How many shards?

For a given box - let us say 8 cores, 16G RAM, is there a correlation
between number of shards and the performance (response time/
throughput). My guess is that number of shards should be the same as
number of cores - is it true? dos it matter?

A single shard can utilize several cores happily. Its more a question of
load as each shard is a Lucene index, which comes with an overhead. Its
hard to answer such a question, you will need to run some tests as it
depends on the type of queries, type of data you index. But, the more
shards you have, the more resources that will be used on the machine.

On Tue, Nov 8, 2011 at 6:06 PM, Michael Feingold mfeingold@hill30.comwrote:

For a given box - let us say 8 cores, 16G RAM, is there a correlation
between number of shards and the performance (response time/
throughput). My guess is that number of shards should be the same as
number of cores - is it true? dos it matter?