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From Erick Erickson <erickerick...@gmail.com>
Subject Re: SolrCloud - leader updates not updating followers
Date Tue, 08 Aug 2017 17:22:38 GMT
This _better_ be a problem with your configuration or all my
assumptions are false ;)

What are you autocommit settings? The documents should be forwarded to
each replica from the leader during ingestion. However, they are not
visible on the follower until a hard commit(openSearcher=true) or soft
commit is triggered. Long blog on all this here:

https://lucidworks.com/2013/08/23/understanding-transaction-logs-softcommit-and-commit-in-sorlcloud/

An easy way to check that docs are being sent to the follower is to
tail solr.log and send a doc to the leader. You should see the doc
arrive at the follower. If you do see that then it's your autocommit
settings.

NOTE: Solr promises eventual consistency. Due to the fact that
autocommits will execute at different wall-clock times on the leaders
and followers you can be out of sync by up to your autocommit
interval.

You can force a commit by a URL like
"http://solr:port/solr/collection/update?commit=true" that will commit
on all replicas in a collection that may also be useful for seeing if
it's an autocommit issue.

Best,
Erick

On Tue, Aug 8, 2017 at 9:49 AM, lancasp22
<peter.lancaster@findmypast.com> wrote:
> Hi,
>
> I've recently created a solr cloud on solr 5.5.2 with a separate zookeeper
> cluster. I write to the cloud by posting to update/json and the documents
> appear fine in the leader.
>
> The problem I have is that new documents added to the cloud aren't then
> being automatically applied to the followers of each leader. If I query a
> core then I can get different counts depending on which version of the core
> the query ran over and the solr admin statistics page confirms that the
> followers have fewer documents and are behind the leader.
>
> If I restart the solr core for a follower, it does recover quickly and
> brings itself up-to-date with the leader. Looking at the logs for the
> follower you see that on re-start it identifies the leader and gets the
> changes from that leader.
>
> I think when documents are added to the leader these should be pushed to the
> followers so maybe it's this push process that isn't being triggered.
>
> It’s quite possible that I’ve made a simple error in the set-up but I’m
> baffled as to what it is. Please can anyone advise on any configuration that
> I need to check that might be causing these symptoms.
>
> Thanks in anticipation,
> Peter Lancaster.
>
>
>
>
> --
> View this message in context: http://lucene.472066.n3.nabble.com/SolrCloud-leader-updates-not-updating-followers-tp4349618.html
> Sent from the Solr - User mailing list archive at Nabble.com.

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