We describe effort to make Blackboard SW highly available
Standard BB6.x has two tier setup, the front-end is based on apache and tomcate the back-end are oracle (an example) and NFS server.
To integrate with the Sun Cluster SW, one can use the HA-oracle agent to protect oracle, and HA-NFS agent to protect the NFS.
One can setup a two node cluster and two Logical Hosts, one LH is responsible for HA-Oracle and one LH is responsible for HA-NFS, one node will own the LH for oracle and one node will own the LH for NFS.
The front-end can be protected by the HA-apache and HA-tomcate agent or just set up multiple front-end behind a Load Balancer (LB).
NFS failover is transparent to the clients.
Every time oracle failover to the other host, one need to restart the front-end’s apache and tomcate.
To achive this, one can create a customer agent: its job are just to use ssh to each front-end and restart the apache and tomcate.
Of course one need to setup SSH in such a way one can run ssh command between back-end and front-end with-out the need of input passwd/passphrase.
If one use the collab server then one need to configure a customer agent. In Sun Java ES Cluster SW, one can easily make a HA-agent if one has the start, stop and probe scripts for the collab server. We will describe the procedure in a separate posting.