Disable concurrent segment search for system indices and throttled search requests

[jed326]

Description

From the problem described in #12951, we need to maintain the threadpool isolation for system_read and search_throttled search requests. The threadpool used is decided here:

OpenSearch/server/src/main/java/org/opensearch/search/SearchService.java

Lines 717 to 728 in 52b27f4

	private Executor getExecutor(IndexShard indexShard) {
	assert indexShard != null;
	final String executorName;
	if (indexShard.isSystem()) {
	executorName = Names.SYSTEM_READ;
	} else if (indexShard.indexSettings().isSearchThrottled()) {
	executorName = Names.SEARCH_THROTTLED;
	} else {
	executorName = Names.SEARCH;
	}
	return threadPool.executor(executorName);
	}

This PR disables concurrent segment search when either system indices or throttled indices are present using the same logic as above.

Related Issues

Resolves #12951

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 1ddef54: 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 60fb88e

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/cross-cluster-replication.git, https://github.com/opensearch-project/flow-framework.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/geospatial.git, https://github.com/opensearch-project/opensearch-oci-object-storage.git, https://github.com/opensearch-project/common-utils.git, https://github.com/opensearch-project/k-nn.git, https://github.com/opensearch-project/neural-search.git, https://github.com/opensearch-project/anomaly-detection.git, https://github.com/opensearch-project/security-analytics.git, https://github.com/opensearch-project/performance-analyzer.git, https://github.com/opensearch-project/ml-commons.git, https://github.com/opensearch-project/notifications.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 b48efe9: 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 68450d8: SUCCESS

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 71.32%. Comparing base (b15cb0c) to head (68450d8).
Report is 105 commits behind head on main.

❗ Current head 68450d8 differs from pull request most recent head 60fb88e. Consider uploading reports for the commit 60fb88e to get more accurate results

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #12954      +/-   ##
============================================
- Coverage     71.42%   71.32%   -0.10%     
- Complexity    59978    60266     +288     
============================================
  Files          4985     5017      +32     
  Lines        282275   284021    +1746     
  Branches      40946    41147     +201     
============================================
+ Hits         201603   202586     +983     
- Misses        63999    64633     +634     
- Partials      16673    16802     +129     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[github-actions]

✅ Gradle check result for 60fb88e: 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-12954-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 eba3b572a2ed778ac62cce661a894c7f561ecd48
# Push it to GitHub
git push --set-upstream origin backport/backport-12954-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-12954-to-2.x.