The tradeoff is in that AZs are "engineered to be insulated" as opposed to being actually, or naturally isolated. Prior to their downtime, I've had plenty of conversations with folks that I work with about AWS and we've always assumed that AZs are not 100% isolated. I can see how someone can read "engineered to be insulated" the other way, but I generally read these kinds of materials as guaranteeing nothing beyond the most limited possible reading, and probably not even that.
The quoted statement doesn't say that isolation is 100% or that multiple AZs can't ever ever fail at the same time. It says that if only one AZ goes down and you have servers in another, then those servers will still be up, which should be obvious. Insulated doesn't even mean the same thing as isolated.
And that's why they have multiple fully-isolated regions. Availability zones are a purposeful tradeoff that provides easier to use service with higher inter-zone communication performance and lower cost.
It's not a huge restriction since GAE will happily spin up dozens of instances without any intervention if your load requires it. Getting multiple concurrent requests into each instance will make things like local memory caching somewhat more useful though.
There seems to be a steady stream of these from ex-Googlers, which is frankly what I'd expect from a company of that size. What I'd be interested to know is what percentage of SWE's are leaving each year, and of course how do the people that are left feel about the company. The ones that I've heard from have a range of opinions from It's Ok to It's Great, but those are of course anecdotes.
Also, "behaviors that lead to success" are not necessarily the same as "behaviors of the successful". Lots of folks have effectively won the lottery.
Programming is not tedious, and it is hard. Listing instructions for the computer to follow is only 10% of the job. Most of the job is figuring out how to deal with complexity in a way that is economical, maintainable, and satisfies secondary requirements like security and performance.
In any system design involving software, the software is where the complexity goes. To save money, you might replace an electronic component with an algorithm. To make a better product you might replace a tedious user action with an automated system. This is because (some!) software developers/programmers have tools for dealing with complexity. Things like abstraction and re-use that don't trivially map to the concrete world.
Frankly if software were about enumerating steps, I would have been out of this business long long ago.
I bought a Mac Mini and returned it last year. If it had cost 1/2 as much, I wouldn't have returned it. It just didn't do enough for me to justify the price. If something turns out to be worth less to you than (the return value - time and irritation cost of doing the return), you return it.
Last time I heard, twitter still uses MySQL for the statuses (tweets) table. They did have a plan to migrate to Cassandra, but didn't go all the way through with it. So I find it hard to agree with "you just can't scale those". It may be a lot of work, but for some applications you can scale them.
Agreed. These are good places to start because you can just start building and learn as you go. Once you start building, you'll figure out what you need to be reading very quickly.
And IIRC Oracle had been actively attempting to exert this degree of control, to the point of interfering in infrastructure changes that project contributors wanted to make.
Frankly, the great thing about leading edge datastore development right now is that it's all over the map. Many of them will fall off the map over time, but having a couple of additional models to add on to the current great RDBMS tools can only be a plus.
I imagine that a significant driver of datastore heterogeneity is that there are a number of very different in-house datastores that are supporting extremely successful commercial ventures. It used to be that "you don't get fired for choosing Oracle." Now that Amazon and Google, etc, have paved the way, it's much more feasible for a corporate infrastructure developer to try to find a way off of the high-dollar proprietary systems like Teradata.
I also think it's interesting to note that some (most?) of the largest scale commodity RDBMS users couldn't get close to where they are without something like memcached.
Exactly. The semantics is what the words actually mean.