Live updates in Cassandra

[David Boxenhorn <da...@lookin2.com>]

Does anyone have any advice for me about how to do live updates (i.e.
updates on clusters while they are in use)?

My situation is like this:

Some data comes from the "back office" - this data is imported to Cassandra
from Oracle.
Some data comes from users - this data is imported to Oracle from Cassandra.

For nomalized data, I don't see a problem updating Cassandra from Oracle.

But updating my indexes on a live database is tricky, because an update of a
single normalized item results in a complex set of updates to indexes, in
which there are a lot of data inter-dependencies (i.e. the Cassandra
equivalent of complex SQL queries). Deletes are especially tricky.

How about using two Cassandra keyspaces, one live, and one off-line,
updating the off-line keyspace, and then making it live? This would allow me
to start fresh with each update - easier than an incremental update.

What tools to I have to help me with this?

Any other thoughts? All suggestions are welcome!