Starting in 2025 R2.3, you can persist licenses between runs in Ansys Lumerical products. These features allow you to hold onto licenses and avoid having licenses taken by other users when conducting long or resource intensive simulations.
This feature is only available for the enterprise license and is available for all products.
Overview
The persistent checkout feature allows licenses to persist between simulation runs until the GUI is closed or after you disable this option. Instead of returning licenses after each simulation concludes. Enable this option to avoid out of license errors for sweeps and optimizations that requires many consecutive simulations, where license may be taken by other users between runs.
The number of licenses checked out matches the number of licenses estimated from the license estimation utility. Between runs, if you adjust resources such that more licenses are needed for the next run, the additional licenses will be checked out. However, if you adjust resources such that less licenses are required, extra licenses aren’t returned to the pool until you close the GUI or run another simulation after turning off the feature.
The difference in when license check out occurs is shown in the diagram below, using a parameter sweep as an example.
Turning this feature off while the application is open results in already checked out license being returned immediately.
GUI access
You can enable the persistent checkout feature from the GUI by checking the “Persist checkouts” button in the “Resource license settings” section of the resource configuration window.
Script access
To set persistent checkout from script, use setpersistcheckouts.
Command line access
The command line flag (Windows/Linux) -persist-solve-checkout controls the persistent checkout feature. When the flag is present, the feature is enabled. This command line flag overrides the selection made in the GUI.
Environment variable
The environment variable (Windows/Linux) LUM_PERSIST_CHECKOUTS controls the persistent checkout feature. Setting LUM_PERSIST_CHECKOUTS=1 enables the feature and setting LUM_PERSIST_CHECKOUTS=0 disables the feature.
This environment variable overrides selections made inside the product GUI. When this environment variable is detected, a warning is shown in the Resource Configuration window.
See Also
Ansys optics solve, accelerator, and Ansys HPC license consumption, setpersistcheckouts