Obtaining Read/Write Ratio -Replication

I am looking into a replication strategies to improve performance and
redundancy for a MySQL 4.1 database running on
Linux/Apache2/mod_python.

I am curious as to the standard way of obtaining a Read/Write Ratio.

What patterns of usage suit One-Way or Two-Way replication?

In my situation I have a database that intermittent bursts of inserts
through the day, a lot of batched deletes/inserts/updates over night
and fairly constant selects. I'd expect the RW Ratio would fluctuate
dramatically in a 24 hour period.

I'd be happy to recieve any pointers on regarding performance analysis
and replication strategies.