Getting an Account

SCRP accounts are assigned to students in the Department of Economics at the beginning of each term. Faculty members can request an account by email.

You will need to set a password before you can access the cluster. You can change or reset your password here.

What Resources do I have Access to?

Software

SCRP users have access to all software installed on the cluster, including Stata, R, Python and MATLAB.

Computation

Login Nodes

Each user can use up to four CPU cores and 4GB of RAM on a login node. Since login node resources are shared by all users, actual allocation might be less than the limit.

Compute Nodes

Different tiers of users are granted different amount of resources on the compute nodes, administered through the Slurm workload manager. The resource limits are as follows:

User Type Logical CPUs GPUs Job Duration
Faculty and staff 128 8 5/30 daysa
Research postgraduate student 128 4 5/30 daysa
Taught postgraduate student and
Senior undergraduate student		 16 1 5 days
Undergraduate student 4 1 1 day

a30 days under the more restrictive limit of 16 logical CPUs and 1 GPU.

On most compute nodes, one logical CPU represents one physical CPU core. The exception is the large memory node, where there are two logical CPUs for each physical CPU core.

These limits represent the maximum amount of resources each type of user are allowed to request. The partition a compute node belongs to can impose additional restrictions.

If the resources requested are not immediately available, the request will be put in a queue. The following priority is observed:

  • The time a job has been on the queue is the main determinant.
  • Faculty, staff and research postgraduate students have a two-day priority over other user types.
  • A small bonus that scales inversely with usage.

Storage

SCRP has different types of storage for different purposes—there is, for example, a specific high-speed directory for large datasets. See Storage for details.

Current storage quotas are as follow:

Location Quota Shared across Nodes Backup
~/ 2/20/50GBc Yes Daily
~/large-data 20/500/1000GBd Yes No
~/archive 20/1000/5000GBd Yes No
/tmp 0.3-3.7TB (shared) No No

cQuotas for junior undergraduates/senior undergraduates and postgraduates/faculty and staff respectively.
dQuotas for senior undergraduates and taught postgraduates/research postgraduates/faculty and staff respectively.

Important: do not put any file you cannot afford to lose in locations that have no backup! We advise users to put anything that is generated and too important to lose in the ~/. For files too large to fit into ~/, you should keep your primary copy in ~/large-data and a backup copy in /archive.

Request More Resources

Students undertaking research projects are eligible for additional resources. Please seek your supervisor’s support when you apply. Students taking certain courses offered by the Department of Economics might also be granted additional resources.

Accessing the Cluster

Methods of Access

There are three ways to access the cluster:

Method Advantages Disadvantages
Web Access Most convenient
Works on all devices		 No GUI applications other than Jupyter, MATLAB and RStudio
Remote Desktop Easiest way to use GUI applications Memory intensive
SSH Most flexible Requires familiarity with Linux command-line interface

Option 1: Web Access

Using Jupyter, MATLAB or RStudio requires no special software other than a browser. You can also access any applications that does not have a graphical user interface—for example, Stata in console mode—through Jupyter’s terminal.

To access the cluster through a browser, navigate to one of the following URLs:

For other software with a GUI you will either need a Secure Shell (SSH) connection or a remote desktop connection.

Option 2: Remote Desktop

Remote desktop connection is the easiest way to use applications with a graphical user interface. This is the recommended method of access if you are just beginning to use the cluster and need to use the GUI version of Stata.

Prerequisite

You need to be either physically on campus or connected to the campus network via CUHK VPN.

Windows

  1. Launch the built-in ‘Remote Desktop Connection’ app.

  2. In Remote Desktop Connection:
    • Enter either scrp-login.econ.cuhk.edu.hk or scrp-login-2.econ.cuhk.edu.hk as the computer.
    • Optionally, enter your username and save your password.
    • Choose an appropriate resolution under [Show Options] > [Display].
      • If your monitor has high pixel density, you should select a relatively low resolution (e.g. 1600x1200) and zoom in after you have established a connection. Zooming is available under the drop-down menu at the top-left corner of the remote desktop window.
    • To enable file transfer, navigate to [Local Resources] > [Local devices and resources], then:
      • Uncheck the ‘Printers’ option.
      • Click ‘More’ and select the drives you want.
      • The drives you selected will appear under your home directory in a folder named thinclient_drives.

  3. Click ‘Connect’.

  4. When prompted:
    • Make sure session is ‘Xorg’.
    • Enter username and password.

    Click ‘OK’

Remote Desktop

Mac OS

Install Microsoft Remote Desktop app and follow the instructions for Windows.

