Nonce-sense

At http://www.teaminfocenter.com/ProgrammingNotes2/HowToExample/groovenonce.htm, John Giudice introduces what I interpret as the kernal of Groove replication thinking - the nonce. As far as I understand it, all events are relative to that value, which is written uniquely when a Groove client first starts. The matter comes to mind partly because somehow even from the early days Groove has had a history of replication issues. Granted that 99.999% of Groove replication is by and large a wonderful thing, it has to be asked under what circumstances could it fail steadily over such a long period? Also granted that the main task of Groove is replication, so if it is going to "fail", then that's the area of focus.

As I look at my Groove inbox I see one message from someone with a datestamp ahead of others. New IMs are coming in and being religated, according to datestamp as earlier that this message that actually came in some hours ago. I am not saying that Groove is wrong in the way it presents this wierd event. I have taken part in live Groove Chat sessions where peoples responses are inserted above the latest posts. But is it right?

Everything is displayed in date order. But date order is not the order in which events happen. Of course why nonce's exist is to avoid the human interpretation. but at some point Groove must create an interface between the nonce and human dates. As far as I understand it the nonce is trying to be an independent way of replacing time-stamp thinking. Given the fickleness of human time-stamps including incorrect clocks, time-zones etc you can see the logic.

The result however is to put the nonce on a pedastel. The fact is that in some parts of Groove coding, at some level things are not perfect. Let me not paint a picture of Groove is unreliable, when the opposite is true. But my guess is there are nonce-related gremlins in there. My guess is that Groove's engineers have found many of them over the products life-span. However my guess also is that there are still a few left.

And where do these gremlins occur? Trying to imagine where the lack of nonce-sense lies I would guess it is in assuming information about the remote computer. Visibly errors typically do not in core data replication - not that that such a thing for a normal user to confirm! With Groove you see data arrive, you do not know what does not arrive! Issues that are obvious tend to occur in the messaging around that replication, invitations, IMs, notifications. These are the obvious manifestation of Groove's transport.

An important note is that a challenge for Groove is performance. And does it perform. Groove can replicate very effectively. But at what cost? Are there assumptions in that replication made to boost performance that are not being trapped, or the cost of trapping is too much to consider?

Am I talking nonsense? Probably, but my gut feeling is that solving this kind of puzzle is a lateral thinker's dream challenge. Oh, and by the way, in case anyone is unclear - the above is my supposition based on experience. I have no access to Groove internals. And in some (non-)senses perhaps that is a strength :-)

posted by Andy Swarbrick/PopG at 4:49

(Update. Looks like I may be way off beam on the above. Hugh Pyle (and he should know) pointed out that the nonce is a security measure for GWS, and that's all it is. It is nothing to do with dynamcs. Oh, well, it sounded good to me. - thanks Hugh.)

BT gets into VoIP (sic!)

http://www.reuters.co.uk/newsArticle.jhtml?type=internetNews&storyID=6158117&section=news

Supposedly BT are getting into competition with Skype. What a j.o.k.e. A company that only knows how to employ people with skills to defend its monoplistic markets is going to take on one of the brightest projects on the Internet. Chalk & Cheese.

The fact is that the kind of market that Skype is in is one of the Internet's success stories. Skype thrives by driving customer costs down to approximately zero and then building up. Users of Skype recognize that logic and hunt it down in similar projects such as Linux, and the vast array of very high-quality freeware.

The fact is that traditional companies cannot begin to deal with these upstarts. Skype and its ilk come from nowhere. Companies like Skype have the ability to adapt to their own growing marketplace, turning their business plan upside down every week if necessary. The momontum inside BT only permit it to lumber on. Skype et al can gain incredible market share in new markets, and the only option for a company like BT is to attempt to buy them for astonishing amounts

The idea of BT gaining some foothold in Skype's marketshare? Thanks for the laugh. Now, if you want a company that could take on Skype - that would be Apple. Apple is riding a wave right now with its phonomenally successful iPod and iTunes. If it moved on VoIP (which is possibly is, but my ignorance keeps me in the dark right now) and integrated into the iPod concept it could create an equivalent of BT's domininance of the last mile and own the connectivity of VoIP devices in the home & office to VoIP services such as Skype.

The other critical advantage of Apple is its global focus. BT's UK/EU focus hampers it beyond belief. It means it will only be taken seriously by its exsiting and diminishing customer base, who will all contunue to pay through the nose for second rate services.

Yours, a BT customer ;-(

posted by Andy Swarbrick/PopG at 3:07

"By the way great system"

This is just one of a range of quotes coming at us from our Creighton university students.

posted by Andy Swarbrick (d)/PopG at 16:38