/etc/and.priorities - priority database for the auto nice daemon.
VERSION
This manual page documents and.priorities for
and version 1.2.1.
DESCRIPTION
This is the priority database file for
and. It stores (user, group, command, parent, nicelevels) tuples (hereafter called
entries) to determine the new nice level (or the kill signal, for that
matter) when a job reaches one of the time limits defined in
/etc/and.conf. (See lv1time, lv2time, and lv3time on the and.conf manual page for
details.) See the
affinity setting in
/etc/and.conf for how ambiguities between the fields (user, group, command, parent)
are dealt with when searching the database to determine the new nice
level for a job.
Note that if more than one entry matches with the same accuracy (e.g.
with a parent= entry and an ancestor= entry), the
last entry wins!
Comments start with a # in the
first column. Empty lines are ignored. Unlike with other configuration files, lines
cannot be concatenated with a backslash. Furthermore, this file is
case sensitive. and allows for host-specific sections in the configuration file. These work
as lines of the form
on somehost and work as follows: the parser determines if the host name (as returned
by gethostname) matches the extended regular expression that follows the
on keyword. If it does, it just keeps processing the file as if nothing had
happened. If it does not match, however, everything up to the next
on keyword is skipped. So if you want to end a host-specific section, you
must write
on .* (which matches all hosts) to switch back to normal.
Don't forget to
kill -HUP the auto nice daemon to enable the changes.
SETTINGS
A valid entry consists of a line of six columns, separated by one or
more spaces. These columns are: (in that order)
user
The user ID the command is running under. May be a user name (which will
be looked up in the password file and, if enabled, via NIS), or a numeric
user ID, or an asterisk for any user.
group
The group ID the command is running under. May be a group name (which will
be looked up in the group file and again, if enabled, via NIS), or a numeric
group ID, or an asterisk for any group.
command
The name of the command, without path. May be a command, a regular
expression to match multiple commands, or an asterisk for any command.
Note that "foobar" will
not match "/usr/bin/foobar" - you probably mean ".*foobar" or even ".*foobar.*".
parent
There are two modes of operation for the parent field, determined by a
keyword:
parent=foobar will match if a process' direct parent process matches the command or regular
expression after the equal sign, whereas
ancestor=foobar will match if
any ancestor process matches. After the keyword and the equal sign goes the
name of the parent process, without path. May be a command, a regular
expression to match multiple commands, or an asterisk for any command.
(You can just use the asterisk if you want to ignore parents for this
entry.) Note that again "foobar" will
not match "/usr/bin/foobar", as with command.
nicelevel 1
The nice level after lv1time CPU time was used by the command. Positive
numbers and 0 are interpreted as nice levels; negative numbers are
interpreted as signals to be sent to the command. A "nice level" of
19 will almost stop the job, -9 will actually kill it. (Like in kill -9.)
lv1time can be set in
/etc/and.conf
nicelevel 2
Same but after lv2time.
nicelevel 3
Same but after lv3time.
EXAMPLES
Here are some entries from the real world (i.e. from "my" cluster
at the Institute). As lv[123]time, 5 min., 20 min., and 1 hour is
assumed. (Which is the default. See
/etc/and.conf for details.) You might also check the default priority database
that comes with
and.
# A finer default nice level
* * * * 4 8 12
# User dau is an idiot, so treat him like accordingly
dau * * * 19 19 19
# Netscape sometimes goes berserk, we must stop it
* * netscape * 4 -9 -9
# Most hosts are free for everyone but some are
# especially for the FOO group
* * * * 4 8 12
on (bar|baz)
* * * * 8 12 16
# ... or, more radical: * * * * -9 -9 -9
* foo * * 4 8 12
on .*
# KDE screen savers...
* * .*kss * 16 16 16
# Grid jobs (assuming they are started by a master
# process)
* * * ancestor=grid_master 10 10 10
# Now some clever yet deceitful user might start all
# his jobs using a shell script named grid_master.
# He shall regret... whereas the original grid_master
# (owned by grid) is left alone.
* * grid_master * -9 -9 -9
grid * grid_master * 0 0 0
FILES
/etc/and.priorities
The priority database (in plain text). Contains the (user, group, command,
nicelevels) tuples. This is what this manual page is about.
