Piranha: a CORBA tool for high availability
Silvano Maffeis · Computer · 1997
Despite the most careful planning, system applications can be dogged by unexpected failures. Our firm is keenly aware of the need for availability. To help meet that need, I developed an experimental CORBA-based restart service and monitor called Piranha, which both monitors and manages distributed applications to help systems attain high availability. First, Piranha acts as a network monitor that reports failures through a graphical user interface. Second, Piranha acts as a manager: it automatically restarts failed CORBA objects, replicates stateful objects (objects that maintain an internal set of values) on-the-fly, migrates objects from one host to another and enforces predefined replication degrees-numbers of copies-on groups of objects. As a backdrop to the discussion of Piranha's design and implementation, this article first examines the ways in which a CORBA ORB should support availability. I then explain how Piranha affords availability.