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 is as follows:

@version: 3.15
@include "scl.conf"

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

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

@version: 3.15
@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: 3.15
@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

For a brief introduction to configuring the syslog-ng application, see the quickstart guide.

• 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 built-in parsers (csv-parser(), db-parser(), kv-parser(), ...)
• normalize, crunch, and process logs as they flow through the system
• hand over 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 to 600-800k messages per second.
• But classification, parsing, and filtering still produce several tens of thousands messages per second.

Community:

• syslog-ng is developed by a community of volunteers, the best way to contact us is via our github project page project, our gitter channel or our mailing list.
• syslog-ng is integrated into almost all Linux distributions and 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 "star" on github, an email with "thanks" in it is lots already, but learning about your use case, 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.

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

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

$ ./configure && make && make install

If you don't have a configure script (because of cloning from git, for example), then run ./autogen.sh to generate it.

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

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

For instructions on how to install syslog-ng on Debian/Ubuntu distributions, see the blog post Installing the latest syslog-ng on Ubuntu and other DEB distributions.

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.

For instructions on how to install syslog-ng on RPM distributions, see the blog post Installing latest syslog-ng on RHEL and other RPM distributions.

If you wish to install the latest RPM package that comes from a recent commit in Git for testing purposes, then read the blog post RPM packages from syslog-ng Git HEAD.

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

Binaries are also available as a Docker image. To find out more, check out the blog post Your central log server in Docker.

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