Libensemble

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:Date: May 22, 2019

* Added local (multiprocessing) and TCP options for manager/worker communications, in addition to mpi4py. (42).

* Example: libEnsemble can be run on MOM/launch nodes (e.g., those of ALCF/Theta & OLCF/Summit) and can remotely detect compute resources.
* Example: libEnsemble can be run on a system without MPI.
* Example: libEnsemble can be run with a local manager and remote TCP workers.

* Added support for Summit/LSF scheduler in job controller.
* MPI job controller detects and retries launches on failure; adding resilience. (143)
* Job controller supports option to extract/print job times in libE_stats.txt. (136)
* Default logging level changed to INFO. (164)
* Logging interface added, which allows user to change logging level and file. (110)
* All worker logging and calculation stats are routed through manager.
* libEnsemble can be run without a gen_func, for example, when using a previously computed random sample. (122)
* Aborts dump persis_info with the history.

:Note:

* **This version no longer supports Python 2.**
* Tested platforms include Local Linux, Theta (Cray XC40/Cobalt), Summit (IBM Power9/LSF), and Bebop (Cray CS400/Slurm).

:Known issues:

* Open-MPI does not work with direct MPI job launches in mpi4py comms mode, since it does not support nested MPI launches
(Either use local mode or Balsam job controller).
* Local comms mode (multiprocessing) may fail if MPI is initialized before forking processors. This is thought to be responsible for issues combining with PETSc.
* Remote detection of logical cores via LSB_HOSTS (e.g., Summit) returns number of physical cores since SMT info not available.
* TCP mode does not support (1) more than one libEnsemble call in a given script or (2) the auto-resources option to the job controller.

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:Date: February 20, 2019

* Logging no longer uses root logger (also added option to change libEnsemble log level). (105)
* Added wait_on_run option for job controller launch to block until jobs have started. (111)
* persis_info can be passed to sim as well as gen functions. (112)
* Postprocessing scripts added to create performance/utilization graphs. (102)
* New scaling test added (not part of current CI test suite). (114)

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:Date: November 7, 2018

* Separated job controller classes into different modules including a base class (API change).
* Added central_mode run option to distributed type (MPI) job_controllers (API addition). (93)
* Made poll and kill job methods (API change).
* In job_controller, set_kill_mode is removed and replaced by a wait argument for a hard kill (API change).
* Removed register module - incorporated into job_controller (API change).
* APOSMM has improved asynchronicity when batch mode is false (with new example). (96)
* Manager errors (instead of hangs) when alloc_f or gen_f don't return work when all workers are idle. (95)

:Known issues:

* Open-MPI is not supported with direct MPI launches since nested MPI launches are not supported.

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:Date: September 7, 2018

* Issues with killing jobs have been fixed. (21)
* Fixed job_controller manager_poll to work with multiple jobs. (62)
* API change: persis_info now included as an argument to libE and is returned from libE instead of gen_info
* Gen funcs: aposmm_logic module renamed to aposmm.
* New example gen and allocation functions.
* Updated Balsam launch script (with new Balsam workflow).
* History is dumped to file on manager or worker exception and MPI aborted (with exit code 1). (46)
* Default logging level changed to DEBUG and redirected to file ensemble.log.
* Added directory of standalone tests (comms, job kills, and nested MPI launches).
* Improved and sped up unit tests. (68)
* Considerable documentation enhancements.

:Known issues:

* Open-MPI is not supported with direct MPI launches since nested MPI launches are not supported.

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:Date: June 29, 2018

* Added job_controller interface (for portable user scripts).
* Added support for using the Balsam job manager. Enables portability and dynamic scheduling.
* Added autodetection of system resources.
* Scalability testing: Ensemble performed with 1023 workers on Theta (Cray XC40) using Balsam.
* Tested MPI libraries: MPICH and Intel MPI.

:Known issues:

* Killing MPI jobs does not work correctly on some systems (including Cray XC40 and CS400). In these cases, libEnsemble continues, but processes remain running.
* Open-MPI does not work correctly with direct launches (and has not been tested with Balsam).

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:Date: November 30, 2017

* Initial release.