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Parallel Shell - How to use it?

How to use Parallel Shell feature.

Overview: This article outlines how to utilize Parallel Shell on an SSH gateway to execute commands simultaneously across server groups, ensuring users are granted appropriate privileges and explaining features like MExec lists and command execution summaries, including exit status explanations.

Parallel shell allows the SSH gateway users to execute commands on multiple servers simultaneously. Commands can be executed on different server groups that the SSH gateway user has access to or the user can run the command on all servers that the user has access to or the user can create a custom group of servers (mExec lists)  where the user wants to run the command.

Ensure that the SSH gateway user has been granted the privilege to use a parallel shell. By default, it's only available for the admin user alone and this privilege has to be granted explicitly to other users.

Refer to Grant Parallel Shell Privilege

To access the Parallel Shell, log on to the ezsh shell, and click on the shortcut which is usually f7 or * to access the parallel shell in the backend (Help Menu in the ezsh shell). Once you have the Mexec group listing, navigate to the group of servers where you would like to execute the command. In the example below, the 'All Servers' group has been selected. 

parallel shell menu 

 Press the enter key on the keyboard type the command uptime and press enter again to execute the command on the server group 'All servers'.

parallel shell command

  Refer to the following: Mexec List Feature.

The MExec lists created would be viewable to other users only if the creator of the list decides to set it as public. If it is not set as public then the users will only be able to view normal server groups.

How to view the summary in a parallel shell?

This feature is available from Ezeelogin version 7.33.0. Refer below article to upgrade to the latest version.

Upgrade the Ezeelogin jump server to the latest version.

1. Command successfully executed on all servers:

2. Command failed to execute on all servers, and the summary of the failed servers will be shown:

3. Remote exited with non-zero status explained.

  • exit 1:           General failure
  • exit 2:           Misuse of shell builtins (e.g., incorrect syntax)
  • exit 126:      Command not executable
  • exit 127:      Command not found
  • exit 128:      Invalid argument to exit

Related Articles:

Grant parallel shell privilege to the user.

Increase the execution speed in a parallel shell.