Comments on Cars N Code: Switchable Grails DataSource

Only suggestion I have is to try and debug through...

2011-11-18T07:18:05.560+10:00

Only suggestion I have is to try and debug through the DBCP code and see where it's getting too. Maybe there are some bean properties missing/wrong?

Thanks for your reply, Lee. I get the following ex...

2011-11-18T07:11:05.097+10:00

Thanks for your reply, Lee. I get the following exception after the connection attempt times out:

org.hibernate.util.JDBCExceptionReporter Cannot get a connection, pool error Timeout waiting for idle object

Nothing else interesting is logged, even when I turn on debug for all classes. MySQL general logging, interestingly, shows that grails is connecting to the database during startup, but nothing further is logged afterward.

Can't think of any reason why a pooled data so...

2011-11-18T06:00:00.674+10:00

Can't think of any reason why a pooled data source shouldn't work. What kind of errors are you getting?

Hi Lee - we discovered during load testing that th...

2011-11-18T02:44:30.277+10:00

Hi Lee - we discovered during load testing that this solution (which does work great otherwise) does not implement database connection pooling. Is there any particular reason why the DriverManagerDataSource must be used instead of a pooling one?

I substituted BasicDataSource for it in the code (making sure the maxActive, initialSize, etc. properties were read into the bean), but Hibernate is unable to make a connection after Grails starts up. I just wanted to see if there was a compelling reason not to use a pooling datasource before I go too deep into the rabbit hole. Thanks again!

Hi, I don't have any free time at the moment ...

2011-11-14T05:08:12.042+10:00

Hi,
I don't have any free time at the moment to do a plugin, sorry!

We were trying during many days to use grails mult...

2011-11-14T03:52:23.450+10:00

We were trying during many days to use grails multi tenant plugin in singleTenant mode without success.
We will try your solution.
Is it possible to make it a plugin?

Hi Lee - thanks for supplying this great informati...

2011-10-21T04:09:11.307+10:00

Hi Lee - thanks for supplying this great information. In regard to my previous posts, where it seemed that SwitchableDataSource.determineTargetDataSource() was getting called in an infinite loop, I was mistaken. I was using a couple of remote databases, and while the method is called many times (resulting in my integration tests timing out), it is not infinite, and when I point to local databases, your solution works perfectly. Thanks again!

I haven't used the spring security plugin befo...

2011-10-16T06:16:00.721+10:00

I haven't used the spring security plugin before but if it uses the standard grails dataSource bean then it would work. You would need to find the right place in the filter chain to switch the dataSource though. You should be able to use a Filter to do that.

Hi, Is it possible to use springsecurity plugin f...

2011-10-16T00:37:43.642+10:00

Hi,

Is it possible to use springsecurity plugin for switching database?

1. Keep user/authentication/requestmap details in master database.

2. Login using spring security from database.

3. Once the login is successful, switch the database based on user.

Regards,

Kishore

Not an issue that I have seen before sorry, cheer...

2011-10-11T07:04:14.229+10:00

Not an issue that I have seen before sorry,

cheers

Lee

Hi Lee, thanks for your response. No, I don't ...

2011-10-11T06:04:18.171+10:00

Hi Lee, thanks for your response. No, I don't get any error - Grails just keeps calling SwitchableDataSource.determineTargetDataSource() every few seconds, and the application just seems to hang. I have fitted your code into our application though, so it is not an exact copy of your demo code.

However, the fact that Grails seems to be hung up on resources.groovy and doesn't even run the other application code made me wonder if this was a known issue.

Is it a StackOverflowError? I havent' seen any...

2011-10-11T04:55:31.906+10:00

Is it a StackOverflowError? I havent' seen any problem like that before sorry,

Thanks for this post! Unfortunately, I get what se...

2011-10-11T04:28:57.016+10:00

Thanks for this post! Unfortunately, I get what seems to be an infinite loop, where Grails keeps calling SwitchableDataSource.determineTargetDataSource() and never moves on.

If I comment out the following in resources.groovy:
dataSource(SwitchableDataSource) {
targetDataSources = dataSources

}

Then I don't see the problem (but then of course the SwitchableDataSource is not used). Have you or anyone here seen this behavior before? Thanks again!

Hi, are you trying to use a different dialect for...

