Today, we have added support for so-called “tags” to liblognorm (and it’s base library libee). This new capabilities permits very easy classification of syslog message and log records in general. So you can not only extract data from your various log source, you can also classify events, for example, as being a “login”, a “logout” or a firewall “denied access”. This makes it very easy to look at specific subsets of messages and process them in ways specific to the information being conveyed.

To see how it works, let’s first define what a tag is: A tag is a simple alphanumeric string that identifies a specific type of object, action, status, etc. For example, we can have object tags for firewalls and servers. For simplicity, let’s call them “firewall” and “server”. Then, we can have action tags like “login”, “logout” and “connectionOpen”. Status tags could include “success” or “fail”, among others. The idea of tags is based on early CEE concepts. We will try to keep consistent with whatever CEE heads to. Tags form a flat space, there is no inherent relationship between then (but this may be added later on top of the current implementation). Think of tags like the tag cloud in a blogging system. Tags can be defined for any reason and need (though obviously we must strive to get to a standard set, something we hope CEE will provide in the not too distant future). A single event can be associated with as many tags as required. (more…)