On 4/8/11 5:46 PM, Drew Kutcharian wrote:
I'm interested in this too, but I don't think this can be done with Cassandra
alone. Cassandra doesn't support transactions. I think hector can retry
operations, but I'm not sure about the atomicity of the whole thing.
On Apr 8, 2011, at 1:26 PM, Alex Araujo wrote:
Hi, I was wondering if there are any patterns/best practices for creating
atomic units of work when dealing with several column families and their
inverted indices.
For example, if I have Users and Groups column families and did something like:
Users.insert( user_id, columns )
UserGroupTimeline.insert( group_id, { timeuuid() : user_id } )
UserGroupStatus.insert( group_id + ":" + user_id, { "Active" : "True" } )
UserEvents.insert( timeuuid(), { "user_id" : user_id, "group_id" : group_id, "event_type"
: "join" } )
Would I want the client to retry all subsequent operations that failed against other
nodes after n succeeded, maintain an "undo" queue of operations to run, batch
the mutations and choose a strong consistency level, some combination of these/others,
etc?
Thanks,
Alex
Thanks Drew. I'm familiar with lack of transactions and have read about
people using ZK (possibly Cages as well?) to accomplish this, but since
it seems that inverted indices are common place I'm interested in how
anyone is mitigating lack of atomicity to any extent without the use of
such tools. It appears that Hector and Pelops have retrying built in to
their APIs and I'm fairly confident that proper use of those
capabilities may help. Just trying to cover all bases. Hopefully
someone can share their approaches and/or experiences. Cheers, Alex.
