The 81% Solution

Ovid on 2009-06-26T15:27:37

Whether you're talking about git, Mercurial, SVK or some other distributed version control system, it's very important to realize that one of its strongest benefits is "distributed". Many people don't care about this, but it can tremendously boost productivity when combined as a part of overall development strategy.

Recently I got so fed up with our dev box that I install Ubuntu on my work computer so I could work locally. This was because our dev box was routinely running with loads around 20, and on one occasion hit a load of 57. Seems the admins thought it would be a good idea to let a bunch of other teams develop on that server but not tell us about it. I just couldn't work like that. Instead of using my computer as a dumb workstation with Windows, I now develop locally and am (usually) not dependent on our dev box being available.

That's also the reason why I have MySQL server installed locally, rather than using our test database. Sometimes that test database goes down, so I don't want to depend on that, either. And the admins thought it would be a good idea to let a bunch of other teams develop on that server but not tell us about it.

In fact, sometimes I break down. With a recent back injury, I was working from home for a week. It was slow, frustrating and painful because I wasn't really set up to work from home and this caused me to lose even more productivity. Had I been able to work from my laptop, there would have been no performance hit. Of course, even without a back injury, we had thousands of employees unable to work full hours because of a Tube strike.

Which brings me back to version control. More than once I've been unable to check in code because the subversion server has been down (never mind when the repository simply freaks out and tells me I can't commit). With something like git, I could do all of my work locally and if I can't push to the central repository, oh well.

So yeah, you know all this, but seriously, do the math. Let's be really generous and assume that our dev box, subversion server, mysql server and ability to be physically present at work all run at 99% availability. This means that your chance being "available" to work is .99^4, or about 96%. If the average availability of all of those things seems around 95%, then your "availability" drops to about 81%. Before I started working so hard to "disconnect" from the network at work, my availability was often lower than 81%. It was awful.

Now imagine sitting in a job interview and telling them that you're only going to work 81% of the time. You're not going to get the job. But the reality is, many corporate environments enforce 81% availability. This is insane, but common. And of course, we also know that those four items aren't the only things which can disrupt your productivity, but those are the four which most impact mine, so that's why I chose them.

When you're setting up a dev environment for programmers and you want it to be as productive as possible, don't force them to depend on things they can't control, such as network availability. Of course, as an employee, it's always fun when the network goes down and you see everyone wandering around with a coffee cup in hand, having been electronically muzzled. What on earth could convince people that this is a sane development environment?


I completely agree

mpeters on 2009-06-26T16:31:24

This is why at work each developer gets a pretty powerful laptop and does all their work on it. At a conference but need to do a little work? Want to travel for a week visiting relatives but not use any vacation time? Need to go home a little early because the baby sitter didn't show up?



None of these are problems if each dev has their own portable environment. Sure we're at the office 81% of the time working normally, but that extra flexibility for that other 19% is great.

Re:I completely agree

Ovid on 2009-06-26T16:41:50

That sounds great. Wish more companies did that.

something else is wrong

link on 2009-06-26T19:23:40

I tend to prefer shared over local as long as the shared resources are in the same office and have reasonable rights. Servers located in different continents or where I have not got enough rights to do my job are a pain.
If your test db servers are down as often as they are up, 20 is a normal load on your server or you often don't have network connectivity in your office then you probably have bigger problems than the relative merits of centralized verses distributed development.

I gotta say...

Alias on 2009-06-29T13:57:36

I've been at my current $work for a year and a half.

Luckily for me, I've never seen our SVN repo go down, I've never seen our Oracle dev instance go down, and all our dev and test servers are on a VMWare cluster, which I've never seen go down.

Frankly, I've had more problems with my desktop machine due to virus checking, remote admin and network drives than I've had problem with server gear.

Maybe we're just lucky... :/