2011-09-30T17:56:28.040+10:00

Hi,

are you trying to use a different dialect for each data source?

That isn't possible as the Hibernate plugin creates a single session factory and looks up the dialect as it bootstraps.

You would need to somehow create a new sessionFactory for each dataSource and switch them like we switch the dataSources.

If you just want to use the oracle dialect then the usual place in DataSource.groovy will still work.

cheers

Lee

Lee - where in your structure would you add dialec...

2011-09-30T16:00:45.065+10:00

Lee - where in your structure would you add dialect for the times it is needed; such as:

dialect = "org.hibernate.dialect.Oracle10gDialect"

Sorry Kishore, I'm really busy at the moment. ...

2011-09-20T07:16:52.504+10:00

Sorry Kishore, I'm really busy at the moment. Someone on the Grails User mailing list or StackOverflow might take a look.

I have uploaded switchable data source project sou...

2011-09-19T19:46:06.782+10:00

I have uploaded switchable data source project source code [ https://docs.google.com/leaf?id=0B3j9inzR_LLhMzIyYzI3MmEtMjRjMS00Mjc1LTg2Y2YtMTI3NTM3MzA0Nzg0&hl=en_US ] and problem description [ https://docs.google.com/leaf?id=0B3j9inzR_LLhOTNhYTQ0OTYtNGM5Yi00YjIwLThkODMtNjU2YmE3YTk0NWE3&hl=en_US ].

Can I get help on this?

Thanks,
Kishore

Take a look at the documentation for GenericApplic...

2011-08-31T20:17:21.743+10:00

Take a look at the documentation for GenericApplicationContext. You can call registerBeanDefinition and override the definition for "dataSource"

Thanks Lee. I created controller which implements ...

2011-08-27T20:44:26.745+10:00

Thanks Lee.
I created controller which implements ApplicationContextAware.

import org.springframework.context.ApplicationContextAware
import org.springframework.context.ApplicationContext
import org.springframework.beans.BeansException

class DataSrcController implements ApplicationContextAware {

private static ApplicationContext ctx = null;
public static ApplicationContext getApplicationContext() {
return ctx;
}
public void setApplicationContext(ApplicationContext ctx) throws BeansException {
// Assign the ApplicationContext into a static method
this.ctx = ctx;
}

}

But, no idea how to create beans here.Could you please help

Your controller can implement ApplicationContex...

2011-08-16T22:41:00.678+10:00
Your controller can implement ApplicationContextAware which will give you access to the Grails ApplicationContext. You should then be able to register a new BeanDefinition for the new datasource. You will need to create the BeanDefinition to match the settings in resources.groovy including getting the correct parent bean definition from the ApplicationContext. The rest of the code should all still work once the new datasource bean definition has been added to the ApplicationContext.

Hi, I'm currently using this code. It is work...

2011-08-16T22:23:50.233+10:00
Hi,

I'm currently using this code. It is working perfectly fine.
Now, I need add another functionality to it. Can anyone help me on this?

The requirement is:
Currently it is possible to create datasources from resources.groovy file (which is one time). Bit, I should be able to add a datasource dynamically from controller call.

Please share your ideas.

- kishore

Hi Rodrigo, that's a mistake, the env param i...

2011-07-11T06:00:47.999+10:00
Hi Rodrigo,

that's a mistake, the env param is not actually used. The spring datasource uses the EnvironmentHolder class to lookup the right data source for the current thread.

Hi, why do you have a parameter in the function ...

2011-07-11T02:02:35.410+10:00
Hi,

why do you have a parameter in the function getDataSourceForEnv(env) ?

It is not being used. Shouldnt it be used to cretae a neew Datasource with the environment Data?

Thanks!

Hi, I have a question: why do you have a paramet...

2011-07-11T02:00:58.846+10:00
Hi, I have a question:

why do you have a parameter in the function

private def getDataSourceForEnv(env) {
def servletContext = ServletContextHolder.servletContext
def ctx = servletContext
.getAttribute(
ApplicationAttributes.APPLICATION_CONTEXT)
return ctx.dataSource
}

you ar not using the parameter "env" ... is that ok? shouldnt you be using the parameter there?
Thanks

Great worked perfectly. Thanks for the post.

2011-06-23T22:54:20.628+10:00
Great worked perfectly.
Thanks for the post.