Question

HINT : My hosting tomcat system provides only 20 db connections

My working project in localhsot

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"
          p:driverClassName="${jdbc.driverClassName}" p:url="${jdbc.url}"
          p:username="${jdbc.username}" p:password="${jdbc.password}" />

This worked good in localhost, but in production it run for a while and Exception : “user has allready max no of connection”.

After many google

I used c3p0

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close" >
        <property name="driverClass" value="${jdbc.driverClassName}" />
        <property name="jdbcUrl" value="${jdbc.url}" />
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

This worked in localhost, but same problem in production server

Hint: I think some config in c3p0 can solve this. Please help me with you suggestion (My hosting provides only 20 connections)

Also i tried tomcat

<bean id="dataSource" class="org.apache.tomcat.jdbc.pool.DataSourceFactory">
        <property name="driverClassName" value="${jdbc.driverClassName}" />
        <property name="url" value="${jdbc.url}" />
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
        <property name="maxActive" value="20"/>
    </bean>

The above tomcat code is wrong and will not work – because wrong property (I know that). How to set this for my production use(only 20 connections)

If you know how to use tomcat pool please help us.

I also used bonecp

<bean id="dataSource" class="com.jolbox.bonecp.BoneCPDataSource" destroy-method="close" >
        <property name="driverClass" value="${jdbc.driverClassName}" />
        <property name="jdbcUrl" value="${jdbc.url}" />
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
        <property name="idleConnectionTestPeriod" value="60"/>
        <property name="idleMaxAge" value="240"/>
        <property name="maxConnectionsPerPartition" value="10"/>
        <property name="minConnectionsPerPartition" value="5"/>
        <property name="partitionCount" value="1"/>
        <property name="acquireIncrement" value="5"/>
        <property name="statementsCacheSize" value="1000"/>
        <property name="releaseHelperThreads" value="3"/>
    </bean>

This worked in localhost but same problem in production “user has to many connections”.

I also tried apache-dbcp

As per tomcat 7 documentation – dbcp is no longer and tomcat will be bundled with pool. Even though i used dbcp and i cannot run my program. (I added only one jar and error was some class not found during project run)

As per my own idea :

I think above mentioned settings will be problem. Please help me with your suggestions. I’m not using hibernate up to now because of heavy weight. If hibernate can solve this problem please let us know.

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EDITED

Currently I’m using this code. Is this code correct to my use(20 connection)

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close"
      p:driverClass="${jdbc.driverClassName}" p:jdbcUrl="${jdbc.url}"
      p:user="${jdbc.username}" p:password="${jdbc.password}"

      p:acquireIncrement="1" 
      p:checkoutTimeout="1"
      p:idleConnectionTestPeriod="5"           
      p:maxIdleTime="5" 
      p:maxIdleTimeExcessConnections="1" 
      p:maxPoolSize="20" p:maxStatements="0" p:maxStatementsPerConnection="0" 
      p:minPoolSize="1" 
      p:numHelperThreads="100"
      p:overrideDefaultUser="${jdbc.username}" p:overrideDefaultPassword="${jdbc.password}"
      p:propertyCycle="3" 
      p:testConnectionOnCheckin="true"
      p:unreturnedConnectionTimeout="5" />

DAO code :

@Repository
public class TutorialsDAOImpl implements TutorialsDAO {
//---
private JdbcTemplate jdbcTemplate;
    private DataSource dataSource;

    @Autowired
    public void setDataSource(DataSource dataSource) {
        this.jdbcTemplate = new JdbcTemplate(dataSource);
    }
//---
@Override
    public List<TutorialsCategory_vo> getTutorialsCategory() {
        sql = "SELECT * FROM `tutorials_category` ORDER BY `slug` ASC;";
        List<TutorialsCategory_vo> vo = null;
        try {
            vo = this.jdbcTemplate.query(sql, new Object[]{}, tutorialsCategory_mapper);
        } catch (Exception e) {
            log.log(Level.SEVERE, null, e);
        }
        return vo;
    }

These are the codes i’m using. If there is any error/corrections pls correct me.

---

Edited (for Arun P Johny ‘s question)

My current project url.

I updated my current code above.

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Answer 1

This is my final c3p0 settings:

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close"
          p:driverClass="${jdbc.driverClassName}" p:jdbcUrl="${jdbc.url}"
          p:user="${jdbc.username}" p:password="${jdbc.password}"

          p:acquireIncrement="1" 
          p:checkoutTimeout="3000"
          p:idleConnectionTestPeriod="5"           
          p:maxIdleTime="3" 
          p:maxIdleTimeExcessConnections="1" 
          p:maxPoolSize="20" p:maxStatements="20000" p:maxStatementsPerConnection="1000" 
          p:minPoolSize="1" 
          p:numHelperThreads="1000"
          p:overrideDefaultUser="${jdbc.username}" p:overrideDefaultPassword="${jdbc.password}"
          p:propertyCycle="3" 
          p:statementCacheNumDeferredCloseThreads="1"
          p:testConnectionOnCheckin="true"
          p:unreturnedConnectionTimeout="7" />

This works fine, but taking more time(1 or 2 secounds – not more than 3 secounds).

I also checked this code by shutting down mysql. My program waited up to, i start mysql. This is good. This code waits for all db connections to complete and out put correctly.

Can we make this settings even faster? Hint: my server provides only 20 connections.

If you provide a correct answer i’ll make it as right answer, after checking.