[ConfigNode] Fix RegionGroup creation race with database deletion

[CRZbulabula]

Description

CreateRegionGroupsProcedure could race with DeleteDatabaseProcedure. If the database partition table had already been removed when a replicated CreateRegionGroupsPlan was applied, PartitionInfo#createRegionGroups treated the database as not pre-deleted and dereferenced a missing DatabasePartitionTable, causing an NPE in the ConfigRegion state machine.

Simply skipping a missing database is unsafe because Region replicas may already have been created on DataNodes, and a delayed plan could be applied to a later database that reuses the same name.

This PR:

• adds a monotonically increasing lifecycle generation for each database incarnation and records it in RegionGroup allocation plans, procedure state, and PartitionInfo snapshots;
• validates the complete CreateRegionGroupsPlan batch before mutation and returns explicit statuses for missing, pre-deleted, or generation-mismatched databases;
• serializes CreateRegionGroupsProcedure and DeleteDatabaseProcedure against each other with database-level lifecycle locks, including atomic lock acquisition for multi-database plans;
• submits independent RemoveRegionGroupProcedure compensation for replicas that were created on DataNodes when RegionGroup persistence is rejected;
• advances the RegionGroup ID high-water mark even for rejected replicated plans; and
• keeps snapshot and procedure deserialization compatible with data written before lifecycle generations were introduced.

Tests

The added tests cover:

• pre-deleted and fully removed databases;
• rejection of a stale plan after same-name database recreation;
• atomic validation of batched plans;
• RegionGroup ID advancement on rejected plans;
• snapshot, plan, and procedure serialization across recovery/leader changes;
• mutual exclusion between RegionGroup creation and database deletion; and
• compensation that removes only replicas successfully created on DataNodes.

Validation performed:

mvn spotless:apply -pl iotdb-core/confignode
mvn test -pl iotdb-core/confignode -Dtest=PartitionInfoTest,CreateRegionGroupsProcedureTest,ConfigPhysicalPlanSerDeTest
mvn compile -pl iotdb-core/confignode -DskipTests
mvn test-compile -DskipTests
mvn test-compile -P with-zh-locale -DskipTests

The targeted test run completed with 121 tests and no failures. Both full-reactor locale builds completed successfully.

This PR has:

• been self-reviewed.
  • concurrent write
• added comments explaining non-obvious concurrency and recovery behavior.
• added or updated unit tests for the new code paths.
• added integration tests.
• been tested in a test IoTDB cluster.

Key changed/added classes

• PartitionInfo
• DatabasePartitionTable
• CreateRegionGroupsPlan
• CreateRegionGroupsProcedure
• DeleteDatabaseProcedure
• AbstractDatabaseProcedure

[Copilot]

Pull request overview

This PR hardens ConfigNode RegionGroup allocation against races with database deletion by introducing a per-database lifecycle generation fence, validating CreateRegionGroupsPlan batches before mutation, and serializing lifecycle-changing procedures with database-scoped locks. It also adds compensation procedures to clean up Region replicas created on DataNodes when persistence is rejected, and extends snapshot/procedure/plan serialization to remain compatible with pre-generation data.

Changes:

• Introduce database lifecycle generations and propagate them through allocation plans, persistence validation, and PartitionInfo snapshots.
• Add database-level lifecycle locks (including atomic multi-database acquisition) to serialize CreateRegionGroupsProcedure and DeleteDatabaseProcedure.
• Add targeted unit tests for rejection/compensation, atomic validation, ID advancement on rejected plans, and serialization compatibility.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
iotdb-core/confignode/src/test/java/org/apache/iotdb/confignode/procedure/impl/CreateRegionGroupsProcedureTest.java	Adds tests for persist rejection cleanup and mutual exclusion between create/delete database lifecycle locks.
iotdb-core/confignode/src/test/java/org/apache/iotdb/confignode/persistence/PartitionInfoTest.java	Adds tests for pre-deleted/missing database rejection, stale plan fencing after recreation, atomic batch validation, and region ID advancement.
iotdb-core/confignode/src/test/java/org/apache/iotdb/confignode/consensus/request/ConfigPhysicalPlanSerDeTest.java	Adds SerDe coverage for CreateRegionGroupsPlan generation map and updates procedure SerDe expectations.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/procedure/scheduler/LockQueue.java	Adds isIdle() to support removing unused per-database lock queues.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/procedure/impl/schema/DeleteDatabaseProcedure.java	Moves to AbstractDatabaseProcedure and declares database name(s) for lifecycle locking.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/procedure/impl/region/CreateRegionGroupsProcedure.java	Adds pre-validation, persists generation metadata, and submits cleanup procedures on persistence rejection.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/procedure/impl/AbstractDatabaseProcedure.java	New base procedure that holds exclusive lifecycle locks for its database set until completion.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/procedure/env/ConfigNodeProcedureEnv.java	Adds per-database lock map and atomic multi-lock acquisition/release APIs; exposes plan validation.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/persistence/partition/PartitionInfo.java	Adds generation tracking, plan validation, snapshot format changes, and advances region group ID high-water mark on rejected plans.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/persistence/partition/DatabasePartitionTable.java	Stores immutable database generation and includes it in equality/hash.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/manager/partition/PartitionManager.java	Exposes generation and plan validation to higher-level components.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/manager/load/balancer/RegionBalancer.java	Records current database generation into allocation plans.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/consensus/request/write/region/CreateRegionGroupsPlan.java	Adds generation map + SerDe support with backward compatibility.
iotdb-core/confignode/src/main/i18n/zh/org/apache/iotdb/confignode/i18n/ConfigNodeMessages.java	Adds localized log/message constants for CreateRegionGroupsPlan rejection reasons.
iotdb-core/confignode/src/main/i18n/en/org/apache/iotdb/confignode/i18n/ConfigNodeMessages.java	Adds localized log/message constants for CreateRegionGroupsPlan rejection reasons.

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