Comments on: Load balancing across MySQL servers using JDBC

By: Todd Huss

Todd Huss — Sun, 13 Aug 2006 20:19:46 +0000

Hi Andy, last time I checked the Spring source code, they had changed it so that it doesn’t call conn.setReadOnly so I do it myself in my own Spring interceptor. The best way to be sure is to try it yourself with some real code though and see.

By: Andy

Andy — Sun, 06 Aug 2006 12:58:23 +0000

hi,
i am using the Spring transaction framework. this should set readOnly(true) automatically?

i am right ?

By: Todd Huss

Todd Huss — Wed, 31 May 2006 16:00:38 +0000

Hibernate will not do it for you so the latter is what you need to do, however, I would abstract all of the transaction management and setting readonly of the connection out as an interceptor.

By: Jack Gorden

Jack Gorden — Wed, 31 May 2006 12:47:45 +0000

One question regarding Hibernate … does it do the required con.setReadOnly calls behind the scenes or did you use the raw connection?

@@ Read/Write @@

factory.getCurrentSession().beginTransaction();

// Do some work
factory.getCurrentSession().save(…);

factory.getCurrentSession().getTransaction().commit();

Or:

boolean readOnly = factory.getCurrentSession().connection().getReadOnly();
factory.getCurrentSession().connection().setReadOnly(false);
factory.getCurrentSession().beginTransaction();

// Do some work
factory.getCurrentSession().save(…);

factory.getCurrentSession().getTransaction().commit();
factory.getCurrentSession().connection().setReadOnly(readOnly);

@@ Read-Only @@

factory.getCurrentSession().beginTransaction();

// Do some work

factory.getCurrentSession().getTransaction().commit();

Or:

boolean readOnly = factory.getCurrentSession().connection().getReadOnly();
factory.getCurrentSession().connection().setReadOnly(true);
factory.getCurrentSession().beginTransaction();

// Do some work

factory.getCurrentSession().getTransaction().commit();
factory.getCurrentSession().connection().setReadOnly(readOnly);

By: Mathias Bogaert

Mathias Bogaert — Thu, 02 Feb 2006 10:17:57 +0000

Exactly what I needed. Didn’t know this was possible, thanks!

By: Mark Matthews

Mark Matthews — Wed, 01 Feb 2006 17:33:46 +0000

Todd,

Let me know how it goes, and if you find any issues that need to be addressed! I’m always glad to see folks try this kind functionality, as I think it’s one of the value-add’s MySQL’s JDBC driver brings.