––thursday #7: git-new-workdir

Often I’ll fix a bug (call it “bug A”), kick off some tests, and then get stuck. I’d like to start working on bug B, but I can’t because the tests are running and I don’t want to change the repo while they’re going. Luckily, there’s a git tool for that: git-new-workdir. It basically createsContinue reading “––thursday #7: git-new-workdir”

––thursday #5: diagnosing high readahead

Having readahead set too high can slow your database to a crawl. This post discusses why that is and how you can diagnose it. The #1 sign that readahead is too high is that MongoDB isn’t using as much RAM as it should be. If you’re running Mongo Monitoring Service (MMS), take a look atContinue reading “––thursday #5: diagnosing high readahead”

––thursday #4: blockdev

Disk IO is slow. You just won’t believe how vastly, hugely, mind-bogglingly slow it is. I mean, you may think your network is slow, but that’s just peanuts to disk IO. The image below helps visualize how slow (post continues below). (Originally found on Hacker News and inspired by Gustavo Duarte’s blog.) The kernel knowsContinue reading “––thursday #4: blockdev”

––thursday #3: a handy git prompt

Everyone says to use git branches early and often, but I inevitably lose track of what branch I’m on. My workflow generally goes something like: Check out a branch Lunch! Get back to my desk and make an emergency bug fix Commit emergency fix Suddenly realize I’m not on the branch I meant to beContinue reading “––thursday #3: a handy git prompt”

––thursday #2: diff ‘n patch

I’m trying something new: every Thursday I’ll do a short post on how to do something with the command line. I always seem to either create or apply patches in the wrong direction. It’s like stalagmites vs. stalactites, which I struggled with until I heard the nemonic: “Stalagmites might hang from the ceiling… but theyContinue reading “––thursday #2: diff ‘n patch”

––thursday #1: screen

I’m trying something new: every Thursday I’ll go over how to do something with the command line. Let me know what you think. If you are using a modern-ish browser, you probably use tabs to keep multiple things open at once: your email, your calendar, whatever you’re actually doing, etc. You can do the sameContinue reading “––thursday #1: screen”