Actions

Login to cluster

From ALICE Documentation

To login to the ALICE cluster, you need to perform a hop-like login sequence. The two login nodes of the ALICE cluster cannot be accessed directly. One must first log in to an ssh gateway and then to one of the login nodes. This mechanism is required for both login and file transfer operations.

Best Practices

  1. Know when you are on a login node.  You can use your Linux prompt or the "hostname" command.  It is where you land when you choose login1 or login2 from the SSH-GW node.  To differentiate, the SSH-GW host is a secure portal from the outside and serves no compute function.
  2. Appropriate activities: Compile code, Developing applications, Defining and submitting your job, Post-processing and managing data, Monitoring running applications.
  3. Avoid computationally intensive activity.
    1. Don't run research applications.  Use an interactive session if running a job is not appropriate.
    2. Don't launch too many simultaneous processes.  While it is fine to compile on a login node "make -j 14" will use half of the cores.
    3. That script you run to monitor job status several times a second should probably run every few minutes.
    4. I/O activity can slow the login node for everyone, like multiple copies or "ls -l" on directories with 000's of files.
  4. Hyperthreading is turned off.  Running multiple threads per core is generally not productive.  MKL is an exception to that if it is relevant to you.

Login to ALICE from Linux

The login nodes are named:

login1.alice.universiteitleiden.nl (10.161.0.12)
login2.alice.universiteitleiden.nl (10.162.0.13)

The Storage device is named:

 campusdata20.alice.universiteitleiden.nl (10.161.0.33)

Setup ssh JUMP

In your Linux server write in ~/.ssh/config for instance

Host hpc1 
  HostName login1.alice.universiteitleiden.nl
  User <USERNAME>
  ProxyJump <USERNAME>@ssh-gw.alice.universiteitleiden.nl:22
  
Host hpc2
  HostName login2.alice.universiteitleiden.nl
  User <USERNAME>
  ProxyJump <USERNAME>@ssh-gw.alice.universiteitleiden.nl:22
Host hpcdata
  HostName campusdata20.alice.universiteitleiden.nl
  User <USERNAME>
  ProxyJump <USERNAME>@ssh-gw.alice.universiteitleiden.nl:22

(Replace <USERNAME> by your own ULCN account name.)

If you want to look at the monitoring tools that are running on the management node too, you could add additional tunnelling commands to the config for a specific host. Do not add tunnels to all definitions as they may produce conflicts when you use the same tunnel twice. So add the tunnel commands, for instance, to one host like:

Host hpc1tunnel
  HostName login1.alice.universiteitleiden.nl
  User <USERNAME>
  ProxyJump <USERNAME>@ssh-gw.alice.universiteitleiden.nl:22
  LocalForward 8081 management.alice.universiteitleiden.nl:8081
  LocalForward 8080 management.alice.universiteitleiden.nl:443

Alternatively, if your OpenSSH server isn't that recent and doesn't recognize the ProxyJump alias, try this:

Host hpc1 
  HostName login1.alice.universiteitleiden.nl
  ForwardX11 yes
  User <USERNAME>
  ProxyCommand ssh -X <USERNAME>@sshgw.alice.univesiteitleiden.nl -W %h:%p

Login to ssh-gw.alice.unversiteitleiden.nl (ssh <USERNAME>@ssh-gw.alice.universiteitleiden.nl and use your ULCN password for this) and put your public key in

~/.ssh/authorized_keys

Login through to the HPC login1 node ''ssh login1.alice.universiteitleiden.nl' (use your ALICE provided password) and put the same public key in

~/.ssh/authorized_keys

Direct login to login node 1

 ssh hpc1

and you can even forward X11 now.

Tunneling to monitors

Having set up the ssh tunneling required to access the monitoring tools on the cluster you are now able to access port 443 (general secure web server on the management node) and port 8081 (specific port in use by the Bright Cluster Manager monitoring tools).

So in a browser, you could type:

https://localhost:8080

to gain access to the management main web server, or you could type:

https://localhost:8081/userportal

to gain access to the Bright Cluster Manager User Portal.

Login to ALICE from Windows

There are multiple ways to connect to ALICE. Below a list in order of complexity using:

MobaXterm

Putty

Login to ALICE from MAC OS

Logging in with a Mac requires no extra installation on your local machine.

  • Under “File”, open a new finder window. Navigate to the “Applications” folder, then the “Utilities” folder. Open a terminal window.
  • Edit your ~/.bash_profile to incorporate:
   export LC_ALL=en_US.UTF-8
   export LANG=en_US.UTF-8 


  • Open a new tab to make sure these settings are in effect (Shell -> New Tab).
  • Edit your ~/.ssh/config file and put in:
Host hpc1 
  HostName login1.alice.universiteitleiden.nl
  User <USERNAME>
  ProxyJump <USERNAME>@ssh-gw.alice.universiteitleiden.nl:22

(Replace <USERNAME> by your own ULCN account name.)

Now you can login to the ALICE login 1 node by typing on the command line:

ssh hpc1
Macterm2.png

All other settings are similar to the Linux login setup