If localhost:8900 is down but localhost:8983 contain replica of the same
shard(s) that 8900 was running, all data/documents are still available.
You cannot query the shutdown server (port 8900), but you can query any
of the other servers (8983, 7574 or 7500). If you make a distributed
query to collection1 you should still be able to find all of your
documents, even though 8900 is down.
It is cumbersome to keep a list of crashed/shutdown servers, in order to
make sure you are always querying a server that is not down. The
information about what servers are running (and which are not) and which
replica they run are all in ZooKeeper. So basically, just go look in
ZooKeeper :-) Ahh, Solr has tool to help you do that - at least if you
are running your client in java-code. Solr implement different kinds of
clients (called XXXSolrServer - yes, obvious name for a client). There
are HttpSolrServer that can do queries against a particular server (wont
help you), there are LBHttpSolrServer that can do load-balancing over
several HttpSolrServers (ahh, still not there), and there are
CloudSolrServer that watches ZooKeeper in order to know what is running
and where to send requests. CloudSolrServer uses LBHttpSolrServer behind
the scenes. If you use CloudSolrServer as a client everything should be
smooth and transparent with respect to querying when servers are down.
CloudSolrServer will find out where to (and not to) route your requests.
Regards, Per Steffensen
On 18/02/14 14:05, Vineet Mishra wrote:
Hi All,
I want to have clear idea about the Fault Tolerant Capability of SolrCloud
Considering I have setup the SolrCloud with a external Zookeeper, 2 shards,
each having a replica with single collection as given in the official Solr
Documentation.
https://cwiki.apache.org/confluence/display/solr/Getting+Started+with+SolrCloud
*Collection1*
/ \
/ \
/ \
/ \
/ \
/ \
*Shard 1 Shard 2*
localhost:8983 localhost:7574
localhost:8900 localhost:7500
I Indexed some document and then if I shutdown any of the replica or Leader
say for ex- *localhost:8900*, I can't query to the collection to that
particular port
http:/*/localhost:8900*/solr/collection1/select?q=*:*
Then how is it Fault Tolerant or how the query has to be made.
Regards
