It's a little bit off-topic but have a look at "How to set up a load-balanced MySQL cluster" (http://www.howtoforge.com/loadbalanced_mysql_cluster_debian). If you use a load-balancing server in front of the mysql cluster you don't have to change your application. The HowTo uses UltraMonkey to wrap the cluster behind a virtual IP that you have to use in your application. It works fine.
> -----Ursprüngliche Nachricht----- > Von: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Im Auftrag von Will Glass-Husain > Gesendet: Dienstag, 5. Dezember 2006 23:43 > An: Apache Torque Users List; [EMAIL PROTECTED] > Betreff: Re: duplicate ID exception in cluster > > > Hi Henning! > > It's a real (Tomcat) cluster. Two instances of Tomcat > talking to a single database. (no database replication). I > use Apache/mod_jk to split requests (based on session) > between the two Tomcats. Allows me to run high number of > users with a memory-heavy application. > > Thought briefly about database replication but since this is > write-heavy application it didn't seem to make sense. > > thanks, > WILL > > On 12/5/06, Henning P. Schmiedehausen <[EMAIL PROTECTED]> wrote: > > "Will Glass-Husain" <[EMAIL PROTECTED]> writes: > > > > >Hi, > > > > >I just set up a new 2 server cluster with two instances of Tomcat > > >both reading/writing from a single database. I'm using > Torque 3.0, > > >the default ID Broker and MySQL 5. (InnoDB) > > > > Real cluster or just master/slave (or master/master with only one > > master active at a time)? The latter is just replication, > not a real > > cluster. > > > > >My problem... Under heavy load, I notice that most write > requests on > > >one of the servers fails with a duplicate ID error. > Typically, each > > >page request that fails does 10-20 insert statements. > > > > >Any tips as to how I might make this cluster work with > simultaneous > > >writes? > > > > a) in a master/master config, you can not write to both > masters at the > > same time. End of story. I had a summer project where we tested > > exactly that *very* extensively. It does not work. No > matter what you > > google on the internet or what mysql.com wants to tell > you. You will > > get the described error sooner or later. If you want to have > > master/master with failover, that is fine. Two active > masters not. > > > > b) you probably run into the AUTO_INCREMENT problem. Make > sure that you > > have 5.0.20 at least. See > http://dev.mysql.com/doc/refman/5.0/en/replication-features.html > > for some docs. > > > > > > Best regards > > Henning > > > > -- > > Henning P. Schmiedehausen -- [EMAIL PROTECTED] | J2EE, Linux, > > 91054 Buckenhof, Germany -- +49 9131 506540 | Apache person > > Open Source Consulting, Development, Design | Velocity - Turbine guy > > > > "Save the cheerleader. Save the world." > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > -- > Forio Business Simulations > > Will Glass-Husain > [EMAIL PROTECTED] > www.forio.com > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
