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ctel

NAME

cssh, crsh, ctel - Cluster administration tool

SYNOPSIS

cssh [options] [[user@]<server>|<tag>] [...] crsh [options] [[user@]<server>|<tag>] [...] cssh [options] [[user@]<server>[:port]|<tag>] [...] crsh [options] [[user@]<server>[:port]|<tag>] [...] ctel [options] [<server>|<tag>] [...] ctel [options] [<server>|<tag>] [...]

DESCRIPTION

The command opens an administration console and an xterm to all specified hosts. Any text typed into the administration console is replicated to all windows. All windows may also be typed into directly.

This tool is intended for (but not limited to) cluster administration where the same configuration or commands must be run on each node within the cluster. Performing these commands all at once via this tool ensures all nodes are kept in sync.

Connections are opened via ssh so a correctly installed and configured ssh installation is required. If, however, the program is called by ``crsh'' then the rsh protocol is used (and the communications channel is insecure), or by ``ctel'' then telnet is used.

Extra caution should be taken when editing system files such as /etc/inet/hosts as lines may not necessarily be in the same order. Assuming line 5 is the same across all servers and modifying that is dangerous. Better to search for the specific line to be changed and double-check before changes are committed.

Further Notes

•

The dotted line on any sub-menu is a tear-off, i.e. click on it and the sub-menu is turned into its own window.

•

Unchecking a hostname on the Hosts sub-menu will unplug the host from the cluster control window, so any text typed into the console is not sent to that host. Re-selecting it will plug it back in.

•

If the code is called as crsh instead of cssh (i.e. a symlink called crsh points to the cssh file or the file is renamed) rsh is used as the communications protocol instead of ssh.

•

If the code is called as ctel instead of cssh (i.e. a symlink called ctel points to the cssh file or the file is renamed) telnet is used as the communications protocol instead of ssh.

•

When using cssh on a large number of systems to connect back to a single system (e.g. you issue a command to the cluster to scp a file from a given location) and when these connections require authentication (i.e. you are going to authenticate with a password), the sshd daemon at that location may refuse connects after the number specified by MaxStartups in sshd_config is exceeded. (If this value is not set, it defaults to 10.) This is expected behavior; sshd uses this mechanism to prevent DoS attacks from unauthenticated sources. Please tune sshd_config and reload the SSH daemon, or consider using the ~/.ssh/authorized_keys mechanism for authentication if you encounter this problem.

•

If client windows fail to open, try running:

"cssh -e {single host name}"

This will test the mechanisms used to open windows to hosts. This could be due to either the "-xrm" terminal option which enables "AllowSendEvents" (some terminal do not require this option, other terminals have another method for enabling it - see your terminal documention) or the "ConnectTimeout" ssh option (see the configuration option "-o" or file "csshrc" below to resolve this).

OPTIONS

Some of these options may also be defined within the configuration file. Default options are shown as appropriate.

-h|-?

Show basic help text, and exit

-H

Show full help test (the man page), and exit

-v

Show version information and exit

-d

Enable basic debugging mode (can be combined with -D)

-D

Enable extended debugging mode (can be combined with -d)

-q|-Q

Enable|Disable automatically quiting after the last client window has closed (overriding the config file)

-u

Output the current configuration in the same format used by the $HOME/.csshrc file.

-g|-G

Enable|Disable window tiling (overriding the config file)

-c <file>

Use supplied file as additional cluster file (see also ``FILES'')

-C <file>

Use supplied file as additional configuration file (see also ``FILES'')

-l $LOGNAME

Specify the default username to use for connections (if different from the currently logged in user). NOTE: will be overridden by <user>@<host>

-T "CSSH"

Specify the initial part of the title used in the console and client windows

-o "-x -o ConnectTimeout=10" - for ssh connections

-o "" - for rsh connections

Specify arguments to be passed to ssh or rsh when making the connection.

NOTE: any ``generic'' change to the method (i.e. specifying the ssh port to use) should be done in the medium's own config file (see ssh_config and $HOME/.ssh/config).

-s

IN BETA: Show history within console window. This code is still being worked upon, but may help some users.

-t ""

Specify arguments to be passed to terminals being used

-i

THIS OPTION IS DEPRECATED. It has been left in so current systems continue to function as expected.

