4d5a289cb13787ecdcf2d6ae890c7f21a54aa15086d4acf2c5894a1d332420

This PR is just for abstracting out the code from 1 single file to 3 different files for better extensibility.

[github-actions]

❌ Gradle check result for 9fe6a07: FAILURE

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 result for ad0026a: FAILURE

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?

[sachinpkale]

Please fix the build.

[github-actions]

✅ Gradle check result for d7903f7: SUCCESS

[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:

# Navigate to the root of your repository
cd $(git rev-parse --show-toplevel)
# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/OpenSearch/backport-2.x 2.x
# Navigate to the new working tree
pushd ../.worktrees/OpenSearch/backport-2.x
# Create a new branch
git switch --create backport/backport-12441-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 b15cb0c52be59ceaad16f2f47b3af3018a563211
# Push it to GitHub
git push --set-upstream origin backport/backport-12441-to-2.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/OpenSearch/backport-2.x

Then, create a pull request where the base branch is 2.x and the compare/head branch is backport/backport-12441-to-2.x.