RE: Issue: Synch/Asynch Web services

Hi, Roger,
 
Here is my understanding about Synch/Asynch Web services.  Is it over
simplified?
 
Suppose we have two agents in a well-controlled environment (super fast,
reliable network). Agent A sends a message m1 to Agent B and expects Agent B
to return a message m2, however long it may take. This scenario seems to me,
is a typical case of sync Web services. The essences of this process are:
1. that Agent A can relate m1 and m2 by sequence  (sending m1 to B is prior
to receiving m2 from B). 
2. that there can be no other messages between two related messages.
 
If we remove those two constraints, the process becomes async. Agent A can
send a number of messages to Agent B after sending m1.  When it receives m2
from Agent B, it can relate m1 and m2 together using other mechanism,
however that mechanism may be.
 
Interestingly, a process can be sync at the infrastructure level but be
async at the application level. For example, m2 can be a receipt rather than
final results an application intends to get. 
 
Hao