-e [user@]<hostname>[:port]

Display and evaluate the terminal and connection arguments so display any potential errors. The <hostname> is required to aid the evaluation.

ARGUMENTS

The following arguments are support:

[user@]<hostname>[:port] ...

Open an xterm to the given hostname and connect to the administration console. An optional port number can be used if sshd is not listening on standard port (e.g not listening on port 22) and ssh_config cannot be used.

<tag> ...

Open a series of xterms defined by <tag> within either /etc/clusters or $HOME/.csshrc (see ``FILES'').

KEY SHORTCUTS

The following key shortcuts are available within the console window, and all of them may be changed via the configuration files.

Control-q

Quit the program and close all connections and windows

Control-+

Open the 'Add Host(s) or Cluster(s)' dialogue box. Mutiple host or cluster names can be entered, separated by spaces.

Alt-n

Paste in the correct client name to all clients, i.e.

"scp /etc/hosts server:files/<Alt-n>.hosts"

would replace the <Alt-n> with the client's name in all the client windows

Alt-r

Retile all the client windows

FILES

/etc/clusters

This file contains a list of tags to server names mappings. When any name is used on the command line it is checked to see if it is a tag. If it is a tag, then the tag is replaced with the list of servers. The formated is as follows:

<tag> [user@]<server> [user@]<server> [...]

   i.e.
 
   # List of servers in live
   live admin1@server1 admin2@server2 server3 server4
 
 

All comments (marked by a #) and blank lines are ignored. Tags may be nested, but be aware of recursive tags which are not checked for.

Clusters may also be specified either directly (see "clusters" configuration options) or indirectly (see "extra_cluster_file" configuration option) in the users $HOME/.csshrc file.

/etc/csshrc & $HOME/.csshrc

This file contains configuration overrides - the defaults are as marked. Default options are overwritten first by the global file, and then by the user file.

NOTE: values for entries do not need to be quoted unless it is required for passing arguments, i.e.

   terminal_allow_send_events="-xrm '*.VT100.allowSendEvents:true'"
 
 

should be written as

   terminal_allow_send_events=-xrm '*.VT100.allowSendEvents:true'
 
 

always_tile = yes

Setting to anything other than "yes" does not perform window tiling (see also -G).

auto_quit = yes

Automatically quit after the last client window closes. Set to anything other than ``yes'' to disable. Can be overridden by "-Q" on the command line.

clusters = <blank>

Define a number of cluster tags in addition to (or to replace) tags defined in the /etc/clusters file. The format is:

  clusters = <tag1> <tag2> <tag3>
  <tag1> = host1 host2 host3
  <tag2> = user@host4 user@host5 host6
  <tag3> = <tag1> <tag2>
 
 

As with the /etc/clusters file, be sure not to create recursivly nested tags.

comms = ssh

Sets the default communication method (initially taken from the name of program, but can be overridden here).

console_position = <null>

Set the initial position of the console - if empty then let the window manager decide. Format is '+<x>+<y>', i.e. '+0+0' is top left hand corner of the screen, '+0-70' is bottom left hand side of screen (more or less).

extra_cluster_file = <null>

Define an extra cluster file in the format of /etc/clusters. Multiple files can be specified, seperated by commas. Both ~ and $HOME are acceptable as a to reference the users home directory, i.e.

  extra_cluster_file = ~/clusters, $HOME/clus
 
 

ignore_host_errors

THIS OPTION IS DEPRECATED. It has been left in so current systems continue to function as expected.

key_addhost = Control-plus

Default key sequence to open AddHost menu. See below notes on shortcuts.

key_clientname = Alt-n

Default key sequence to send cssh client names to client. See below notes on shortcuts.

key_paste = Control-v

Default key sequence to paste text into the console window. See below notes on shortcuts.

key_quit = Control-q

Default key sequence to quit the program (will terminate all open windows). See below notes on shortcuts.

key_retilehosts = Alt-r

Default key sequence to retile host windows. See below notes on shortcuts.

mouse_paste = Button-2 (middle mouse button)

Default key sequence to paste text into the console window using the mouse. See below notes on shortcuts.

rsh_args = <blank>

ssh_args = "-x -o ConnectTimeout=10"

Sets any arguments to be used with the communication method (defaults to ssh arguments).

NOTE: The given defaults are based on OpenSSH, not commercial ssh software.

