Handler command and concurrent DDL can cause node hanging
|MySQL patches by Codership||Status tracked in 5.6|
|Percona XtraDB Cluster||Status tracked in Trunk|
Table handler session can enter into unresolved MDL lock wait with a replicated DDL statement.
The problem happens when a handler session is aborted due to replication conflict. The wsrep abort handler does not release exclusive MDL lock, which remains effective for following sessions. If the connection issues DDL statement as next step, there can be MDL conflict between this DDL and some other replicated DDL.
To reproduce, start two nodes and run two sessions of randgen handler.yy tests against separate nodes.
|Changed in codership-mysql:|
|status:||New → In Progress|
|importance:||Undecided → Low|
|assignee:||nobody → Seppo Jaakola (seppo-jaakola)|
|milestone:||none → 5.5.34-24.9|
|no longer affects:||codership-mysql/5.5|