!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 practical 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.

SEE ALSO

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

ipc

ipc—System V interprocess communication mechanisms.

SYNOPSIS

# include <sys/types.h>

# include <sys/ipc.h>

# include <sys/msg.h>

# include <sys/sem.h>

# include <sys/shm.h>

DESCRIPTION

The manual page refers to the Linux implementation of the System V interprocess communication mechanisms: message queues, semaphore sets, and shared memory segments. In the following, the word resource means an instantiation of one among such mechanisms.

Resource Access Permissions

For each resource, the system uses a common structure of type struct ipc_perm to store information needed in determining permissions to perform an ipc operation. The ipc_perm structure, defined by the <sys/ipc.h> system header file, includes the following members:

ushort cuid; /* creator user id */

ushort cgid; /* creator group id */

ushort uid; /* owner user id */

ushort gid; /* owner group id */

ushort mode; /* r/w permissions */