Long description

Three data server blocks are shown here. On top of the first block it is labeled: These applications can read and modify data in the master. On top of the next two blocks it is labeled: These applications can only read data in the subordinates. Two arrows labeled Web applications, points to the data server in all the three data server blocks. Below the first data server block it is labeled Master and below the next two blocks it is labeled Subordinates. All the three blocks are connected by arrows, and below the arrow it is labeled: Modification to master data are propagated out to all subordinates.