On 10/16/2013 11:51 AM, Christopher Gross wrote: > Ok, so I think I was confusing the terminology (still in a 3.X mindset I > guess.) > > From the Cloud->Tree, I do see that I have "collections" for what I was > calling "core1", "core2", etc. > > So, to redo the above, > Servers: index1, index2, index3 > Collections: (on each) coll1, coll2 > Collection (core?) on index1: coll1new > > Each Collection has 1 shard (too small to make sharding worthwhile). > > So should I run something like this: > http://index1:8080/solr/admin/collections?action=CREATEALIAS&name=coll1&collections=col11new > > Or will I need coll1new to be on each of the index1, index2 and index3 > instances of Solr?
I don't think you can create an alias if a collection already exists with that name - so having a collection named core1 means you wouldn't want an alias named core1. I could be wrong, but just to keep things clean, I wouldn't recommend it, even if it's possible. That CREATEALIAS command will only work if coll1new shows up in /collections and shows green on the cloud graph. If it does, and you're using an alias name that doesn't already exist as a collection, then you're good. Whether coll1new is living on one server, two servers, or all three servers doesn't matter for CREATEALIAS, or for most other collection-related topics. Any query or update can be sent to any server in the cloud and it will be routed to the correct place according to the clusterstate. Where things live and how many replicas there are *does* matter for a discussion about redundancy. Generally speaking, you're going to want your shards to have at least two replicas, so that if a Solr instance goes down, or is taken down for maintenance, your cloud remains fully operational. In your situation, you probably want three replicas - so each collection lives on all three servers. So my general advice: Decide what name you want your application to use, make sure none of your existing collections are using that name, and set up an alias with that name pointing to whichever collection is current. Then change your application configurations or code to point at the alias instead of directly at the collection. When you want to do your reindex, first create a new collection using the collections API. Index to that new collection. When it's ready to go, use CREATEALIAS to update the alias, and your application will start using the new index. Thanks, Shawn
