To go further, it is assumed you have set a Physical Standby Database on Peoplesoft OVM as shown in my previous blog entry : PSOVM and Activate Data Guard : Physical Standby Database
As explained in previous post, we created a Physical Standby Database, it should be relatively straightforward to enable the Active Data Guard. That will allow end users to query (in read only mode) the standby database whilst the redo are applying onto that standby database, feature known to be real-time query.
At the end of this stage, the architecture will be as follow (in blue the change compared to the previous post) :
As explained in previous post, we created a Physical Standby Database, it should be relatively straightforward to enable the Active Data Guard. That will allow end users to query (in read only mode) the standby database whilst the redo are applying onto that standby database, feature known to be real-time query.
At the end of this stage, the architecture will be as follow (in blue the change compared to the previous post) :
1. dg_broker_start init parameter
Set the dg_broker_start to true on primary database and on secondary database
SQL> alter system set dg_broker_start=true;
System altered. Set the dg_broker_start to true on primary database and on secondary database
SQL> alter system set dg_broker_start=true;
2. Create the dataguard configuration
On the primary site, start the Data Guard Manager client command line for the configuration settings :
[oracle@psovmhcmdb dbs]$ dgmgrl
DGMGRL for Linux: Version 11.1.0.7.0 - 64bit Production
Copyright (c) 2000, 2005, Oracle. All rights reserved. On the primary site, start the Data Guard Manager client command line for the configuration settings :
[oracle@psovmhcmdb dbs]$ dgmgrl
DGMGRL for Linux: Version 11.1.0.7.0 - 64bit Production
Welcome to DGMGRL, type "help" for information.
DGMGRL> connect sys/oracle@H91TMPLT (connection to the primary database)
Connected.
DGMGRL> create configuration psovmdgmgrl
> as primary database is H91TMPLT
> connect identifier is H91TMPLT;
Configuration "psovmdgmgrl" created with primary database "h91tmplt"
DGMGRL> add database H91STBY
> as connect identifier is H91STBY
> maintained as physical;
Database "h91stby" added
DGMGRL>
DGMGRL> enable configuration
Enabled.
DGMGRL> show configuration
Configuration
Name: psovmdgmgrl
Enabled: YES
Protection Mode: MaxPerformance
Databases:
h91tmplt - Primary database
h91stby - Physical standby database
Fast-Start Failover: DISABLED
Current status for "psovmdgmgrl":
SUCCESS
DGMGRL>
3. Turn off the redo apply (dgmgrl)
In order to have an active data guard, we should stop the replication first (run dgmgrl on primary site) :
DGMGRL> edit database h91stby set state=apply-off;
Succeeded.
DGMGRL>
In order to have an active data guard, we should stop the replication first (run dgmgrl on primary site) :
DGMGRL> edit database h91stby set state=apply-off;
Succeeded.
DGMGRL>
4. Read-only mode
Now, we can open the secondary database in read-only mode (on the further startups, that mode will be the default one):
SQL> alter database open read only;
Database altered. Now, we can open the secondary database in read-only mode (on the further startups, that mode will be the default one):
SQL> alter database open read only;
5. Turn on the redo apply (dgmgrl)
Now, we can turn the redo apply on again (run dgmgrl on primary site)
DGMGRL> edit database h91stby set state=apply-on;
Succeeded.
DGMGRL>
Now, we can turn the redo apply on again (run dgmgrl on primary site)
DGMGRL> edit database h91stby set state=apply-on;
Succeeded.
DGMGRL>
6. Test
We will see if the replication is working whilst the standby database is open in read-only mode and “query-able” as SYSADM user.
6.1 On the secondary database
SQL> select instance_name,host_name from v$instance
SQL> /
INSTANCE_NAME HOST_NAME We will see if the replication is working whilst the standby database is open in read-only mode and “query-able” as SYSADM user.
6.1 On the secondary database
SQL> select instance_name,host_name from v$instance
SQL> /
---------------- ----------------------------------------------------------------
H91TMPLT psovmhcmdb2
SQL> conn sysadm/SYSADM
Connected.
SQL> select count(*) from psoprdefn;
COUNT(*)
----------
155
SQL> select oprid from psoprdefn where trunc(LASTPSWDCHANGE)=trunc(sysdate);
no rows selected
6.2 Within the front-end application, we’ll duplicate PS user as following
6.3 And now, on the secondary database, re-run the previous query, it should return one more row
SQL> select oprid from psoprdefn where trunc(LASTPSWDCHANGE)=trunc(sysdate);
OPRID 
6.3 And now, on the secondary database, re-run the previous query, it should return one more row
SQL> select oprid from psoprdefn where trunc(LASTPSWDCHANGE)=trunc(sysdate);
---------------------------------------------------
NICOLAS
SQL> select count(*) from psoprdefn;
COUNT(*)
----------
156
SQL>
=> the new created user is coming to the secondary database, and we can check it directly from PSOPRDEFN (that would not be possible without Active Data Guard).
7. For the record, show the dgmgrl status (configuration and databases)
[oracle@psovmhcmdb ~]$ dgmgrl
DGMGRL for Linux: Version 11.1.0.7.0 - 64bit Production
Copyright (c) 2000, 2005, Oracle. All rights reserved. [oracle@psovmhcmdb ~]$ dgmgrl
DGMGRL for Linux: Version 11.1.0.7.0 - 64bit Production
Welcome to DGMGRL, type "help" for information.
DGMGRL> connect sys/oracle@H91TMPLT
Connected.
DGMGRL> show configuration
Configuration
Name: psovmdgmgrl
Enabled: YES
Protection Mode: MaxPerformance
Databases:
h91tmplt - Primary database
h91stby - Physical standby database
Fast-Start Failover: DISABLED
Current status for "psovmdgmgrl":
SUCCESS
DGMGRL> show database h91stby
Database
Name: h91stby
Role: PHYSICAL STANDBY
Enabled: YES
Intended State: APPLY-ON
Instance(s):
H91TMPLT
Current status for "h91stby":
SUCCESS
DGMGRL> show database h91tmplt
Database
Name: h91tmplt
Role: PRIMARY
Enabled: YES
Intended State: TRANSPORT-ON
Instance(s):
H91TMPLT
Current status for "h91tmplt":
SUCCESS
DGMGRL>
Now we can talk, query a database without loading the primary database while the redo continue to be applied. That's really helpful, especially for users who run a lot of reports through a tier query tool. Once more, PSOVM allow us to test it easily before implementing it in real live.
But it can be not enough. An other great feature coming with the latest PSOVM and Peopletools 8.51 is the StandbyDBName configuration possiblity on Batch and AppServer. That's obviously the next step. To be continued.
But it can be not enough. An other great feature coming with the latest PSOVM and Peopletools 8.51 is the StandbyDBName configuration possiblity on Batch and AppServer. That's obviously the next step. To be continued.
Read my next articles :
Documentation, find out more :
http://download.oracle.com/docs/cd/B28359_01/server.111/b28282/configbp006.htm#HABPT04477
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