On 2/3/2013 1:18 PM, Isaac Hebsh wrote:
Hi.
I have a SolrCloud cluster, which contains some servers. each server runs
multiple cores.
I want to distribute the requests over the running cores on each server,
without knowing the cores names in the client.
Question 1: Do I have any reason to do this (when indexing? when querying?).
All of these cores are sharing the same system resources, but I guess that
I still get a better performance if same amount of requests are going to
each core. Am I right?
If you are using a cloud-aware API (such as CloudSolrServer from SolrJ),
your client knows about your zookeeper setup. Behind the scenes, it
consults zookeeper about how to find the various servers and cores. You
never have to configure any core names on the client.
If you are not using a cloud-aware API, shouldn't you be talking to the
collection, not the cores? That is, talk to /solr/test, not
/solr/test_shard1_replica1 in your program. That should cause Solr
itself to figure out where the cores are and forward requests as
necessary. Couple that with a load balancer and it approaches what a
cloud-aware API gives you in terms of reliability.
From my attempts to help people in the IRC channel, I have concluded
that Solr 4.0 may use the name of the collection as the name of the core
on each server. I have not actually used SolrCloud in 4.0, so I cannot say.
Solr 4.1 does not do this. If you create a collection named test with 2
shards and 2 replicas with the collections API, you get the following
cores distributed among your servers:
test_shard1_replica1
test_shard1_replica2
test_shard2_replica1
test_shard2_replica2
Question 2:
I've implemented a nice ServletFilter, which replaces the magic name
"/randomcore/" with a random core name (retrieved from CoreContainer). I'm
using RequestDispatcher.forward, on the new URI. It works, very cool :)
But, for making it work, I had to set "<dispatcher>FORWARD</dispatcher>" on
SolrRequestFilter. this setting is explicitly inadvisable in web.xml. Can
anyone explain why?
No idea here.
Thanks,
Shawn
