Process sets, XLA

Remote filesystem support, estimator fixes

PyTorch Lightning support, Nsight profiling, PyTorch 1.9 compatibility

Hotfix for TensorFlow 2.4, grouped allreduce updates

PyTorch 1.8 compatibility, Spark on Gloo stdout forwarding, bugfixes

Bugfixes for Ray, Databricks, and Spark Estimators

Local gradient aggregation, grouped allreduce

Correctly handle grads_and_vars passed in as zips for TF Keras 2.4 w/…

… local gradient aggregation (horovod#2394)

Signed-off-by: aaron276h <[email protected]>
(cherry picked from commit 744fbc9)

Elastic Horovod on Ray

Support gradient aggregation for TF2.