Remove Concurrent Segment Search feature flags for feature launch

[jed326]

Description

Remove concurrent segment search feature flag. Included related changes are as follows:

• Remove featureFlagSettings() override from all affected *IT.java classes
• Update the cat.shards and cat.thread_pool rest-api-spec tests. Some are still failing due to bwc and need this change to be backported.
• Change concurrent segment search cluster setting default to false.
• Change SettingsModuleTests.java related to concurrent segment search feature flag.
• Change SearchModuleTests.java related to concurrent segment search feature flag.
• Change SearchServiceTests.java related to concurrent segment search feature flag.
• Fix RestShardsActionTests.java

Related Issues

Resolves #9100

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]

❌ Gradle check result for 78e05b6: 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 2f69ad0: 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 69c742f

Incompatible components

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

[github-actions]

❌ Gradle check result for f77f40e: 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 b18ee7d: 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 802284b: 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 7e9741c: 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?

[jed326]

• we won't fail with "unknown feature flag" right?

I think this must be the case, otherwise the Mixed cluster client tests would be failing. @andrross I know you have experience with removing feature flags from searchable snapshots, do you have anything else to add here?

[andrross]

@jed326 The feature flag should be removed from the default configuration file as well: https://github.com/opensearch-project/OpenSearch/blob/main/distribution/src/config/opensearch.yml#L118-L123

[jed326]

@jed326 The feature flag should be removed from the default configuration file as well: https://github.com/opensearch-project/OpenSearch/blob/main/distribution/src/config/opensearch.yml#L118-L123

@andrross I just realized the same...already pushed a commit to remove :)

[github-actions]

❌ Gradle check result for 7c521dc: 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 a0e3b47: 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?

[jed326]

@andrross @reta created a new issue for improving feature flag management: #12150

[github-actions]

✅ Gradle check result for 69c742f: SUCCESS

[reta]

@andrross @ticheng-aws what do you think folks?

[ticheng-aws]

@andrross @ticheng-aws what do you think folks?

LGTM, thanks @jed326.

[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-12074-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 26a66f0749164f3c988ea228ac3913eb9e81e9c3
# Push it to GitHub
git push --set-upstream origin backport/backport-12074-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-12074-to-2.x.

[jed326]

Thanks @andrross! Will do the 2.x PR and main bwc PR shortly.