Fix memory leak issue in ReorganizingLongHash

[neetikasinghal]

Description

I am able to figure out the root-cause of the memory leak happening.

During the execution of the index search in the test, GlobalOrdinalsStringTermsAggregator is initialized that has an initialization of a collection strategy in its constructor.

The collection strategy initialization flow is as follows:

new RemapGlobalOrds() -> LongKeyedBucketOrds.build() -> new FromSingle(bigArrays) -> new ReorganizingLongHash(bigArrays) -> ReorganizingLongHash constructor

In the ReorganizingLongHash's constructor, there are two big arrays initialized whose memory is accounted by the Circuit Breaker here.

In the happy case scenario, the GlobalOrdinalsStringTermsAggregator is initialized which initializes the collectionStrategy and the arrays in ReorganizingLongHash's constructor are accounted by the CircuitBreaker. When a CircuitBreakingException is hit on any other code flow, the SearchContext.close() is called which further calls close on GlobalOrdinalsStringTermsAggregator and since the collectionStrategy is not null, close is called on ReorganizingLongHash's arrays as well, accounted by the CircuitBreaker and hence there is no memory leak.
However, when the CircuitBreakingException happens during the initialization of the keys array in ReorganizingLongHash's constructor, then the collection strategy is null and hence the ReorganizingLongHash's close is not called which leads to tables array in ReorganizingLongHash's constructor not getting closed, not accounted by the CircuitBreaker and hence leading to memory leak.

In order to deal with this, close needs to be explicitly called in ReorganizingLongHash's constructor when an exception is encountered. This is done as part of the PR #11953

Related Issues

Resolves #10154

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.
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[github-actions]

Compatibility status:

Checks if related components are compatible with change 8d49908

Incompatible components

Incompatible components: [https://github.com/opensearch-project/observability.git, https://github.com/opensearch-project/custom-codecs.git, https://github.com/opensearch-project/cross-cluster-replication.git, https://github.com/opensearch-project/asynchronous-search.git, https://github.com/opensearch-project/reporting.git, https://github.com/opensearch-project/sql.git, https://github.com/opensearch-project/performance-analyzer.git, https://github.com/opensearch-project/performance-analyzer-rca.git]

Skipped components

Compatible components

Compatible components: [https://github.com/opensearch-project/security-analytics.git, https://github.com/opensearch-project/geospatial.git, https://github.com/opensearch-project/notifications.git, https://github.com/opensearch-project/opensearch-oci-object-storage.git, https://github.com/opensearch-project/job-scheduler.git, https://github.com/opensearch-project/neural-search.git, https://github.com/opensearch-project/security.git, https://github.com/opensearch-project/ml-commons.git, https://github.com/opensearch-project/common-utils.git, https://github.com/opensearch-project/anomaly-detection.git, https://github.com/opensearch-project/k-nn.git, https://github.com/opensearch-project/index-management.git, https://github.com/opensearch-project/alerting.git]

[github-actions]

❌ Gradle check result for bb99414: 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 8d49908: 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 780b2d2: 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?

[neetikasinghal]

❌ Gradle check result for 780b2d2: 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?

#10006 - flaky
#11849 - flaky

[deshsidd]

Good catch!

[github-actions]

✅ Gradle check result for 8d49908: SUCCESS

[codecov]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (e265355) 71.41% compared to head (8d49908) 71.45%.

Files	Patch %	Lines
...g/opensearch/common/util/ReorganizingLongHash.java	60.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #11953      +/-   ##
============================================
+ Coverage     71.41%   71.45%   +0.03%     
+ Complexity    59397    59388       -9     
============================================
  Files          4923     4923              
  Lines        279212   279214       +2     
  Branches      40595    40596       +1     
============================================
+ Hits         199408   199515     +107     
+ Misses        63223    63111     -112     
- Partials      16581    16588       +7     

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[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-11953-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 84f303b6069893cf9350556a4c316153ba526901
# Push it to GitHub
git push --set-upstream origin backport/backport-11953-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-11953-to-2.x.

[reta]

@neetikasinghal could you please backport to 2.x manually? thank you