Reland #2 "[C10] PG observability hooks. (#108815)"#111069
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wconstab wants to merge 1 commit intogh/wconstab/204/basefrom
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Reland #2 "[C10] PG observability hooks. (#108815)"#111069wconstab wants to merge 1 commit intogh/wconstab/204/basefrom
wconstab wants to merge 1 commit intogh/wconstab/204/basefrom
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This reverts commit ff0358b. (original PR #108815 desc copied below) Expose a set of observability hooks into C10D such that our users can detect collectives failure both faster and more easily. The design is similar to NCCL desync debug that it minimized the overhead by doing most of the work out of the main thread. This PR introduces a new module torch.distributed.hooks that exposes the following set of methods: register_collective_start_hook register_collective_end_hook register_process_group_hook The process group hook exposes PG creation on the member ranks and call them inline from the the PG creation code. This is fine since this happens during initialization and a limited number of times. The collective start/end hooks are fired from a single background thread. It reads events from a C++ queue and dispatches over. Queue notification is oddly done using a pipe, this is needed so python can abort the thread on shutdown and have it as background thread. This is not possible with more reasonable choices like a condvar. [ghstack-poisoned]
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This reverts commit ff0358b. (original PR #108815 desc copied below) Expose a set of observability hooks into C10D such that our users can detect collectives failure both faster and more easily. The design is similar to NCCL desync debug that it minimized the overhead by doing most of the work out of the main thread. This PR introduces a new module torch.distributed.hooks that exposes the following set of methods: register_collective_start_hook register_collective_end_hook register_process_group_hook The process group hook exposes PG creation on the member ranks and call them inline from the the PG creation code. This is fine since this happens during initialization and a limited number of times. The collective start/end hooks are fired from a single background thread. It reads events from a C++ queue and dispatches over. Queue notification is oddly done using a pipe, this is needed so python can abort the thread on shutdown and have it as background thread. This is not possible with more reasonable choices like a condvar. ghstack-source-id: 9b17d0d Pull Request resolved: #111069
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Stack from ghstack (oldest at bottom):
This reverts commit ff0358b.
(original PR #108815 desc copied below)
Expose a set of observability hooks into C10D such that our users can
detect collectives failure both faster and more easily.
The design is similar to NCCL desync debug that it minimized the
overhead by doing most of the work out of the main thread.
This PR introduces a new module torch.distributed.hooks that exposes the following set of methods:
The process group hook exposes PG creation on the member ranks and call them inline from the
the PG creation code. This is fine since this happens during initialization and a limited number of times.
The collective start/end hooks are fired from a single background thread. It reads
events from a C++ queue and dispatches over.
Queue notification is oddly done using a pipe, this is needed so python can abort the thread on shutdown
and have it as background thread. This is not possible with more reasonable choices like a condvar.