Random mumblings of an SSE Scott Howard's Weblog

Lies, Damn Lies, and Statistics - that seems to be the best way to describe JetStar's (Qantas' "cut-price" airline) on-time performance figure.

Their website says they had an on-time performance of 84% in October (a bit above their normal of about 80%), but when you think about it that means that there's about a 1 in 3 chance that you'll have a delayed flight on a return trip - and of course "on-time" actually means more than 15 minutes - less than that and it's an on-time flight.

On Sunday I was booked on JQ209 - the 16:25 flight from the Gold Coast to Sydney. I did the right thing before I left for the airport and checked on their website to make sure that the flight was on-time.  The result?  A "Server Error" on the website when I tried to check that flight. Other flights before and after were ok, just not the one I was booked on.  Oh well, off to the airport and hope the flights on time...

When I made it to the airport I discovered the cause of the error - the magic word CANCELLED flashing on the monitors next to my flight number.

Welcome to the first rule of on-time calculations - Cancelled flights don't count!  That's right - if a flight leaves 20 minutes late then it counts as a hit against your on-time performance.  If it never leaves at all - no hit!

After around an hour in the check-in line I was finally moved to another flight - almost 4 hours and 3 flights to Sydney later than the one I had originally been booked on.  Of course I was compensated for the delay, in the form of an $8 refreshment voucher. Apparently my time it worth about $2/hour.

But it was what I saw in the 4 hours I was sitting in the departure lounge that amazed me. Every flight that departed whilst I was there (all 5 of them including my flight) departed late by more than 15 minutes.  But according to the monitors in the airport, and JetStar's website, all but 1 departed "on-time" (ie, no more than 15 minutes late).

 Presuming JetStar use the same numbers to calculate their on-time performance they are going to report that 80% of these departures were on-time, when in fact 0% of them were. That's a big difference!

Apparently a picture is worth 1000 words, so how about this (the top left corner is a zoom of the sign below it):

 That photo was taken at 19:35 and as the board says, the flight was "Closed", which should mean that everyone is on board. But at the point that photo was taken, not a single person had boarded - you can clearly see the passengers lining up waiting to be allowed on board.  They were finally allowed to start boarding about 5 minutes later at around 19:40.  According to JetStar, this flight departed at 19:45, only 10 minutes later than scheduled and thus within the magic 15 minutes for an on-time departure.  So somehow they apparently managed to get 177 passengers across the tarmac, into the plane, seated, and the door closed in about 5 minutes.  Somehow I think not.  Not surprisingly the flight landed almost 30 minutes later than scheduled.

 

The next flight out was  JQ229 - the flight I was transfered to. According to JetStar this flight departed only 15 minutes late at 20:20 - and 15 minutes late is "on-time".  This photo was taken at 20:16 :

Again you can see the line of people waiting to board the flight which is already closed.  Despite JetStar's claims that we departed at 20:20, we actually started boarding at about that time - I was still seated in the terminal at the time we apparently departed.

 It wasn't just Sydney flights this was occuring for either. At 20:15 Jetstar staff announced that the plane that was to run JQ283 to Melbourne was "On finals" to land, and that they would be boarding in about 10 minutes.  10 Minutes to land, taxi, unload, clean the plane, and then start boarding - not a hope.  Apparently JQ283 left at 20:35 (10 minutes late - "on-time"), but the stairs were clearly still attached when we taxied out at 20:41 - and it certainly takes more than 20 minutes to go from final approach to departure.

 

All up I managed to arrive in Sydney only minutes before the Sydney Airport 11pm cerfew kicked in, over 4 hours after I was originally scheduled to land. Now JetStar did at least acknowledge that this flight landed 30 minutes late (ie, not "on-time"), but the 4 hours and 15 minutes late I left Gold Coast is considered "On-Time"  - go figure!

 

A few months ago I found myself planning what to take for my 5 week trip to the USA and Peru.  Once the essentials were covered (the camera, the tripod and the like) I came to the age-old decision - to take my notebook or not.

Of course, being a geek, the obvious answer was "hell yes!", but when you're already carrying over 10kg (22 pounds) of camera gear, the thoughts of adding an additional few kilograms of fragile computer to the carry-on luggage isn't as tempting as it should be.

