HCloud, a Healthcare-Oriented Cloud System with Improved Efficiency in Biomedical Data Processing - Cloud Computing with e-Science Applications - page 171

Services Interaction Layer

Mobile Devices

Services Presentation Layer

Wap, Web, Ftp Provided

Cloud Engine

Hit

Ye s No

Upload

Ye s No

Cloud Storage Layer

Distributed Database Cluster

Until Message Queue Is Empty

Until User Exits

FIGURE 8.3
Six layers of a health care cloud platform. (Redrawn from He, C., Fan, X., and Li, Y., IEEE
Transactions on Biomedical Engineering 60, no. 1 (January 2013): 230-234.)

without redrawing. In fact, this session's architecture is a big hashed
key/value table.
• A cloud engine is a dispatcher to make components cooperate with
each other to make the cloud run using a message-driven mode via
a message queue (MQ) cluster. The functionalities of the queue man-
agement are provided by this layer, which is regarded as a critical
core for scheduling tasks. A message is the unit of data transmitted
between two modules. The MQ is a container to save the message
during the transmission process. By introducing a message queue
into the platform, the coupling between different modules can be
significantly reduced.