Long description

The figure consists of 3 sections. The first section consists of a Web Server with D B M S server and a global Transaction Manager. The local D B M S transactions are handled by the Transaction Manager. The second and third sections placed at the bottom left and right of the first section, respectively, each consists of Local Server with D B M S server and Resource Manager. The local D B M S transactions are handled by the resource Manager.

The transactions are processed as follows:

Step 1: Transaction Manager sends the Prepare command to the Resource Managers of both the Local Servers.

Step 2: The Resource Managers sends Prepare done as their response.

Step 3: If everything prepared then send commit messages, otherwise send out rollback messages to each resource manager.

Steps 1 and 2 take place multiple times between the Transaction Manager and the Resource Managers until step 3.