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From:Johan De Meersman Date:November 4 2010 9:21am
Subject:Re: Replication on MySQL databases
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If your sites are busy with *writes*, you're kind of stuck. Replication
means that every write that happens on one side, also MUST happen on the
other side, so you win nothing. Well, you win a little delay on half of your
writes, which is, to most people, really a downside, not an upside.

Your best bet in that scenario would be horizontal partitioning, that is,
put part of your tables on a second cluster. This entails quite some changes
to your application, though, and a hefty analysis of what tables you NEVER
use together in a single query. Can be quite the bugger to implement :-)
Keep in the back of your mind (but never tell management) that you *can*
actually use federated tables for accessing remote tables, but there's
plenty of drawbacks to that.

If you're talking mostly reads, you have more options. Even then, though, it
is best if your application is keenly aware of what's going on, as you have
no guarantee about the time it takes for an insert to replicate to all your
slaves - your application shouldn't panic if it can't immediately see the
data it just wrote.

Other people here will undoubtedly tell you about MMM - I keep hearing that
that's pretty good, but I (still) have no personal experience with it,

On Thu, Nov 4, 2010 at 10:04 AM, Machiel Richards <machielr@stripped>wrote:

> Good day all
>      I am hoping that someone can perhaps help me with some resources
> or info.
>     I need to go to a meeting in the next hour and was requested this
> morning to research possible load balancing options for MySQL database.
>      What is currently running is a website (balanced over a couple of
> web servers all connecting to the same database) using apacje and jdk.
>       2 MySQL databases running as Masler/Slave replication with all
> reads and writes going to the master and the slave being used for data
> exports and failover if required.
>        The websites are rather busy and during times of high load the
> master server takes some strain.
>          The Databases are being to new upgraded hardware soon,
> including a database upgrade.
>         The idea is that they also want to introduce load balancing for
> the MySQL databases in order to manage the high load situations.
>        Any help would be appreciated as google has not yet turned up
> any sufficient info for me in this short time I had been given.
> Regards
> Machiel

Bier met grenadyn
Is als mosterd by den wyn
Sy die't drinkt, is eene kwezel
Hy die't drinkt, is ras een ezel

Replication on MySQL databasesMachiel Richards4 Nov
  • Re: Replication on MySQL databasesJohan De Meersman4 Nov
    • Re: Replication on MySQL databasesMachiel Richards4 Nov
      • Re: Replication on MySQL databasesWalter Heck5 Nov