In-situ Visualisation on JUQUEEN

• check this presentation ​pdf
• instrument your code
• link your code with libsim

• start simulation
• connect with GUI to simulation

instrument your code

link your code with libsim

LibsimV2 is compiled as a static library on JUQUEEN and has dependencies to multiple other libraries. Hence, linking libsimV2 to a simulation results in a long link line.

more...

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Steps On JUQUEEN

start simulation

1) prepare jobscript

Error: Failed to load processor ShellExample

No macro or processor named 'ShellExample' found

• Run I/O operations with POSIX rules or VisIt cannot send/recv short commands ==> BG_SYSIODPOSIXMODE=1
  • 0 == I/O operation that is initiated from a compute node can cause multiple I/O operations on the I/O node.
  • 1 == Each I/O operation that is initiated from a compute node completes atomically.
• Set $HOME or VisIt segfaults

2) submit job

Error: Failed to load processor ShellExample

No macro or processor named 'ShellExample' found

3) wait until job has started

Error: Failed to load processor ShellExample

No macro or processor named 'ShellExample' found

4) check sim2 file written by simulation

Error: Failed to load processor ShellExample

No macro or processor named 'ShellExample' found

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Steps On Local Machine (using Host profile)

1) create host profile

2) connect with host profile

3) open sim2 file on with VisIt GUI

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Steps On Local Machine (manual)

connect with GUI to simulation

1) tunnel port on compute node of rank 0 to local machine (forward connection)

Error: Failed to load processor ShellExample

No macro or processor named 'ShellExample' found

• <USER>@juqueen.fz-juelich.de is your login to the front node
• -L <LOCAL-PORT>:<COMPUTE-NODE>:<REMOTE-PORT> defines the start and end of the tunnel
• -f tells ssh to go into the background
• -N instructs OpenSSH to not execute a command on the remote system

example:

Error: Failed to load processor ShellExample

No macro or processor named 'ShellExample' found

2) copy/modify sim2 file to client

Error: Failed to load processor ShellExample

No macro or processor named 'ShellExample' found

example:

Error: Failed to load processor ShellExample

No macro or processor named 'ShellExample' found

modify to:

Error: Failed to load processor ShellExample

No macro or processor named 'ShellExample' found

3) open sim2 file on with VisIt GUI

4) tunnel port on local machine to compute node of rank 0 (backward connection)