On Wed, Jan 26, 2011 at 08:58, Mck <m...@apache.org> wrote: >> You are correct that microseconds would be better but for the test it >> doesn't matter that much. > > Have you tried. I'm very new to cassandra as well, and always uncertain > as to what to expect...
IMHO it's matter of use-case. In my use-case there is no possibility for two (or more) processes to write/update the same key so miliseconds are fine for me. BTW how to get current time in microseconds in Java? > As far as moving the clone(..) into ColumnFamilyRecordWriter.write(..) > won't this hurt performance? Normally i would _always_ agree that a > defensive copy of an array/collection argument be stored, but has this > intentionally not been done (or should it) because of large reduce jobs > (millions of records) and the performance impact here. The size of the queue is computed at runtime: ColumnFamilyOutputFormat.QUEUE_SIZE, 32 * Runtime.getRuntime().availableProcessors() So the queue is not too large so I'd say the performance shouldn't get hurt. -- Patrik
