Gareth Klose

Don’t expect that new iPad 4G to be 4G outside North America

The brief period where we almost had spectral harmony, seems to be over, looks the iPad 4G as being sold in the UK, will never work with UK 4G networks.

Yesterday the “New iPad” was unveiled. It’s an evolution of the iPad 2 with a “retina display” screen and more processing oomph. And an improved cellular modem, giving it faster 3G, and the even faster LTE or “4G”.

The UK has yet to launch LTE networks: the spectrum clearing and auction hasn’t got underway, but we do know that they will be running on 800 MHz and 2,600 MHz. (the 800 MHz provides great coverage, so good for rural areas, while the 2,600 MHz will provide capacity in cities because of smaller cell-size).

It looks like there are two variants of the iPad 4G, the AT&T (LTE at 700/2,100 MHz) and the Verizon version (LTE at 700 MHz along with CDMA support). Comparing the US and the UK specs, it looks like the AT&T variant is the ‘global’ one.

All the pages on apple.com have many caveats: 4G coverage is limited by carrier and by area. They make no claims for universal 4G availability. Only certain US and Canadian carriers are listed as supported.

Here’s the potential confusion though: the iPad 4G (as currently shipped) will never work with UK LTE networks. Our networks will be running on frequencies that the device cannot support. There is an outside chance that some carriers might reuse their 3G spectrum at 2,100 MHz – but the most likely to do so, 3, recently ruled this out.

The same situation exists in Australia, where Telstra have launched their LTE network on 1,800 MHz.

The brief period where we almost had spectral harmony, or at least when devices supported enough bands to make it look like we did, seems to be over.

I would still buy the “4G” version, the better 3G support will make your browsing faster, and I like connecting directly without tethering to, and using the battery of, my phone.

By the time LTE arrives in the UK in 2013, Apple will have doubtless have launched the “New New iPad” and this probably goes away. But, if you’re selling a “4G” product in the UK, it’s not unreasonable to expect it would work with 4G in the UK.

Pessimistic about TV Apps

I spoke on Guardian’s Tech Weekly Today, about how I see the future for dedicated TV Apps somewhat lacking.

I was on an episode of Tech Weekly today (23 minutes in) talking about Connected TV alongside the head of the DTG, Richard Lindsay-Davies. I was perhaps a bit down on TV apps and wanted to expand on that a little, in the hope of being more nuanced.

I think that Video Apps on the TV video are great: I love using iPlayer and NetFlix on my TV/PS3/AppleTV far more than on my laptop. You can glance away, and glance back when something interesting happens, in the way you watch TV. You’re not cmd-tabbing through windows to try and find the iPlayer tab before the interesting bit ends.

The BBC Olympics application will let fans have access to nearly all the sports, not constrained by how many channels the BBC has – a useful extension and I think it will be popular. The Twitter app on my TV? Not so much, I used it once, and used it to say how awful sending that tweet was.

I really don’t think we’ll manage to have that many TV-only apps. No developer without lots of video (the Broadcasters, Netflixs and YouTubes of the world) is going to pick up a TV SDK – they’re going to learn Android or iOS programming. There’s already a lot of fragmentation in the TV space and billing is never going to be as easy, and lucrative, as on the mobile platforms.

I think that in the future we’ll see some of these phone/tablet apps throwing interesting graphics and content to the TV screen, like the scores at the end of a round. There’s scope for real innovation here, but it’s about feedback, not interaction.

The TV should be the easiest screen to get content on, you shouldn’t have to think about how you get content there: It’s about leaning back and relaxing. We tried ordering pizza via TV in 1998, it didn’t really work. Today we’d just do it from our tablet or smartphone.

Have a listen, let me know what you think, am I being too pessimistic?

should I apply for that job?

The all-purpose guide to if you should apply for a job?

Quite often I see people asking online, “I’ve just seen this new job, should I apply for it?”. I don’t think this is a hard question, so I’ve pulled together a handy flowchart.

The less flippant version is: Worry about what you do when you’re offered the job, not when you’re thinking about applying… Easier said than done, but make the opportunities then decide.

The Need Not to be Needy

Emailing me with 24 hours of using your service getting me to invite friends, feels kinda needy.

I recently installed the iPhone version of a social app that was previously iPad only.

In less than a day I got the “welcome to the iPhone version, you want to invite your friends?” email.

It was needy. I’m not inviting them.

Calls to Action are a pain to write. Too passive and they won’t drive people, too pushy and they’ll drive people away. And invariably what works for some won’t work for others. Judging the assertiveness/aggression is tough; but easier is never, ever, sounding needy.

