Can I use multiple C3P0 datasources for DB instance?
c3p0, connection-pooling, datasource, jdbc, spring
Solution
That's absolutely fine. You'll run into some configuration issues like:
autowiring `DataSource` by type won't work
`@Transactional`/declarative transactions will work only against one, selected `DataSource`. Alternatively you'll have to manually tell which transaction manager you want to use (thus you'll need two transaction managers as well: `transactionManager1` and `transactionManager2`):
@Transactional("transactionalManager2")
Besides, there's nothing wrong with this configuration. Actually it's a pretty good idea (+1): if some layers/components of your application saturate the pool, others can still operate.
The only thing I recommend is to use lesser known `abstract`/`parent` bean declarations to avoid repetition:
<bean id="dataSource" abstract="true" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
<property name="driverClass" value="${db.driverClassName}"/>
<property name="user" value="${db.username}"/>
<property name="password" value="${db.password}"/>
<property name="acquireIncrement" value="1" />
<property name="idleConnectionTestPeriod" value="100"/>
<property name="minPoolSize" value="5" />
<property name="maxPoolSize" value="50" />
<property name="maxIdleTime" value="1800" />
</bean>
<bean id="dataSource1" parent="dataSource">
<property name="jdbcUrl" value="${db.url}/schema1"/>
</bean>
<bean id="dataSource2" parent="dataSource">
<property name="jdbcUrl" value="${db.url}/schema2"/>
</bean>
See also:
- What is meant by abstract="true" in spring?
Problem
I was wondering if I can run multiple c3p0 datasources for one DB, something like: ``` <bean id="dataSource1" class = "com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close"> <property name="driverClass" value="${db.driverClassName}"/> <property name="jdbcUrl" value="${db.url}/schema1"/> <property name="user" value="${db.username}"/> <property name="password" value="${db.password}"/> <property name="acquireIncrement" value="1" /> <property name="idleConnectionTestPeriod" value="100"/> <property name="minPoolSize" value="5" /> <property name="maxPoolSize" value="50" /> <property name="maxIdleTime" value="1800" /> </bean> <bean id="dataSource2" class = "com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close"> <property name="driverClass" value="${db.driverClassName}"/> <property name="jdbcUrl" value="${db.url}/schema2"/> <property name="user" value="${db.username}"/> <property name="password" value="${db.password}"/> <property name="acquireIncrement" value="1" /> <property name="idleConnectionTestPeriod" value="100"/> <property name="minPoolSize" value="5" /> <property name="maxPoolSize" value="50" /> <property name="maxIdleTime" value="1800" /> </bean> ``` They will be used by difference persistence services. Thanks.