Manual Failover procedure
By hstsao on Jun 08, 2004
manual FailoverFor many business critical application, we are used to relied on the vendor cluster software to accomplsh the HA requirement.
But in some case, some user many just want to setup a manual failover procedure, so in case one node need to be repaired one can manual switch the application to the second node
requirementThis note describe the main requirement for a manual failover in a two node situation
- the Storage need to be shared but will be controlled by one node at time simplest way to do this is using SVM (Solaris Volume Manager) in Solairs 9, or Veritas VM (vxvm). Please refer to the HW setup document in the Cluster Sw for how to setup SCSI or FC storage.
- Your application will need to use the Logical Hostname and not the Physical Nodename. It is always a good idea to use the LH, this way you can always relocate the application to different physical host.
You will need to setup Diskset in SVM or Diskgroup in VxVM, and your script will contain the procedure to release (deport) or take(import) the Diskset(Diskgroup), and mount the FS
How to setup LH?You use the Logical Interface of your NIC. e.g if your physical interface is ce0 then the Logical Interface will be ce0:3 for example.
scriptThe script will include the procedure to plumb and unplumb the LI and associate the LH with the LI at different Physical host.
The code will be the following:
to switchover from node1 to node2
- at node1: bring down the LI, unmount the FS, release the Diskset
- at node2: take the Diskset, Mount the FS and plumb the LI and bring up the LI