To clarify, solr indexes are not distributed in the same way that Cassandra data is stored.
With Cassandra, each node receives a fraction of the keyspace (based on your replication factor and token assignment). With DSE Search, writes to Cassandra are hooked and each node independently indexes its data and keeps this index on the local file system. If you have keyspace with RF=3 then three nodes will index each document. Indexes, unlike from Solr, only store the docids and the actual field values are stored in Cassandra. When it comes to search, DSE splits up the search so in the example above only one of those RF=3 nodes will be queried for a particular token range so that data can be unioned across all the nodes with different token ranges. Not sure about Solandra, but you do need to be aware that there's a number of Solr search options that are not supported on distribute searches/DSE Search. http://wiki.apache.org/solr/DistributedSearch http://wiki.apache.org/solr/FieldCollapsing Also, be aware that while Cassandra has knobs to allow you to get consistent read results (CL=QUORUM), DSE Search does not. If a node drops messages for whatever reason, outtage, mutation, etc. its solr indexes will be inconsistent with other nodes in its replication group. On Mon, Sep 30, 2013 at 1:06 PM, Robert Coli <rc...@eventbrite.com> wrote: > On Mon, Sep 30, 2013 at 8:50 AM, Ertio Lew <ertio...@gmail.com> wrote: > >> Solr's data is stored on the file system as a set of index files[ >> http://stackoverflow.com/a/7685579/530153]. Then why do we need anything >> like Solandra or DataStax Enterprise Search? Isn't Solr complete solution >> in itself ? What do we need to integrate with Cassandra ? >> > > Solr's index sitting on a single machine, even if that single machine can > vertically scale, is a single point of failure. > > The value add of DES is that the index has the same availability > characteristics as the underlying data, because it is stored in the same > cluster. > > =Rob > > -- *Ken Hancock *| System Architect, Advanced Advertising SeaChange International 50 Nagog Park Acton, Massachusetts 01720 ken.hanc...@schange.com | www.schange.com | NASDAQ:SEAC<http://www.schange.com/en-US/Company/InvestorRelations.aspx> Office: +1 (978) 889-3329 | [image: Google Talk:] ken.hanc...@schange.com | [image: Skype:]hancockks | [image: Yahoo IM:]hancockks [image: LinkedIn]<http://www.linkedin.com/in/kenhancock> [image: SeaChange International] <http://www.schange.com/>This e-mail and any attachments may contain information which is SeaChange International confidential. The information enclosed is intended only for the addressees herein and may not be copied or forwarded without permission from SeaChange International.
