Category: Random observations

Nigel bought a motorbike yesterday. It’s a Suzuki Across. He won’t get it until Thursday though.

Today we watched Whale Rider. Not a bad film at all. I tend to like films with lots of culture in them, and this one was full of Maori culture.

Last night we saw Intolerable Cruelty, which was excellent. The Coen brothers are definitely among my favourite directors. I’ve liked every film of theirs that I’ve seen so far (probably four or five). Their style of humour is right down my alley. George Clooney and Catherine Zeta-Jones were at their best, and they worked well together in this movie.

Friday was another excellent day in terms of Ph.D work and other spheres. I fixed up any remaining glitches with the wide-area part of my protocol. To be completely honest, I’d conveniently overlooked the problem of how to ensure correctness of my protocol during the short period of time after a new Superstring resolver joins the network. In my prototype, services descriptions are purged from a resolver thirty minutes after they are advertised. Therefore services are required to re-advertise themselves every thirty minutes if they wish to be discoverable. This is just a typical soft-state protocol. If a new resolver joins the network, then because of the way Superstring makes use of an underlying distributed hash table, queries which formerly might have been directed to one resolver could be directed at the new resolver. If, just prior to the new resolver joining, a service has just re-advertised itself, queries that would match this service will go unresolved for a thirty minute period (that is, until the service re-advertises itself again). This state of affairs is not acceptable in many circumstances. To combat this, for the first thirty minutes after joining, the new resolver executes the query itself and forwards the query to the resolver which would formerly have been responsible for resolving the query. It then performs the union of the two resulting sets of matching services, and returns this as the response to the query. After the initial thirty minute window of uncertainty everything is as it should be, and it no longer needs to forward any queries. The forwarding of queries by a new node for the first thirty minutes after joining is a small price to pay, especially for long-lived environments which the wide-area half of this protocol is intended for.

So far, during debugging, I’ve tested the wide-area protocol in an environment consisting of three machines. Query resolution is fast, even for detailed queries. However, a new node seems to take quite a long time to join the network due to the underlying distributed hash table protocol (Chord). I’m not sure if this is due to Chord itself, or whether I’ve done something incorrectly in my Chord implementation. I’ll have to check this out.

Today I finished reading Jude the Obscure and started reading Two on a Tower. Jude was very heavy and ultimately quite depressing, though I still love Hardy’s writing style. The last hundred and fifty pages or so were read very speedily. In my last entry I reported that I was feeling very happy. That was until I reached a certain part of Jude, which brought me back down to Earth rather quickly. Anyone who has read the book will undoubtedly know the event in the book to which I allude. Overall, I think I appreciated Tess of the D’Urbervilles a bit more than Jude. Thankfully, Two on a Tower has started more brightly than either of those two books. It could even be said to be humorous in parts. I thought the passage in chapter 2 involving the choir was particularly amusing!

Time for dinner!

It’s been a really good couple of days with respect to my Ph.D work. Today I finished debugging the wide-area half of my service discovery protocol. It’s all working very nicely, which is kind of exciting. However, I’ve changed a few of the classes that were being shared by the local-area part of the protocol, so I have to go back and touch up the Ants stuff. Shouldn’t be a big problem. So here’s what I’ve accomplished so far with respect to my prototype, and the order in which I accomplished them:

• Query/Advertisement parser
• Expression scanner/parser/matcher
• Ant-based service discovery protocol for small, dynamic environments
• Chord implementation (Distributed Hash Table layer)
• Wide-area service discovery protocol, including distributed query/advertisement parsing with scoping

The scoping function allows queries to relax their requirements so that, for example, if the query tries to find a printer a particular room on a particular floor in a particular building and so on, but there is no matching printer in the specified room, then the query backs off and returns any matching printer on the specified floor. If there is still no match, it backs off even further until the scope boundary is reached. Scoping is not automatic. A scope needs to be specified in the query, just in case the user would prefer no match rather than a partial match.

