Login Node Policies
The login nodes are shared resources intended for editing and managing files, submitting and monitoring jobs, as well as compiling and linking. Use of scp, sftp, or rsync for large file transfers should be avoided.
Long running processes
To regulate the use of the login nodes (h2ologin[1-4]) a process watcher has been implemented. The process watcher monitors processes running on the login nodes recording the CPU utilization per task per user per login node.
The policy for long running user tasks are:
Unattended/idle sessions have an ssh session timeout of 4 hours. Screen sessions may persist longer, but left unattended/idle, will timeout and be terminated after 3 days. These policies exist for both security and resource management purposes.
The use of rsync can impact the experience of all users of a login node if used improperly. Rsync is recommended for transfer of source code and small amounts of data between Blue Waters and other systems. Large data transfers should use the recommended method of Globus Online.
To regulate usage, user rsync processes utilizing Blue Waters login nodes [h2ologin1-4] as a source or destination are restricted to one instance per user per login node. An error message will be displayed with our policy details for rsync processes originating from Blue Waters login nodes. External rsync processes above our limit of one will be denied connection with an error message "protocol version mismatch -- is your shell clean? (see the rsync man page for an explanation) rsync error: protocol incompatibility (code 2) at compat.c(171) [sender=3.0.4]"
The use of crontab tool is not allowed on Blue Waters. This policy is implemented to prevent the potential interference of user processes with maintenance work, and to improve the transparency of processes running on the service nodes. Upon execution of crontab tool, a message will be printed "You (username) are not allowed to use this program (crontab)".