INNWATCH.CTL(5) 						File Formats Manual						   INNWATCH.CTL(5)

NAME

       innwatch.ctl - control Usenet supervision by innwatch

DESCRIPTION

       The file /etc/news/innwatch.ctl is used to determine what actions are taken during the periodic supervisions by innwatch.

       The file consists of a series of lines; blank lines and lines beginning with a number sign (``#'') are ignored.	All other lines consist of
       seven fields, each preceded by a delimiting character:
	      :label:state:condition:test:limit:command:reason

       The delimiter can be any one of several non-alphanumeric characters that does not appear elsewhere in the line; there is no way to quote it
       to  include  it in any of the fields.  Any of ``!'', ``,'', ``:'', ``@'', ``;'', or ``?'' is a good choice.  Each line can have a different
       delimiter; the first character on each line is the delimiter for that line.  White space surrounding delimiters, except before  the  first,
       is ignored, and does not form part of the fields, white space within fields is permitted.  All delimiters must be present.

       The  first field is a label for the control line.  It is used as an internal state indicator and in ctlinnd messages to control the server.
       If omitted, the line number is used.

       The second field specifies when this control line should be used.  It consists of a list of labels, and special	indicators,  separated	by
       whitespace.   If  the current state matches against any of the labels in this field, this line will be used as described below.	The values
       that may be used are:

       -      This line matches if the current state is the same as the label on this line, or if the current state is ``run,'' the initial state.
	      This is also the default state if this field is empty.

       +      This line matches if the current state is ``run.''

       *      This line always matches.

       label  This line matches if the current state is the specified ``label.''

       -label This line matches if the current state is not the specified ``label.''

       The third field specifies a shell command that is invoked if this line matches.	Do not use any shell filename expansion characters such as
       ``*'', ``?'', or ``['' (even quoted, they're not likely to work as intended).  If the command succeeds, as indicated by its exit status, it
       is expected to have printed a single integer to standard output.  This gives the value of this control line, to be used below.  If the com-
       mand fails, the line is ignored.  The command is executed with its current directory set to the news spool directory, /var/spool/news.

       The fourth field specifies the operator to use to test the value returned above.  It should be one of the two letter numeric test operators
       defined in test(1) such as ``eq'', ``lt'' and the like.	The leading dash (`'-'') should not be included.

       The fifth field specifies a constant with which to compare the value using the operator just defined.  This is done by invoking the command
	      test value -operator constant
       The line is said to ``succeed'' if it returns true.

       The sixth field specifies what should be done if the line succeeds, and in some cases if it fails.  Any of the following words may be used:

       throttle
	      Causes innwatch to throttle the server if this line succeeds.  It also sets the state to the value of the line's label.  If the line
	      fails, and the state was previously equal to the label on this line (that is, this line had previously succeeded), then a go command
	      will  be sent to the server, and innwatch will return to the ``run'' state.  The ``throttle'' is only performed if the current state
	      is ``run'' or a state other than the label of this line, regardless of whether the command succeeds.

       pause  Is identical to ``throttle'' except that the server is paused.

       shutdown
	      Sends a ``shutdown'' command to the server.  It is for emergency use only.

       flush  Sends a ``flush'' command to the server.

       go     Causes innwatch to send a ``go'' command to the server and to set the state to ``run.''

       exit   Causes innwatch to exit.

       skip   The result of the control file is skipped for the current pass.

       The last field specifies the reason that is used in those ctlinnd commands that require one.  More strictly, it is part of  the	reason	--
       innwatch appends some information to it.  In order to enable other sites to recognize the state of the local innd server, this field should
       usually be set to one of several standard values.  Use ``No space'' if the server is rejecting articles because of  a  lack  of	filesystem
       resources.  Use ``loadav'' if the server is rejecting articles because of a lack of CPU resources.

       Once  innwatch  has  taken  some  action as a consequence of its control line, it skips the rest of the control file for this pass.  If the
       action was to restart the server (that is, issue a ``go'' command), then the next pass will commence almost immediately, so  that  innwatch
       can discover any other condition that may mean that the server should be suspended again.

EXAMPLES

	      @@@df .|awk 'NR==2 {print $4}'@lt@10000@throttle@No space
	      @@@df -i .|awk 'NR==2 {print $4}'@lt@1000@throttle@No space (inodes)

       The  first  line  causes the server to be throttled if the free space drops below 10000 units (using whatever units df uses), and restarted
       again when free space increases above the threshold.

       The second line does the same for inodes.

       The next three lines act as a group and should appear in the following order.  It is easier to explain them, however, if they are described
       from the last up.
	      !load!load hiload!loadavg!lt!5!go!
	      :hiload:+ load:loadavg:gt:8:throttle:loadav
	      /load/+/loadavg/ge/6/pause/loadav
       The  final line causes the server to be paused if innwatch is in the ``run'' state and the load average rises to, or above, six.  The state
       is set to ``load'' when this happens.  The previous line causes the server to be throttled when innwatch is  in	the  ``run''  or  ``load''
       state, and the load average rises above eight.  The state is set to ``hiload'' when this happens.  Note that innwatch can switch the server
       from ``paused'' to ``throttled'' if the load average rises from below six to between six and seven, and then to	above  eight.	The  first
       line  causes  the  server  to be sent a ``go'' command if innwatch is in the ``load'' or ``hiload'' state, and the load average drops below
       five.

       Note that all three lines assume a mythical command loadavg that is assumed to print the current load average as an integer.  In more prac-
       tical circumstances, a pipe of uptime into awk is more likely to be useful.

BUGS

       This  file  must  be  tailored for each individual site, the sample supplied is truly no more than a sample.  The file should be ordered so
       that the more common problems are tested first.

       The ``run'' state is not actually identified by the label with that three letter name, and using it will not work as expected.

       Using an ``unusual'' character for the delimiter such as ``('', ``*'', ``&'', ```'', ``''', and the like, is likely to lead to obscure  and
       hard to locate bugs.

HISTORY

       Written by <kre@munnari.oz.au> for InterNetNews.  This is revision 1.5, dated 1996/09/06.

SEE ALSO

       innd(8), ctlinnd(8), news.daily(8).

																   INNWATCH.CTL(5)