doc::Smokeping::probes::basefork(3)SmokePindoc::Smokeping::probes::basefork(3)



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

OVERVIEW
       Like Smokeping::probes::basevars, but supports the probe-specific prop-
       erty `forks' to determine how many processes should be run concur-
       rently. 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 con-
       current 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 mul-
       tiplied 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 vari-
       able '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 dif-
           ferent from the one specified in the 'Database' section. Note that
           the step in the RRD files is fixed when they are originally gener-
           ated, 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 num-
           ber 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



2.4.2                             2008-07-2doc::Smokeping::probes::basefork(3)
