Tales of an IT Nobody

devbox:~$ iptables -A OUTPUT -j DROP

System admin ‘helper’: Zebra stripe log / console output August 25, 2011

Looking at an ASCII data table can be difficult – so to start a small trip into Perl programming – I tossed together a simple Perl script, with no module requirements – zebra.pl as I call it, and it zebra stripes the output. It adds a nice touch to say vmstat or viewing something like the interrupts on a multicore box. It’s super simple and done in the nature of Aspersa. (Now a part of percona toolkit).

It doesn’t work 100% like I want – I would have liked it to take an $ARGV; to do that it seems like I’d have to create a dependency with a module (something like GetOpts) – so I decided one can simply modify the script to change how many X rows are striped.

You can fetch it here.

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Categories: linux purdy servers

On coining terms: Kiloreq, Megareq, Gigareq, Terareq August 9, 2011

I’m inventing these terms. You heard them here first!

Ok so the idea goes like this:
We use kilo(bit/byte, etc) as measurements of rate, and size – even weight (kinda).

I thought it’d be fun to come up with another terminology that’s right in line with the nature of these units of measurement geared toward server load: “R” for request – prexed accordingly: Kiloreq, Megareq, Gigareq, etc.

So for example, if you get 1000 requests a second, you can say “I get 1KR/sec”, if you have 500 request per second, instead of ‘500 rps’, use the standardized “KR” (Kiloreq) suffix: 0.5KR/sec

How many requests did foo Apache server handle this month?
About 3MR. 3 mega reqs. (3MR * 1000KR * 1000R = 3,000,000 requests).

Or how about for the year? (Assuming a flat rate of 300MR over 12 months)
3.6GR. Gigareqs!

Far fetched? Yes. But I plan on using them in my day-to-day language to try and make them stick :)

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Categories: servers

Netflix is run by monkeys! August 4, 2011

An entertaining read for the HA operations for netflix – a good sense of humor and a very cool, hardcore philosophy for testing!

http://techblog.netflix.com/2011/07/netflix-simian-army.html

It’s nice to see Netflix stepping up their involvement in the technical community even more; with the Netflix prize and their blog and API feedback – I hope they become even more successful because of these investments.

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Categories: netflix servers

MySQL – max_allowed_packet – what is going on?

So there’s enough noise in the MySQL community about what’s covered well here (https://www.facebook.com/note.php?note_id=10150236650815933)

Unfortuantely the bug is private for the time being; in my conversation with others, the general premise seems to be what good does max_allowed_packet really do? 

First off, I’d like to point out what seems to be what I hope is heading for deprecation – otherwise it just feels a bit sloppy; the default max_allowed_packet for the MySQL client is 1GB. (AKA: Maximum).

As the FB  post recognizes, there’s some ambiguity to how this setting is even enforced in the first place, especially when considering a master->slave configuration (Why does replication even have to follow that rule? Maybe replication clients can have a hard-coded packet to the maximum to get over this?)

I’d propose one of the two:

1. Enforce max_allowed_packet at the server – negotiate a loose communication with the client, where the client will obtain the server’s value and take it for it’s own.

2. Better yet, allow it to be set on a per user basis, following #1.

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Categories: mysql servers