GitLab

* update distributed training doc.

* explain data split.

* fix message passing.

* id mapping.

* fix.

* test data reshuffling.

* fix a bug.

* fix test.

* Revert "fix."

This reverts commit 2d025e9e1a5c05c3da9b803a035a788ced59bd77.

* Revert "id mapping."

This reverts commit 2a6a93ceb81fbdff86e6e9e5a58e1ace1e9d9882.

* Revert "fix message passing."

This reverts commit ed8a86bf2b015e5e4f64ba160e81b207ad2a1d65.

* Revert "explain data split."

This reverts commit 4338ddf8a336014cf92d4cb9a1db02b9badc0e55.

* Revert "update distributed training doc."

This reverts commit dda1c35c44536934c19715534f01f832afda6ad2.

* add more tests.

* fix.

* fix.

* fix.
Co-authored-by: Zheng <dzzhen@3c22fba32af5.ant.amazon.com>
Co-authored-by: xiang song(charlie.song) <classicxsong@gmail.com>