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Subject: Re: Atomicity Strategies
From: Drew Kutcharian <drew@venarc.com>
In-Reply-To: <4D9F6F7E.5010907@alex.otherinbox.com>
Date: Fri, 8 Apr 2011 15:46:36 -0700
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Message-Id: <5F856847-796F-4716-859F-73F05F567206@venarc.com>
References: <4D9F6F7E.5010907@alex.otherinbox.com>
To: user@cassandra.apache.org

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.
>=20
> For example, if I have Users and Groups column families and did =
something like:
>=20
> 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" } )
>=20
> 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?
>=20
> Thanks,
> Alex
>=20
>=20