Oracle Application Server Disaster Recovery
We were struggling to setup disaster recovery for Oracle Application Server 10.1.4.3 since couple of months and the experiences through out this was excellent. I would like to cover the hurdles that we came across, the thought process and recommended approaches from Oracle and so on.
Our environment has:
- There are two sites Active and Stand-by which has 2 physical servers each with different hostnames say primary1.oracle.com, primary2.oracle.com, standby1.oracle.com, standby2.oracle.com. Only one site is active and the infrastructure in both sides are identical.
- Oracle Database 10.2.0.4 in RAC mode
- Oracle Application Server has OID 10.1.4.3, OSSO 10.1.4.3
- OAM 10g
- Custom applications and Legacy Applications such as Oracle Portal 11g, SIEBEL, PEOPLESOFT, Oracle Financials etc.,
Customer has purchased a 3rd party product which does the replication between Database server of Primary and Stand-by for every 1 hour. Not to forget, the database hostnames in both sides are different say dbprimary1.oracle.com, dbprimary2.oracle.com, dbstandby1.oracle.com, dbstandby2.oracle.com.
From the network point of view – Servers in primary and Stand-by are in different geographic locations and there is no connectivity for application nodes between Primary and Stand-by sites.
When ever the Primary site goes down, all the applications in Primary site are stopped and Stand-by site will act as Primary.
OSSO is very important here because certain applications such as Oracle Financials and Oracle BPEL worklist 10g was integrated with OSSO 10g – in turn with OAM 10g.
First take: Primary and Stand-by sites are setup individually with respect to their own DB servers. DB servers got replicated between Primary to Stand-by sites. Applications are started in Stand-by site. Only OID process came up fine in both nodes but not OC4J_SECURITY process. We were able to login to OIDADMIN tool.
Our troubleshooting went to a point where we modified the ias.properties file, orcldescnetstring in OIDADMIN tool and so on but OC4J was not started. Working with Oracle for resolution did not take us anywhere.
Second Take: We used same hostnames for application nodes between Primary and Stand-By sites but with different Database hostnames .
Reinstalled the Oracle Application server instances in both nodes of Stand-by site with latest hostname. Please note that Virtual Hostname between Primary and Stand-By sites are same.
DB replication is done. Tried starting opmn services in Stand-by site. This time, OID service itself did not come up. Upon making some work arounds, OID and OC4J came up fine. I have to admit that there are lots of tweaking done which is not recommended by Oracle. However when I tried logging into OIDDAS console, it redirected to error page. The logs show that Partner Configuration not found. This means each and every partner application registered in OSSO has unique site2pstoretoken which seems not a valid token when the DB gets replicated.
Third Take: We worked with Oracle and they suggested us to use same hostname for application nodes and database servers including virtual hostname for DB servers. Applications are not reinstalled in Stand-by site this time. We just copied the application level folder between Primary and Stand-By sites but not oraInventory files/folders.
DB got replicated. The opmn services are started in Stand-by site and it came up without even a single change.
Just in case if we dont have OSSO in the architecture, then just DB replication alone would suffice the job.
However there is a different approach which is Oracle Application Server Guard for replication between Oracle App servers of Active and Stand-by sites and Oracle Data Guard can be used for replication between DB servers of Active and Stand-by sites.
This post may be at a high level, please reach out to me for low level details and work arounds followed to overcome those issues.
About the Author Mahendra
I am engulfed in Oracle Identity & Access Management domain. I have expertise on providing the optimized solutions for user provisioning, web access management, Single Sign-On and federation capabilities etc., I am also well versed with complex integrations within Identity Management and other product domains. I have expertise on building demos and implementation experience on products Oracle Access Manager, Oracle Adaptive Access Manager, Oracle Entitlement Server, Oracle Virtual Directory, Oracle Internet Directory etc., Look @ my blog: http://talkidentity.blogspot.com