How Service uses referred and avileable to fix sessions to one node and switch to another node after downtime
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Service uses referred and avileable fixed session to connect to a database server, which will switch to another database server when it goes down
In the DB managed by the administrator, service is divided into:
-preferred instance: when the service is started, the instance on which it is started is preferred instance.
-available instance: the instance where the service resides crashes, and Clusterware starts the service in another available instance.
Must be executed under oracle user
[root@node1] # srvctl add service-d orcl-s srv1-r orcl1-an orcl2
PRCD-1026: Failed to create service srv1 for database orcl
PRKH-1014: Current user "root" is not the oracle owner user "oracle" of oracle home "/ u01/app/oracle/product/11.2.0/dbhome_1"
[oracle@node1 ~] $lsnrctl status
LSNRCTL for Linux: Version 11.2.0.3.0-Production on 24-AUG-2017 19:56:25
Copyright (c) 1991, 2011, Oracle. All rights reserved.
Connecting to (ADDRESS= (PROTOCOL=tcp) (HOST=) (PORT=1521))
STATUS of the LISTENER
-
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.3.0-Production
Start Date 24-AUG-2017 19:19:59
Uptime 0 days 0 hr. 36 min. 49 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File / u01/app/11.2.0/grid/network/admin/listener.ora
Listener Log File / u01/app/grid/diag/tnslsnr/node1/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION= (ADDRESS= (PROTOCOL=ipc) (KEY=LISTENER)
(DESCRIPTION= (ADDRESS= (PROTOCOL=tcp) (HOST=192.168.92.20) (PORT=1521))
(DESCRIPTION= (ADDRESS= (PROTOCOL=tcp) (HOST=192.168.92.22) (PORT=1521))
Services Summary...
Service "+ ASM" has 1 instance (s).
Instance "+ ASM1", status READY, has 1 handler (s) for this service...
Service "orcl" has 1 instance (s).
Instance "orcl1", status READY, has 1 handler (s) for this service...
Service "orclXDB" has 1 instance (s).
Instance "orcl1", status READY, has 1 handler (s) for this service...
The command completed successfully
[oracle@node2 ~] $lsnrctl status
LSNRCTL for Linux: Version 11.2.0.3.0-Production on 24-AUG-2017 19:55:48
Copyright (c) 1991, 2011, Oracle. All rights reserved.
Connecting to (ADDRESS= (PROTOCOL=tcp) (HOST=) (PORT=1521))
STATUS of the LISTENER
-
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.3.0-Production
Start Date 24-AUG-2017 19:24:29
Uptime 0 days 0 hr. 31 min. 29 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File / u01/app/11.2.0/grid/network/admin/listener.ora
Listener Log File / u01/app/grid/diag/tnslsnr/node2/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION= (ADDRESS= (PROTOCOL=ipc) (KEY=LISTENER)
(DESCRIPTION= (ADDRESS= (PROTOCOL=tcp) (HOST=192.168.92.24) (PORT=1521))
(DESCRIPTION= (ADDRESS= (PROTOCOL=tcp) (HOST=192.168.92.23) (PORT=1521))
Services Summary...
Service "+ ASM" has 1 instance (s).
Instance "+ ASM2", status READY, has 1 handler (s) for this service...
Service "orcl" has 1 instance (s).
Instance "orcl2", status READY, has 1 handler (s) for this service...
Service "orclXDB" has 1 instance (s).
Instance "orcl2", status READY, has 1 handler (s) for this service...
The command completed successfully
Add a service:srv1,orcl1 is prefer,orcl2 is available:
Srvctl add service-d orcl-s srv1-r orcl1-an orcl2
Srvctl start service-d orcl-s srv1
[oracle@node1 ~] $lsnrctl status
LSNRCTL for Linux: Version 11.2.0.3.0-Production on 24-AUG-2017 20:09:06
Copyright (c) 1991, 2011, Oracle. All rights reserved.
Connecting to (ADDRESS= (PROTOCOL=tcp) (HOST=) (PORT=1521))
STATUS of the LISTENER
-
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.3.0-Production
Start Date 24-AUG-2017 19:19:59
Uptime 0 days 0 hr. 49 min. 12 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File / u01/app/11.2.0/grid/network/admin/listener.ora
Listener Log File / u01/app/grid/diag/tnslsnr/node1/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION= (ADDRESS= (PROTOCOL=ipc) (KEY=LISTENER)
(DESCRIPTION= (ADDRESS= (PROTOCOL=tcp) (HOST=192.168.92.20) (PORT=1521))
(DESCRIPTION= (ADDRESS= (PROTOCOL=tcp) (HOST=192.168.92.22) (PORT=1521))
Services Summary...
