- run a command on a cluster in sequence
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 incremented in sequence on each invocation of
The following options are available:
option modifies the behavior of seq when dealing with stdin. Normally
all commands from stdin are run on the same machine. Specifying the
option causes each command to be run on the next node in the seqence.
option is specified, stderr from remote commands will not be reported
to the user.
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
option does not issue any commands, but displays information about the cluster.
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
option will run the command on the same node as many times as it
appears in the file specified by the
environment variable. This option is silently ignored if used with the
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.
option is specified, followed by a comma delimited list of machine names,
will be run on each node in the list. Without this option,
runs on the nodes listed in the file pointed to by the
option can be used to exclude specific nodes from the cluster. The
format is the same as the
option, a comma delimited list of machine names. This option is
silently ignored if used with the
utilizes the following environment variables.
Contains a filename, which is a newline separated list of nodes
in the cluster.
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
The username to connect to remote machines as by default.
Specifies a specific sequence file. This is a temporary file, which
saves the number of the last node run on. It defaults to
is the pid of the parent process of
It may be useful to wire the
to a particular file, in order to keep proper sequence when invoking
from subshells or scripts.
Exit status is 0 on success, 1 if an error occurs.
command appeared in clusterit 1.1.
was written by Tim Rightnour.
command works fine when used with the
flags. However the user may find that if the arguments are changed, or
the flags are omitted on a subsequent run, the next node picked may not be
predictable. The sequence is calculated on each invocation of
and the sequence numbers recorded in the temporary file may not match up
to a new sequence placed on the command line.