Introduction to Continuous Integration

As mentioned in Key Concepts in Modern Application Development, continuous integration (CI) is a software development practice whereby developers on a team regularly integrate their working copies of code to a shared repository. Once a change is integrated to the repository, the application is automatically rebuilt. Automated tests are run before and after the application is rebuilt, to check that no regressions are introduced. If any of the automated tests fail, developers can be notified automatically so that they can provide a fix.

Using continuous integration provides a number of benefits:

• Developers can find problems earlier than they would be able to if builds happened only every day or every week.
• When a problem does occur, pinpointing the cause of the problem is quicker and easier because only a small change should have been made since the last working build.
• The time taken to resolve integration issues is reduced because each change is integrated as required.
• There is always a working version of the product that contains the latest changes.

Tools that provide CI functionality are known as CI servers. There are many tools available that can be used as CI servers, but the following list shows some of the more commonly used:

• Bamboo
• Cruise Control
• Hudson
• Jenkins
• Team Foundation Server

For detailed information on how to use Visual COBOL with Jenkins, see Using Visual COBOL with Jenkins.