If the row cache is enabled the read path will not use the sstables. Depending on the workload I would then look at setting *low* memtable flush settings to use as much memory as possible for the row cache. If the row is in the row cache the read path will not look at SSTables.
Then set the row cache save settings per CF to ensure the cache is warmed when the node starts. The write path will still use the WAL so if you may want to disable the commit log using the durable_writes setting on the keyspace. Hope that helps. ----------------- Aaron Morton Freelance Cassandra Developer @aaronmorton http://www.thelastpickle.com On 10/09/2011, at 4:38 AM, kapil nayar wrote: > Hi, > > Can we configure some column-families (or keyspaces) in Cassandra to perform > as a pure in-memory cache? > > The feature should let the memtables always be in-memory (never flushed to > the disk - sstables). > The memtable flush threshold settings of time/ memory/ operations can be set > to a max value to achieve this. > > However, it seems uneven distribution of the keys across the nodes in the > cluster could lead to java error no-memory available. In order to prevent > this error can we overflow some entries to the disk? > > Thanks, > Kapil
