Thomas Kunz Systems and Computer Engineering
5
Current Middleware Solutions
No support for heterogeneity either
Not scalable as no support for transparent replication, access & migration
Fault-tolerance implemented using message queues
Asynchronous message delivery.
More scalable and easy broadcast but difficult for synchronous requests
Through Notification, Request and Reply messages. Content includes information
Component heterogeneity supported but no support for data heterogeneity
Support load balancing & replication of server components
Fault-tolerant due to DTP and 2 phase commit protocol.
Support for transactions
Through synchronous and asynchronous methods.
Support for activation policies
Client requests are grouped into transactions
Heterogeneity
Scalability
Reliability
Coordination
Network Communication
Model