Asking me to invite people within 1 day of installing something feels that.

It might be a considered decision to strike while the iron is hot, but failed; for me, at least.

Performance: still hard

Performance is still hard: Artur Bergman of Fastly talks about what you’re doing wrong.

I watched @crucially’s video from the velocity conference, where once again it’s a good talk where he plays the Grumpy Bastard with aplomb. Soon, soon I promise, I will “Buy a Fucking SSD”.

That’s Magic!

If you don’t understand stuff, it’s magic. And if you’re relying on something that’s magic, your platform can disappear in a puff of smoke. This especially true of newer things – I don’t understand MySQL but it’s long in the tooth enough I can (mostly) trust it. Some of the newer NoSQL techs do not have that lineage…

Open Source allows you to get under the hood of all these things, to look behind the curtain and reverse-engineer what is going on. You invariably have to as the documentation is a TODO item. This means that when you do hit these extreme edge cases situations you can fix them, eventually.

But that’s only once you’ve really understood the problem. In black-box situations it’s all too easy to pull the levers you have until it seems the problem has gone away, but all you’ve done is masked, displaced, or deferred it. You have to understand the whole stack and not just “your bit”. (This reminded me a bit of a conversation with a friend who does network security, where decisions not to collect some data for “safety” actually made potential targets more obvious)

There are no gremlins

My favourite point was this: Computers are (mostly) deterministic.

We talk about bugs, issues, intermittent and transient faults – almost resigning ourselves to sometimes “things just happen”.

As Artur points out, computers are deterministic state machines, this randomness doesn’t really exist. Yes, the complex interplay of our interconnected systems can give the appearance of a random system, but that is just the appearance.

There is pattern in there, and when find it, you can fix it. How? Lots of monitoring, lots of measuring, and good old-fashioned investigation.

Stop throwing boxes & sharding at things

The easy availability of horizontal scale-out makes us lazy and complacent: “we’ll just throw another amazon instance at the problem”. That can be a valid approach, but only when your existing instances are actually spending all of their time doing meaningful work and not stuck queuing on some random service. If you’re site is sluggish because of poor code, database performance or tuning, you’re not really solving the problems.

Latency is even more critical(Google PDF), and scaling out a broken system may just let more people use it slowly – not make it faster.

Post-Cloud Call to Arms?

Scaling was hard: ordering servers took ages and it was all confusing. CDNs cost lots of money, were hard to use and only for the big boys.

Then “The Cloud” appeared: people like amazon and others made stuff cheaper and faster to get machines from. For a while we could ignore the complexity and just throw money at it.

But latency isn’t as simple as capacity, and we’re back to the situation that isn’t always about throwing more boxes into the battle.

On loving the internet version of Countdown

The web implementation of the TFL Busses countdown data is useful, and pleasing.

Every time I use countdown.tfl.gov.uk or more commonly the mobile version I find it inexplicably pleasing. I thought I’d try to figure out why:

It meets a real need. Knowing whether to wait for the irregular but useful 355 was the bane of a previous commute. If it was due I could be at Brixton in 5 minutes, if it was running late I could walk faster than wait the 15+ minutes for it.
It super serves that need: no longer am I restricted to viewing the stop I’m at: I can answer “do i get this bus at stop x or that bus at stop y” from my phone. If services are rare, I can time my exit from the house to avoid standing in the rain.
It just feels future-y. Interactions of things in the real world with that panel of glass in your pocket always feel a bit more special than posting a funny tweet.

I mean, sure I’ve nearly missed the bus arriving sometimes because I’ve been too busy checking when it’s due, but still, it’s just pleasing.

Farewell Radiotalk

The Radio Academy’s RadioTalk podcast is no more.

At the end of the coverage of the Radio Festival, Trevor Dann revealed the weekly podcast is no more.

I’ve never really worked in radio beyond running a mixer evaluation for Radio2 (the glamour), but RadioTalk often left me wishing I had done. It had a decent range of voices on, the roster was the right size that you could remember most of them. Even industry big-wigs like Tim Davie popped in from time-to-time. It had the pleasingly conversational tone of good radio, and combined with the occasional fuck-ups around the Academy-MDF as previous the non-studio studio was known, was an accessible listen to an outsider.

Anyway, thanks to Trevor and (long-suffering?) producer Heather Davies for creating something good for the last few years.

http://www.radioacademy.org/podcasts/

Anatomy of Ticketing ‘Fail’

Having failed to get tickets for something in an annoying day of pressing reload, I try to write something constructive about scaling for big things

(Or what happens when a company that isn’t eventbrite tries to be eventbrite)

A friend wanted to book some tickets for an event. I had some time today, so I said I’d book them.