Service "+ ASM" has 1 instance (s).
Instance "+ ASM1", status READY, has 1 handler (s) for this service...
Service "orcl" has 1 instance (s).
Instance "orcl1", status READY, has 1 handler (s) for this service...
Service "orclXDB" has 1 instance (s).
Instance "orcl1", status READY, has 1 handler (s) for this service...
Service "srv1" has 1 instance (s).
Instance "orcl1", status READY, has 1 handler (s) for this service...
The command completed successfully
[oracle@node2 ~] $lsnrctl status
LSNRCTL for Linux: Version 11.2.0.3.0-Production on 24-AUG-2017 20:09:10
Copyright (c) 1991, 2011, Oracle. All rights reserved.
Connecting to (ADDRESS= (PROTOCOL=tcp) (HOST=) (PORT=1521))
STATUS of the LISTENER
-
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.3.0-Production
Start Date 24-AUG-2017 19:24:29
Uptime 0 days 0 hr. 44 min. 44 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File / u01/app/11.2.0/grid/network/admin/listener.ora
Listener Log File / u01/app/grid/diag/tnslsnr/node2/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION= (ADDRESS= (PROTOCOL=ipc) (KEY=LISTENER)
(DESCRIPTION= (ADDRESS= (PROTOCOL=tcp) (HOST=192.168.92.24) (PORT=1521))
(DESCRIPTION= (ADDRESS= (PROTOCOL=tcp) (HOST=192.168.92.23) (PORT=1521))
Services Summary...
Service "+ ASM" has 1 instance (s).
Instance "+ ASM2", status READY, has 1 handler (s) for this service...
Service "orcl" has 1 instance (s).
Instance "orcl2", status READY, has 1 handler (s) for this service...
Service "orclXDB" has 1 instance (s).
Instance "orcl2", status READY, has 1 handler (s) for this service...
The command completed successfully
Turn off orcl1 abnormally, and after a while, you will see that srv1 is started on orcl2.
[root@node1 ~] # crsctl stop crs
[oracle@node2 ~] $lsnrctl status
LSNRCTL for Linux: Version 11.2.0.3.0-Production on 24-AUG-2017 21:11:40
Copyright (c) 1991, 2011, Oracle. All rights reserved.
Connecting to (ADDRESS= (PROTOCOL=tcp) (HOST=) (PORT=1521))
STATUS of the LISTENER
-
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.3.0-Production
Start Date 24-AUG-2017 19:24:29
Uptime 0 days 1 hr. 47 min. 28 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File / u01/app/11.2.0/grid/network/admin/listener.ora
Listener Log File / u01/app/grid/diag/tnslsnr/node2/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION= (ADDRESS= (PROTOCOL=ipc) (KEY=LISTENER)
(DESCRIPTION= (ADDRESS= (PROTOCOL=tcp) (HOST=192.168.92.24) (PORT=1521))
(DESCRIPTION= (ADDRESS= (PROTOCOL=tcp) (HOST=192.168.92.23) (PORT=1521))
Services Summary...
Service "+ ASM" has 1 instance (s).
Instance "+ ASM2", status READY, has 1 handler (s) for this service...
Service "orcl" has 1 instance (s).
Instance "orcl2", status READY, has 1 handler (s) for this service...
Service "orclXDB" has 1 instance (s).
Instance "orcl2", status READY, has 1 handler (s) for this service...
Service "srv1" has 1 instance (s).
Instance "orcl2", status READY, has 1 handler (s) for this service...
The command completed successfully
You can add multiple preferred instances to the service so that you do not need available instances:
Srvctl add service-d orcl-s srv2-r orcl1,orcl2
Srvctl start service-d orcl-s srv2
[oracle@node1] $srvctl status service-d orcl-s srv2
Service srv2 is running on instance (s) orcl1,orcl2
Service can define only preferred instances, not available instances. But then there is no HA.
In this way, when the instance in which the service resides crashes, the service will not failover to another instance.
Run srv1 from orcl1 to orcl2:
Srvctl relocate service-d orcl-s srv1-I orcl1-t orcl2
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