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From Andrus Adamchik <and...@objectstyle.org>
Subject Re: Reconnecting automatically after DB downtime
Date Tue, 08 Mar 2016 14:37:29 GMT
Also pretty easy - define a custom DataSourceFactory:

builder.addModule(b -> b.bind(DataSourceFactory.class).to(MyImpl.class));

Andrus

> On Mar 8, 2016, at 3:20 AM, Hugi Thordarson <hugi@karlmenn.is> wrote:
> 
> Not quite done :).
> 
> I have a project that uses multiple Cayenne models connected to multiple databases. The
connection information is currently stored in the models and I’m constructing the ServerRuntime
like this:
> 
> ServerRuntimeBuilder b = new ServerRuntimeBuilder( "Netbokhald" );
> b.addConfig( "cayenne-core/cayenne-project.xml" );
> b.addConfig( "cayenne-reporting/cayenne-project.xml" );
> 
> How would I go about programmatically configuring separate DataSources for each model?
> 
> Cheers,
> - hugi
> 
> 
> 
>> On 7. mar. 2016, at 21:03, Hugi Thordarson <hugi@karlmenn.is> wrote:
>> 
>> Well, that was easy! Up and running in production.
>> 
>> HikariConfig config = new HikariConfig();
>> config.setJdbcUrl( "jdbc:mysql://server:3306/database?useUnicode=true&characterEncoding=utf8&autoReconnect=true&connectTimeout=0"
);
>> config.setUsername( “myUsername" );
>> config.setPassword( “myPassword" );
>> 
>> HikariDataSource dataSource = new HikariDataSource( config );
>> serverRuntimeBuilder = serverRuntimeBuilder.dataSource( dataSource );
>> 
>> Thanks,
>> - hugi
>> 
>> 
>>> On 7. mar. 2016, at 20:51, Andrus Adamchik <andrus@objectstyle.org> wrote:
>>> 
>>> Yep. Cayenne built-in pool is intentionally basic with a minimal number of features
(Here we may be dealing with a bug though, and I'd like to fix it, but that's a separate issue).
So yeah, using a third party DS may be a good idea. Here is an example how you can set it
up:
>>> 
>>> DataSource ds = // instantiate it via API specific to you DS provider
>>> 
>>> ServerRuntime runtime = ServerRuntimeBuilder.builder().dataSource(ds).build();
>>> // of course add any other things you need to add to the builder to get a working
Cayenne stack.
>>> 
>>> Andrus
>>> 
>>> 
>>>> On Mar 7, 2016, at 12:45 PM, Hugi Thordarson <hugi@karlmenn.is> wrote:
>>>> 
>>>> Thanks John! I’m going to try my hand at HikariCP.
>>>> 
>>>> Are there any examples anywhere on how to configure Cayenne to use a third
party connection pool?
>>>> 
>>>> Cheers,
>>>> - hugi
>>>> 
>>>> 
>>>> 
>>>> 
>>>>> On 7. mar. 2016, at 20:39, John Huss <johnthuss@gmail.com> wrote:
>>>>> 
>>>>> EOF can do JNDI, but that's not going to do anything to fix your problem.
>>>>> 
>>>>> The connection pool in cayenne had some changes somewhat recently so
it's
>>>>> entirely possible there are bugs.
>>>>> 
>>>>> In practice it turns out many people don't use the connection pool built-in
>>>>> to Cayenne at all, and rather use a third-party connection pool, of which
>>>>> there are several.  The cayenne one is decent, but it is very limited
in
>>>>> functionality and less robust due to having a smaller user base and being
a
>>>>> non-core feature.
>>>>> 
>>>>> You can use another pool like:
>>>>> hikari <https://github.com/brettwooldridge/HikariCP> - If I was
starting a
>>>>> new project I'd use this
>>>>> tomcat-jdbc <https://tomcat.apache.org/tomcat-7.0-doc/jdbc-pool.html>
