Galera hangs on Freeing items

[Ákos Kóczán]

Hi All, I have a mariadb 10.4.18 galera cluster with 5 node. Randomly on one node hangs a request with "Freeing items" state and "Busy" command. It stops all the write queries on all nodes forever. I have to kill mariadb on the hanging node, because I can't stop it normal way. After kill, other nodes start working correctly. After restart full SST required. Error log is empty.

Process list:

----------------------------------------------------------

ID: 19717900

USER: xxx

HOST: xxx:44464

DB:

COMMAND: Busy

TIME: 28

STATE: Freeing items

INFO:

TIME_MS: 28497.852

STAGE: 0

MAX_STAGE: 0

PROGRESS: 0.000

MEMORY_USED: 82232

MAX_MEMORY_USED: 178320

EXAMINED_ROWS: 1

QUERY_ID: 1328408265

INFO_BINARY:

TID: 36964

----------------------------------------------------------

ID: 23

USER: system user

HOST:

DB:

COMMAND: Busy

TIME: 28

STATE: committing

INFO:

TIME_MS: 28496.583

STAGE: 0

MAX_STAGE: 0

PROGRESS: 0.000

MEMORY_USED: 65136

MAX_MEMORY_USED: 81584

EXAMINED_ROWS: 0

QUERY_ID: 1328408270

INFO_BINARY:

TID: 12877

----------------------------------------------------------

Please help.