Input Methods

The default input method is English. Follow the steps below to add another method:

  • Right click on the keyboard icon on the top-right corner and select [Preferences].
  • Under the [General] tab, add a new Keyboard shortcut for switching input methods by clicking the […] button. The default <Super>space does not work.
  • Under the [Input Method] tab, add the input methods you want.

Alternatively, you can run the following commands in a terminal within remote desktop:

  • Cantonese Pinyin: 
    gsettings set org.freedesktop.ibus.general.hotkey triggers \
  "['<Control>space', '<Super>space']"
gsettings set org.freedesktop.ibus.general preload-engines \
  "['table:cantonese', 'xkb:us::eng']"
  • Mandarin Pinyin: 
    gsettings set org.freedesktop.ibus.general.hotkey triggers \
  "['<Control>space', '<Super>space']"
gsettings set org.freedesktop.ibus.general preload-engines \
  "['sunpinyin', 'xkb:us::eng']"

You should then be able to switch to the chosen input method by pressing Ctrl-space.

Option 3: SSH

SSH provides the highest degree of flexibility. This is the recommended method of access if you intend to run computationally-intensive analysis.

Prerequisite

You need to be either physically on campus or connected to the campus network via CUHK VPN.

Windows

We recommend using MobaXterm. You can also use PuTTY, VcXsrv and WinSCP in combination as an alternative.

  1. Download, install and launch MobaXterm.

  2. If you intend to use MATLAB, enable hardware OpenGL acceleration in MobaXterm.

  3. To log in:

    • Select [Session], followed by [SSH].

    • Enter either scrp-login.econ.cuhk.edu.hk or scrp-login-2.econ.cuhk.edu.hk as the remote host.

    • You can optionally enter your username under ‘Specify username’.

    Click ‘OK’ to start the session.

  4. When prompted, follow the instructions to enter your username and password. For students, your username is your CUHK Compute ID. When entering your password, neither its length nor its content will be shown.

    Use middle click to paste content instead of typing Ctrl+V.

    MobaXterm_login

Mac OS

  1. Install XQuartz.

  2. Launch Application > Utilities > XQuartz.

  3. In XQuartz’s terminal, type:

    ssh -Y username@scrp-login.econ.cuhk.edu.hk

    or

    ssh -Y username@scrp-login-2.econ.cuhk.edu.hk

    For students, username is your CUHK Compute ID.

Linux

  1. Open a terminal and type

    ssh -Y username@scrp-login.econ.cuhk.edu.hk

    or

    ssh -Y username@scrp-login-2.econ.cuhk.edu.hk

    For students, username is your CUHK Compute ID.

You can now access software installed on the cluster.

File Transfer

Option 1: Web Access

You can upload files to your home directory through the web interface of either Jupyter or RStudio. To access other directories you will need an SFTP connection.

Option 2: Remote Desktop

Prerequisite

You need to be either physically on campus or connected to the campus network via CUHK VPN.

Windows

To enable file transfer, navigate to [Local Resources] > [Local devices and resources] in the remote desktop client, then:

  • Uncheck the ‘Printers’ option.
  • Click ‘More’ and select the drives you want.

The drives you select will appear in the file manager under a separate device called ‘thinclient_drives’. Files inside can be copied and pasted as usual.

Option 3: SFTP

Prerequisite

You need to be either physically on campus or connected to the campus network via CUHK VPN.

Windows

You can drap and drop files to the file explorer on the left hand side of MobaXterm’s interface.

Consider WinSCP if you prefer a standalone SFTP client.

macOS

  1. Download and install FileZilla.

  2. Enter either scrp-login.econ.cuhk.edu.hk or scrp-login-2.econ.cuhk.edu.hk as the host.

  3. Choose ‘SFTP’ as the server type.

  4. After entering your username and password, click ‘Connect’.

Linux

  1. Open terminal and type

    sftp username@scrp-login.econ.cuhk.edu.hk

    or

    sftp username@scrp-login-2.econ.cuhk.edu.hk

  2. Enter password when prompted.

Remember to check out the guide on storage to see where different types of files should go.

Using the Ubuntu Operating System

All SCRP nodes run on Ubuntu 20.04 LTS, a popular version of the Linux operating system. While you might be able to get by relying on the web interfaces of Jupyter and RStudio for simple tasks, familiarity with Linux is going to be very helpful for anything slightly more advanced. Here are some tips on how to use Linux if you are unfamiliar with it.