Disallow snapshot deletion while a v2 snapshot is in progress

[gbbafna]

Description

Earlier we were accepting deletes while a create/clone v2 operation was going on . Post create/clone, we did a runNextQueuedOperation to run the queued operation . However , runNextQueuedOperation creates a pending task of NORMAL priority . In cases where pending tasks are high , this will starve. Meanwhile , the new create/clone v2 snapshots also can't start as it won't get the repo lock .

To solve for this, we are not accepting deletes when a create/clone v2 operation is going on and have now removed the runNextQueuedOperation.

% curl localhost:9200/_cat/pending_tasks
374716  3.7s HIGH   cluster_reroute(reroute after balanced shards allocator timed out)
374646 24.1m NORMAL Run ready deletions

Check List

• Functionality includes testing.
• API changes companion pull request created, if applicable.
• Public documentation issue/PR created, if applicable.

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 2907d52: 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 00bbd7e: SUCCESS

[codecov]

Codecov Report

Attention: Patch coverage is 63.63636% with 4 lines in your changes missing coverage. Please review.

Project coverage is 71.97%. Comparing base (1982427) to head (00bbd7e).
Report is 8 commits behind head on main.

Files with missing lines	Patch %	Lines
...ava/org/opensearch/snapshots/SnapshotsService.java	63.63%	3 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #16430      +/-   ##
============================================
- Coverage     72.11%   71.97%   -0.15%     
+ Complexity    65044    64973      -71     
============================================
  Files          5313     5313              
  Lines        303287   303296       +9     
  Branches      43883    43884       +1     
============================================
- Hits         218729   218300     -429     
- Misses        66593    67080     +487     
+ Partials      17965    17916      -49     

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

[sachinpkale]

Changes are covered as part of integ tests, bypassing CodeCov