The sys admin's daily grind: RSyslog
Where To Next?
Well-used services write reams of log information to disk, which is not only bothersome from a storage perspective but also pushes grep and the usual group of statistics tools to their limits. Will hitching the syslog daemon up to a database help?
Who said length doesn't matter? My spam filters alone give me a 3GB logfile daily, which would be fine if I just needed the beast to check up on the occasional error. Because I need to extract a whole bunch of statistics about spam and virus threats from the file, grepping such enormous files takes ages, besides creating far too much I/O overhead.
RSyslog [1] took me a giant leap closer to finding a solution – it logs directly to a MySQL or PostgreSQL database, meaning that I can replace my grep commands with fast SQL statements. RSyslog is included with many distributions and is the default application in Fedora 8, for example. By default, my Ubuntu lab environment runs sysklogd, making it easy for me to switch to RSyslog. For the time being, I can even keep my old syslog.conf. For the most part, RSyslog's configuration file is the same as the legacy format, although it does support a couple of additional options for linking up with the database.
First I need to set up a database. To do so, I run the createDB.sql script, which is provided with the RSyslog package:
mysql -u root -pPasswort < ./createDB.sql
This command line automatically creates a database called Syslog along with the required tables.
At the MySQL prompt, I then create a user and assign privileges:
> grant ALL ON Syslog.* to rsyslog@localhost identified by 'secret'; > flush privileges;
Next, telling RSyslog to use the database is refreshingly simple – just two lines in /etc/rsyslog.d/mysql.conf:
$ModLoad MySQL mail.* >localhost,Syslog,rsyslog,secret
The first line loads the module that RSyslog needs to access the database. The second line defines the log facility containing the entries RSyslog will push to the database. The mail facility data are all I need to create spam filter statistics, followed by the access parameters for the MySQL database: hostname, database name, MySQL user name, and password.
After rebooting, I was pleased to see the RSyslog daemons filling the database (Figure 1). All done! This won't magically improve your spam statistics, but at least it will get the job done faster. Incidentally, the example here works with the current 2.0.2. stable release. RSyslog's author, Rainer Gerhards, is working hard on a 3x version, which he promises will add even more neat features.

Infos
- RSyslog: http://www.rsyslog.com
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you've found an article to be beneficial.
News
-
Linux Mint Finally Receiving Support for Gestures
If you use the Linux Mint Cinnamon desktop, you'll be thrilled to know that 21.2 is getting support for gestures on touchscreen devices and touchpads.
-
An All-Snap Version of Ubuntu is In The Works
Along with the standard deb version of the open-source operating system, Canonical will release an-all snap version.
-
Mageia 9 Beta 2 Ready for Testing
The latest beta of the popular Mageia distribution now includes the latest kernel and plenty of updated applications.
-
KDE Plasma 6 Looks to Bring Basic HDR Support
The KWin piece of KDE Plasma now has HDR support and color management geared for the 6.0 release.
-
Bodhi Linux 7.0 Beta Ready for Testing
The latest iteration of the Bohdi Linux distribution is now available for those who want to experience what's in store and for testing purposes.
-
Changes Coming to Ubuntu PPA Usage
The way you manage Personal Package Archives will be changing with the release of Ubuntu 23.10.
-
AlmaLinux 9.2 Now Available for Download
AlmaLinux has been released and provides a free alternative to upstream Red Hat Enterprise Linux.
-
An Immutable Version of Fedora Is Under Consideration
For anyone who's a fan of using immutable versions of Linux, the Fedora team is currently considering adding a new spin called Fedora Onyx.
-
New Release of Br OS Includes ChatGPT Integration
Br OS 23.04 is now available and is geared specifically toward web content creation.
-
Command-Line Only Peropesis 2.1 Available Now
The latest iteration of Peropesis has been released with plenty of updates and introduces new software development tools.