In the end I decided to compromise. Rather than taking my existing notebook, I'd buy a new, smaller, lighter one - a Sony UX17.  OK, so the truth was that I had pretty much wanted a UX17 from the day I had first seen a picture of one, and even more so from the day I first played with one at the local Sony store, so it was more a case of a solution looking for a problem - and I'd found my problem!

For those who haven't see the UX17 (or the UX280 in the US) it's a fully featured notebook which is roughly the same size as a typical paperback novel, and not that much heavier than one at a tiny 517 grams (about 18 ounces).

Of course, with such a small form factor there's compromises - the most obvious being the screen, which is less than 1/4 of the area of the normal "ultra-light" notebooks at only 4.5", and the keyboard which is even smaller than the screen. The other specs are at the low end of current systems, but still adequate for most tasks - a 1.2Ghz Intel Core Solo U1400 processor, 512Mb memory (UX280 is 1Gb), 30Gb hard disk (UX280 is 40Gb), 802.11a/b/g wifi, Bluetooth, two cameras (yes, two - it is a Sony after all), plus CF, MemoryStick and USB slots. Not bad for 517 grams!

 So after 5 weeks on the road, from the bright lights of Broadway, to the beaches of Miami, to the ruins of Machu Picchu and the Amazon Jungle I've got to say that this is the greatest travelling geek toy ever - at least for someone who takes a lot of photos.  The keyboard is a real limiting factor - it's fine for tapping out a basic email, but it's certainly not designed for the touch-typist. The screen is far less of a limiting fact that I first thought it would be.  Even for viewing and editing photos it's excellent, due mainly due to it's relatively high resolution (for it's size) of 1024 x 600 pixels, and the touch-screen and stylus which makes editing much easier than using a mouse.

For someone who takes far more photos than I should (my record this trip was over 600 in one day), and as a general rule hates writing long emails, this makes it the perfect on-the-road PC for me. The ability to view, edit and even upload photos whilst on the go was brilliant, and meant that I was able to keep my Flickr account up to date with photos as I went - in fact the longest time between any photo being taken and available on the web was about 4 days, and that's only because there's no WiFi on the Inca Trail!

 

 The Good :

• It's small - real small!
• It's fast - at least for it's size.
• The screen, though small, is clear and high-res at 1024x600 and has a very accurate touch-screen.
• Built-in everything - Wifi, Bluetooth, USB, Firewire (on the docking station only), Compact Flash, finger-print reader - just no optical drive. (The US version also has EDGE wireless built in)
  

The Bad :

• The keyboard. OK for web browsing or a quick email, but not much more.
• The "mouse". Slow to use accurately, and the texture wears off far to easily - although the touchscreen/stylus makes up for it.
• Battery life. The quoted 3.5" hours is optimistic as you'd expected, although I did managed to get almost 2 hours of Divx playback out of it. In general 2-3 hours seems to be the norm.
  

And then there's the outright silly. As well as a functional docking station, it comes with a tiny plastic stand that can be used to told it upright on a table. Between this stand, a USB keyboard (I have a small travel keyboard that is far more functional that the built in one) and the touchscreen/stylus it should be possible to turn this into a reasonably functional "desktop" setup, rather than hand-held as you'd normally use it. I say should because for some reason Sony decided to put the power connector on the bottom of the unit, which means that you can't use the stand whilst it's plugged into power - only whilst on batteries. I'm guessing that this is one of the compromises they had to make to keep the system so small/light, but it's a real limiting factor if you're trying to use it in a hotel room/office/etc for any period of time.

 Overall, as I said above, it's probably the best "geek toy" I've ever owned. Even if I only use it for 1 or 2 months of the year it was worth every cent that I paid for it! Sure, basically everything about it is a compromise in some form or other, but when you're "adventure travelling", a 517 gram compromise is a better option than either carrying 2+ kg of standard notebook, or taking no notebook at all. At least, it is when you're a geek! :)

 

Sometime within the coming week the Western Australian government will vote upon a bill to commence a 3 year trial of Daylight Savings in WA.

