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To: cs551@merlot.usc.edu
Subject: Re: CS551 : Final project 1
Date: Mon, 06 Oct 2008 10:55:41 -0700
From: Bill Cheng <william@bourbon.usc.edu>

Someone wrote:

  > In the design you  mentioned each writing thread has an input queue of
  > its own and along with that there is a main queue which the event
  > dispatcher uses to direct requests to, is that right?

Yes.
--
Bill Cheng // bill.cheng@usc.edu <URL:http://merlot.usc.edu/william/usc/>




  On Mon, Oct 6, 2008 at 9:05 AM, Bill Cheng <william@bourbon.usc.edu> wrote:
  > I forgot to mention...  This thread also acts as the
  > network-write thread in slide 19 of lecture 9.  Therefore,
  > it needs to check its input queue to see if there is work
  > to do, i.e., data to send.
  > --
  > Bill Cheng // bill.cheng@usc.edu <URL:http://merlot.usc.edu/william/usc/>
  >
  >
  >
  >  -----Original Message-----
  >  Date: Mon, 06 Oct 2008 08:42:21 -0700
  >  From: Bill Cheng <william@bourbon.usc.edu>
  >  To: cs551@merlot.usc.edu
  >  Subject: Re: CS551 : Final project 1
  >
  >  Someone wrote:
  >
  >    > After the startup, every node will send hello to
  >    > every neighbor node. What the node (the client part) will do after the
  >    > startup??  Should it close the connection and exit the client thread??
  >    > If it close the connection then should it has to send notify message.
  >    >
  >    > Hello should be sent at the start up time or before initiating a data
  >    > transfer??
  >    >
  >    > If we have keepalive message then why we need hello?
  >
  >  If you look at slide 14 of lecture 9, when you see that there
  >  is a line drawn between two nodes, it means that there is an
  >  *active* connection between the two nodes.
  >
  >  If you close a connection, the link will be gone.
  >
  >  On slide 19 of lecture 9, I have shown a design (just a
  >  design and not "the" design) where two threads are used per
  >  socket.  It's perfectly fine to use one thread per socket,
  >  like you are suggesting above.
  >
  >  What does such a thread do?  Well, this is a network.  The
  >  main job for a node in the network is to *forward* packets.
  >  So, a thread would just wait for a packet to arrive,
  >  decrement its TTL, and decide what to do with the packet.
  >
  >  If you decide to bring down an active connection, you should
  >  always send NOTIFY before you shutdown and close the socket.
  >  --
  >  Bill Cheng // bill.cheng@usc.edu <URL:http://merlot.usc.edu/william/usc/>