In today’s article we will learn to Switchover Using DGMGRL.<\/p>\n
We can also do Switchover from DGMGRL. Switchover from DGMGRL is easier. It automatically executes all the commands we run using SQL.<\/p>\n
Those that need to be closed from instances close themselves. In summary, the processing steps are much less and easier than SQL.<\/p>\n
In Oracle 12c, whether Primary and Standby Database is ready for Switchover can be done with validate commands from DGMGRL. But 11g does not have these commands, as in SQL, the controls must be done manually.<\/p>\n
If the checks are made and the result is successful, the Switchover process from DGMGRL is as follows.<\/p>\n
1. We query the status of the Broker configuration from DGMGRL.<\/p>\n
DGMGRL> show configuration\r\n\r\nConfiguration - Broker_Configuraiton\r\n\r\n Protection Mode: MaxPerformance\r\n Databases:\r\n primary - Primary database\r\n standby - Physical standby database\r\n logical - Logical standby database\r\n\r\nFast-Start Failover: DISABLED\r\n\r\nConfiguration Status:\r\nSUCCESS\r\n<\/pre>\n2.We check whether Primary and Standby Database are ready for Switchover with SQL commands.<\/p>\n
3.We perform the Switchover operation from DGMGRL.<\/p>\n
DGMGRL> switchover to 'standby';\r\nPerforming switchover NOW, please wait...\r\nOperation requires a connection to instance \"primary1\" on database \"standby\"\r\nConnecting to instance \"primary1\"...\r\nConnected.\r\nNew primary database \"standby\" is opening...\r\nOperation requires startup of instance \"primary1\" on database \"primary\"\r\nStarting instance \"primary1\"...\r\nORA-01017: invalid username\/password; logon denied\r\n\r\nWarning: You are no longer connected to ORACLE.\r\n\r\nPlease complete the following steps to finish switchover:\r\n start up instance \"primary1\" of database \"primary\"\r\n<\/pre>\nThe reason for getting this error is that a static listener must be defined so that the broker can STARTUP the database after SHUTDOWN. Since this definition could not be made exactly correctly, it could not start automatically.<\/p>\n
4. We have a New Physical Standby Database startup, which cannot start automatically due to the Static Listener not being set correctly.<\/p>\n
[Primary-1] SQL> startup;\r\nORACLE instance started.\r\n\r\nTotal System Global Area 6480490496 bytes\r\nFixed Size 2265384 bytes\r\nVariable Size 1241517784 bytes\r\nDatabase Buffers 5217714176 bytes\r\nRedo Buffers 18993152 bytes\r\nDatabase mounted.\r\nDatabase opened.\r\n<\/pre>\n5.We start the checks.<\/p>\n
a. We query the status of instances.<\/p>\n
[Physical-1] SQL> select status from gv$instance;\r\n\r\nSTATUS\r\n------------\r\nOPEN\r\nOPEN\r\n<\/pre>\n[Primary-1] SQL> select status from gv$instance;\r\n\r\nSTATUS\r\n------------\r\nOPEN\r\nOPEN\r\n<\/pre>\n[Logical-1] SQL> select status from gv$instance;\r\n\r\nSTATUS\r\n------------\r\nOPEN\r\nOPEN\r\n<\/pre>\nb. After the switchover, we question whether EskiPhysical Standby is Primary.<\/p>\n
[Physical-1] SQL> select open_mode, database_role, protection_mode from gv$database;\r\n\r\nOPEN_MODE DATABASE_ROLE PROTECTION_MODE\r\n-------------------- ---------------- --------------------\r\nREAD WRITE PRIMARY MAXIMUM PERFORMANCE\r\nREAD WRITE PRIMARY MAXIMUM PERFORMANCE\r\n<\/pre>\n[Primary-1] SQL> select open_mode, database_role, protection_mode from gv$database;\r\n\r\nOPEN_MODE DATABASE_ROLE PROTECTION_MODE\r\n-------------------- ---------------- --------------------\r\nREAD ONLY WITH APPLY PHYSICAL STANDBY MAXIMUM PERFORMANCE\r\nREAD ONLY WITH APPLY PHYSICAL STANDBY MAXIMUM PERFORMANCE\r\n<\/pre>\n[Logical-1] SQL> select open_mode, database_role, protection_mode from gv$database;\r\n\r\nOPEN_MODE DATABASE_ROLE PROTECTION_MODE\r\n-------------------- ---------------- --------------------\r\nREAD WRITE LOGICAL STANDBY MAXIMUM PERFORMANCE\r\nREAD WRITE LOGICAL STANDBY MAXIMUM PERFORMANCE\r\n<\/pre>\nc. We query whether the Redo Apply processes have started.<\/p>\n
