-multidir for runs with different number of steps only runs for the shortest number of steps - Redmine #1857
Archive from user: Viveca Lindahl
I ran multiple simulations with varying number of steps set in the mdp-file using -multidir but all simulations ended at the same time, i.e. at the wrong step count for some runs.
(from redmine: issue id 1857, created on 2015-11-23 by gmxdefault, closed on 2016-06-27)
- relates #692 (closed)
- Revision d5bd278b by Mark Abraham on 2016-06-27T17:31:02Z:
Removed unnecessary inter-simulation signalling Generally, multi-simulation runs do not need to couple the simulations (discussion at #692). Individual algorithms implemented with multi-simulations might need to do so, but should take care of their own details, and now do. Scaling should improve in the cases where simulations are now decoupled. It is unclear what the expected behaviour of a multi-simulation should be if the user supplies any of the possible non-uniform distributions of init_step and nsteps, sourced from any of .mdp, .cpt or command line. Instead, we report on the non-uniformity and proceed. It's always possible that the user knows what they are doing. In particular, now that multi-simulations are no longer explicitly coupled, any heterogeneity in the execution environment will lead to checkpoints and -maxh acting at different time steps, unless a user-selected algorithm requires that the simulations stay coordinated (e.g. REMD or ensemble restraints). In the implementation of signalling, we have stopped checking gs for NULL as a proxy for whether we should be doing signalling at that communication phase. Replaced with a helper object in which explicit flags are set. Added unit tests of that functionality. Improved documentation of check_nstglobalcomm. mdrun now reports the number of steps between intra-simulation communication to the log file. Noted minor TODOs for future cleanup. Added some trivial test cases for termination by maxh in normal-MD, multi-sim and REMD cases. Refactored multi-sim tests to make this possible without duplication. This is complicated by the way filenames get changed by mdrun -multi by the former par_fn, so cleaned up the way that is handled so it can work and be re-used better. Introduced mdrun integration-test object library to make that build system work a little better. Made some minor improvements to Doxygen setup for integration tests. Fixes #860, #692, #1857, #1942. Change-Id: I5f7b98f331db801b058ae2b196d79716b5912b09