Rsyslog is an
open-source
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentrali ...
software utility used on
UNIX
Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...
and
Unix-like
A Unix-like (sometimes referred to as UN*X, *nix or *NIX) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Uni ...
computer systems for forwarding
log messages in an
IP network. It implements the basic
syslog protocol, extends it with content-based filtering, rich filtering capabilities, queued operations to handle offline outputs,
support for different module outputs, flexible configuration options and adds features such as using
TCP for transport.
The official RSYSLOG website defines the utility as "the rocket-fast system for log processing".
Protocol
Rsyslog uses the standard
BSD
The Berkeley Software Distribution (BSD), also known as Berkeley Unix or BSD Unix, is a discontinued Unix operating system developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley, beginni ...
syslog protocol, specified in
RFC 3164. As the text of RFC 3164 is an informational description and not a standard, various incompatible extensions of it emerged. Rsyslog supports many of these extensions. The format of relayed messages can be customized.
The most important extensions of the original protocol supported by rsyslog are:
*
ISO 8601
ISO 8601 is an international standard covering the worldwide exchange and communication of date and time-related data. It is maintained by the International Organization for Standardization (ISO) and was first published in 1988, with updates in ...
timestamp with millisecond granularity and time zone information
* the addition of the name of relays in the host fields to make it possible to track the path a given message has traversed
* reliable transport using
TCP
* support
GSS-API and
TLS
* logging directly into various database engines.
* support for RFC 5424, RFC 5425, RFC 5426
* support for
RELP
* support for buffered operation modes where messages are buffered locally if the receiver is not ready
* complete input/output support for
systemd journal
History
The rsyslog project began in 2004, when
Rainer Gerhards, the primary author of rsyslog, decided to write a new strong syslog daemon to compete with
syslog-ng, because, according to the author, "A new major player will prevent monocultures and provide a rich freedom of choice."
Rainer Gerhards worked on rsyslog inside his own company, Adiscon GmbH.
Related RFCs and working groups
*
RFC 3164 - The BSD syslog Protocol (obsoleted by
RFC 5424)
*
RFC 5424 - The Syslog Protocol (obsoletes
RFC 3164)
*
RFC 5425 - Transport Layer Security Mapping for Syslog
*
RFC 5426 - Transmission of Syslog Messages over UDP
See also
*
NXLog
*
fluentd
* logstash
*
journald – incorporates
syslog-like functionality
*
syslog-ng
References
External links
*
*
* {{Freshmeat, rsyslog
Logging software
Internet protocols
Internet Standards
System administration
Network management
Free network-related software