RSyslog - Features

This page lists both current features as well as those being considered for future versions of rsyslog. If you think a feature is missing, drop Rainer a note. Rsyslog is a vital project. Features are added each few days. If you would like to keep up of what is going on, you can also subscribe to the rsyslog mailing list.

Current Features

• native support for writing to MySQL databases
• native support for writing to Postgres databases
• support for (plain) tcp based syslog - much better reliability
• support for sending and receiving compressed syslog messages
• ability to configure backup syslog/database servers - if the primary fails, control is switched to a prioritized list of backups
• support for receiving messages via reliable RFC 3195 delivery
• ability to generate file names and directories (log targets) dynamically, based on many different properties
• control of log output format, including ability to present channel and priority as visible log data
• good timestamp format control; at a minimum, ISO 8601/RFC 3339 second-resolution UTC zone
• ability to reformat message contents and work with substrings
• support for log files larger than 2gb
• support for file size limitation and automatic rollover command execution
• support for running multiple rsyslogd instances on a single machine
• support for ssl-protected syslog (via stunnel)
• ability to filter on any part of the message, not just facility and severity
• ability to use regular expressions in filters
• support for discarding messages based on filters
• ability to execute shell scripts on received messages
• control of whether the local hostname or the hostname of the origin of the data is shown as the hostname in the output
• ability to preserve the original hostname in NAT environments and relay chains
• ability to limit the allowed network senders
• powerful BSD-style hostname and program name blocks for easy multi-host support
• multi-threaded (is this important? why?)
• very experimental and volatile support for syslog-protocol compliant messages (it is volatile because standardization is currently underway and this is a proof-of-concept implementation to aid this effort)
• experimental support for syslog-transport-tls based framing on syslog/tcp connections
• a copy of klogd.c has been included under the name of rklogd for those Linux systems that need one. So rsyslog is a full replacement for the sysklogd package
• support for IPv6
• ability to control repeated line reduction ("last message repeated n times") on a per selector-line basis
• supports sub-configuration files, which can be automatically read from directories. Includes are specified in the main configuration file
• supports multiple actions per selector/filter condition
• MySQL and Postgres SQL functionality as a dynamically loadable plug-in
• modular design for outputs - easily extensible

Upcoming Features

The list below is something like a repository of ideas we'd like to implement. Features on this list are typically NOT scheduled for immediate inclusion. We maintain a feature request tracker at sourceforge.net. This tracker has things typically within reach of implementation. Users are encouraged to submit feature requests there (or via our forums). If we like them but they look quite long-lived (aka "not soon to be implemented"), they will possibly be migrated to this list here and at some time moved back to the sourceforge tracker.

• create a plug-in-interface - we are very close to this. A neat interface is already used internally for output modules and the MySQL module already works as a plug-in. However, no interface definition is yet formally published.
• implement native email-functionality in selector (probably best done as a plug-in)
• port it to more *nix variants (eg AIX and HP UX) - this needs volunteers with access to those machines and knowledge
• provide an on-disk queue for syslog messages; should be combined with reliable delivery to the next hop
• support for native SSL enryption of plain tcp syslog sessions. This will most probably happen based on syslog-transport-tls.
• even more enhanced multi-threading, with a message queue for each action (when implementing this, search for CHECKMULTIQUEUE comments in the source - they already contain hints of what to look at). Some detail information on this can already be found in Rainer's blog.
• pcre filtering - maybe (depending on feedback)  - simple regex already partly added. So far, this seems sufficient so that there is no urgent need to do pcre
• support for RFC 3195 as a sender - this is currently unlikely to happen, because there is no real demand for it. Any work on RFC 3195 has been suspend until we see some real interest in it.  It is probably much better to use TCP-based syslog, which is interoperable with a large number of applications. You may also read my blog post on the future of liblogging, which contains interesting information about the future of RFC 3195 in rsyslog.

To see when each feature was added, see the rsyslog change log (online only).