-
>>>>> This is what I currently use
>>>>> commonds-dbcp <https://commons.apache.org/proper/commons-dbcp/>
>>>>> c3po <http://www.mchange.com/projects/c3p0/>
>>>>> 
>>>>> The main reason I turned to a third-party connection pool was to get
>>>>> fair-scheduling which will provide connections to whoever has been waiting
>>>>> the longest, which helps avoid unnecessary errors caused by serving
>>>>> requests out of order.
>>>>> 
>>>>> John
>>>>> 
>>>>> On Mon, Mar 7, 2016 at 2:31 PM Michael Gentry <mgentry@masslight.net>
wrote:
>>>>> 
>>>>>> Well, I'm not sure what you are using to run your web application,
but
>>>>>> Tomcat, Jetty, JBoss, etc all have mechanisms to provide JNDI lookups
of DB
>>>>>> connection pools.  You just tell Cayenne Modeler to use JNDI lookup
and
>>>>>> give it the JNDI name, then configure the container to provide the
DB
>>>>>> connection.
>>>>>> 
>>>>>> Is your WO application using EOF or Cayenne?  Been a while since
I used WO,
>>>>>> but I'd be stunned if EOF cannot use a JNDI lookup as well.
>>>>>> 
>>>>>> mrg
>>>>>> 
>>>>>> 
>>>>>> On Mon, Mar 7, 2016 at 3:07 PM, Hugi Thordarson <hugi@karlmenn.is>
wrote:
>>>>>> 
>>>>>>> Hi Michael,
>>>>>>> does using JNDI change anything about the connection itself,
isn’t it
>>>>>> just
>>>>>>> a different method of looking up connection information?
>>>>>>> 
>>>>>>> But I probably can’t use it anyway since one of the apps is
a WebObjects
>>>>>>> app and doesn’t provide a JNDI service (at least I’ve never
used it).
>>>>>>> 
>>>>>>> Thanks,
>>>>>>> - hugi
>>>>>>> 
>>>>>>> 
>>>>>>>> On 7. mar. 2016, at 19:13, Michael Gentry <mgentry@masslight.net>
>>>>>> wrote:
>>>>>>>> 
>>>>>>>> Hi Hugi,
>>>>>>>> 
>>>>>>>> Since this appears to be a web-based application, can you
switch to
>>>>>> using
>>>>>>>> JNDI?
>>>>>>>> 
>>>>>>>> mrg
>>>>>>>> 
>>>>>>>> 
>>>>>>>> On Mon, Mar 7, 2016 at 5:46 AM, Hugi Thordarson <hugi@karlmenn.is>
>>>>>>> wrote:
>>>>>>>> 
>>>>>>>>> Hi all,
>>>>>>>>> This is still happening, even after I added a validationQuery,
our app
>>>>>>> is
>>>>>>>>> dying quite frequently :(.  I’m not quite sure how
to debug this, is
>>>>>>> there
>>>>>>>>> any way for me to catch where connections are being opened
in the code
>>>>>>> and
>>>>>>>>> at what location they’re hanging?
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>> 
>>>>>> https://www.dropbox.com/s/8jkmh6513s6wwkn/Screenshot%202016-03-07%2010.21.53.png?dl=0
>>>>>>>>> 
>>>>>>>>> Cheer,
>>>>>>>>> - hugi
>>>>>>>>> 
>>>>>>>>> // Hugi Thordarson
>>>>>>>>> // http://www.loftfar.is/
>>>>>>>>> // s. 895-6688
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>>> On 29. feb. 2016, at 11:25, Andrus Adamchik <andrus@objectstyle.org>
>>>>>>>>> wrote:
>>>>>>>>>> 
>>>>>>>>>> 
>>>>>>>>>>> On Feb 29, 2016, at 2:20 PM, Hugi Thordarson
<hugi@karlmenn.is>
>>>>>>> wrote:
>>>>>>>>>>> 
>>>>>>>>>>> What does validationQuery do?
>>>>>>>>>> 
>>>>>>>>>> Periodically executes for each pooled connection,
and kills
>>>>>> connections
>>>>>>>>> that throw during validation. So it ensures that all
pooled
>>>>>> connections
>>>>>>> are
>>>>>>>>> in a good state.
>>>>>>>>>> 
>>>>>>>>>> Andrus
>>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>> 
>>>> 
>>> 
>> 
> 


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