cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jonathan Ellis (JIRA)" <>
Subject [jira] Created: (CASSANDRA-876) Support session consistency
Date Wed, 10 Mar 2010 19:35:27 GMT
Support session consistency

                 Key: CASSANDRA-876
             Project: Cassandra
          Issue Type: New Feature
          Components: Core
            Reporter: Jonathan Ellis

In and
Amazon discusses the concept of "eventual consistency."  Cassandra uses eventual consistency
in a design similar to Dynamo.

Supporting session consistency would be useful and relatively easy to add: we already have
the concept of a Memtable (see ) to "stage"
updates in before flushing to disk; if we applied mutations to a session-level memtable on
the coordinator machine (that is, the machine the client is connected to), and then did a
final merge from that table against query results before handing them to the client, we'd
get it almost for free.

Of course, the devil is in the details; thrift doesn't provide any hooks for session-level
data out of the box, but we could do this with a threadlocal approach fairly easily.  CASSANDRA-569
has some (probably out of date now) code that might be useful here.

This message is automatically generated by JIRA.
You can reply to this email to add a comment to the issue online.

View raw message