Large Scale DSO for Parametric Analysis
Large Scale DSO for parametric analysis operates through a non-graphical batch application called desktopjob. You can run the desktopjob command line to perform parametric analysis DSO. The command-line interface supported by this batch program is similar to the command line used for regular DSO jobs.
Large Scale DSO is used for large scale parallel jobs, which either fail or scale poorly
as regular DSO jobs. A Large Scale DSO job does not support the output of full parametric results,
but produces reduced datasets corresponding to predefined rectangular plots. The extracted columns
of data are saved as CSV files. Typically, there is one CSV file per-trace, per-variation. These CSV
outputs can be used directly in downstream applications (for example, Microsoft Excel). They can also
be imported as dataset solutions for post-processing. Non-rectangular plots of the design
For a machine with n cores, it should be expected that running n, single core, distributed simulations in parallel will encounter additional overhead due to the need to spawn n unique solve processes. Therefore, it should not be expected to observe an n times speed up over the time taken to run n analyses in series with a single core. The relative impact of this overhead increases as the size of the simulation and time to complete a single solve shrink.
The basic Large Scale DSO process involves:
- Preparing the model for Large Scale DSO Analysis.
- Submitting the Large Scale DSO job through Tools> Job Management or via command line.
- Monitoring the job's progress.
- Post-processing the results.
For details, refer to the following sections:
- Prerequisites for Large Scale DSO
- Job Management Interface for Large Scale DSO
- Command Line Syntax
- Deployment/Configuration
- Tutorial Example for HFSS
- Job Outputs
- Job Monitoring
- Process Limits for Large Scale DSO on Windows
- Known Issues/Troubleshooting for Large Scale DSO
Large Scale Distributed Solve Operation could submit a parametric setup to be solved in multiple machines, each machine may launch multiple EM-Desktop processes to solve the assigned variations (Design Points). Variations are distributed to each task (EM-Desktop process) equally, regardless of the machine hardware and each variation’s complexity. In practice, some tasks may finish earlier than others, in some extreme case some tasks may hours behind fastest task. DSO can redistribute tasks when a task finishes before other task. Variations are removed from slow tasks and reassigned to fast tasks. If you abort a task, they can be re-assigned to the running task, when the running task finish its original assignment. For more information, see Large Scale DSO theory.
Large Scale DSO offers two new batchoptions related to the redistribution ability.
LargeScaleDSO/VarRedistribution, where 0 disables redistribution (default), and 1 enables it.
LargeScaleDSO/RedistributionLimit, is a positive integer specifying the minimum estimated remaining time (in minutes) for variations to redistribute to another task. The default is 3.
Aborting a Large Scale DSO Simulation
To abort the whole Job, select the Abort button on the Job Monitor dialog.
To abort using the Job progress bar, click the button next to the Job progress bar, Click the Abort menu item in the popup.
To abort all tasks in a Node(host), click the button next to the node progress bar., and click the Abort menu item in the popup. Aborted Variations will be redistributed to other running Nodes, if redistribution is turned on.
To abort an individual task, click the button next to the node progress bar, and click the “Detail” menu item in the popup. In the Task status dialog box, click the Task button in the grid. In the variation status dialog box, click Abort button. Aborted Variations will be redistributed to other running tasks, if redistribution is turned on.
To terminate a hanging EM-Desktop process, the hanging ansysedt.exe process won’t respond to the first abort command. Send a second abort command to terminate the hanging process. Remaining variations will be redistributed to other running tasks, if redistribution is turned on.
For an EM-Desktop process crashed or killed by Windows Task manager or other tools, the task status will be shown as aborted, Remaining variations will be redistributed to other running tasks, if redistribution is turned on.