Thanks for the detailed response Erik, you helped me a lot in clarifying many Solr concepts!
Best, Flavio On Mon, Jul 8, 2013 at 1:59 PM, Erick Erickson <erickerick...@gmail.com>wrote: > Flavio: > > I think you're missing a critical bit about SolrCloud, > namely Zookeeper (ZK), see here on the SolrCloud page > for a start: > http://wiki.apache.org/solr/SolrCloud#ZooKeeper > > You'll notice that each Solr node, when it is started, > requires the address of your ZK ensemble, NOT a > solr node. That allows ZK to "know" where all the > nodes are in your cluster. > > So each of the nodes "just knows" where all the other > shards are since that info is kept it ZK, so any request > to any node in the cluster "does the right thing", whether > update or query. So updates are forwarded to all > correct leaders, queries are sent to a member of > each shard etc, all automatically. > > Now take a look at CloudSolrServer (assuming that > you're using SolrJ from your client). The constructor > takes the address of ZK too. Using this info the client > code has access to information about the state of the > entire cluster, so you don't have to do anything, the > client code will just "know" how to connect to Solr. > > So for 1, 2 and 3 above, don't do anything <G>. Just > start up all the solr nodes with the proper > zkHost (or zkRun) parameter and send requests > to any node. You do NOT have to configure shards > in solrconfig.xml or anything else. > > > For <4>, I'm going to pass on the shard splitting details > since I haven't had time to dive into that yet. But increasing > capacity comes in two "flavors". If you simply need to > get more query throughput, just add more nodes. Solr > will assign them to "the right" shard (although you can > control this), copy the index for that shard down and > start automatically routing new requests to that node too. > > The second "flavor" is when your index is too big to fit > on your physical hardware and you need more shards (as > opposed to more replicas). Then you need to do the shard > splitting thing which I'm going to skip rather than > mislead you. > > Final note: The other thing that's confusing you I think is > the distinction between SolrCloud and Solr Master/Slave. > SolrCloud is the new way of doing things. Master/Slave > is a situation in where all the automatic stuff you can do with > SolrCloud must be done manually, things like assigning > documents to particular shards, configuring solrconfig.xml > with the addresses of all the other shards, all that stuff. > > Best > Erick > -- Flavio Pompermaier *Development Department *_______________________________________________ *OKKAM**Srl **- www.okkam.it* *Phone:* +(39) 0461 283 702 *Fax:* + (39) 0461 186 6433 *Email:* f.pomperma...@okkam.it *Headquarters:* Trento (Italy), fraz. Villazzano, Salita dei Molini 2 *Registered office:* Trento (Italy), via Segantini 23 Confidentially notice. This e-mail transmission may contain legally privileged and/or confidential information. Please do not read it if you are not the intended recipient(S). Any use, distribution, reproduction or disclosure by any other person is strictly prohibited. If you have received this e-mail in error, please notify the sender and destroy the original transmission and its attachments without reading or saving it in any manner.
