@tkramar raised the question on Twitter, why every desktop client for that service seems to be built on top of Adobe Air (here). That’s something, I also was wondering about. And in fact you often hear people complain: “Why AIR? Why not a native application?” Let me try to give the answer while having breakfast. 
Jun 21
Jun 06
I have to admit that I really like C#. The last 4 or 5 months, I’ve hardly touched any other programming language. And so it happened to be my first choice when I was asked to develop a “reasonably fast” logging server.
So what is this Octopus thing about? In a nutshell it’s a server, which takes HTTP requests with a defined set of URL parameters, confirms receipt the client, and then asynchronously stores the request into a database. The interesting bit is the part between accepting the request and storing it to the DB.
Basically, we’ve got three levels of storage: a in-memory queue, a flat file buffer, and the database. The tricky thing was to optimise processing, while still being fault-tolerant. I kind of managed that, I think. Octopus can (depending on the hardware it runs on) easily accept up to 2,000 requests per second, and will store them into either a MySQL or SQLite database at the moment. Please read more about it on the Octopus Website.
Sep 14
I was quite fed up with BIND (zonefile editing, serial number increasing, master/slave setups), so I was searching for alternatives to run Master/Slave DNS services. More or less randomly, I again came across PowerDNS. Again, because I have heard a couple of times that big providers quite often use it. So I decided to give it a go. On FreeBSD it’s quite easy. You just install it together with its MySQL modules, activate the modules in the configuration files, import the database schemata, and fill it with content. A script to import BIND zone files directly to the DB is also included. Couldn’t be easier.
Once you’ve set it up and got it running, you of course need a slave server as well. So all you got to do is either to install another PowerDNS/MySQL instance on another machine and connect it to the same database (you wouldn’t really want to do that), or connect it to a second MySQL server, which ideally is a replication slave of the first one. Then you have a fully redundant setup and don’t need to worry about failures of either of those. All DNS record changes go directly to the master DB server, which will be picked up by the slave in almost real time. Plus, you don’t need to worry about serial numbers. Change a record in the DB and this change will be published instantly.
If you fancy web interfaces, you can either go for an open source one, or you can write one on your own. As the DB structure of PowerDNS is kept very simple, it’s easy to add/modify records via script also. Do whatever you want and don’t worry about the stupid restrictions and configuration hurdles you used to run into when going for a BIND server.
May 25
Did you ever receive spam mails which seem to originate from your own mail address? Or did anybody else complain about you sending those emails? Then you should take a look at SPF. In a nutshell, it plugs the holes in the SMTP protocoll, which does not allow to verify if a sender (or anybody who pretends to be that sender) really may use a particular mail server to transmit their mails. Unfortunately, SPF is not yet very wide-spread. Almost everybody (including me) has come across this abbreviation and/or heard that it might protect misuse of mail addresses. But most people (including me) cannot be bothered to implement it.
Apr 24
Generally it is quite easy to sync calendars between one Mac and a Nokia N95 (or any other model). All you need is iSync and the Nokia iSync Plugin. The setup is quite straight-forward. But as the computers store the synchronisation information, conflicts are very likely to happen. So we need another solution to keep two (or more) computers and a mobile phone in sync.
