Just started to play with the row cache feature in trunk: it seems to be working fine so far except that for RowsCached parameter you need to specify number of rows rather than a percentage (e.g., "20%" doesn't work). Thanks for this great feature that improves read latency dramatically so that disk i/o is no longer a serious bottleneck.

The problem is: when you write to Cassandra it doesn't seem to put the new keys in row cache (it is said to update instead invalidate if the entry is already in cache). Is it easy to implement this feature? What are the classes that should be touched for this? I'm guessing that RowMutationVerbHandler should be the one to insert the entry in row cache?