Interactive post-processing with paraview on ARCHER2

In this post, you will learn how to run an interactive job on ARCHER2 for postprocessing using PARAVIEW

first you need to load the paraview on the ARCHER2

module load paraview

This will load paraview 5.9.1 with spray ray tracing. You need to have the exact same version installed on your system.

To start an interactive job using 1 node, for 2 hours run the following command

srun --nodes=1 --exclusive --time=02:00:00 \
               --partition=standard --qos=standard \
               --account=Allocation_code \
               --pty /bin/bash

replace the values according to your needs. Note that you are also required to provide the account code/allocation code which is the same code you use for running jobs on ARCHER2.

Note: if you want to use the shortqos for interactive jobs (20min or less) use the following:

srun --nodes=1 --exclusive --time=00:20:00 \
               --partition=standard --qos=short --reservation=shortqos \
               --account=Allocation_code \
               --pty /bin/bash

after you run the command, you will see the following message:

srun: job 913186 queued and waiting for resources

When the resources are allocated the following additional messages will appear on the screen

srun: job 913186 has been allocated resources
user-ID@nid001363:/work/proj_code/proj_code/user_ID/myRuns/postprocess> 

Note that in the above messages, 913186 is the job number and will be different when you run your command. Also, user_iD and proj_code will be replaced with your user id and project code. For example, if my archer username is mlahooti and my project code is e01 the message will read

mlahooti@nid001363:/work/e01/e01/mlahooti/myRuns/postprocess> 

Now you are in the interactive mode. First, you need to run the paraview on the ARCHER2. If you remember, I requested one node which has 128 cores. I am going to run the paraview in parallel using all these cores as follows:

module load paraview

srun -n 128 --oversubscribe --distribution=block:block --hint=nomultithread --ntasks=128 pvserver --mpi --force-offscreen-rendering

running the above command will launch the pvserver and the following message will appear on the screen:

Waiting for client...
Connection URL: cs://nid001363:11111
Accepting connection(s): nid001363:11111

Open a new terminal on your machine and connect to the ARCHER2 using the nid given by ARCHER2

ssh -L 11111:nid001363:11111 user@login.archer2.ac.uk

NOTE: use the same nid (coloured by orange) when connecting to ARCHER2 again. In our example it is nid001363

now open a tab in your terminal and run the paraview on your local machine. Then you can connect to the pv server. To do so, from File choose to connect, select the archer2 server and press connect.

Note: You need to configure the archer2 server for the first time. From file, click on the connect, in the opened page, add server set the name to archer2, set the server type to client/server, use localhost for Host and 11111 for port.