Hi All,

I'm using Mysql 5 (with replication) on CentOS 4.4 OS with 2 CPU and 8GB
of RAM.
Master & Slave servers have same hardware configration.

Now i want to know, should i use slave server for fetching read only
queries.
if yes, then how ?.

Thanks
Ashok

On Fri, 07 Sep 2007 07:05:31 +0200, Ashok Chauhan <ashok.linux@gmail.com>
wrote:

> Hi All,
>
> I'm using Mysql 5 (with replication) on CentOS 4.4 OS with 2 CPU and 8GB
> of RAM.
> Master & Slave servers have same hardware configration.
>
> Now i want to know, should i use slave server for fetching read only
> queries.
> if yes, then how ?.

You could do it in the application logic, i.e. create a separate
connection to the slave server that you use for reading, or perhaps this
would be a good use of the MySQL Proxy <URL:
http://forge.mysql.com/wiki/MySQL_Proxy >.

In any case, you should be aware that the replication is not synchronous,
so there might be data on the master that has not yet been added to the
slave. Various things can affect this, such as heavy queries, for
instance. Wether or not this is a problem for you will depend on your
application.

One option could be to use slave servers for users or data where
up-to-date information is not necessarily required.

--
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

> On Fri, 07 Sep 2007 07:05:31 +0200, Ashok Chauhan <ashok.linux@gmail.com>
> wrote:
>
>> Hi All,
>>
>> I'm using Mysql 5 (with replication) on CentOS 4.4 OS with 2 CPU and 8GB
>> of RAM.
>> Master & Slave servers have same hardware configration.
>>
>> Now i want to know, should i use slave server for fetching read only
>> queries.
>> if yes, then how ?.
>
> You could do it in the application logic, i.e. create a separate
> connection to the slave server that you use for reading, or perhaps this
> would be a good use of the MySQL Proxy <URL:
> http://forge.mysql.com/wiki/MySQL_Proxy >.

This doesn't look like it will work just yet

http://forge.mysql.com/wiki/MySQL_Pr...from_writes.3F

Which is a real shame because I can't see that sqlrelay can do this either

http://sqlrelay.sourceforge.net/sqlr...lfailover.html

Dave

It seems that the trunk version supports RO/RW splitting:
http://jan.kneschke.de/2007/8/1/mysq...-r-w-splitting and
http://jan.kneschke.de/2007/8/26/mys...-r-w-splitting

--
Augusto Bott

On 9/7/07, dave@cpfc.org <dave@cpfc.org> wrote:
>
> > On Fri, 07 Sep 2007 07:05:31 +0200, Ashok Chauhan <ashok.linux@gmail.com
> >
> > wrote:
> >
> >> Hi All,
> >>
> >> I'm using Mysql 5 (with replication) on CentOS 4.4 OS with 2 CPU and
> 8GB
> >> of RAM.
> >> Master & Slave servers have same hardware configration.
> >>
> >> Now i want to know, should i use slave server for fetching read only
> >> queries.
> >> if yes, then how ?.
> >
> > You could do it in the application logic, i.e. create a separate
> > connection to the slave server that you use for reading, or perhaps this
> > would be a good use of the MySQL Proxy <URL:
> > http://forge.mysql.com/wiki/MySQL_Proxy >.
>
> This doesn't look like it will work just yet
>
>
> http://forge.mysql.com/wiki/MySQL_Pr...from_writes.3F
>
> Which is a real shame because I can't see that sqlrelay can do this either
>
> http://sqlrelay.sourceforge.net/sqlr...lfailover.html
>
> Dave
>
>
> --
> MySQL Replication Mailing List
> For list archives: http://lists.mysql.com/replication
> To unsubscribe:
> http://lists.mysql.com/replication?u...bott@gmail.com
>
>

Ashok Chauhan wrote:
> Hi All,
>
> I'm using Mysql 5 (with replication) on CentOS 4.4 OS with 2 CPU and 8GB
> of RAM.
> Master & Slave servers have same hardware configration.
>
> Now i want to know, should i use slave server for fetching read only
> queries.
> if yes, then how ?.
>
> Thanks
> Ashok
>
>

The simple way is to use the --read-only startup parameter on the slave.
The only updates it will allow must come through replication or from a
SUPER user.

http://dev.mysql.com/doc/refman/5.0/...sqld_read_only



--
Shawn Green, Support Engineer
MySQL Inc., USA, www.mysql.com
Office: Blountville, TN
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