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Re: [Xen-devel] [RFC] Lightweight socket communication between domainsin

Hi there,

> I attached a PPT file that has some note on the implementation, comparing
> to XenSocket.
> In each slide of the PPT, I wrote a few lines of slide note. Please read
> the note for more details.

So, to summarise, the main points of your approach are:

1) shared memory data transfers for streams of data - effectively a 
Xen "device" channel per stream
2) use existing TCP syscall interface and protocol code to handle connection 
setup and teardown (+ calls into additional setup / teardown code for Xway 
itself, of course)
3) allow TCP-oriented applications to leverage Xway without any modification 
whatsoever, using the same API as usual

It looks like a nice side effect of your strategy of leveraging TCP is that 
you could perhaps modify your "Xway switch" to plumb the data stream either 
through the TCP stack, or the Xway shared memory at will - allowing you to 
fall back to TCP when migrating off a host, and allowing you to transparently 
switch to Xway when migrating to be colocated with the server you're talking 

You seem to get some impressive throughput numbers when working on shared 
memory ;-)  Do you think there are any further optimisations that you could 
do here?

I'm curious as to how you handle addressing...  Is an IP-address->local domain 
id lookup process happening somewhere?  How does this work?  Can any TCP 
connection take advantage of Xway, or is some advance configuration required?

> Since I don't know much about XenSocket I comapred only a few features that
> I'm interested in.

Perhaps the XenSocket folks can comment more on this.  It would be good to 
identify how much commonality in code / purpose there are between the two 

> I know that this summary slide is not enough to understand the whole things
> of Xway.
> However, let's start discussion on Xway as well as XenSocket.

Dave: Just a question. What use is a unicyle with no seat?  And no pedals!
Mark: To answer a question with a question: What use is a skateboard?
Dave: Skateboards have wheels.
Mark: My wheel has a wheel!

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