You have to assign the preferredLeader role first. You can do that node-by-node via ADDREPLICAPROP or have the system do it for you with BALANCESHARDUNIQUE.
As I said before, in SolrCloud the leader forwards the raw document to each follower. There is no pre-processing, analysis anything else done on the leader first. Best, Erick On Mon, Jan 11, 2016 at 9:19 AM, Gian Maria Ricci - aka Alkampfer <alkamp...@nablasoft.com> wrote: > Thanks. > > This arise a different question: when I index a document, it is assigned to > one of the three shard based on the value of the ID field. Actually indexing > a document is usually a CPU and RAM intensive work to parse text, tokenize, > etc. How this works in SolrCloud? I probably incorrectly assumed that the > indexing task is carried out by the shard leader, then data is propagated to > replica of that shard. This lead me to think that, having all three leader > shards in a node, it does not use other nodes to index data and performance > will suffer. > > I've tried to use REBALANCELEADERS but nothing changes (probably because > there are few shards). > > -- > Gian Maria Ricci > Cell: +39 320 0136949 > > > > -----Original Message----- > From: Shawn Heisey [mailto:apa...@elyograg.org] > Sent: lunedì 11 gennaio 2016 17:49 > To: solr-user@lucene.apache.org > Subject: Re: Change leader in SolrCloud > > On 1/11/2016 8:45 AM, Gian Maria Ricci - aka Alkampfer wrote: >> Due to the different reboot times probably, I’ve noticed that upon >> reboot all three leader shards are on a single machine. I’m expecting >> shard leaders to be distributed evenly between machines, because if >> all shard leader are on a same machine, all new documents to index >> will be routed to the same machine, thus indexing load is not subdivided. > > You're looking for the REBALANCELEADERS functionality ... but because you > only have three nodes, the fact that one machine has the leaders for all > three shards is not really a problem. > > https://cwiki.apache.org/confluence/display/solr/Collections+API#CollectionsAPI-RebalanceLeaders > > This feature was added for a use case where there are hundreds of nodes and > hundreds of total shards, with the leader roles heavily concentrated on a > small number of nodes. With REBALANCELEADERS, the leader roles can be spread > more evenly around the cluster. > > It is true that the shard leader does do a small amount of extra work, but > for a very small installation like yours, the overhead is nothing to be > concerned about. You can do something about it if it bothers you, though. > > Thanks, > Shawn >
