Florent Clairambault

TINC – Simple P2P VPN

The world is full of good surprises. If you joined the NoSQL gang like me, chose Cassandra to store your data and you distributed your system among different datacenters. Wouldn’t it be great to interconnect all your nodes on a virtual private network with no single point of failure? Well, TINC does just that. In fact, it does a little bit more because it’s able to establish a meshed network if hosts can’t directly contact each other (in case of a routing issue, a NAT firewall, etc).


I’m a huge fan of all the cloud technologies. I’ve been working on a M2M project on top of cassandra and I can really say I love this distributed database. I’d like to give my feedback on this great database. Easy management Cassandra doesn’t require any kind of manual management for complex operations like sharding data accross node restore a crashed server or put a new or a previous disconnected node back into the cluster.

cron-apt and the perfect update system

On my spare time, I manage a handful of servers. And even if it’s not really my job, I try to do it well and efficiently. All of them work on Debian because it’s simple to manage. I started using cron-apt a few years ago. I started by upgrading everything automatically, this was a big mistake. I switched to only sending mails on available upgrades and doing the upgrade manually. But this is also quite painful because 95% of the time, it consists in typing “apt-get dist-upgrade -y” and waiting and I have lots more interestings things to do.

btrfs for a simple and powerful backup system

I’ve been testing btrfs for some months now. One of the most interesting features of this file-system is its snapshoting capabilities. Before that I was using rsnapshot. The issue with rsnapshot is that its lowest atomic level for snapshotting is the files themselves using hard-links. So any database table where one row is changed is copied completely. Btrfs as you might guess will only copy the modified chunks (I don’t know the atomicity of them [but who cares?

Debian 6.0

Debian released a new version of their system. I updated it on the server that powers this blog, it took me something like one hour to do the whole system upgrade. There was only a little glitch with mysql’s my.cnf file that had an unsupported “skip-bdb” line. Everything else went fine… The very good thing in this new release is the new kfreebsd version (available in i386 and x86_64). It brings the power of the FreeBSD kernel to the great Debian OS.