What is a connection pool in Java?

Asked By: Giulia Unterkircher | Last Updated: 18th February, 2020
Category: technology and computing databases
4.7/5 (201 Views . 32 Votes)
Connection pooling is a pattern used by software applications to connect to databases using a pre-created set of reusable connection objects. When a new connection is required, an existing connection is retrieved from the pool. Many Java Application Frameworks include their own connection pooling APIs.

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Thereof, what is a JDBC connection pool?

A connection pool contains a group of JDBC connections that are created when the connection pool is registered—when starting up WebLogic Server or when deploying the connection pool to a target server or cluster. Connection pools use a JDBC driver to create physical database connections.

Similarly, how does a connection pool work? It manages connections by keeping alive a set of active connections for each given connection configuration. Whenever a user calls Open on a connection, the pooler looks for an available connection in the pool. If a pooled connection is available, it returns it to the caller instead of opening a new connection.

Then, what is connection pooling in Java with example?

JDBC Connection Pool Example. Connection pooling is a mechanism to create and maintain a collection of JDBC connection objects. The primary objective of maintaining the pool of connection object is to leverage re-usability and improve the overall performance of the application.

What is pooling in Java?

An object pool is a collection of a particular object that an application will create and keep on hand for those situations where creating each instance is expensive. The pool checks instances in and out for users like books out of a library. Usually object pooling is handled by a Java EE application server.

39 Related Question Answers Found

What is database connection pool size?

A connection pool is created for each unique connection string. When a pool is created, multiple connection objects are created and added to the pool so that the minimum pool size requirement is satisfied. Connections are added to the pool as needed, up to the maximum pool size specified (100 is the default).

What is c3p0?

c3p0 is an easy-to-use library for augmenting traditional (DriverManager-based) JDBC drivers with JNDI-bindable DataSources, including DataSources that implement Connection and Statement Pooling, as described by the jdbc3 spec and jdbc2 std extension.

How do you test connection pooling?

Testing a Connection Pool
  1. In the Administration Console, open the Resources component, open the JDBC component, select Connection Pools, and select the connection pool you want to test. Then select the Ping button in the top right corner of the page.
  2. Use the asadmin ping-connection-pool command.

What is max pool size?

Max Pool Size: The maximum number of connections allowed in the pool. The default value is 100. Min Pool Size: The minimum number of connections allowed in the pool. The default value is zero.

Should I use connection pooling?


Connection pooling is great for scalability - if you have 100 threads/clients/end-users, each of which need to talk to the database, you don't want them all to have a dedicated connection open to the database (connections are expensive resources), but rather to share connections (via pooling).

What is the difference between JDBC and JNDI?

Well these are two different things. JDBC is Java Database Connectivity API, while JNDI is Java Naming and Directory Interface API. In short words: JDBC is Database realm, JNDI lets you store Objects in a virtual context (the Directory) that can be local, remote (implementation details usually don't matters).

What is pool in database?

Database connection pooling is a method used to keep database connections open so they can be reused by others. Pooling keeps the connections active so that, when a connection is later requested, one of the active ones is used in preference to having to create another one.

What is JNDI name?

A JNDI name is a user-friendly name for an object. These names are bound to their objects by the naming and directory service that is provided by a J2SE server. Because J2SE components access this service through the JNDI API, an object's user-friendly name is its JNDI name.

What is DataSource in Java?

An alternative to the DriverManager facility, a DataSource object is the preferred means of getting a connection. An object that implements the DataSource interface will typically be registered with a naming service based on the JavaTM Naming and Directory (JNDI) API.

What is JDBC connection?


Java Database Connectivity (JDBC) is an application programming interface (API) for the programming language Java, which defines how a client may access a database. A JDBC-to-ODBC bridge enables connections to any ODBC-accessible data source in the Java virtual machine (JVM) host environment.

What is HTTP connection pooling?

For CICS as an HTTP client, connection pooling can provide performance benefits where multiple invocations of CICS web support applications, web services applications, or the HTTP EP adapter make connection requests for the same host and port, or where a web services application makes multiple requests and responses.

What is connection pooling and why it is used?

In software engineering, a connection pool is a cache of database connections maintained so that the connections can be reused when future requests to the database are required. Connection pools are used to enhance the performance of executing commands on a database.

How does JDBC connection work?

The JDBC Driver is a set of classes that implement the JDBC interfaces to process JDBC calls and return result sets to a Java application. The database (or data store) stores the data retrieved by the application using the JDBC Driver. A Connection object controls the connection to the database.

How does c3p0 connection pooling work?

Connection Pooling with the c3p0 Library
c3p0 is an easy-to-use library for making traditional JDBC drivers "enterprise-ready" by augmenting them with functionality defined by the jdbc3 spec and the optional extensions to jdbc2. As of version 0.9. 5, c3p0 fully supports the jdbc4 spec.

What is JDBC DataSource?


JDBC DataSource is an interface of package javax. sql. DataSource. This interface is mostly preferred over DriverManager class because it allows the detail about database to your application program. DataSource object increases the application portability .

What does setAutoCommit false do?

setAutoCommit(false) will allow you to group multiple subsequent Statement s under the same transaction. This transaction will be committed when connection. commit() is invoked, as opposed to after each execute() call on individual Statement s (which happens if autocommit is enabled).

What is connection pooling in Ado net?

ADO.NET uses a technique called connection pooling, which minimizes the cost of repeatedly opening and closing connections. Connection pooling reuses existing active connections with the same connection string instead of creating new connections when a request is made to the database.