Ask again: how Sandesha works

[Jian J Zhang]

I sent out a note asking how Sandesha works. Someone of the list replied but I deleted the reply email
by mistake before I had had a chance to read it. I could not find the reply in the archive either.

Can the person who replied reply again?

I really apprciate it.

-------------------------- The original note


Here I'd like to understand how Sandesha works.Your help is appreciated.

As far as I understand, Sandesha saves the request first in the
persistence and then sends out the acknowledgement.
Then it invokes the web service (the application code).  The reliability
is guaranteed because the message is saved and can
be resent to the web service if needed, just like messaging system.

Here is what I do not understand:

    Assume that the sandesha successfully saves the message into the
database (database transaction is committed) and sends out the
acknowledgement,
    while before it forwards the message to the web service, the server
crashes.

    Now we restart the server and AXIS plus Sandesha are ready to serve
new requests.  But how about the saved request?
   AXIS  is only invoked when we have a HTTP/SOAP message. If  we do not
get new request, then the message will never be reforwarded again?