[IGNITE-11349] MVCC: Deadlock in query pool when executing DML over caches with queryParallism > 1

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Component/s: mvcc, sql
• Labels: mvcc_stability
• Assignee: Unassigned
• Reporter: Roman Kondakov
• Created: 18/Feb/19 19:24
• Updated: 25/Aug/23 08:28
• Resolved: 25/Aug/23 08:28

Description

Reproducer: CacheMvccSelectForUpdateQueryBasicTest

There is possible deadlock in QUERY_POOL when running massive SQL updates using queries without reducer when cache.queryParallelism > 1. These updates fire two step queries on each data node and both map and reduce phases are executed in the same QUERY_POOL which can lead to deadlock because reduce phase has blocking operation GridReduceQueryExecutor#awaitAllReplies.

Issue Links

• is related to: IGNITE-8596 SQL: remove unnecessary index lookups when query parallelism is enabled