cook_rsh(1)cook_rsh(1)NAME
cook - load balancing rsh
SYNOPSIS
cook [ option... ] architecture command [ argument... ]
cook -Help
DESCRIPTION
The cook program is a wrapper around rsh(1) which does simple load
balancing. It obtains its load information by running the rup(1)
command, and selects the most suitable host hased on the architecture
you specify, and the least load of all hosts of that architecture.
The first command line argument is the architecture name which is used
to get the list of possible hosts. From that list the rup(1) command
is run to determine the host with the lowest load, which is in turn
used as the first argument of the eventual rsh(1) command.
COOKBOOKS
In order to make use of this program, somewhere in your cookbook, you
need to add a line which reads
parallel_rsh = "cook";
If the host chosen is the same as the caller (build host) then this
program just exec the command skipping the rsh. So it costs nothing
to use this in a one machine network!
For each recipe you want distributed to a remote host, you need to add
a host-binding attribute to. Typical usage is where you have a muti-
architecture build.
%1/%0%.o: %0%.c
host-binding %1 {
cc -o [target] -c [resolve %0%.c]; }
In the recipe given here, each architecture has its object files
placed into a separate architecture-specific directory tree. The
architecture name (%1) is used in the host-binding, so that the
compiles may be load-balanced to all machines of that architecture.
If you need a command to run on a specific host (say, because that's
where a specific application license resides), then simply use the
host name in the host-binding attribute, rather than an architecture
name.
DEFINING THE CLASSES
The /host_lists.pl file is expected to exist, and to contain variable
definitions used to determine if hosts are members of particular
architectures.
The /host_lists.pl file defines a perl HOL "hash of lists" The hash is
%ArchNames and it maps names of architectures as user want to see
them, to list references as the actual lists are stored.
The names of each architecture could be any form you wish but the
convention is to use the GNUish names such as "sparc-sun-solaris2.8".
For each architecture, define one or more lists of machines according
to what function each machine set may do. This can be as simple or as
elaborate as required. The form of the list variable name can be any
valid perl identifier but may as well be like the architecture name
with dash changed to underbar and dot removed, and the type added.
For example one might define solaris hosts as:
@sparc_sun_solaris28_hosts = (
"mickey", "minny", "scrooge" );
And linux hosts as:
@i386_linux22_hosts = (
"goofy", "scrooge" );
If there is a need to define different sets of machines for different
types of jobs then add a suffix to the names in the host-binding
directive on each of the recipes, and lists here with the same suffix.
The hash to map argument names to lists is defined like:
%ArchNames = (
"sparc-solaris2.8", => @sparc_solaris28_hosts,
"i586-unknown-linux22", => @i386_linux22_hosts, );
Of course if users have differing opinions as to what the architecture
names should look like, you can define "alias" mappings as well.
"sun4-SunOS-5.8", => @sparc_solaris28_hosts,
Or maybe the level is of no importance, then define
"sparc-solaris", => @sparc_solaris28_hosts,
"sparc-solaris2.7", => @sparc_solaris28_hosts,
Also, this list isn't allowed to be empty.
And finally, curtesy of Perl, the last line of the file must read
1; for obscure and magical reasons.
SYSLOG LOGGING
Typical commands seen during a build would look like
sh -c 'cd /aegis/dd/gumby2.2.C079 && \ sh -ce
/aegis/dd/gumby2.2.C079/.6.1; \ echo $? >
/aegis/dd/gumby2.2.C079/.6.2'
So we can extract the project/ change from the command quite easily
and logging it via syslog would be a trivial addition.
OPTIONS
This command is not usually given any options.
-h Help - show usage info
-vP Verbose - report choice
-Tn Trace value for testing
FILES
/exclude.hosts
This file is used to list those host which must not be used by
this script. Simply list excuded hosts, one hostname per
line. If the file is absent, all hosts reported by rup(1) may
be used.
/host_lists.pl
This file defines the classes of hosts for each architecture.
AUTHOR
Jerry Pendergraft <jerry@endocardial.com>
Reference Manual Cook cook_rsh(1)
