epylog - Syslog new log notifier and parser.
epylog [-c epylog.conf] [-d LOGLEVEL] [--last PERIOD]
[--store-offsets] [--quiet] [--cron]
Epylog is a new log notifier and parser which runs periodically out of
cron, looks at your logs, processes the entries in order to present
them in a more comprehensive format, and then provides you with the
output. It is written specifically with large network clusters in mind
where a lot of machines (around 50 and upwards) log to the same loghost
using syslog or syslog-ng.
Alternatively, Epylog can be invoked from the command line and provide
a log report based on a certain provided time period. In this case it
relies on syslog timestamps to find the offsets, as opposed to the end-
of-log offsets stored during the last run, though this behavior is not
as reliable and is easily thwarted by skewed clocks.
Provide an alternative config file to Epylog. By default, it
will look in /etc/epylog/epylog.conf.
Logging level. The default is 1. 0 will produce no output except
for critical errors (useful for cron runs). 2 and above are
debugging levels. 5 is the most verbose.
Will make a report on events that occurred in the last PERIOD.
PERIOD can be either "hour", "day", "week", "month", or more
granular: "1h", "2h", "3d", "2w", etc. When --last is specified,
epylog will ignore the saved offsets and locate the entries by
timestamps. CAUTION: this process is not to be trusted, since
the timestamps are not checked for any validity when arriving to
the loghost. One reporting machine with a skewed clock may
confuse Epylog enough to miss a lot of valid entries.
When specified, will store the offset of the last log entry
processed in offsets.xml. During the cron runs epylog relies on
the offset information to find out what new entries to process.
This is more trustworthy than relying on timestamps. The default
behavior is not to store the offsets, as this allows to run
epylog both from cron and manually without the two interfering
with each-other. The location of offset.xml is specified in
epylog.conf. See epylog.conf(5) for more details.
In every way identical to -d 0.
--cron This is essentially --quiet --store-offsets, plus a lockfile
will be created and consulted, preventing more than one instance
of epylog from running. You can still run epylog manually -- the
lockfile is only checked when running in --cron mode.
The core of epylog is written in python. It handles things like
timestamp lookups, unwrapping of "last message repeated" lines,
handling of rotated files, preparing and publishing the reports,
The modules are pluggable and can be either "internal", written
in python, or external. External modules can be written in any
language, but at a price of some convenience. For more info see
Depending on the size of your logs, you might want to initialize
your offsets before letting epylog run from cron. When the
offsets.xml file is missing, epylog will by default process the
entire log, and depending on your configuration, that can be a
lot of entries. A good way to init epylog is to run:
epylog --last day --store-offsets
The useful way to run from a command line is with --last. E.g.:
epylog --last day
epylog --last 2w
When running from cron, you want to store the offsets and not rely on
timestamps. There is a mode that allows you to do this:
Konstantin Ryabitsev <email@example.com>