Saturday, February 04, 2012

Mac OS X Lion: stepping backwards

I finally took the plunge and upgraded my MacBook Pro to Lion. Technically I went to 10.7.2. The immediate motivation was to upgrade to the current version of Xcode. I'd delayed for two reasons: I'd heard about issues with a number of major applications, and I knew there were a couple of major changes that would, at best, take some getting used to.

My assumption is that by this point companies have fixed their Lion-related issues, so I just made sure I had all the relevant updates and so far so good. The known changes were another thing, though.

Yes, scrolling is “backwards” now. I understand (and agree with) the motivation for changing it, but I can see it is going to take me a long time to get used to it, particularly since I regularly use Linux and Windows boxes too.

The other major change is that "full-screen mode" uses separate desktops now, so applications on the second monitor disappear. I hate this, as apparently do many other people. I'd say about 50% of the time I'd have one application in full screen mode on one monitor and one or more activities on the other that I was peripherally monitoring... no more of that now that I'm on Lion. No more making Chrome full-screen for writing a blog entry while watching some long-running process in a Terminal on another monitor... like I'm doing right now, except not full-screen. I think I understand why Apple did this too: the previous ways of doing full-screen didn't work well for a lot of scenarios and each application did it in a different way. But it's rather annoying to me since the pre-Lion methods mostly worked really well for my scenarios.

The separate-desktop for full-screen mode idea works great when you have just a single screen. But since I have multiple screens, I want the main activity full-screen (no distractions!) on the main monitor and all the side activities on the second monitor. I hope Apple comes up with a good paradigm for that, but I suspect they don't see it as an issue that needs to be resolved. There are hacks to work around this problem but there are significant issues to them. People say “just don't use full-screen” but there is no “no-chrome” mode on most applications to achieve the effect that I'd get with most full-screen implementations on Snow Leopard. That's what I really want, a way to get rid of the excess application chrome. Perhaps Apple should provide a standard mechanism for that.

The final Lion issue (for this post anyway) is Preview. In Snow Leopard, small images would scale badly (no anti-aliasing etc) when you enlarged them in Preview. On the other hand, other software like Google Chrome scaled images nicely. But that's ok, I'd go full-screen in Preview and then the images would look good. I was hoping Lion would fix this. Lion did, indeed, make the behaviour consistent... full-screen images now look like garbage too. See the image at the top for the difference between what Chrome does (left) and what Preview does (right).

One more issue: the Finder crashed while I was writing this. I don't remember the last time the Finder crashed on Snow Leopard.

So with all the negativity out of the way, I will say that I do like Launchpad and Preview does seem a lot faster than it was.

Thursday, February 02, 2012

Amazon S3 reliability

According to the Amazon Web Services Blog, they currently have 762 billion objects in Amazon S3. That's impressive. The popularity of Amazon S3 isn't hard to understand: it's easy to use, only $0.14 per gigabyte-month in most regions, and is “designed to provide 99.999999999% durability and 99.99% availability of objects over a given year” (quoted from Amazon Simple Storage Service (Amazon S3)).

That's an impressive statement: 99.999999999% durability. That means that for my 7,038,080 objects, I could expect to lose one in 14,208 years, or to put it another way I have a 0.007% chance of losing an object in a particular year. That seems like a pretty minuscule risk.

But then you look at the scale of Amazon Web Services. There are 762 billion objects in Amazon S3. That means by their design criteria (ignoring the reduced redundancy storage option) they expect to lose at least seven of those objects this year. Have you checked your objects today?

Now I doubt that the “99.999999999%” probability is a “normal operating conditions” number. I suspect that's a guess at the probability of three Amazon data centres being taken out at once, or something like that. In normal operations I suspect that you might as well just call it 100% reliable in terms of preserving your object. But I find it amazing that they're at the scale where such minuscule probabilities become certainties (if you na├»vely apply them).