Whether you're a fan of daylight savings or not, the bill has one fatal flaw - it is due to commence at 2am on the 3rd of December, 2006. Less than 2 weeks from today, or about 10-12 days from when it goes before a vote of the upper house.

If it is passed, the implications of this change are significant and wide ranging. From an IT perspective it means that every computer in WA will need to be updated to be aware of the change - preferably by installing an updated timezone file beforehand, or at a minimum by manually modifying the time on the 3rd (although this will result in GMT/offset issues).

But it goes much further than that.  All flights into WA from other states/countries will arrive an hour later than expected (or leave an hour early, which is unlikely).  Flights out will most likely need to be rescheduled to allow for the late arrivals. Airlines normally build daylight savings changes into their schedules months in advance, but with less than 2 weeks notice they are not going to be able to do so.

The same goes for pretty much anything else that crosses the state border - call centre staff communicating with other states, other transport, B2B communications (especially in a state which hasn't had daylight savings for 15 years), etc. These are issues that occur in other states that already have daylight savings, but in those cases we've all had more than 10 days to plan for them!

Of course, this impact has either not occurred to the politicians, or they simply don't care. Given that the bill originally had a start date of the 1st of December (ie, Friday morning) which was changed to the 3rd they do obviously realise that there would be an impact, so...

If you happen to be in WA, or have Solaris systems that use the Australia/Perth or Australia/West timezones for some other reason, then you will need to take action if this legislation is passed. As we most likely won't have time to get a patch created and through Sun's patch testing process in less than the 2 weeks the government is going to give us we've instead created InfoDoc 87748 which describes a workaround to update the Solaris timezone files with the new details. This document will be updated as more details are available.

It's been a fun 3 weeks, but my holiday in Peru is about to end.

There only so much you can do in 3 weeks, but it turns out that visiting half a dozen cities, staying on Lake Titicaca, walking the Inca Trail for 4 days, visiting Machu Picchu and the Amazon, and drinking a few too many Pisco Sours can be fit in if you try.

Thanks to the purchase of a Sony UX before I left home (a full PC which is smaller than a paperback novel and about the same weight - more about that later) I've been able to upload some of the pictures I've taken as we travelled - they are available at http://www.docbert.org/flickr

New York for a few days is next, before the long flight back to Sydney.

And if you ever happen to find yourself in Lima's airport you'll be pleased to know it's got the cheapest WiFi access of any airport I've seen - starting at only US$1 for 30 minues and US$3 for 4 hours!

They are two terms which are often used to refer to the same thing, but Redundant and Fault Tolerant are actually very different - and one certainly doesn't imply the other.

Redundant
As you'd pretty much expect, redundant means that you've got more of something than you need. The tyres on your car are redundant - you only need 4 to drive, but you have 5, including a spare.

Reduntant doesn't imply that there is no impact to service when a component fails, it simply means that you are able to recover the service - to at least a working (although possibly degraded) state - without the need for any external components.  If you get a flat tyre on your car you need to stop and replace it with the spare (redundant) tyre. This has an impact, but it still allows you to recover from the flat without needing any external assistance.


Fault Tolerant
As the name implies, Fault Tolerant refers to the ability to tolerate a fault. The exact definition of  Fault Tolerant will vary depending on who you ask, but generally it implies the ability for a service to continue running despite a fault. eg, "run flat" tyres on a car could be an example of fault tolerant - despite the failure you are able to continue driving without an "outage".


Redundant components, Fault Tolerant systems
Fault tolerant systems are usually designed by using redundant components. Probably the most common form of fault tolerance we are used to is "RAID" - Redundant Array of Inexpensive Disks - but why does RAID have "redundant" in it's name if it's actually fault tolerant?

The distinction comes down to the difference between the individual componets and the entire system itself.  Individually, the disks within a RAID array are redundant, but they are not fault tolerant - if a disk fails, then it is dead. However as a system, a RAID array is fault tolerant - if a disk fails the array, and your data, is able to continue without interuption (although probably with degregation).

The Component - the disk - is redundant.
The System - the array - is fault tolerant.


