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From Furkan KAMACI <furkankam...@gmail.com>
Subject Re: SolrCloud Leaders
Date Mon, 22 Apr 2013 13:41:15 GMT
Hi Jack;

You said: "An hour from now some other replica may be the leader"

What is the criteria to change a leader of a shard?

2013/4/15 Jack Krupansky <jack@basetechnology.com>

> 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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