[PrithMDP]

Issues

• My PR addresses the following Helix issues and references them in the PR description:

Fixes #3192

Description

• Here are some details about my PR, including screenshots of any UI changes:

AssignableInstanceManager.release() only returned quota to _globalThreadBasedQuotaMap when the raw quota type was configured. For a task whose job type is not in the quota config, tryAssign() schedules it as DEFAULT, so assign() decrements the global DEFAULT quota. On release, the raw (undefined) type was not in the map, so nothing was added back. Each such task permanently leaked 1 from global DEFAULT. Eventually hasGlobalCapacity("DEFAULT") returned false, blocking scheduling of DEFAULT and unknown-type jobs until global capacity was recomputed (instance/config change or controller restart).

Fix: release() now treats a null or unconfigured quota type as DEFAULT, mirroring tryAssign(). Per-instance usage in AssignableInstance was already symmetric and is unchanged.

Tests

• The following tests are written for this issue:

TestAssignableInstanceManagerQuotaRelease

• testReleaseUndefinedQuotaTypeRestoresGlobalDefault

• testReleaseNullQuotaTypeRestoresGlobalDefault

• testReleaseRemovedQuotaTypeDoesNotInflateDefault

• The following is the result of the "mvn test" command on the appropriate module:
  $ mvn -pl helix-core test -Dtest=TestAssignableInstanceManagerQuotaRelease
  [INFO] -------------------------------------------------------
  [INFO] T E S T S
  [INFO] -------------------------------------------------------
  [INFO] Running org.apache.helix.task.TestAssignableInstanceManagerQuotaRelease
  [INFO] Tests run: 3, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.412 s - in org.apache.helix.task.TestAssignableInstanceManagerQuotaRelease
  [INFO]
  [INFO] Results:
  [INFO]
  [INFO] Tests run: 3, Failures: 0, Errors: 0, Skipped: 0
  [INFO]
  [INFO] BUILD SUCCESS
  [INFO] Total time: 14.8 s

Changes that Break Backward Compatibility (Optional)

None.

Commits

• My commits all reference appropriate Apache Helix GitHub issues in their subject lines.

Code Quality

• My diff has been formatted using helix-style.xml

[PrithMDP]

@narendly @junkaixue can you PTAL? Please let me know if something needs adjusting.

[junkaixue]

lgtm. thanks for contributing this.

[PrithMDP]

This PR is ready to be merged

Final commit message:

Fix global DEFAULT quota leak on release (#3192)

release() returned global quota only when the raw quota type was
configured. Tasks with a null or undefined quota type are scheduled
as DEFAULT, so assign() deducted from global DEFAULT but release()
never restored it. Each such task leaked one unit until global
capacity was recomputed, eventually blocking DEFAULT scheduling.

Return the quota to the type that was actually deducted, and do not
inflate DEFAULT when a quota type was removed while its task ran.

@junkaixue