With a few historic exceptions, no Sun systems are completely "Fault Tolerant", although they frequently contain fault tolerant sub-systems, such as :
* Power Supplies
* Fans
* Disks (using RAID)
* RAM (using ECC - Error Checking and Correcting memory)

In most (all?) cases this fault tolerancy is achieved using redundancy - multiple power supplies, multiple fans, multiple disks in a configuration where the failure of any one can be transparently handled without an outage.

Some high-end Sun systems can go a step further and be configured to be completely Reundant. This still doesn't mean that they can transparently handle any failure, but much like a flat tyre on your car the system is able to re-configure itself to map out the failed component, and come back up in a (possibly) degraded configuration. Whilst there is obviously an impact in doing this, it's far better than the alternative of being non-redundant, and far far (far!) cheaper than the alternative of being fully fault tolerant in hardware.

100 kms - teams of 4 - 48 hours

 Think you could manage to walk 100km (around 62 miles), primarily through bushlands, with 3 other people, all within 48 hours?  How about 24 hours?

Well the winners of this years Oxfam Trailwalker Sydney managed to do it in just 12 hours and 37 minutes, slightly above the course record of 11 hours 59 minutes.

Trailwalker is an annual event held in a number of cities around the world as a fundraiser for Oxfam. The Sydney event this year is expected to raise around A$2 million dollars.

What's this got to do with Sun? Like many large companies Sun recognises the importance of supporting the community, and as such provides support to staff who want to Volunteer for such events. I managed to spend most of today (Friday) delivering supplies to the checkpoints and assisting with their setup - all with the full support of Sun.

For more information of Trailwalker, visit the website at http://www.oxfam.org.au/trailwalker/sydney/ and while you're there why not help out yourself by making a donation to one of the teams!

You may not have heard the term viral marketing, but you've almost certainly experienced it, and most likely even played a part in it's spread.

Virtal Marketing is what we used to call word of mouth, grown up for the Internet.  It's where a marketing company relys on others to spread their message using the Internet - blogs, web forums, usenet, websites, etc. In order to do this, they need to come up with something with a high coolness factor - something that people will want to share with others.

Many Australians will be aware of the Carlton Draft "Big Ad", which was released on the net 2 weeks before it was first played on TV. In that 2 week window it was downloaded from the internet over a million times - before it even appeared once on TV!  How did they do this? Google for "carlton draught" "big ad" and you'll see how - almost 37,000 pages containing these terms, most of them blogs or other user-created websites.

About 3 weeks ago I discovered first-hand exactly how viral marketing works.  It all started innocently enough - a webpage containing a photo I had taken of Sydney Harbour. It wasn't exactly your average photo - but more about that in a later blog entry.

I put the photo on a webpage, and told almost exactly nobody. I emailed the URL to a few friends, and pasted it to 2 IRC channels with collectively about 20 active people on them.  A few days later I checked my weblogs and noticed that I was getting some hits from http://forums.overclockers.com.au/ - someone from one of the IRC channels has posted the URL into the forum. A few hundred hits over a few days - I thought nothing more of it.

A few days later I checked the logs again, and found that I was now setting hits from a few dozen different blogs and forums. These ones hadn't come directly from me, but were 2nd, 3rd, 4th generation of people forwarding on the link, and were resulting in around a thousand visitors per day.

Over the next 2 weeks things escalated a little. First it was digg.com, then the New York Times website, and literally thousands of others (well over 3000 different refering URLs at last count). The few hundred visitors has grown to over 400,000 visits, and over 3/4Tb of traffic.

Let me say that again - I gave the URL to around 30 people, maybe half of whom bothered to look at it. Through word of mouth those 15-odd people passed it onto, directly and indirectly, almost half a million people!  All with a marketing budget of exactly $0.

Try doing that without the Internet!

Well it's been over 2 years since I first created this blog, so I've decided it's about time I actually start writing something in it!

So who am I? I'm a System Support Engineer (SSE) working in Support Services, based in Sydney, Australia. Exactly what the SSE position entails varies a bit over the world, but here in Australia SSE's are the people who look after most of the support for Sun systems under Platinum support, especially for bigger customers. I like to think I push the limit of what an SSE does a bit more than most - hopefully you'll get to see what I mean as I post more here...