Fixes #3192 Fix global DEFAULT quota leak when releasing tasks with an undefined …

[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

• The following is the result of the "mvn test" command on the appropriate module:

<paste the output of: mvn -pl helix-core test -Dtest=TestAssignableInstanceManagerQuotaRelease>

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.