bq: However what will happen to that 10 nodes when I specify replication factor?
I think they just sit around doing nothing. Best Erick On Mon, Apr 22, 2013 at 7:24 AM, Furkan KAMACI <[email protected]> wrote: > Sorry but if I have 10 shards and a collection with replication factor of 1 > and if I start up 30 nodes what happens to that last 10 nodes? I mean: > > 10 nodes as leader > 10 nodes as replica > > if I don't specify replication factor there was going to be a round robin > system that assigns other 10 machine as: > + 10 nodes as replica > > However what will happen to that 10 nodes when I specify replication factor? > > > 2013/4/22 Erick Erickson <[email protected]> > >> 1) Imagine you have lots and lots and lots of different Solr indexes >> and a 50 node cluster. Further imagine that one of those indexes has 2 >> shards, and a leader + shard is adequate to handle the load. You need >> some way to limit the number of nodes your index gets distributed to, >> that's what replicationFactor is for. So in this case >> replicationFactor=2 will stop assigning nodes to that particular >> collection after there's a leader + 1 replica >> >> 2> In the system you described, there won't be more than one >> shard/node. But one strategy for growth is to "overshard". That is, in >> the early days you put (numbers from thin air) 10 shards/node and they >> are all quite small. As your index grows, you move to two nodes with 5 >> shards each. And later to 5 nodes with 2 shards and so on. There are >> cases where you want some way to make the most of your hardware yet >> plan for expansion. >> >> Best >> Erick >> >> On Sun, Apr 21, 2013 at 3:51 PM, Furkan KAMACI <[email protected]> >> wrote: >> > I know that: when using SolrCloud we define the number of shards into the >> > system. When we start up new Solr instances each one will be a a leader >> for >> > a shard, and if I continue to start up new Solr instances (that has >> > exceeded the number number of shards) each one will be a replica for each >> > leader as a round robin process. >> > >> > However when I read wiki there are two parameters: *replicationFactor >> *and * >> > maxShardsPerNode. >> > >> > *1) Can you give details about what are they. If all newly added Solr >> > instances becomes a replica what is that replication factor for? >> > 2) If what I wrote is true about that round robin process what is that * >> > maxShardsPerNode*? How can be more than one shard at the system I >> described? >>