[Primary-1] SQL> select recovery_mode from v$archive_dest_status where dest_id < 2;\r\n\r\nRECOVERY_MODE\r\n-----------------------\r\nMANAGED REAL TIME APPLY\r\n<\/pre>\n[Logical-1] SQL> select recovery_mode from v$archive_dest_status where dest_id < 2;\r\n\r\nRECOVERY_MODE\r\n-----------------------\r\nLOGICAL REAL TIME APPLY\r\n<\/pre>\n\u00e7. We check if there is Redo Transport and Apply LAG in the Standby Databases.<\/p>\n
[Primary-1] SQL> set linesize 9000\r\n[Primary-1] SQL> column name format a25\r\n[Primary-1] SQL> column value format a20\r\n[Primary-1] SQL> column time_computed format a25\r\n[Primary-1] SQL> SELECT name, value, time_computed FROM v$dataguard_stats;\r\n\r\nNAME VALUE TIME_COMPUTED\r\n------------------------- -------------------- -------------------------\r\ntransport lag +00 00:00:00 01\/28\/2017 12:37:09\r\napply lag +00 00:00:00 01\/28\/2017 12:37:09\r\napply finish time +00 00:00:00.000 01\/28\/2017 12:37:09\r\nestimated startup time 23 01\/28\/2017 12:37:09\u00f6\r\n<\/pre>\n[Logical-1] SQL> set linesize 9000\r\n[Logical-1] SQL> column name format a25\r\n[Logical-1] SQL> column value format a20\r\n[Logical-1] SQL> column time_computed format a25\r\n[Logical-1] SQL> SELECT name, value, time_computed FROM v$dataguard_stats;\r\n\r\nNAME VALUE TIME_COMPUTED\r\n------------------------- -------------------- -------------------------\r\ntransport lag +00 00:00:00 01\/28\/2017 11:54:45\r\napply lag +00 00:00:00 01\/28\/2017 11:54:45\r\napply finish time +00 00:00:00.000 01\/28\/2017 11:54:45\r\nestimated startup time 22 01\/28\/2017 11:54:45\r\n<\/pre>\nd.With this method, we also check whether the Log Switch operation is done properly and whether there are Redo and Transport LAGs afterwards.<\/p>\n
[Physical-1] SQL> select max(sequence#),thread# from v$archived_log where first_time > to_date('27\/01\/2017 13:41:50', 'DD-MM-YYYY HH24:MI:SS') group by thread#;\r\n\r\nMAX(SEQUENCE#) THREAD#\r\n-------------- ----------\r\n 40 1\r\n 41 2\r\n<\/pre>\nThe reason for adding the first_time condition to the WHERE condition in the query is because the databases eat RESETLOGS due to previous tests and therefore SEQUENCE#’s are reset.<\/p>\n
[Primary-1] SQL> select max(sequence#),thread# from v$archived_log where first_time > to_date('27\/01\/2017 13:41:50', 'DD-MM-YYYY HH24:MI:SS') group by thread#;\r\n\r\nMAX(SEQUENCE#) THREAD#\r\n-------------- ----------\r\n 40 1\r\n 41 2\r\n<\/pre>\n[Logical-1] SQL> SELECT max(sequence#),thread#,applied FROM dba_logstdby_log where first_time > to_date('27\/01\/2017 13:41:50', 'DD-MM-YYYY HH24:MI:SS') group by thread#, applied;\r\n\r\nMAX(SEQUENCE#) THREAD# APPLIED\r\n-------------- ---------- --------\r\n 40 1 YES\r\n 41 2 YES\r\n<\/pre>\n[Physical-1] SQL> alter system switch logfile;\r\n\r\nSystem altered.\r\n\r\n[Physical-1] SQL> alter system switch logfile;\r\n\r\nSystem altered.\r\n\r\n[Physical-1] SQL> select max(sequence#),thread# from v$archived_log where first_time > to_date('27\/01\/2017 13:41:50', 'DD-MM-YYYY HH24:MI:SS') group by thread#;\r\n\r\nMAX(SEQUENCE#) THREAD#\r\n-------------- ----------\r\n 42 1\r\n 42 2\r\n<\/pre>\n[Primary-1] SQL> select max(sequence#),thread# from v$archived_log where first_time > to_date('27\/01\/2017 13:41:50', 'DD-MM-YYYY HH24:MI:SS') group by thread#;\r\n\r\nMAX(SEQUENCE#) THREAD#\r\n-------------- ----------\r\n 42 1\r\n 42 2\r\n<\/pre>\n[Logical-1] SQL> SELECT max(sequence#),thread#,applied FROM dba_logstdby_log where first_time > to_date('27\/01\/2017 13:41:50', 'DD-MM-YYYY HH24:MI:SS') group by thread#, applied;\r\n\r\nMAX(SEQUENCE#) THREAD# APPLIED\r\n-------------- ---------- --------\r\n 42 1 YES\r\n 42 2 YES\r\n<\/pre>\n<\/p>\n
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