Linköpings universitet > Department of Computer and Information Science > Real-Time Systems Lab > TRANSORG

Combining TRANSactions with CORBA Replicated Groups
Phone: +46-13-28 24 16
Fax: +46-13-28 40 20
Office: Building B, First floor, Room 3B:440

The goal of the project is to provide a better understanding of fault tolerance/performance trade-offs, in particular:

  • What are the overheads in the absence of failures?
  • How fast is the failover mechanism with different strategies?
  • How are these affected by application size (state) and number of replicas and by choice of middleware?

Two platforms have been built: one based on the OMG FT-CORBA standard and the other grounded on a consensus-based algorithm that provides full availability (FA-CORBA).
The FT-CORBA platform provides tolerance against application crashes, but not infrastructure crashes. The FA-CORBA platform, on the other hand, is robust in both senses.

The FT-CORBA architecture:

Fault Monitor (FM)
Object Factory (OF)
Replication Manager (RM) Fault Notifier (FN)
Logging and Recovery Controller (LRC)

The FA-CORBA architecture:

Leader Election Unit (LEU)
Consensus Object (CO)
Server interceptor (SI)
Application Server Object (ASO)
Application Client Object (ACO)

Evaluation results based on a telecom application server have provided insights into the overheads for providing various degrees of availability.

For more details see the publications.

Last modified on Wednesday August 06, 2003 by Diana Szentiványi