- Original Message -
From: Rajal Shah [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Thursday, December 19, 2002 15:51
Subject: RE: Design question on using Java classes v/s hashes or arrays
I see your point.. If business functionality changes though, then maybe
you
need to change the method name or something and deprecate the old method..
to solve the issue you bring up. (and work on your SLAs with the clients
to
make them understand the new behavior or provide both business logic
options).
I am referring to the versioning of services for extending the
functionality
of a data object. And having 2 end points can serve the needs to backward
compatibility and avoid me to define my objects as hashes.
If you use doc/lit messaging rather than rpc/enc, you can add new stuff to a
message (But obviously these need to be optional additions, you cannot
subtract, and you need to keep semantics 100% consistent. Even so, it does
give doc/lit a bit of flexibility. And equally importantly, shows up
versioning issues in API signatures fast.
I talk about versioning a bit in http://iseran.com/Steve/papers/wstw/
Your document is pretty comprehensive and well thought out!
I still have doubts there. There are lots of issues we are let to learn, and
only that trial and error will find. I sort of wrote that paper as I was
going along, but decided it was time to get stuff out the door.
with my current project I wrote the proto server, then did the client (swing
based), and soon redid bits of the api for ease of programming and long haul
perf. For example one call returned #of items in a queue, another listed the
queueID of all elements, and the third took one queueID and returned
info about that element.
Now what do I do for long haul? Do I boost throughput with a message that
lets you specify a list of queue items. Good for http1.0 nagling, saves on
net sockets used (good for the server),... But it could make the UI less
responsive. Right now I can fill the list in one at a time, with a worker
thread to talk to the server. But with a bulk call I dont get an update till
the update is complete.
I dont see any 'best answer' here. I'll probably add the bulk call for when
somebody wants it, but maybe only fetch small chunks, say 4 items at a time,
for responsiveness.
-steve
