SwapAction = restartSystem Issue

[Conf]
CPU : 14 Core (Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz)
Memory : 28Gbytes
Disk : External Storage (/usr/local/mariadb/columnstore/data1)
CentOS release 6.9 (Final)
SoftwareVersion = 1.1.4 , combined single node
SoftwareRelease = 1

TotalUmMemory : 25
TotalPmUmMemory :10
NumBlocksPct :50
<SwapAction>restartSystem</SwapAction>

max_length_for_sort_data : 2048
innodb_buffer_pool_size = 128M

[Question]
After setting SwapAction to restartSystem and executing SELECT SQL, the following log is recorded in info.log
All ssh sessions and no connections. An OS hang occurs.
Please refer to the log below.

Jul 11 13:22:19 EDWPOCDB1 joblist[5359]: 19.142655 |0|0|0| I 05 CAL0000: IDB-2052: Out of UM memory, switching to disk-based join.
Jul 11 13:22:19 EDWPOCDB1 joblist[5359]: 19.163140 |0|0|0| I 05 CAL0000: IDB-2052: Out of UM memory, switching to disk-based join.
Jul 11 13:23:10 EDWPOCDB1 ServerMonitor[5207]: 10.425116 |0|0|0| I 09 CAL0000: Local Memory above Critical Memory threshold with a percentage of 100 ; Swap 32
Jul 11 13:23:10 EDWPOCDB1 ServerMonitor[5207]: 10.454046 |0|0|0| I 09 CAL0000: Local-Memory usage at percentage of 100 , Alarm set: 7
Jul 11 13:23:10 EDWPOCDB1 ServerMonitor[5207]: 10.780321 |0|0|0| I 09 CAL0000: Memory Usage for Process: DMLProc : Memory Used 1184 : % Used 1
Jul 11 13:23:10 EDWPOCDB1 ServerMonitor[5207]: 10.782910 |0|0|0| I 09 CAL0000: Memory Usage for Process: mysqld : Memory Used 3416 : % Used 1
Jul 11 13:23:10 EDWPOCDB1 ServerMonitor[5207]: 10.783005 |0|0|0| I 09 CAL0000: Memory Usage for Process: WriteEngineServ : Memory Used 123383 : % Used 5
Jul 11 13:23:10 EDWPOCDB1 ServerMonitor[5207]: 10.783074 |0|0|0| I 09 CAL0000: Memory Usage for Process: ExeMgr : Memory Used 1286296 : % Used 45
Jul 11 13:23:10 EDWPOCDB1 ServerMonitor[5207]: 10.783147 |0|0|0| I 09 CAL0000: Memory Usage for Process: PrimProc : Memory Used 1395679 : % Used 49
Jul 11 13:31:07 EDWPOCDB1 ServerMonitor[5207]: 07.357300 |0|0|0| I 09 CAL0000: Swap above Minor Memory threshold with a percentage of 72
Jul 11 13:31:07 EDWPOCDB1 ServerMonitor[5207]: 07.367925 |0|0|0| I 09 CAL0000: Swap usage at percentage of 72 , Alarm set: 12
Jul 11 13:31:08 EDWPOCDB1 ServerMonitor[5207]: 08.371554 |0|0|0| I 09 CAL0000: Swap above Minor Memory threshold with a percentage of 74
Jul 11 13:31:09 EDWPOCDB1 ServerMonitor[5207]: 09.375483 |0|0|0| I 09 CAL0000: Swap above Minor Memory threshold with a percentage of 74
Jul 11 13:31:10 EDWPOCDB1 ServerMonitor[5207]: 10.380719 |0|0|0| I 09 CAL0000: Swap above Minor Memory threshold with a percentage of 74
...
Jul 11 13:32:33 EDWPOCDB1 ServerMonitor[5207]: 33.180240 |0|0|0| I 09 CAL0000: Swap above Minor Memory threshold with a percentage of 78
Jul 11 13:32:34 EDWPOCDB1 ServerMonitor[5207]: 34.186631 |0|0|0| I 09 CAL0000: Swap above Major Memory threshold with a percentage of 80
Jul 11 13:32:34 EDWPOCDB1 ServerMonitor[5207]: 34.193804 |0|0|0| I 09 CAL0000: Swap usage at percentage of 80 , Alarm set: 11
Jul 11 13:32:34 EDWPOCDB1 ProcessManager[3011]: 34.296494 |0|0|0| I 17 CAL0000: MSG RECEIVED: Restart System request...
Jul 11 13:32:34 EDWPOCDB1 ProcessMonitor[2921]: 34.363129 |0|0|0| I 18 CAL0000: MSG RECEIVED: Stop All process request...
Jul 11 13:32:34 EDWPOCDB1 ProcessMonitor[2921]: 34.365556 |0|0|0| I 18 CAL0000: STOPALL: ACK back to ProcMgr, STATUS_UPDATE only performed

ref) If SwapAction is set to none, only ExeMgr is restarted and the columnstore is normalized.