Number generator and counter module (mmsequence) — rsyslog 8.37.0 documentation

# Number generator and counter module (mmsequence)

Module Name: mmsequence

Author:Pavel Levshin <pavel@levshin.spb.ru>

Status:Non project-supported module - contact author or rsyslog mailing list for questions

This module is deprecated in v8 and solely provided for backward compatibility reasons. It was written as a work-around for missing global variable support in v7. Global variables are available in v8, and at some point in time this module will entirely be removed.

Do not use this module for newly crafted config files. Use global variables instead.

Available since: 7.5.6

Description:

This module generates numeric sequences of different kinds. It can be used to count messages up to a limit and to number them. It can generate random numbers in a given range.

This module is implemented via the output module interface, so it is called just as an action. The number generated is stored in a variable.

Action Parameters:

Note: parameter names are case-insensitive.

- mode “random” or “instance” or “key”

  Specifies mode of the action. In “random” mode, the module generates uniformly distributed integer numbers in a range defined by “from” and “to”.

  In “instance” mode, which is default, the action produces a counter in range [from, to). This counter is specific to this action instance.

  In “key” mode, the counter can be shared between multiple instances. This counter is identified by a name, which is defined with “key” parameter.

- from [non-negative integer], default “0”

  Starting value for counters and lower margin for random generator.

- to [positive integer], default “INT_MAX”

  Upper margin for all sequences. Note that this margin is not inclusive. When next value for a counter is equal or greater than this parameter, the counter resets to the starting value.

- step [non-negative integer], default “1”

  Increment for counters. If step is “0”, it can be used to fetch current value without modification. The latter not applies to “random” mode. This is useful in “key” mode or to get constant values in “instance” mode.

- key [word], default “”

  Name of the global counter which is used in this action.

- var [word], default “$!mmsequence”

  Name of the variable where the number will be stored. Should start with “$”.

Sample:

    # load balance
    Ruleset(
        name="logd"
        queue.workerthreads="5"
        ){

        Action(
            type="mmsequence"
            mode="instance"
            from="0"
            to="2"
            var="$.seq"
        )

        if $.seq == "0" then {
            Action(
                type="mmnormalize"
                userawmsg="on"
                rulebase="/etc/rsyslog.d/rules.rb"
            )
        } else {
            Action(
                type="mmnormalize"
                userawmsg="on"
                rulebase="/etc/rsyslog.d/rules.rb"
            )
        }

        # output logic here
    }
        # generate random numbers
        action(
            type="mmsequence"
            mode="random"
            to="100"
            var="$!rndz"
        )
        # count from 0 to 99
        action(
            type="mmsequence"
            mode="instance"
            to="100"
            var="$!cnt1"
        )
        # the same as before but the counter is global
        action(
            type="mmsequence"
            mode="key"
            key="key1"
            to="100"
            var="$!cnt2"
        )
        # count specific messages but place the counter in every message
        if $msg contains "txt" then
            action(
                type="mmsequence"
                mode="key"
                to="100"
                var="$!cnt3"
            )
        else
            action(
                type="mmsequence"
                mode="key"
                to="100"
                step="0"
                var="$!cnt3"
                key=""
            )

Legacy Configuration Parameters:

Note: parameter names are case-insensitive.

Not supported.

See also

Help with configuring/using `Rsyslog`:

- Mailing list - best route for general questions
- GitHub: rsyslog source project - detailed questions, reporting issues that are believed to be bugs with `Rsyslog`
- Stack Exchange (View, Ask) - experimental support from rsyslog community

See also

Contributing to `Rsyslog`:

- Source project: rsyslog project README.
- Documentation: rsyslog-doc project README