Hi, Seth. On Sat, Sep 4, 2010 at 5:59 PM, Seth Falcon <s...@userprimary.net> wrote:
> I'm working on a project where we have a webmachine-backed service > that talks to Riak. I currently initialize one pb client for each > node in the cluster as part of the webmachine startup. Then the > resources in the webmachine app ask for one of these clients for each > request. > > Your comment above about reusing clients for non-concurrent requests > makes me wonder if this is the wrong approach. Comments or > suggestions? Each instantiated riak_client has a unique client-id that will represent that client in all updates (put-requests) that it makes. That is, the entries in the vector clock will match that client-id. Much of the value of vector clocks can vanish if concurrent writes to the same values can be issued with the same client-id. Sharing connections as you describe might be fine, depending on the details. However, if your resources might overlap in a way like the following example then you probably have a problem. A and B are resource instances handling separate concurrent HTTP requests but sharing a client-id C. A issues get(K), receiving object X with vector clock V B issues get(K), receiving object X with vector clock V A issues put(K,Xa) where Xa is an update to X B issues put(K,Xb) where Xb is an update to X You can lose one of the two updates, as they are both a single update to V from client C. It is assumed that a given client will not compete with itself for updates. I hope that this explanation is helpful. -Justin _______________________________________________ riak-users mailing list riak-users@lists.basho.com http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
