Application Server Disaster Recovery Solution : AS Guard – Things You should Know

ASGuard which stands for Application Server Guardis Disaster Recovery Solution for Oracle Application Server/Fusion Middleware.
  AS Guard in background uses Datagaurd for database (automatically creates standby database) and for middle tier configuration files it uses OracleAS backup and recovery tool.

If you are implementing Oracle AS Guard, key points You should be aware of

1. If there are multiple ORACLE_HOME installed in same machine which are part of Oracle Application Server/ Fusion Middle Ware (like Middle Tier, Infrastructure Tier) then they should use single global inventory. (To Know more about Inventory Click Here)

2. If multiple ORACLE_HOMES are installed on one machine (owned by different users) then owner of one ORACLE_HOME should be able read $ORACLE_HOME/dsa/dsa.conf file of other user.

         Assume user infa is owning infrastructure tier under ORACLE_HOME /oracle/infra and on same machine user iasmid is owning middle tier under ORACLE_HOME /oracle/iasmidthen infra & iasmid should be able to read $OH/dsa/dsa.conf file in each other’s oracle_home

3.ASGuard should have minimum 10.1.2.2.0 Version; To find out ASGuard/DSA version use ( $ORACLE_HOME/OPatch/opatch lsinventory -detail | grep Guard )

You should see output like

Oracle Application Server Guard Client                           10.1.2.2.0
Oracle Application Server Guard Common                     10.1.2.2.0
Oracle Application Server Guard Server                          10.1.2.2.0
Oracle Application Server Guard                                        10.1.2.2.0

4.It is recommended to use same superuser (ias_admin) password for all instances part of ASG (Application Server Guard)
5. If oracle application server is installed on multiple machines (middle tier on one machine, infra tier on another) then DSA/ASG port(defined in $OH/dsa/dsa.conf) should be open across firewall.

Things good to know
1.
ASG (Application Server Guard) and DSA are used interchangeably
2.To Start ASGuard component use opmnctl startproc ias-component=DSA
3.Configuraration file for ASG/DSA is $ORACLE_HOME/dsa/dsa.conf
4.Log file for ASG/DSA are in $ORACLE_HOME/dsa/log
5. You can enable extra logging by adding “trace_flags=all” in dsa.conf or  “set trace on <traceflags>” from ASG command line tool.
6.If you wish to apply any oracle patch (patch which updates database; like middle tier patch) or CPU patch on ORACLE_HOME with ASGuard, to apply patch in standby site break primary-standby relationship, apply patch on primary & standby site and reinstantiate standby site with primary site.
7. If your infrastructure database was created using RepCA(Repository Creation Assistant) then you can install standalone ASGuard (DSA) in that home from companion CD.

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Related
Oracle’s AS Guard Documentation

About the Author Masroof Ahmad

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