There are several options for replication and clustering DB2. Which one
is right depends on what you are trying to achieve, and what
constraints you are working against.

Are you trying to scale the performance of your database by off loading
reads from the master database to a read farm? (It sounds like this is
what you are doing)
Are you looking for a high availablity?
Can the secondary databases be slightly out of date, or do you need
full transactional integrity?

Autur, is right, you should look at Q-replication, and also DB2's
SQL-replcation. SQL-replication is slower, but is pretty flexible (it
may be cheaper? - I don't remember). You can use it to transform and
ship transactions to different databases other than DB2. Q-replication
is faster, but less flexible. For DB2 LUW, both are add-on products (I
think SQL-rep is included in DB2 for z/OS). If you give your db2 sales
rep a call they should be able to help you out.

Both of these are asynchronous master-slave replication products. That
means the secondary databases lag behind the master by some period of
time, from milliseconds to several seconds. The replication itself is
also not ACID compliant. For most applications this is fine, for some
it is not.

If transactional integrity is a constraint, my company (xkoto) makes a
clustering solution for DB2 that is designed to ensure transactional
integrity across a cluster of fully active database servers. We also
simply the process of reading off the secondary boxes by handling the
load balancing of reads across the cluster.

If you are interested I can send you more info.