Re: Hello! I have a problem with reconnection...

I had similar problems with my project when I first
began. Part of my problem was that I had many threads
running and accessing the various jxta input and
output pipes, and I wasn't careful with
synchronization. After cleaning that part up a bit, I
haven't had much problem.

--- Rodney Eng <[email protected]> wrote:

> Hello,
> 
> I'm currently working with a group on a prototype
> secure P2P file sharing
> system as an academic project.
> We're working with JXTA through the EZEL/JAL lib,
> though not purely; there
> seem to be some problems with the JAL libraries (for
> instance, one of the
> JAL EZMinimalPeer() constructors forgets to add the
> peer as a listner on
> incoming message events, something that befuddled us
> for some time), so
> we've tried to use JAL where it works and where it
> doesn't, we delve deeper
> into the underlying JXTA code to get things done.
> 
> For testing, I've set up one copy of our program
> running on my desktop and
> one on my laptop (they're not on the same subnet,
> BTW; one is running on
> Time Warner cable, the other is hooked into a campus
> wireless network) with
> the desktop as a rendezvous peer and the laptop as
> an edge peer.  When run
> for the first time (i.e. without having any
> configuration files in place),
> everything seems to work.  The laptop finds the
> desktop and I can exchange
> messages between the two computers; I've been able
> to send messages
> containing books from Project Gutenberg from one
> computer to the other
> without that much trouble.
> 
> However, I get problems with I halt the program on
> the laptop.  First, the
> desktop doesn't realize the laptop is gone, and
> second, when I bring the
> program back online on the laptop and try to send a
> message, the desktop
> receives the message and responds, but the laptop
> doesn't receive the
> message response sent by the desktop.  If I bring
> both computers offline and
> turn them back on with the configuration files
> created in the initial
> session, then they can't exchange messages at all. 
> Nothing seems to cure
> this besides completely wiping out the .jxta
> configuration folder, which is
> troubling.
> I've been doing some research on this problem, and
> I'm guessing, does this
> have to do with the Peer and Pipe Advertisements for
> peers and their pipes
> going stale?  As in, even though a peer goes
> offline, all the other
> computers in the network still have its
> advertisements.  Thus, they still
> think it's online, and when it comes back online for
> real and they try to
> send it a message, the message gets routed to a
> stale pipe advertisement,
> never making it to its intended recipient?
> If I'm right, how could I fix this?  Set the
> advertisement lifetime lower?
> If I do that, do I need threads constantly
> republishing the advertisements
> for a peer?
> 
> Secondly, could someone give me an overview of the
> security features of
> JXTA?  Generally, how could I get peers to
> authenticate with each other to
> exchange messages securely?
> 
> Thank you all very much for your help!
> 
> - Rodney Eng, Cornell University
> 



 
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