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From:Johan De Meersman Date:April 3 2012 10:26am
Subject:Re: HA & Scalability w MySQL + SAN + VMWare: Architecture Suggestion Wanted
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----- Original Message -----
> From: "Ian" <mysql3@stripped>
> 
> with each master having any number of slaves.  Set MySQL Proxy to
> send writes to the masters and reads to the slaves.

Yes, except when you have replication delays (asynchronous, remember?) like someone else
recently posted, your application writes a value, and consequently can't find it again.
Boom goes the software :-)

I'm sure proxy has it's uses, but I remain extremely sceptical about both performance and
trustworthyness of the read/write splitting scheme as long as the application isn't aware
of it.

Now, if you could somehow cough up a *context*, say, by having proxy pass all requests
from a connection that has done a write to the master, that would help, but...
 * it would yield less scaling - master must again serve some selects
 * with replication delays, you still risk updating the master based off old data from a
not-up-to-date slave
 * in a web context, connections are not permanent; to keep track of a single stream you'd
need the proxy to be aware of something like a browser session or whatnot

No, if you *really* want to do horizontal scaling, have a look at SchoonerSQL, Clustrix
and the like. They're third-party, but they (claim to) have proper multimaster
replication. I've not actually looked at any of them in depth myself - we're in an
environment where we have a lot of smaller clusters.


-- 
Bier met grenadyn
Is als mosterd by den wyn
Sy die't drinkt, is eene kwezel
Hy die't drinkt, is ras een ezel
Thread
HA & Scalability w MySQL + SAN + VMWare: Architecture SuggestionWantedWes Modes30 Mar
  • Re: HA & Scalability w MySQL + SAN + VMWare: Architecture SuggestionWantedRick James30 Mar
  • Re: HA & Scalability w MySQL + SAN + VMWare: Architecture SuggestionWantedKaren Abgarian30 Mar
  • Re: HA & Scalability w MySQL + SAN + VMWare: Architecture SuggestionWantedshawn green30 Mar
    • Re: HA & Scalability w MySQL + SAN + VMWare: Architecture SuggestionWantedWes Modes2 Apr
      • Re: HA & Scalability w MySQL + SAN + VMWare: Architecture SuggestionWantedRick James2 Apr
      • Re: HA & Scalability w MySQL + SAN + VMWare: Architecture SuggestionWantedshawn green2 Apr
        • Re: HA & Scalability w MySQL + SAN + VMWare: Architecture SuggestionWantedWes Modes2 Apr
          • Re: HA & Scalability w MySQL + SAN + VMWare: Architecture Suggestion WantedTim Dunphy3 Apr
          • Re: HA & Scalability w MySQL + SAN + VMWare: Architecture SuggestionWantedIan3 Apr
            • Re: HA & Scalability w MySQL + SAN + VMWare: Architecture Suggestion WantedJohan De Meersman3 Apr
            • Re: HA & Scalability w MySQL + SAN + VMWare: Architecture SuggestionWantedWes Modes3 Apr
            • Re: HA & Scalability w MySQL + SAN + VMWare: Architecture SuggestionWantedWes Modes4 Apr
        • Re: Replication rings/maatkit (was: HA & Scalability w MySQL + SAN+ VMWare)Wes Modes3 Apr
          • Re: Replication rings/maatkit (was: HA & Scalability w MySQL + SAN + VMWare)Eric Bergen3 Apr
Re: HA & Scalability w MySQL + SAN + VMWare: Architecture SuggestionWantedWes Modes4 Apr