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From:Bruce Dembecki Date:September 21 2005 3:04am
Subject:Re: Circular Replication
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On Sep 16, 2005, at 11:07 AM, Jeff wrote:

> There shouldn't be a problem if:
>
> server A is ver 4.0.x
> server B is ver 4.1.x
>
> should there?
>

There will totally by a problem here... The 4.1 server will take the  
4.0 feed without issue. The 4.1 server however puts all sorts of  
information into the binary log which isn't in the original query,  
like what sort of collation to use, and which character set it uses  
and so on... 4.0 doesn't understand such commands and lots of things  
break in this situation.

As a side note we deploy servers in pairs, with circular replication.  
We did three and four server circles, but it gets messy if  
replication stops somewhere, the data becomes unpredictably  
inconsistent (assuming all the servers in the circle are getting  
production updates). Now we do simple two way replication between a  
pair, and we hang a third server off the pair somewhere just  
reading... the third server we use for backups, data dumps, reports  
and other non production issues. Essentially it is something like A<- 
 >B->C, where A and B have two way replication and C is used for  
backups/reports etc... anything that changes the data happens on A or B.

We do some other black magic to manage the replication on C so it's  
perpetually behind the master servers by between 15 minutes and 2  
hours... that way if we have a stupid operator error or some other  
data corrupting event we can stop replication on the backup server  
before it executes and start from there rather than having to go back  
to yesterdays backup or something.

Best Regards, Bruce
Thread
Circular ReplicationJeff16 Sep
  • Re: Circular ReplicationDan Nelson16 Sep
    • RE: Circular ReplicationJeff16 Sep
      • Re: Circular ReplicationDevananda16 Sep
  • Re: Circular ReplicationStefan Kuhn16 Sep
    • Re: Circular ReplicationRaphaĆ«l 'SurcouF' Bordet27 Oct
      • Re: Circular ReplicationStefan Kuhn27 Oct
        • Re: Circular ReplicationJigal van Hemert27 Oct
          • Re: Circular ReplicationDevananda28 Oct
RE: Circular ReplicationJeff McKeon16 Sep
  • RE: Circular ReplicationJeff16 Sep
    • Re: Circular ReplicationDevananda16 Sep
      • Re: Circular ReplicationSid Lane19 Sep
        • Re: Circular ReplicationAlec.Cawley19 Sep
          • Re: Circular ReplicationSid Lane19 Sep
          • RE: Circular ReplicationJeff20 Sep
            • Re: Circular ReplicationDevananda20 Sep
    • Re: Circular ReplicationBruce Dembecki21 Sep
RE: Circular ReplicationJeff20 Sep
RE: Circular ReplicationJeff21 Sep
  • Re: Circular ReplicationBruce Dembecki22 Sep
    • Re: Circular ReplicationHank26 Sep
      • Re: Circular ReplicationHank26 Sep