Re: [coldsync-hackers] Real life experiences with netsync

[Andrew Arensburger <arensb+CShackers at ooblick dot com>]

On Fri, Nov 01, 2002 at 11:58:11AM +0000, Andy Mayer wrote:
> I am thinking of writing some conduits to allow end users to sync their
> palms with my web applications. For this I am planning to build some
> custom conduits and use coldsync on my web/app server with end-user
> access through netsync.
> 
> So I was wondering what peoples' real life experiences are with using
> the netsync functionality of Coldsync. In particular:
> 
> 1. How scalable is the solution for enterprise use?

	Alessandro has touched the source a lot more recently than I
have, so hopefully he'll contradict me, but the last time I seriously
hacked the netsync stuff, it was more of a sketch than a rigorous
implementation. Everything _should_ be there, but I never tested it
under anything but trivial conditions.

> 2. How practical is it for end-users, who are often firewalled, to
> access ports 14237 & 14238 over the Internet?

	I believe one of Palm's administrator manuals says you should
punch a hole in your firewall for these two ports, on the server end.
	A lot of firewalls allow workstations inside the firewall to
open TCP connections to arbitrary ports on the outside. These users
shouldn't have any problems. On the server end, the firwall needs to
know that an incoming connection to port 14237 or 14238 on the server
is okay.

> 3. Does the developer community have any positive real life experiences
> of using netsync across the Internet, for anything other than personal
> use?

	None that I can recall off the top of my head. You can be a
pioneer :-)

> 4. For my application, would it be better not to use netsync, and
> instead provide end-users with conduits for their worksation platforms
> that remotely access my web applications using SOAP or some other http
> based protocol?

	I'd say try the direct approach, and see if that's good
enough. In an office environment with a reasonable network (> 56kbps),
you'll probably be okay.
	You may want to do a couple of back-of-the envelope
calculations: take the size of a typical database to be synced, and
figure out how long it'll take to transmit that over your network.
Then double that time, to take into account new records sent from the
server, and protocol overhead.

	If that turns out to be unacceptable, you can take a two-stage
approach: instead of having ColdSync forward the connection to your
server, just have it sync with the desktop, in the normal way.
	Then you can write a Dump conduit that'll send any changes to
the server; it might take a long time, especially if the server is
busy, but that doesn't matter because by the time the Dump conduit
runs, the user has disconnected ver PDA.
	You can also have a cron job that fetches the latest version
of the data from the server once an hour, and writes it to
~/.palm/backup/MyDB.pdb.

-- 
Andrew Arensburger                      This message *does* represent the
arensb@ooblick.com                      views of ooblick.com
		      You lost WHAT source code?

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