How to identify the Master Node in RAC

How to identify the Master Node in RAC
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In RAC only Masternode is responsible for take backup of OCR.

[grid@rac1 bin]$ ./oclumon manage -get MASTER

Master = rac1
[grid@rac1 bin]$


[root@rac1 bin]# ./ocrconfig -manualbackup

rac2     2019/02/02 22:49:23     +DATA:/rac/OCRBACKUP/backup_20190202_224923.ocr.327.999211765     70732493
[root@rac1 bin]#

[root@rac1 bin]# ./ocrconfig -showbackup

rac2     2018/12/12 20:09:04     +DATA:/rac/OCRBACKUP/backup00.ocr.283.994709331     70732493

rac2     2018/12/12 20:09:04     +DATA:/rac/OCRBACKUP/day.ocr.284.994709345     70732493

rac2     2018/12/12 20:09:04     +DATA:/rac/OCRBACKUP/week.ocr.285.994709347     70732493

rac2     2019/02/02 22:49:23     +DATA:/rac/OCRBACKUP/backup_20190202_224923.ocr.327.999211765     70732493
[root@rac1 bin]#
[root@rac1 bin]# ./ocrconfig -showbackup auto

rac2     2018/12/12 20:09:04     +DATA:/rac/OCRBACKUP/backup00.ocr.283.994709331     70732493

rac2     2018/12/12 20:09:04     +DATA:/rac/OCRBACKUP/day.ocr.284.994709345     70732493

rac2     2018/12/12 20:09:04     +DATA:/rac/OCRBACKUP/week.ocr.285.994709347     70732493
[root@rac1 bin]#
[root@rac1 bin]# ./ocrconfig -showbackup manual

rac2     2019/02/02 22:49:23     +DATA:/rac/OCRBACKUP/backup_20190202_224923.ocr.327.999211765     70732493
[root@rac1 bin]#



[grid@rac1 trace]$ cat ocssd.trc |grep 'master node'
2019-01-21 12:39:42.772 :    CSSD:2787034880: clssgmCMReconfig: GM master node for incarnation 443540379 is node rac1, number 1, with birth incarnation 443540379, the old master is 65535 and new master is 1
2019-01-21 12:39:42.976 :    CSSD:2787034880: clssgmCMReconfig: reconfiguration successful, incarnation 443540379 with 2 nodes, local node number 1, master node rac1, number 1
2019-01-21 12:39:49.250 :    CSSD:2788611840: clssgmCMReconfig: GM master node for incarnation 443540380 is node rac1, number 1, with birth incarnation 443540379, the old master is 1 and new master is 1
2019-01-21 12:39:49.255 :    CSSD:2788611840: clssgmCMReconfig: reconfiguration successful, incarnation 443540380 with 1 nodes, local node number 1, master node rac1, number 1
2019-01-21 12:48:05.570 :    CSSD:832739072: clssgmCMReconfig: GM master node for incarnation 443540883 is node rac1, number 1, with birth incarnation 443540883, the old master is 65535 and new master is 1
2019-01-21 12:48:05.571 :    CSSD:832739072: clssgmCMReconfig: reconfiguration successful, incarnation 443540883 with 1 nodes, local node number 1, master node rac1, number 1
2019-01-21 13:13:57.075 :    CSSD:834316032: clssgmCMReconfig: GM master node for incarnation 443540884 is node rac1, number 1, with birth incarnation 443540883, the old master is 1 and new master is 1
2019-01-21 13:13:59.038 :    CSSD:834316032: clssgmCMReconfig: reconfiguration successful, incarnation 443540884 with 2 nodes, local node number 1, master node rac1, number 1
2019-01-22 23:46:52.347 :    CSSD:2292303616: clssgmCMReconfig: GM master node for incarnation 443666809 is node rac1, number 1, with birth incarnation 443666809, the old master is 65535 and new master is 1
2019-01-22 23:46:52.350 :    CSSD:2292303616: clssgmCMReconfig: reconfiguration successful, incarnation 443666809 with 1 nodes, local node number 1, master node rac1, number 1
2019-02-02 21:20:12.712 :    CSSD:4233729792: clssgmCMReconfig: GM master node for incarnation 444608391 is node <null>, number 2, with birth incarnation 444608390, the old master is 65535 and new master is 2
2019-02-02 21:20:13.044 :    CSSD:4233729792: clssgmCMReconfig: reconfiguration successful, incarnation 444608391 with 2 nodes, local node number 1, master node rac2, number 2
[grid@rac1 trace]$



[grid@rac1 trace]$ cat crsd.trc |grep 'master'
2019-02-02 21:21:34.370 :  OCRMAS:1811937024: th_master_check_hashids_helper: Comparing device hash IDs between local and master.
2019-02-02 21:21:34.370 :  OCRMAS:1811937024: th_master_check_hashids_helper: Local dev (987031272, 1028247821, 0, 0, 0)
2019-02-02 21:21:34.370 :  OCRMAS:1811937024: th_master_check_hashids_helper: Master dev (987031272, 1028247821, 0, 0, 0)
2019-02-02 21:21:34.370 :  OCRMAS:1811937024: th_connect_master: Using GIPC type to connect
2019-02-02 21:21:34.370 :  OCRMAS:1811937024: th_connect_master:10: Master host name [rac2]
2019-02-02 21:21:34.370 :  OCRMAS:1811937024: proath_connect_master: Attempting to connect to master at address [rac2:1494-d8b5-fb40-8a6a]
2019-02-02 21:21:34.826 :  OCRMAS:1811937024: proath_master: SUCCESSFULLY CONNECTED TO THE MASTER
2019-02-02 21:21:34.826 :  OCRMAS:1811937024: th_master: NEW OCR MASTER IS 2
2019-02-02 21:21:34.829 :  OCRSRV:2758700032: th_reg_master_change: Master change callback registered. Client:[1]
2019-02-02 21:21:34.829 :  OCRSRV:2758700032: th_reg_master_change: Notified master change
2019-02-02 21:21:34.829 :  OCRAPI:2758700032: a_reg_master_change: Registered master change callback. flags:[4]
2019-02-02 21:21:34.842 : CRSMAIN:2758700032:  Registering for mastership change events...
2019-02-02 21:21:34.842 :  OCRSRV:2758700032: th_reg_master_change: Master change callback registered. Client:[0]
2019-02-02 21:21:34.842 :  OCRSRV:2758700032: th_reg_master_change: Notified master change
2019-02-02 21:21:34.843 :  OCRAPI:2758700032: a_reg_master_change: Registered master change callback. flags:[2]
2019-02-02 21:24:24.651 :UiServer:1595901696: {1:60436:2} Master change notification has received. New master: 2
[grid@rac1 trace]$
[grid@rac1 trace]$

[grid@rac1 trace]$ pwd
/u01/app/grid/product/18.0.0.0/grid_base/diag/crs/rac1/crs/trace
[grid@rac1 trace]$