WPs hang when frequently checking Preconditions

Document ID : KB000115754
Last Modified Date : 25/09/2018
Show Technical Document Details
Issue:
When checking Preconditions with short intervals WPs can freeze and cause a deadlock.

Message comparable to the below appear in the WP logs:
20180622/184150.246 - U00029108 UCUDB: SQL_ERROR    Database handles  DB-HENV: c38b80  DB-HDBC: cae9b8
20180622/184150.246 - U00003591 UCUDB - DB error info: OPC: 'OCIStmtExecute' Return code: 'ERROR'
20180622/184150.246 - U00003592 UCUDB - Status: '' Native error: '22922' Msg: 'ORA-22922: nonexistent LOB value'
20180622/184150.246 - U00003536 UCUDB: FATAL DATA BASE ERROR: Re-connection will be attempted in 10 seconds.
20180622/184150.415 - U00003538 UCUDB: Re-connection to database successful. Processing will continue.
20180622/184153.416 - U00000006 DEADLOCK
20180622/184153.416 - U00003594 UCUDB Ret: '6' opcode: 'INSR' SQL Stmnt: 'INSERT INTO ABLOB (ABLOB_AH_Idnr, ABLOB_Key, ABLOB_Content, ABLOB_OH_Idnr, ABLOB_Name, ABLOB_ModCnt, ABLOB_Type, ABLOB_ModDate, ABLOB_ReplaceVar, ABLOB_Version) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)'
20180622/184153.416 - U00003524 UCUDB: ===> Time critical DB call!       OPC: 'INSR' time: '4:291.375.000'
20180622/184153.416 - U00029131 UCUDB - List of bind parameters:
20180622/184153.416 - U00029132 UCUDB: 'ABLOB_AH_Idnr      = <IDnr>'
20180622/184153.416 - U00029132 UCUDB: 'ABLOB_Key          = VAR2T'
20180622/184153.416 - U00029132 UCUDB: 'ABLOB_OH_Idnr      = 0'
20180622/184153.416 - U00029132 UCUDB: 'ABLOB_Name         = VAR2T'
20180622/184153.416 - U00003525 UCUDB: ===> 'INSERT INTO ABLOB (ABLOB_AH_Idnr, ABLOB_Key, ABLOB_Content, ABLOB_OH_Idnr, ABLOB_Name, ABLOB_ModCnt, ABLOB_Type, ABLOB_ModDate, ABLOB_ReplaceVar, ABLOB_Version) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)'
20180622/184153.422 - U00000006 DEADLOCK

The WPs do not appear to be using a high percentage of CPU time.
There are no blocking sessions for the AE user in Oracle.
Resolution:
The workaround is to restart the WPs.
 

Solution:

Update to a fix version listed below or a newer version if available.

 

Fix version:

Component(s): Automation.Engine

 Automation.Engine 12.2.0 - Available
 Automation.Engine 11.2.8 - Available 
 Automation.Engine 12.1.3 - Available
 Automation.Engine 12.0.6 - Available