Update requests are routed only to leader nodes by CloudSolrServer so there is a 1/numShards probability of avoiding an extra network hop. It is *not* a 1/(number of nodes in cluster) probability as you may think.
You may also be interested in https://issues.apache.org/jira/browse/SOLR-4816 . Perhaps you can try the patch and report your results. On Sun, Jul 7, 2013 at 11:18 AM, Jack Krupansky <j...@basetechnology.com> wrote: > There are three "concepts" to grasp: > > 1. You can send Solr update requests to ANY node of the cluster. Period. > 2. Any extra network traffic (within the cluster) is likely to be negligible > and absolutely not worrying about unless you have definitive evidence to the > contrary. > 3. Leader nodes in SolrCloud are designed to be dynamic and will change over > time. Generally, you won't know which node is the leader for a shard at any > given moment - it may have been a particular node one milliscond ago, but > now maybe another node has been designated as the leader. Neither the > application nor the user designates which node is a leader for a shard - it > is a dynamic election process. Sure, you can check to see which node is > currently the leader, but one millisecond later some other node may have > gotten elected to be the leader. > > To repeat, you DO NOT need to be concerned with sending Solr update requests > to a shard "leader". The SolrCloud concept of "leader" is really only needed > WITHIN the cluster. Clients outside of the SolrCloud cluster need not > concern themselves with shard "leaders." > > "Micro-optimization" and "premature optimization" are very poor tools to > lead a system design. Focus the energy on the data modeling and the overall > application design. > > -- Jack Krupansky > > -----Original Message----- From: vicky desai > Sent: Sunday, July 07, 2013 1:17 AM > To: solr-user@lucene.apache.org > Subject: Re: Is it possible to find a leader from a list of cores in solr > via java code > > > Hi Erik, > > I just wanted to clarify if u got my concern right. If i send some documents > to the replica core wont it first have to send the documents to the leader > core which in turn would be sending it back to the replica cores. If yes > then this will lead to additional network traffic which can be avoided by > sending the documents directly to leader. > > Please correct me if I have got the concept incorrect.Any help is > appreciated > > > Thanks, > Vicky > > > > -- > View this message in context: > http://lucene.472066.n3.nabble.com/Is-it-possible-to-find-a-leader-from-a-list-of-cores-in-solr-via-java-code-tp4074994p4076016.html > Sent from the Solr - User mailing list archive at Nabble.com. -- Regards, Shalin Shekhar Mangar.
