Yes, you're right, from now on when I say that, I'll say "except
shards". It is true.
My understanding is that shards functionality's intended use case is for
when your index is so large that you want to split it up for
performance. I think it works pretty well for that, with some
limitations as you mention.
From reading the list, my impression is that when people try to use
shards to solve some _other_ problem, they generally run into problems.
But maybe that's just because the people with the problems are the ones
who appear on the list?
My personal advice is still to try and put everything together in one
big index, Solr will give you the least trouble with that, it's what
Solr "likes" to do best; move to shards certainly if your index is so
large that moving to shards will give you performance advantage you
need, that's what they're for; be very cautious moving to shards for
other challenges that 'one big index' is giving you that you're thinking
shards will solve. Shards is, as I understand it, _not_ intended as a
general purpose "federation" function, it's specifically intended to
split an index accross multiple hosts for performance.
Jonathan
On 2/16/2011 4:37 PM, Bob Sandiford wrote:
Hmmm. Maybe I'm not understanding what you're getting at, Jonathan, when you
say 'There is no good way in Solr to run a query across multiple Solr indexes'.
What about the 'shards' parameter? That allows searching across multiple cores
in the same instance, or shards across multiple instances.
There are certainly implications here (like Relevance not being consistent
across cores / shards), but it works pretty well for us...
Thanks!
Bob Sandiford | Lead Software Engineer | SirsiDynix
P: 800.288.8020 X6943 | bob.sandif...@sirsidynix.com
www.sirsidynix.com
-----Original Message-----
From: Jonathan Rochkind [mailto:rochk...@jhu.edu]
Sent: Wednesday, February 16, 2011 4:09 PM
To: solr-user@lucene.apache.org
Cc: Thumuluri, Sai
Subject: Re: Solr multi cores or not
Solr multi-core essentially just lets you run multiple seperate
distinct
Solr indexes in the same running Solr instance.
It does NOT let you run queries accross multiple cores at once. The
cores are just like completely seperate Solr indexes, they are just
conveniently running in the same Solr instance. (Which can be easier
and
more compact to set up than actually setting up seperate Solr
instances.
And they can share some config more easily. And it _may_ have
implications on JVM usage, not sure).
There is no good way in Solr to run a query accross multiple Solr
indexes, whether they are multi-core or single cores in seperate Solr
doesn't matter.
Your first approach should be to try and put all the data in one Solr
index. (one Solr 'core').
Jonathan
On 2/16/2011 3:45 PM, Thumuluri, Sai wrote:
Hi,
I have a need to index multiple applications using Solr, I also have
the
need to share indexes or run a search query across these application
indexes. Is solr multi-core - the way to go? My server config is
2virtual CPUs @ 1.8 GHz and has about 32GB of memory. What is the
recommendation?
Thanks,
Sai Thumuluri
