Adding garbage collection to Mock USS

[ahaanlimaye]

Is your feature request related to a problem? Please describe.
I want to use Mock USS to simulate flights at a high load. However, since flights are stored in memory, the UpsertFlightPlan request eventually encounters out of memory errors.

Describe the solution you'd like
I would like some periodic garbage collection of the memory taken up by expired flights.

[BenjaminPelletier]

Thanks for highlighting. If it's not practical to provide reproduction steps, could you estimate the current breaking point? For instance, does it crash after 100 or 100,000 flights? Is the problem a concurrency issue (X flights in memory at once) or is it actually a leakage issue (Y cumulative flights causes the problem even if they're created and deleted one at a time)? The flight_planning API has a delete operation for flight plans; could you confirm that it is being used appropriately to close the flights?

[ahaanlimaye]

Due to some limitations in our load testing infrastructure, we’re not currently deleting flight plans after they’ve been created which is likely contributing to/causing the problem. We are wondering if it’s simple to implement clean up of expired intents on the MockUSS side and if that’s something InterUSS would be interested in doing.
There does seem to be a concurrency issue - after we create a large number of flights (order of 100s) without cleaning them up, the MockUSS will crash.

We have also observed a similar issue when the MockUSS used to run in perpetuity for US SCD Automated Testing. Before the MockUSS was stopped and started per test run by RPAS, the MockUSS would crash almost weekly. Is it possible this was also due to a build up flight plans not getting cleaned up? If not that might also indicate a leak.