On 6/19/2015 11:15 AM, Jim.Musil wrote: > I noticed that when I issue the CREATE collection command to the api, it does > not automatically put a replica on every live node connected to zookeeper. > > So, for example, if I have 3 solr nodes connected to a zookeeper ensemble and > create a collection like this: > > /admin/collections?action=CREATE&name=my_collection&numShards=1&replicationFactor=1&maxShardsPerNode=1&collection.configName=my_config > > It will only create a core on one of the three nodes. I can make it work if I > change replicationFactor to 3. When standing up an entire stack using chef, > this all gets a bit clunky. I don't see any option such as "ALL" that would > just create a replica on all nodes regardless of size. > > I'm guessing this is intentional, but curious about the reasoning.
If you tell it replicationFactor=1, then you get exactly that -- one copy of your index. I personally think that it would be a violation of something known as "the principle of least surprise" for Solr to automatically create replicas without being asked to. I would assume that if you are writing automated tools to build indexes and the servers hosting those indexes that your automation will be able to calculate a reasonable replicationFactor, or calculate the number of hosts to create based on a provided replicationFactor. A feature to have Solr itself automatically calculate a replicationFactor based on the number of available hosts and the numShards value provided is not a bad idea. Please create a feature request issue in Jira. One way that this might be done is by setting replicationFactor to "auto" or maybe a special number, perhaps 0 or -1. https://issues.apache.org/jira/browse/SOLR Thanks, Shawn
