Chapter 9. High availability and disaster recovery 253
The second adapter is where all the private network communications are
going through such as the heartbeat monitor, network storage for backups,
and so on.
The third adapter has the IP address that is active all the time. This is used for
all service operations like problem determination, during failover. This is also
used by the maintenance team to perform maintenance on weekends.
Table 9-3 lists the advantages and disadvantages of the mutual takeover HA
Table 9-3 Pros and cons of a mutual takeover HA solution
9.2.2 Information on the lab environment
In our lab environment, we demonstrate clustering at AIX and Windows
At AIX, the HA solution (High-Availability Cluster Multi-Processing (HACMP) is
used to host cluster servers KANAGA and ATLANTIC. The application server is DB2
UDB database server. We provide the steps for setting up idle standby and active
standby. The general setup procedures are:
Install and configure HACMP on the clustered servers.
Set up DB2 UDB databases server for clustering.
Simple high availability solution. Performance may be affected, since the
failover server is also carrying workload
for other applications running on it. (This
can be minimized by shutting down
Cost is minimal as the failover server is
Does not protect against storage
hardware failure. (This can be solved by
having RAID5 and/or buying new
network storage solution.
No changes at Siebel Server (no need to
make changes to node directory at the
Users may never notice an outage.
(Siebel application does a reconnect if it
senses loss of DB2 connection).
Database is always in sync.