Actually, it doesn't really have to be messy. Couldn't one have a custom handler that know how to compute a query hash and map it to a specific node? When the same query comes in again, the same computation will be doen and the same node will be selected to execute the query. No need for any nodes to have any "physical" query->node mapping and no need for nodes to broadcast this sort of info around.
Sounds doable to me. Otis -- Solr & ElasticSearch Support http://sematext.com/ On Mon, Jun 10, 2013 at 5:44 PM, Otis Gospodnetic <otis.gospodne...@gmail.com> wrote: > Yeah, that sounds complique and messy. > Just the other day I was looking at performance metrics for a customer > using master-slave setup and this sort of query->slave mapping behing > the load balancer. > After switching from such a setup to a round-robin setup their > performance noticeably suffered... > > Otis > -- > Solr & ElasticSearch Support > http://sematext.com/ > > > > > > On Mon, Jun 10, 2013 at 8:06 AM, Erick Erickson <erickerick...@gmail.com> > wrote: >> Nothing I've seen. It would get really tricky >> though. Each node in the cluster would have >> to have a copy of all queries received by >> _any_ node which would result in all >> queries being sent to all nodes along with >> an indication of what node that query was >> actually supposed to be serviced by. >> >> And now suppose there were 100 shards, >> then the list of the correct node would get >> quite large. >> >> Seems overly complex for the benefit, but >> what do I know? >> >> FWIW >> Erick >> >> >> >> On Sat, Jun 8, 2013 at 10:38 PM, Otis Gospodnetic >> <otis.gospodne...@gmail.com> wrote: >>> Hi, >>> >>> Is there anything in SolrCloud that would support query-node/shard >>> affinity/stickiness? >>> >>> What I mean by that is a mechanism that is smart enough to keep >>> sending the same query X to the same node(s)+shard(s)... with the goal >>> being better utilization of Solr and OS caches? >>> >>> Example: >>> * Imagine a Collection with 2 shards and 3 replicas: s1r1, s1r2, s1r3, >>> s2r1, s2r2, s2r3 >>> * Query for "Foo Bar" comes in and hits one of the nodes, say s1r1 >>> * Since shard 2 needs to be queried, too, one of its 3 replicas needs >>> to be searched. Say s2r1 gets searched >>> * 5 minutes later the same query for "Foo Bar" comes in, say it hits s1r1 >>> again >>> * Again shard 2 needs to be searched. But which of the 3 replicas >>> should be searched? >>> * Ideally that same s2r1 would be searched >>> >>> Is there anything in SolrCloud that can accomplish this? >>> Or if there a place in SolrCloud where such "query hash ==> >>> node/shard" mapping could be implemented? >>> >>> Thanks, >>> Otis >>> -- >>> Solr & ElasticSearch Support >>> http://sematext.com/
