syslog-ng is an enhanced log daemon, supporting a wide range of input and output methods: syslog, unstructured text, message queues, databases (SQL and NoSQL alike) and more.

The easiest configuration that accepts system logs on /dev/log (from applications or forwarded by systemd) and writes everything to a single file:

@version: 3.8
@include "scl.conf"

log {
	source { system(); };
	destination { file("/var/log/syslog"); };
};

This one also processes logs from the network (TCP/514 by default):

@version: 3.8
@include "scl.conf"

log {
	source {
		system();
		network();
	};
	destination { file("/var/log/syslog"); };
};

Structured/application logging, local submission via JSON, output in key=value format.

@version: 3.8
@include "scl.conf"

log {
	source { system(); };
	destination { file("/var/log/app.log" template("$(format-welf --subkeys .cim.)\n")); };
};

Here's how to submit a structured message using "logger":

$ logger '@cim: {"name1":"value1", "name2":"value2"}'

and the result will be:

name1=value1 name2=value2

• receive and send RFC3164 and RFC5424 style syslog messages
• work with any kind of unstructured data
• receive and send JSON formatted messages
• classify and structure logs with builtin parsers (csv-parser(), db-parser(), kv-parser(), ...)
• normalize, crunch and process logs as they flow through the system
• hand on messages for further processing using message queues (like AMQP), files or databases (like PostgreSQL or MongoDB), and
• forward log messages to big data tools like Elasticsearch, Apache Kafka, or Apache Hadoop.

Performance:

• syslog-ng provides performance levels comparable to a large cluster while running on a single node.
• In the simplest use-case it scales up 600-800k messages per second.
• But classification, parsing and filtering still produces several tens of thousands messages per second.

Community:

• syslog-ng is developed by a community of volunteers, the best way to connect us is via our github project page project, our gitter channel or our mailing list
• syslog-ng is integrated into almost all Linux distributions & BSDs, it is also incorporated into a number of products, see our [powered by syslog-ng] page for more details.

Sponsors:

• Balabit is the original creator and the largest current sponsor of the syslog-ng project, they provide support, professional services and addons you might be interested in.

We are really interested in who uses our software, so if you do and you like what you see, please tell us about it. A simple "thanks" is also enough, but learning about your usecase, experience, things to improve would be most appreciated.

Just send an email to feedback (at) syslog-ng.org.

Should not take more than a minute, right? Now go ahead. Please.

#FeedbackPowersOpenSource.

Releases and tarballs ready to compile are are made available at GitHub.

To compile from source, the usual drill applies (assuming you have the required dependencies):

$ ./configure && make && make install

Some of the functionality is compiled only in case the required development libraries are present. The configure script displays a summary of enabled features at the end of its run. For details, see the syslog-ng compiling instructions

Binaries are available in various Linux distributions and contributors maintain packages of the latest and greatest syslog-ng version for various OSes.

Simply invoke the following command as root:

# apt-get install syslog-ng

Latest versions of syslog-ng are available for a wide range of Debian and Ubuntu releases and architectures from an unofficial repository.

syslog-ng is available as a Fedora package that you can install using yum:

# yum install syslog-ng

You can download packages for the latest versions from here.

Binaries for other platforms are listed at the official third party page.

The documentation of the latest released version of syslog-ng Open Source Edition is available here. For earlier versions, see the Balabit Documentation Page. For ancient versions, see the Balabit Documentation Archive.

If you want to modify the source of syslog-ng, for example, to correct a bug or develop a new module, the syslog-ng gitbook helps you to take the first steps with the code base.