To check the master node in RAC environment


In 3 node  RAC setup,In initial stage–node 3 is the
master node.
[oracle@host01 ~]$ cat
$ORACLE_HOME/log/
host01/cssd/ocssd.log
|grep ‘master node’ |tail -1
2016-09-24 10:14:36.949:
[    CSSD][2778696592]clssgmCMReconfig: reconfiguration
successful, incarnation 248954981 with 3 nodes, local node number 1, master
node number 3
[root@host02 cssd]# cat
$ORACLE_HOME/log/
host02/cssd/ocssd.log
|grep ‘master node’ |tail -1
2016-09-24 10:14:36.953:
[    CSSD][778696592]clssgmCMReconfig: reconfiguration
successful, incarnation 248954981 with 3 nodes, local node number 2, master
node number 3
[root@host03 ~]# cat
$ORACLE_HOME/log/
host03/cssd/ocssd.log
|grep ‘master node’ |tail -1
2016-09-24 10:14:37.001:
[    CSSD][778700688]clssgmCMReconfig: reconfiguration
successful, incarnation 248954981 with 3 nodes, local node number 3
, master node number 3
If I take the OCR backup
right now, it will be taken by node3 (master node).
 [root@host02
cssd]# 
ocrconfig -manualbackup
HOST3

2016/09/24 09:54:48    /u01/app/11.2.0/oracle/cdata/cluster01/backup_095448.ocr

Let us check crsd logs of various nodes, looking for the string OCR
MASTER.Note that node3 is the master node presently.
[oracle@host01 crsd]$ cat
/u01/app/11.2.0/oracle/log/
host01/crsd/crsd.log
|grep ‘OCR MASTER’ | tail -1
2016-09-24 10:15:01.403: [  OCRMAS][2877356944]th_master: NEW
OCR MASTER IS 3
[root@host02 crsd]# cat
/u01/app/11.2.0/oracle/log/host02/crsd/crsd.log |grep ‘OCR MASTER’ | tail -1
2016-09-24 10:15:03.561: [  OCRMAS][876976016]th_master: NEW
OCR MASTER IS 3
[root@host03 crsd]#  cat
/u01/app/11.2.0/oracle/log/host03/crsd/crsd.log |grep ‘OCR MASTER’ | tail -3
2016/09/24 10:11:18.499: [  OCRMAS][877467536]th_master:13I AM THE NEW OCR
MASTER 
at incar 44. Node Number 3
Let me reboot node3 and check which
node is assigned the master node now.
[root@host03 ~]# init 6
check the ocssd logs on the remaining
two nodes (node1 and node2) for the string ‘master node’
 and note that
node 1 is the master node.

[oracle@host01 root]$ cat
$ORACLE_HOME/log/
host01/cssd/ocssd.log |grep
‘master node’ |tail -1
2016/09/24 10:09:23.522:
[    CSSD][2778696592]clssgmCMReconfig: reconfiguration
successful, incarnation 248954982 with 2 nodes, local node number 1, master
node number 1
[root@host02 cssd]# cat
$ORACLE_HOME/log/
host02/cssd/ocssd.log
|grep ‘master node’ |tail -1
2016/09/24 10:09:23.502:
[    CSSD][778696592]clssgmCMReconfig: reconfiguration
successful, incarnation 248954982 with 2 nodes, local node number 2
master node number 1
As can be seen from ocssd logs of the
remaining two nodes, node1 has become the master now.
Now If I take the OCR
backup, 
it is taken by node1 while earlier backups were taken by node3 which was
the then master.

[root@host02 cssd]# ocrconfig -showbackup

host03   2016/09/24 09:54:48    /u01/app/11.2.0/oracle/cdata/cluster01/backup_095448.ocr
[root@host02 cssd]# ocrconfig
-manualbackup
host01  2016/09/24 10:12:29  /u01/app/11.2.0/oracle/cdata/cluster01/backup_101229.ocr 

host03   2016/09/24
09:54:48 /u01/app/11.2.0/oracle/cdata/cluster01/backup_095448.ocr
Let us check crsd logs of
various nodes, looking for the string OCR MASTER
[oracle@host01 crsd]$ cat
/u01/app/11.2.0/oracle/log/
host01/crsd/crsd.log
|grep ‘OCR MASTER’ | tail -1

2016-09-24 10:08:45.884: [  OCRMAS][877356944]th_master:13:  NEW OCR MASTER IS 1
[root@host02 crsd]# cat
/u01/app/11.2.0/oracle/log/
host02/crsd/crsd.log
|grep ‘OCR MASTER’ | tail -1
2016-09-24 10:08:45.364: [  OCRMAS][876976016]th_master: NEW
OCR MASTER IS 1
[root@host03 crsd]#  cat
/u01/app/11.2.0/oracle/log/
host03/crsd/crsd.log
|grep ‘OCR MASTER’ | tail -1
2016-09-24 10:12:20.282: [  OCRMAS][877422480]th_master: NEW
OCR MASTER IS 1

  • October 3, 2016 | 11 views