Hi Sean, thanks for your answer! > I believe it may still be possible for the node to be selected if no other > connections are available in the pool, because the logic used to establish a > new connection might not use the filter.
My problem is not to avoid that a node will be selected again after a fail (well, if this can be avoided by sure it's better...) but to set an order in the nodes: I want to connect first to the node on which my app is running and only in case of fail to the other nodes. The reason is to avoid network traffic: every instance of my app have to connect to the node on the same machine where it resides. How can I suggest a "preferred node" to RiakClient? My first idea was to use a connection with only the preferred node and, using a try/except, use an "emergency connection" with the list of all nodes to be used only in case of fail. But it's not so elegant.... Massimiliano 2014-02-08 13:47 GMT+01:00 Sean Cribbs <s...@basho.com>: > Hi Massimilliano, > > The list of nodes does not imply an order of connection. Usually, a random > node is chosen after nodes with error rates greater than a threshold are > removed from the candidates. You can see the implementation in > RiakClient._choose_node: > https://github.com/basho/riak-python-client/blob/master/riak/client/__init__.py#L278 > > When a request fails such that the connection is known to be bad (such as a > TCP error), the retry logic filters out that node from existing connections. > I believe it may still be possible for the node to be selected if no other > connections are available in the pool, because the logic used to establish a > new connection might not use the filter. I will investigate further and > determine if this is actually the case. > > > On Sat, Feb 8, 2014 at 1:03 PM, Massimiliano Ciancio > <massimili...@ciancio.net> wrote: >> >> Hi all, >> I'm using python client to connect to a five nodes riak server. >> Since I'm running my app on the same servers on which is running Riak, >> I want that the app on server x get and store data asking to the Riak >> on the same server. If the Riak on the same server is not available, >> tha app must connect to another Riak server randomly choosed. >> How can I implement this? >> Does the list of nodes passed to the RiakClient >> (http://basho.github.io/riak-python-client/client.html) imply an >> 'order of connection' ? That is, first connect to the first node then, >> if this fails, connect to the second and so on... >> Thanks in advance >> Massimiliano >> >> _______________________________________________ >> riak-users mailing list >> riak-users@lists.basho.com >> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com > > > > > -- > Sean Cribbs <s...@basho.com> > Software Engineer > Basho Technologies, Inc. > http://basho.com/ _______________________________________________ riak-users mailing list riak-users@lists.basho.com http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
