GlusterFS – migration woes

May 17th, 2015

So I’ve got a GlusterFS cluster that is a simple 1×2 distribute-replicate with two bricks (one on each server). So I need to migrate this from one data centre to another with little or no downtime (which means move one server, perform heal, and then go and shut the other and move it too).

Unfortunately I got stuck in the middle with the moved server not wanting to talk with it’s peer again. As it turns out changing the IPs is … hard. Fortunately I used Private (RFC1819) IP addresses in the original setup on a dedicated cable between the two servers.
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Denial of Service

April 2nd, 2015

Denial of Service attacks is a very vague term for a group of attacks that causes a service to be denied to legitimate users. Obviously when you host your website publicly you want it to be available – so having it taken down by some hacker is highly annoying. And I’m not referring to only websites, there are many other types of applications and services out there that can be “taken down”, or to which “service can be denied”.
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PS1 tips and tricks

September 1st, 2014

So two things have been bugging me off late, knowing if the previous command exited non-zero, and I’ve just now once too many times committed on the wrong git branch. The former question is easy enough to answer with “echo $?” and the latter with “git branch” before “git commit” – but lets be honest – how regularly do you really double check which branch you’re on?
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Asterisk – massively speeding up those REGISTER requests

August 1st, 2013

So recently I started bumping into an issue where I would see a buildup of traffic in the RX queue of asterisk’s SIP port 5060 (udp bound). After some scavenging of the code I quickly came to realize that asterisk only processes a single incoming SIP request (or response) at a time. So I cooked a rather crude patch (that I for the shame of it won’t share here) in an attempt to figure out what went wrong.
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