Connection Pooling

• Pool is a collection of reserved resources.
• Same collection object can be reused multiple times.
• If we required to communicate with database multiple times, then it is not recommended to create a separate connection object every time because and destroying connection object. Every time creates performance problems.
• To overcome above problem, we use connection pool.
• Connection is a pool of already created connection objects
• We request connection to provide connection object object whenever we want to communicate with database. After completing our work, we return the connection back to the pool instead of destroying it.
• Reusing same connection, object helps to improve performance
• Implementing connection pool
• Connection pool is implemented by creating a data source object like DriverManagerDataSource, HikariDataSource,ComboPooledDataSource(c3p0).
• Data source is responsible to manage connections in the connection pool.
• Driver vendor is responsible to provide implementation.
• Driver Manager versus Data source object
• When we create object from driver Manager, it always creates new connection object
• Con=DriverManager.getConnection(url,name,pwd)
• When we create object from data source, it provides connection from data pool.
• Con=DS.getConnection();
• Performance wise data source is a better approach.
• Examples
• https://github.com/gauravmatta/springmvc/blob/master/connectionpooling/src/main/java/com/springimplant/connectionpooling/ConnectionpoolingApplication.java
• https://github.com/gauravmatta/springmvc/blob/master/connectionpooling/src/main/java/com/springimplant/connectionpooling/beans/DataConfig.java