Den 2015-10-22 17:54:44 skrev Shawn Heisey <apa...@elyograg.org>:
On 10/22/2015 8:29 AM, Nikolay Shuyskiy wrote:
I imagined that I could, say, add two new nodes to SolrCloud, and split
shard so that two new shards ("halves" of the one being split) will be
created on those new nodes.
Right now the only way to split shard in my situation I see is to create
two directories (shard_1_0 and shard_1_1) and mount new volumes onto
them *before* calling SPLITSHARD. Then I would be able to split shards,
and after adding two new nodes, these new shards will be replicated, and
I'll be able to clean up all the data on the first node.
The reason that they must be on the same node is because index splitting
is a *Lucene* operation, and Lucene has no knowledge of Solr nodes, only
the one index on the one machine.
Depending on the overall cloud distribution, one option *might* be to
add a replica of the shard you want to split to one or more new nodes
with plenty of disk space, and after it is replicated, delete it from
any nodes where the disk is nearly full. Then do the split operation,
and once it's done, use ADDREPLICA/DELETEREPLICA to arrange everything
the way you want it.
Thank you, that makes sense and is a usable alternative for us for the
time being.
Probably we have to consider using implicit routing for the future so that
we could add new nodes without dealing with splitting.
--
Yrs sincerely,
Nikolay Shuyskiy
