General: Configuring Active/Passive Clustering for Oracle Database ( Single Instance in Crs)
The Oracle database can easily be configured to use the Cluster ware framework for high availability.
Using Grid Infrastructure to protect a database resource is a very cost-effective way of setting up an Active/passive cluster. As an added advantage, using only one vendor’s software stack to implement the cluster can make troubleshooting easier. Staff already familiar with RAC will easily be able to set up and run this configuration because it uses a same software stack: all commands and log files are in familiar locations, and troubleshooting does not rely on the input from other teams.
To set up an active/passive cluster with 11g Release 2, you need to initially install Grid Infrastructure on all nodes of the cluster. Grid Infrastructure will give the user with a cluster logical volume manager: ASM. If for some reason another file system is required, you can choose the supported cluster file systems, including ACFS. Using a cluster file system that is mounted concurrently to both cluster nodes offers the advantage of not having to remount the database files and binaries in case of a node failure. Some configurations we saw suffered from extended fail over periods caused by required file system checks before the file system could be remounted.
On top of the Grid Infrastructure build, you do a local installation of the RDBMS. It is important that you do not choose a cluster installation when prompted so; otherwise, you risk violating your license agreement with Oracle.
Some months ago I have implemented an Active Passive Solution on Oracle 11gr2 for on one of the customers. Basically this was almost reliving old days where tools like HP MC Service Guard (using packages where one or more database and listener configurations are stored) or Veritas Clusterware (where and Agent controls the status of the resources being a database and or a listener). They would monitor the health of the Database/Listener, would stop and start the Database/ Listener. With the technology at hand at that point and time ( implemented 220.127.116.11 Grid Infra with ASM and 18.104.22.168 Rdbms ) it was not having all the required setups to implement anything else. Now we are 9 months further in time, standards have been adapted and we have latest Oracle version at hand ( being 22.214.171.124) so it is time for a fresh start. Besides that recently I have been asked to implement the Active Passive solution on more environments (since it does cover part off HA and it controls the monitoring of the Database/ Instance by HP-Openview).
For a billing environment I have been asked to change the current Real application solution to a HA solution with an Active – Passive Database in the Cluster ware of Oracle (Grid Infrastructure) (126.96.36.199.0). Even though I have had / seen examples of this working in 11gr1 the fact we use 11Gr2 allowed us to skip steps needed in the 11gr1 environment (such as a dedicated virtual Ip address, able to fail over and a listener that has to come along with that as well). This solution is based on the fact that in this project we have set up scan listener(s) and also that we connect via a Service (taf). Also it should be said that the parameters for the cluster ware have changed again between Oracle 11gr1 and 11gr2. So it was a nice challenge to see, adapt and solve the issues
It is my estimate that a maintenance window of app 1 Hour per Database will be needed, doing the analyses, the changes, the removal and adding it back to the cluster and do relocate tests.
Ps i have marked specific cluster commands in yellow.