NOTE: Any ``generic'' change to the method (i.e. specifying the ssh port to use) should be done in the medium's own config file (see ssh_config and $HOME/.ssh/config).

screen_reserve_top = 25

screen_reserve_bottom = 30

screen_reserve_left = 0

screen_reserve_right = 0

Number of pixels from the screen side to reserve when calculating screen geometry for tiling. Setting this to something like 50 will help keep cssh from positioning windows over your window manager's menu bar if it draws one at that side of the screen.

rsh = /path/to/rsh

ssh = /path/to/ssh

Depending on the value of comms, set the path of the communication binary.

terminal = /path/to/terminal

Path to the x-windows terminal used for the client.

terminal_args = <blank>

Arguments to use when opening terminal windows. Otherwise takes defaults from $HOME/.Xdefaults or $<$HOME/.Xresources> file.

terminal_font = 6x13

Font to use in the terminal windows. Use standard X font notation.

terminal_reserve_top = 0

terminal_reserve_bottom = 0

terminal_reserve_left = 0

terminal_reserve_right = 0

Number of pixels from the terminal side to reserve when calculating screen geometry for tiling. Setting these will help keep cssh from positioning windows over your scroll and title bars

terminal_size = 80x24

Initial size of terminals to use (note: the number of lines (24) will be decreased when resizing terminals for tiling, not the number of characters (80))

terminal_title_opt = -T

Option used with "terminal" to set the title of the window

terminal_allow_send_events = -xrm '*.VT100.allowSendEvents:true'

Option required by the terminal to allow XSendEvents to be received

title = cssh

Title of windows to use for both the console and terminals.

unmap_on_redraw = no

Tell Tk to use the UnmapWindow request before redrawing terminal windows. This defaults to ``no'' as it causes some problems with the FVWM window manager. If you are experiencing problems with redraws, you can set it to ``yes'' to allow the window to be unmapped before it is repositioned.

use_hotkeys = yes

Setting to anything other than "yes" will disable all hotkeys.

user = $LOGNAME

Sets the default user for running commands on clients.

window_tiling = yes

Perform window tiling (set to "no" to disable)

window_tiling_direction = right

Direction to tile windows, where ``right'' means starting top left and moving right and then down, and anything else means starting bottom right and moving left and then up

NOTE: The key shortcut modifiers must be in the form ``Control'', ``Alt'', or ``Shift'', i.e. with the first letter capitalised and the rest lower case. Keys may also be disabled individually by setting to the word ``null''.

AUTHOR

Duncan Ferguson

CREDITS

clusterssh is distributed under the GNU public license. See the file LICENSE for details.

A web site for comments, requests, bug reports and bug fixes/patches is available at <http://clusterssh.sourceforge.net/>

KNOWN BUGS

Swapping virtual desktops can can a redraw of all the terminal windows. This is due to a lack of distinction within Tk between switching desktops and minimising/maximising windows. Until Tk can tell the difference between the two events, there is no fix (apart from rewriting everything directly in X)

REPORTING BUGS

•

If you have issues running cssh, first try:

"cssh -e [user@]<hostname>[:port]"

This performs two tests to confirm cssh is able to work properly with the settings provided within the .csshrc file (or internal defaults).

         1. test the terminal window works with the options provided
 
         2. test ssh works to a host with the configured arguments
 
 

Configuration options to watch for in ssh are

         - Doesnt understand "-o ConnectTimeout=10" - remove the option 
           in the F<.csshrc> file
 
         - OpenSSH-3.8 using untrusted ssh tunnels - use "-Y" instead of "-X"
           or use "ForwardX11Trusted yes' in ssh_config (if you change the
           default ssh options from -x to -X)
 
 

•

If you require support, please run the following commands and post it on the web site in the support/problems forum:

"perl -V"

"perl -MTk -e 'print $Tk::VERSION,$/'"

"perl -MX11::Protocol -e 'print $X11::Protocol::VERSION,$/'"

"cat /etc/csshrc $HOME/.csshrc"

•

Use the debug switches (-d, -D, or -dD) will turn on debugging output. However, please only use this option with one host at a time, i.e. ``cssh -d <host>'' due to the amount of output produced (in both main and child windows).

SEE ALSO

<http://clusterssh.sourceforge.net/>, ssh, Tk::overview, X11::Protocol, perl