NAME

       Smokeping::probes::basefork - Yet Another Base Class for implementing SmokePing Probes

OVERVIEW

       Like Smokeping::probes::basevars, but supports the probe-specific property `forks' to
       determine how many processes should be run concurrently. The targets are pinged one at a
       time, and the number of pings sent can vary between targets.

SYNOPSIS

        *** Probes ***

        +basefork

        forks = 5
        offset = 50%
        step = 300
        timeout = 15

        # The following variables can be overridden in each target section
        pings = 5

        # [...]

        *** Targets ***

        probe = basefork # if this should be the default probe

        # [...]

        + mytarget
        # probe = basefork # if the default probe is something else
        host = my.host
        pings = 5

DESCRIPTION

       Not all pinger programs support testing multiple hosts in a single go like fping(1). If
       the measurement takes long enough, there may be not enough time perform all the tests in
       the time available. For example, if the test takes 30 seconds, measuring ten hosts already
       fills up the SmokePing default five minute step.

       Thus, it may be necessary to do some of the tests concurrently. This module defines the
       ping method that forks the requested number of concurrent processes and calls the pingone
       method that derived classes must provide.

       The pingone method is called with one argument: a hash containing the target that is to be
       measured. The contents of the hash are described in Smokeping::probes::basevars(3pm).

       The number of concurrent processes is determined by the probe-specific variable `forks'
       and is 5 by default. If there are more targets than this value, another round of forks is
       done after the first processes are finished. This continues until all the targets have
       been tested.

       The timeout in which each child has to finish is set to 5 seconds multiplied by the
       maximum number of 'pings' of the targets. You can set the base timeout differently if you
       want to, using the timeout property of the probe in the master config file (this again
       will be multiplied by the maximum number of pings). The probe itself can also provide
       another default value if desired by modifying the _default value of the timeout variable.

       If the child isn't finished when the timeout occurs, it will be killed along with any
       processes it has started.

       The number of pings sent can be specified in the target-specific variable 'pings'.

VARIABLES

       Supported probe-specific variables:

       forks
           Run this many concurrent processes at maximum

           Example value: 5

           Default value: 5

       offset
           If you run many probes concurrently you may want to prevent them from hitting your
           network all at the same time. Using the probe-specific offset parameter you can change
           the point in time when each probe will be run. Offset is specified in % of total
           interval, or alternatively as 'random', and the offset from the 'General' section is
           used if nothing is specified here. Note that this does NOT influence the rrds itself,
           it is just a matter of when data acqusition is initiated.  (This variable is only
           applicable if the variable 'concurrentprobes' is set in the 'General' section.)

           Example value: 50%

       step
           Duration of the base interval that this probe should use, if different from the one
           specified in the 'Database' section. Note that the step in the RRD files is fixed when
           they are originally generated, and if you change the step parameter afterwards, you'll
           have to delete the old RRD files or somehow convert them. (This variable is only
           applicable if the variable 'concurrentprobes' is set in the 'General' section.)

           Example value: 300

       timeout
           How long a single 'ping' takes at maximum

           Example value: 15

           Default value: 5

       Supported target-specific variables:

       pings
           How many pings should be sent to each target, if different from the global value
           specified in the Database section. Note that the number of pings in the RRD files is
           fixed when they are originally generated, and if you change this parameter afterwards,
           you'll have to delete the old RRD files or somehow convert them.

           Example value: 5

AUTHORS

       Niko Tyni <ntyni@iki.fi>

SEE ALSO

       Smokeping::probes::basevars, Smokeping::probes::EchoPing