> No, batch_mutate() is an atomic operation. When a node locally applies a > batch mutation, either all of the changes are applied or none of them are.< The steps in my batch are not confined to a single CF, nor to a single key.
The documentation says: datastax: Column updates are only considered atomic within a given record (row). Pycassa.batch: This interface does not implement atomic operations across column families. All the limitations of the batch_mutate Thrift API call applies. Remember, a mutation in Cassandra is always atomic per key per column family only. On Wed, Mar 14, 2012 at 4:15 PM, Tyler Hobbs <ty...@datastax.com> wrote: > On Wed, Mar 14, 2012 at 11:50 AM, A J <s5a...@gmail.com> wrote: >> >> >> Are you saying the way 'batch mutate' is coded, the order of writes in >> the batch does not mean anything ? You can ask the batch to do A,B,C >> and then D in sequence; but sometimes Cassandra can end up applying >> just C and A,B (and D) may still not be applied ? > > > No, batch_mutate() is an atomic operation. When a node locally applies a > batch mutation, either all of the changes are applied or none of them are. > > Aaron was referring to the possibility that one of the replicas received the > batch_mutate, but the other replicas did not. > > -- > Tyler Hobbs > DataStax >
