When HADR standby database is activated, it would clean up old
log files in the active log path before performing its normal
logic. This cleanup step is executed synchronously, so when
there is a large number of old log files to cleanup, it could
cause delay to other operations, including executing a TAKEOVER
command.
The following db2diag.log messages shows an example of this
condition, where it took more than 15 minutes from the
activation of the standby database to complete the deletion of
about 4000 old log files in active log path. This has caused a
delay of more than 6 minutes to execute the TAKEOVER command.
2022-03-30-18.14.56.051378+000 I670027603E504 LEVEL: Info
PID : 2886 TID : 140030647461632 PROC : db2sysc 0
INSTANCE: db2inst1 NODE : 000 DB : MYDB1
APPHDL : 0-14 APPID: *LOCAL.db2inst1.220330181455
AUTHID : DB2INST1 HOSTNAME: myhost1
EDUID : 27 EDUNAME: db2agent (idle) 0
FUNCTION: DB2 UDB, High Availability Disaster Recovery,
hdrEduStartup, probe:21152
MESSAGE : HADR Startup has completed.
2022-03-30-18.15.06.348766+000 I670248052E468 LEVEL: Info
PID : 2886 TID : 140026394437376 PROC : db2sysc 0
INSTANCE: db2inst1 NODE : 000 DB : MYDB1
HOSTNAME: myhost1
EDUID : 105 EDUNAME: db2logalloc.0 (MYDB1) 0
FUNCTION: DB2 UDB, data protection services,
sqlpLogAllocCandidatePool::removeExtraCandidates, probe:10100
DATA #1 :
Delete log extent 4900 from log stream 0.
2022-03-30-18.25.23.176613+000 E675782854E510 LEVEL: Event
PID : 2886 TID : 140030647461632 PROC : db2sysc 0
INSTANCE: db2inst1 NODE : 000 DB : MYDB1
APPHDL : 0-59 APPID: *LOCAL.db2inst1.220330182523
AUTHID : DB2INST1 HOSTNAME: myhost1
EDUID : 27 EDUNAME: db2agent (MYDB1) 0
FUNCTION: DB2 UDB, base sys utilities,
sqeDBMgr::StartUsingLocalDatabase, probe:13
START : Received TAKEOVER HADR command.
2022-03-30-18.31.18.192759+000 I679477958E468 LEVEL: Info
PID : 2886 TID : 140026394437376 PROC : db2sysc 0
INSTANCE: db2inst1 NODE : 000 DB : MYDB1
HOSTNAME: myhost1
EDUID : 105 EDUNAME: db2logalloc.0 (MYDB1) 0
FUNCTION: DB2 UDB, data protection services,
sqlpLogAllocCandidatePool::removeExtraCandidates, probe:10100
DATA #1 :
Delete log extent 8900 from log stream 0.
2022-03-30-18.31.22.944506+000 I679520714E462 LEVEL: Info
PID : 2886 TID : 140026356688640 PROC : db2sysc 0
INSTANCE: db2inst1 NODE : 000 DB : MYDB1
HOSTNAME: myhost1
EDUID : 114 EDUNAME: db2hadrs.0.0 (MYDB1) 0
FUNCTION: DB2 UDB, High Availability Disaster Recovery,
hdrStbyTkHandleInitialRequest, probe:46000
MESSAGE : Standby has initiated a takeover by force peer window
only.
2022-03-30-18.32.00.954001+000 I679884085E443 LEVEL: Info
PID : 2886 TID : 140026356688640 PROC : db2sysc 0
INSTANCE: db2inst1 NODE : 000 DB : MYDB1
HOSTNAME: myhost1
EDUID : 114 EDUNAME: db2hadrp.0.1 (MYDB1) 0
FUNCTION: DB2 UDB, High Availability Disaster Recovery,
hdrStbyTkHandleDoneDrain, probe:46840
MESSAGE : Standby has completed takeover (now primary). |