So it’s been a good week. Furthermore, Jaga has started questioning the importance of implementing the reputation management functionality that I was previously expected to implement in my prototype. The only reason we were going to implement it was to get performance figures for a paper we were writing. We’ve since submitted a shortened version of that paper, and we are unsure exactly what performance figures will tell us anyway. It’s obvious that my service discovery protocol will incur a performance cost if reputation management is added, and there’s no other similar reputation management system to compare it to. So I think we’ve decided that I might implement it if I have time to spare. But the way things are looking at the moment, my thesis could well be finished soon after August. I might not opt to submit my thesis until January in order to take advantage of the six month extension scholarship (yes, I’m scheming), which means that I’ll have near on five months to "spare". I might use that time to convert my thesis into a few papers so that I have more publications listed when it comes time to submit. It would also be cool to set up a few really cool case study/scenario type things to test my protocol on (in addition to whatever testing I do in the next few months). I think we have enough devices of various sorts to do a really neat demo. The PACE group at the DSTC will probably want to integrate my protocol with their system as well, which might require a bit of work. Anyway, I’m really happy at the moment!

I also spent part of today finishing off the assignment 2 handout for the Distributed Computing subject. That didn’t take long. It pretty much amounted to taking the first assignment handout and changing the word "Elvin" to "CORBA". Well okay, not quite, but you get the idea.

Easter was pretty good. Lots of Easter eggs and chocolate rabbits from various sources. I’ve still got heaps left. Maybe I’ll go and eat some now.

My weekend was excellent. I watched two FA Cup semi-finals and the last ever NSL grand-final. Manchester United will play Millwall in the FA Cup final, and Perth Glory won the NSL final. Quite fitting that they won, really. But I was going for Paramatta.

Today was spent fixing up two papers which were then submitted to a workshop which will be held in Spain. Hopefully at least one of them will be accepted. I don’t know whether I would go to the conference or whether Jaga would go. It doesn’t bother me either way, and one of them has to be accepted first!

I’m looking forward to having a great weekend.

Had a big night out last night. This morning I woke up with a very sore bottom. I was a bit hesitant to check what was wrong with it. To my absolute shock and consternation, I found I had Tux the Linux penguin tatooed on one cheek and "Microsoft Sucks" tatooed on the other cheek. This is very surprising, given that my geek attitude is much less in evidence these days. But apparently after a few drinks I am still that geek rebel. Suddenly I’m remembering flashes of the Valley from last night. I wonder what else I did? Anyway, I’ve booked myself into the PA hospital for surgery, because there’s no way in hell I’m living the rest of my life with a penguin tatooed on my arse.

Southampton are back in the top half of the English Premier League table. I hope they stay there! There was yet another cracker of a match between Arsenal and Manchester United. It ended in a draw, but was full of controversy as usual. It looks like Arsenal will run away with the league this year. They would have to have the mother of all collapses if they somehow manage not to finish on top.

By the looks of my last entry, I can’t spell "epitome". I really should get in the habit of checking my entries over before posting them. Nah.

I had a very nice weekend. RA came around on Sunday and we had lunch and dinner at the Three Monkeys, my favourite little cafe. We talked for ages and I’m sure the cafe staff were wondering if we’d ever leave. Anyway, a nice little catch-up.

Today was rather slow. It’s very hard cutting a paper down to size. In this instance I have to cut it down from ten pages to five pages. Some passages were easy to cut out because they were the epitomy of vacuousness. I have a feeling I’m going to have to cut the paper down to about three pages and rewrite the remaining two, otherwise the paper will end up being complete and utter garbage. It will still probably end up complete and utter garbage. Oh well, we’ll just have to wait and see.

RGW was confirmed as a Ph.D candidate today. His confirmation seminar was very interesting. His topic is to do with trust, security and privacy in ubiquitous computing environments.

Some guy was using his mobile phone in a bathroom stall today. At least I hope that’s what he was doing. It was kind of weird walking into the bathroom and hearing a person talking (in Chinese) behind a toilet door. Kind of disconcerting when you’re trying to use the bathroom yourself!

Had a productive day yesterday. Among other things I wrote an XDR class for marshalling and unmarshalling data directly to a stream. It makes sending and receiving Superstring queries and responses much easier. I had another XDR class but it was really only useful for datagram communication. Today was far less productive. I had students to deal with and a two hour prac to supervise. For some reason I was also pretty tired.