How to limit number of connections to a database in spring? - java

I have a Spring based application, deployed on the Tomcat server. What I need is to limit the maximum number of simultaneous connections to a database. This is data source section from my applicationContext.xml:
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="org.postgresql.Driver" />
<property name="url" value="..." />
<property name="username" value="..." />
<property name="password" value="..." />
</bean>
I would like to do it on the application level, not with server configuration.

Set the maxActive property on the dataSource.

Related

Tomcat database connection pool slow in high throughput

I have soap webservice written in Spring 2.X and which connect to Teradata and return the result to client. To connect the data based I am using Tomcat JDBC Connection Pool as the DataSource.
In peak hour (9AM to 6PM) application get about 60k transactions requests. I observed some of the transactions goes in hung state and return response in 2-3 minutes . I suspect some transaction goes in wait status and once connection is available in pool then complete the transactions.
Below is the configuration for the DataSource.
<bean id="dataSource" class="org.apache.tomcat.jdbc.pool.DataSource"
destroy-method="close">
<property name="driverClassName" value="com.teradata.jdbc.TeraDriver"/>
<property name="url" >
<util:constant static-field=" _DB_HOST"/>
</property>
<property name="username">
<util:constant static-field=" DB_USER"/>
</property>
<property name="password">
<util:constant static-field=" DB_PWD"/>
</property>
<property name="initialSize" value="1" />
<property name="maxActive" value="50" />
<property name="minIdle" value="0" />
<property name="maxWait" value="-1" />
<property name="minEvictableIdleTimeMillis" value="1000" />
<property name="timeBetweenEvictionRunsMillis" value="1000" />
</bean>
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
<qualifier value="txnMngr"/>
</bean>
// using JdbcTemplate to read the data from data base.
Here are my questions:
Is there any issue with above configuration based on the load which I mentioned for my application?
Is there any way I can monitor the DB connection pool uses?

Does BasicDataSource use connection pooling by default?

I use the following to connect to DB (spring config)
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName" value="${oracleDriver}" />
<property name="url" value="${db.url}" />
<property name="username" value="${username}" />
<property name="password" value="${password}" />
</bean>
Does this internally use any connection pooling? If yes what is the size?
Yes. The BasicDataSource creates a pool internally.
As in (https://commons.apache.org/proper/commons-dbcp/configuration.html), we can see that the default max number of active connections is 8 (maxTotal parameter).
If you do not want a connection pool, you should consider using an alternative such as: org.springframework.jdbc.datasource.SingleConnectionDataSource

Mysql configuration with spring

I have read Spring Fundamentals. Actually i visited many sites to know how to configure mysql database to spring project. But i have failed to get specific solution about it. so please help me to solve this problem.
<bean name="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/database" />
<property name="username" value="user" />
<property name="password" value="pass" />
</bean>
Springframework documentation
http://docs.spring.io/spring/docs/current/spring-framework-reference/html/jdbc.html#jdbc-datasource

FileNotFoundException while running Spring and Ibatis based application on Tomcat

I am using Spring, ibatis for ORM. My app-config.xml look like
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://192.168.10.50/lmexdb_v1" />
<property name="username" value="lmexdba" />
<property name="password" value="lmexdba123#" />
</bean>
<bean id="sqlMapClient" class="org.springframework.orm.ibatis.SqlMapClientFactoryBean">
<property name="configLocation"
value="classpath:com/platysgroup/lmex/server/mobile/dao/ibatis/SqlMapConfig.xml" />
</bean>
<bean id="mobileController" class="com.platysgroup.lmex.server.controller.MobileController">
<property name="announcementService" ref="announcementService"></property>
<property name="courseService" ref="courseService"></property>
<property name="userService" ref="userService"></property>
</bean>
and I have my sqlmapconfig.xml file in src/webapp/spring.
But when I run my application on tomcat it show me a exception:
java.io.FileNotFoundException: class path resource [com/platysgroup/lmex/server/mobile/dao/ibatis/SqlMapConfig.xml] cannot be opened because it does not exist
put it in src , and it will be available
if you are using maven project then add it to resource

How to inject the driverClassLoader property in spring?

I have the following partial spring context xml file:
<bean name="template" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource" />
</bean>
<bean name="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassLoader" value="" /> <!-- THIS PROPERTY -->
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3061/my_database" />
<property name="username" value="username" />
<property name="password" value="password" />
<property name="initialSize" value="8" />
</bean>
How do I inject the driverClassLoader property? (I'm using some custom plug-in architecture but not the spring dm server so have to provide a classloader to find the mysql driver)
this apache dbcp classloader bug was just fixed in march 2011.
It may fix your root issue so you don't need to inject the classloader...
https://issues.apache.org/jira/browse/DBCP-333
without this bug fix I don't think the driverClassloader setter was working....
I think you want to use the PropertyPlaceholderConfigurer. Look at section 3.7.2.1 in the Spring 2.0 reference guide.

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