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From "Jack Krupansky" <j...@basetechnology.com>
Subject Re: SolrCloud Leaders
Date Mon, 15 Apr 2013 14:23:57 GMT
All nodes are replicas in SolrCloud since there are no masters. It's a fully 
distributed model. A leader is also a replica. A leader is simply a replica 
which was elected to be a leader, for now. An hour from now some other 
replica may be the leader.

It is indeed misleading and inaccurate to suggest that "leader" and 
"replicas" are disjoint.

Once again, I think you are confusing SolrCloud with the older Solr 
master/slave/replication.

Every node in SolrCloud can do indexing. That's the same as saying that 
every replica in SolrCloud can do indexing.

Although we do need to be clear that a given replica will only index 
documents for the shard(s) to which it belongs.

-- Jack Krupansky

-----Original Message----- 
From: Furkan KAMACI
Sent: Monday, April 15, 2013 9:38 AM
To: solr-user@lucene.apache.org
Subject: Re: SolrCloud Leaders

Here writes something:
https://support.lucidworks.com/entries/22180608-Solr-HA-DR-overview-3-x-and-4-0-SolrCloud-and
says:

Both leaders and replicas index items and perform searches.

How replicas index items?


2013/4/15 Furkan KAMACI <furkankamaci@gmail.com>

> Does leaders may response search requests (I mean do they store indexes)
> at when I run SolrCloud at first and after a time later?
>
>
> 2013/4/15 Jack Krupansky <jack@basetechnology.com>
>
>> When the cluster is fully operational, yes. But if part of the cluster is
>> down or split and unable to communicate, or leader election is in 
>> progress,
>> the actual count of leaders will not be indicative of the number of 
>> shards.
>>
>> Leaders and shards are apples and oranges. If you take down a cluster, by
>> definition it would have no leaders (because leaders are running code), 
>> but
>> shards are the files in the index on disk that continue to exist even if
>> the code is not running. So, in the extreme, the number of leaders can be
>> zero while the number of shards is non-zero on disk.
>>
>> -- Jack Krupansky
>>
>> -----Original Message----- From: Furkan KAMACI
>> Sent: Monday, April 15, 2013 8:21 AM
>> To: solr-user@lucene.apache.org
>> Subject: SolrCloud Leaders
>>
>>
>> Does number of leaders at a SolrCloud is equal to number of shards?
>>
>
> 


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