innwatch.ctl - control Usenet supervision by innwatch
The file <pathetc in inn.conf>/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, for example:
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 this control line. It is used as an internal
state indicator and in ctlinnd
messages to control the server. If this
field is empty, 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.
- This line matches if the current state is the specified
- This line matches if the current state is not the specified
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 command fails, the line is ignored. The command is
executed with its current directory set to the news spool articles directory,
<patharticles in inn.conf>
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
(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:
- 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
- Is identical to ``throttle'' except that the server is
- Sends a ``shutdown'' command to the server. It is for
emergency use only.
- Sends a ``flush'' command to the server.
- Causes innwatch to send a ``go'' command to the
server and to set the state to ``run''.
- Causes innwatch to exit.
- The remainder of the control file is skipped for the
The last field specifies the reason that is used in those ctlinnd
commands that require one. More strictly, it is part of the reason —
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
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.
@@@inndf .@lt@10000@throttle@No space
@@@inndf -i .@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 inndf
(8) 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.
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
assumed to print the current load average as an integer. In more practical
circumstances, a pipe of uptime
is more likely to be
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.
Written by <email@example.com> for InterNetNews. This is revision 5909,
inn.conf(5), innd(8), inndf(8), ctlinnd(8), news.daily(8).