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From "Jack Krupansky" <>
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 

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
Subject: Re: SolrCloud Leaders

Here writes something:

Both leaders and replicas index items and perform searches.

How replicas index items?

2013/4/15 Furkan KAMACI <>

> 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 <>
>> 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:
>> Subject: SolrCloud Leaders
>> Does number of leaders at a SolrCloud is equal to number of shards?

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