For reasons of politeness, I’m not going to name the company. The event was massively over-subscribed, there were always going to be people who were annoyed (kinda like the Olympics). I’m just annoyed because I saw things done generally quite ad-hoc, specific technical bugs hit me.

Tickets were delivered in tranches. This is a sure sign there will be massive peaks in demand…

The hour arrives, and, in your all too typical scenario: www.example.com rapidly stopped responding.

A few minutes later everything went 403’d as they killed all access on the server to get the load down. Not great, but it’s a sign somebody is looking at the problem.

example.com then starts redirecting to http://xxxxxxxxxxxxx.cloudfront.net/url1 with all the individual ticket pages iFramed through to an Amazon EC2 instance (http://ec2-xxx-xxx-xxx-xxx.compute-1.amazonaws.com/blah)

The IDs for the events were sequential, some had already been released, and you started to think that people had been gaming the system and ordering tickets prior to their availability windows. This was later denied by the company (which I accept), but given the way the scaling was going, at that time it was all too easy to think they were using security by obscurity to prevent access to the events.

Later in the day, when tickets appeared, it was announced via a tweet. The tweet though didn’t link to the site, but to a mailing list post, which again didn’t reference the actual site.

The site had now changed, example.com was redirecting to http://xxxxxxxxxxxxx.cloudfront.net/url2 again passing through to EC2 instance. Later many people complained on Facebook that they were looking the old page and pressing reload.

Anyway, I tapped. I was at the gym. I was on my iPhone. But I know my credit card number, I know my paypal password, I can even use that tiny keyboard. I’ve topped my starbucks card up while in the queue. I can do this.

There was even a mobile site.

Only the mobile site was erroring because it was asking for a non-existent field/table. I had no way to change my user-agent (and wouldn’t have trusted Opera with my credentials), and in the 10 minutes it took me to get back to my laptop all the tickets had been sold.

No tickets for me+mate. Grumbly me having seen things done badly.

As many will say, this is not life and death – but example.com is primarly not a ticketing company, and that showed today.

If you’re going to compete with the likes of eventbrite, you’re going to have to be as good as eventbrite.

The Constructive “What can we learn” Bit

1. Believe it could happen, no matter how unbelievable.

Ask yourself “if we get off-the-scale load how will we fix it”. Working out volumetrics and scaling is hard, so alongside your “reasonable” load calculations of “we can turn off these bits of our site”, have your plans of “how you’ll move to something big, cloudy and scalable if the unbelievable happens”.

Are there components that you should move upfront? You have something like 15 to 30 minutes of goodwill. What do you need to do upfront, so that in that downtime you can come up fully scaled.

If you’re looking a scalable elastic thing, look at how much it costs to start in that state anyway.

2. Architect things to give you agility

If you can’t host all your website on a scalable platform: Subdomains, DNS expiry times and proxy-passes give you room to move, but only if set up ahead of time.

Had tickets.example.com been available, example.com wouldn’t have had to disappear as it has done until tomorrow. You don’t want your website down for that length of time.

DNS changes can take time, much less if you dial down the expiry times, but again you have to do prior to the event. Amazon’s route 53 is cheap so move the domains ahead of time, and set Times to Live appropriately.

While you’re waiting for that propagation, proxy-passing can be a useful technique to bounce the traffic to the new server, while the DNS propagates. Proxy passing also means that example.com/tickets could have been redirected, rather than an entire domain.

Are you caching what you can at an HTTP level with varnish or a service level with memcache?

3. Be careful sending people onto new URLs that won’t update

Taking the ticketing system off their main website was a good move, but the static page should have remained there. The second you redirected to cloudfront, they were then looking at a page that would get stale.

Many people would have pressed reload, expecting it to appear, but they didn’t because as you can see from above above, the URL changed. They could have used the Cloudfront revocation API, but this wasn’t used.

4. Remember data protection issues

This company used the Virginia data centre (which I think is the AWS default). Without going into the whole world of pain that is data-protection and EU borders – Dublin would have less latent and less problematic compliance wise.

5. Testing is good, as is automatic deployemnt

There were not many tickets and the loading was huge, those were not avoidable. I can’t say the same about the erroring mobile site, that should not have occurred.

6. Rehearse

It’s not fun doing disaster recovery, but if you’re receiving catastrophic load then that is what you’re doing.

Write the script. Have someone else test it.

It’s not a valid plan until you have shown it works.