Input Module to Generate Periodic Statistics of Internal Counters

Module Name: impstats

Available since: 5.7.0+, 6.1.1+

Author: Rainer Gerhards <rgerhards@adiscon.com>

Description:

This module provides periodic output of rsyslog internal counters. Note that the whole statistics system is currently under development. So availability and format of counters may change and is not yet stable (so be prepared to change your trending scripts when you upgrade to a newer rsyslog version).

The set of available counters will be output as a set of syslog messages. This output is periodic, with the interval being configurable (default is 5 minutes). Be sure that your configuration records the counter messages (default is syslog.=info). Besides logging to the regular syslog stream, the module can also be configured to write statistics data into a (local) file.

Note that loading this module has impact on rsyslog performance. Depending on settings, this impact may be noticeable (for high-load environments).

The rsyslog website has an updated overview of available rsyslog statistic counters.

Note that there is a rsyslog statistics online analyzer available. It can be given a impstats-generated file and will return problems it detects. Note that the analyzer cannot replace a human in getting things right, but it is expected to be a good aid in starting to understand and gain information from the pstats logs. <7p>

Module Confguration Parameters:

This module supports module parameters, only.

interval [seconds] (default 300 [5minutes])
Sets the interval, in seconds at which messages are generated. Please note that the actual interval may be a bit longer. We do not try to be precise and so the interval is actually a sleep period which is entered after generating all messages. So the actual interval is what is configured here plus the actual time required to generate messages. In general, the difference should not really matter.
facility [facility number]
The numerical syslog facility code to be used for generated messages. Default is 5 (syslog). This is useful for filtering messages.
severity [severity number]
The numerical syslog severity code to be used for generated messages. Default is 6 (info).This is useful for filtering messages.
resetCounters [off/on] - available since 7.5.3
When set to "on", counters are automatically reset after they are emitted. In that case, the contain only deltas to the last value emitted. When set to "off", counters always accumulate their values. Note that in auto-reset mode not all counters can be reset. Some counters (like queue size) are directly obtained from internal object and cannot be modified. Also, auto-resetting introduces some additional slight inaccuracies due to the multi-threaded nature of rsyslog and the fact that for performance reasons it cannot serialize access to counter variables.
As an alternative to auto-reset mode, you can use rsyslog's statistics manipulation scripts to create delta values from the regular statistic logs. This is the suggested method if deltas are not necessarily needed in real-time.
format [json/cee/legacy] - available since 6.3.8
Specifies the format of emitted stats messages. The default of "legacy" is compatible with pre v6-rsyslog. The other options provide support for structured formats (note the "cee" is actually "project lumberack" logging).
log.syslog [on/off] - available since 7.3.6
This is a boolean setting specifying if data should be sent to the usual syslog stream. This is useful if custom formatting or more elaborate processing is desired. However, output is placed under the same restrictions as regular syslog data, especially in regard to the queue position (stats data may sit for an extended period of time in queues if they are full).
log.file [file name] - available since 7.3.6
If specified, statistics data is written the specified file. For robustness, this should be a local file. The file format cannot be customized, it consists of a date header, followed by a colon, followed by the actual statistics record, all on one line. Only very limited error handling is done, so if things go wrong stats records will probably be lost. Logging to file an be a useful alternative if for some reasons (e.g. full queues) the regular syslog stream method shall not be used solely. Note that turning on file logging does NOT turn of syslog logging. If that is desired log.syslog="off" must be explicitely set.
Ruleset [ruleset] - available since 7.5.6
Binds the listener to a specific ruleset.

Legacx Configuration Directives:

A limited set of parameters can also be set via the legacy configuration syntax. Note that this is intended as an upward compatibilit layer, so newer features are intentionally not available via legacy directives.

$PStatInterval <Seconds> - same as the "interval" parameter.
$PStatFacility <numerical facility> - same as the "facility" parameter.
$PStatSeverity <numerical severity> - same as the "severity" parameter.
$PStatJSON <on/off> (rsyslog v6.3.8+ only)
If set to on, stats messages are emitted as structured cee-enhanced syslog. If set to off, legacy format is used (which is compatible with pre v6-rsyslog).

See Also

rsyslog statistics counter
impstats delayed or lost - cause and cure

Caveats/Known Bugs:

This module MUST be loaded right at the top of rsyslog.conf, otherwise stats may not get turned on in all places.

Samples:

This activates the module and records messages to /var/log/rsyslog-stats in 10 minute intervals:

Legacy Sample:

This activates the module and records messages to /var/log/rsyslog-stats in 10 minute intervals:

In the next sample, the default interval of 5 minutes is used. However, this time stats data is NOT emitted to the syslog stream but to a local file instead.

module(load="impstats" interval="600" severity="7" log.syslog="off" /* need to turn log stream logging off! */ log.file="/path/to/local/stats.log")

And finally, we log to both the regular syslog log stream as well as a file. Within the log stream, we forward the data records to another server:

module(load="impstats" interval="600" severity="7" log.file="/path/to/local/stats.log") syslog.=debug @central.example.net

[rsyslog.conf overview] [manual index] [rsyslog site]