NAME
run
- run a command on a machine at random
SYNOPSIS
run
[-aeiqtv]
[-g rungroup1,...,rungroupN]
[-l username]
[-o porttimeout]
[-p portnum]
[-w node1,...,nodeN]
[-x node1,...,nodeN]
[command ...]
DESCRIPTION
The
run
utility can be used to run a command, or group of commands on a cluster of
machines. The command or commands are run on a single node in the cluster,
which is chosen at random.
The following options are available:
- -a
-
The
-a
option modifies the behavior of seq when dealing with stdin. Normally
all commands from stdin are run on the same machine. Specifying the
-a
option causes each command to be run on a random node.
- -e
-
Unless the
-e
option is specified, stderr from remote commands will not be reported
to the user.
- -i
-
The
-i
option will list information about the current cluster, and command groupings.
It will also show you which command you are about to run, and your username if
specified with the
-l
option.
- -q
-
The
-q
option does not issue any commands, but displays information about the cluster.
- -v
-
Prints the version of ClusterIt to the stdout, and exits.
- -g
-
If the
-g
option is specified, followed by a comma separated list of group
names, the command will only be run on that group of nodes. A node
may be a part of more than one group if desired, however running without the
-g
option will run the command on the same node as many times as it appears in the
file specified by the
CLUSTER
environment variable. This option is silently ignored if used with the
-w
option.
- -l
-
If the
-l
option is specified, followed by a username, the commands will be run
under that userid on the remote machines. Consideration must be taken
for proper authentication, for this to work.
- -o
-
The
-o
option is used to set the timeout in seconds to be used when testing remote
connections. The default is five seconds.
- -p
-
The
-p
option can be used to set the port number that testing should occur on when
testing remote connections. The default behavior is to guess based on the
remote command name.
- -t
-
The
-t
option causes
run
to attempt a connection test to each node prior to attempting to run the
remote command. If the test fails for any reason, the remote command will
not be attempted. This can be useful when clusterfiles have suffered bitrot
and some nodes no longer exist, or might be down for maintenance. The default
timeout is 5 seconds. The timeout can be changed with the
-o
option.
run
will attempt to guess the port number of the remote service based on your
RCMD_CMD
setting. It knows about ssh and rsh. If
run
fails to guess your port correctly, you may use the
-p
argument to set the remote port number. If the
RCMD_TEST
environment variable exists, the testing will automatically take place.
- -w
-
If the
-w
option is specified, followed by a comma delimited list of machine names,
the
command
will be run on each node in the list. Without this option,
run
runs on the nodes listed in the file pointed to by the
CLUSTER
environment variable.
- -x
-
The
-x
option can be used to exclude specific nodes from the cluster. The
format is the same as
the
-w
option, a comma delimited list of machine names. This option is
silently ignored if used with the
-w
option.
ENVIRONMENT
run
utilizes the following environment variables.
CLUSTER-
Contains a filename, which is a newline separated list of nodes
in the cluster.
RCMD_CMD-
Command to use to connect to remote machines. The command chosen must
be able to connect with no password to the remote host. Defaults to
rsh
RCMD_CMD_ARGS-
Arguments to pass to the remote shell command. Defaults to none.
RCMD_USER-
The username to connect to remote machines as by default.
RCMD_PORT-
The port number used to test remote connections. See the
-p
flag.
RCMD_TEST-
When set,
run
will automatically test all hosts before launching the remote command. See the
-t
option for more information.
RCMD_TEST_TIMEOUT-
The timeout in seconds to use when testing for remote connections.
DIAGNOSTICS
Exit status is 0 on success, 1 if an error occurs.
SEE ALSO
dsh(1),
rsh(1),
seq(1),
kerberos(3),
hosts.equiv(5),
rhosts(5)
HISTORY
The
run
command appeared in clusterit 1.1.
AUTHOR
Run
was written by Tim Rightnour.