Fixes#97191
This PR aims to propagate collective exceptions (async error or timeout) up to the program, so as to avoid silent stuck job.
### Previous output in #97191
```
Rank 0 is the problematic rank
Rank 4 completed
Rank 5 completed
Rank 3 completed
Rank 6 completed
Rank 2 completed
Rank 7 completed
Rank 1 completed
[E ProcessGroupNCCL.cpp:464] [Rank 0] Watchdog caught collective operation timeout: WorkNCCL(SeqNum=1, OpType=ALLREDUCE, Timeout(ms)=10000) ran for 10917 milliseconds before timing out.
Rank 0 completed
[E ProcessGroupNCCL.cpp:478] Some NCCL operations have failed or timed out. Due to the asynchronous nature of CUDA kernels, subsequent GPU operations might run on corrupted/incomplete data.
[E ProcessGroupNCCL.cpp:483] To avoid data inconsistency, we are taking the entire process down.
```
Although it says that it is taking the process down, it sometimes fails to do so.
### New output after this PR:
```
...
[E ProcessGroupNCCL.cpp:459] [Rank 0] Watchdog caught collective operation timeout: WorkNCCL(SeqNum=1, OpType=ALLREDUCE, Timeout(ms)=10000) ran for 10599 milliseconds before timing out.
[E ProcessGroupNCCL.cpp:473] Some NCCL operations have failed or timed out. Due to the asynchronous nature of CUDA kernels, subsequent GPU operations might run on corrupted/incomplete data.
[E ProcessGroupNCCL.cpp:479] To avoid data inconsistency, we are taking the entire process down.
[E ProcessGroupNCCL.cpp:818] [Rank 0] NCCL watchdog thread terminated with exception: [Rank 0] Watchdog caught collective operation timeout: WorkNCCL(SeqNum=1, OpType=ALLREDUCE, Timeout(ms)=10000) ran for 10599 milliseconds before timing out.
ERROR:torch.distributed.elastic.multiprocessing.api:failed (exitcode: -6) local_rank: 0 (pid: 194470) of binary: /data/home/kw2501/repos/pytorch-dev-env/bin/python
Traceback (most recent call last):
File "/pytorch-dev-env/bin/torchrun", line 33, in <module>
sys.exit(load_entry_point('torch', 'console_scripts', 'torchrun')())
File "/pytorch-dev/torch/distributed/elastic/multiprocessing/errors/__init__.py", line 346, in wrapper
return f(*args, **kwargs)
File "/pytorch-dev/torch/distributed/run.py", line 794, in main
run(args)
File "/pytorch-dev/torch/distributed/run.py", line 785, in run
elastic_launch(
File "/pytorch-dev/torch/distributed/launcher/api.py", line 134, in __call__
return launch_agent(self._config, self._entrypoint, list(args))
File "/pytorch-dev/torch/distributed/launcher/api.py", line 250, in launch_agent
raise ChildFailedError(
torch.distributed.elastic.multiprocessing.errors.ChildFailedError:
============================================================
hang.py FAILED
------------------------------------------------------------
Failures:
<NO_OTHER_FAILURES>
------------------------------------------------------------
Root Cause (first observed failure):
[0]:
time : 2023-03-20_22:00:42
host : node0
rank : 0 (local_rank: 0)
exitcode : -6 (pid: 194470)
error_file: <N/A>
traceback : Signal 6 (SIGABRT) received by PID 194470
============================================================
```
The log suggests that TorchX monitor is triggered, and job is torn down.
### Major changes in this PR:
1. Merge ncclWatchDog thread and workCleanupLoop thread into one so that the watch action and the throw action are streamlined.
Previously, ncclWatchDog is responsible for watching comm error and timeout, and workCleanupLoop is responsible for watching Work item error and throwing exception. This two-thread design is not streamlined, raising the chance of missing the throw. Also, it is duplicated to watch at multiple level.
2. Rethrow exception at watchdog thread.
3. Clean up a bunch of duplicated functions, e.g. `checkAndThrowException` and `handleNcclException`.
4. Turn on ASYNC_ERROR_HANDLING by default
Pull Request resolved: https://github.com/pytorch/pytorch/pull/97066
Approved by: https://github.com/rohan-varma
Headers under torch/csrc/distributed may be referened with relative path, e.g., "<c10d/...>". However, relative path cannot be gracefully handled by Meta internal build when the NCCL PG is hipified to support AMD/RCCL because the "hipified" header files are generated in other directories. Moreover, using absolute path for header inclusion is the state-of-the-art in most components in Pytorch. Thus, this patch refactors all header paths in torch/csrc/distributed to be absolute.
See D39835774 for more details about Meta internal complication.
**How to test**: commit 9e5d199 removes -I./torch/csrc/distributed in compile options. Thus use it to verify we don't miss any relative path use of torch/csrc/distributed headers.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/85780
Approved by: https://github.com/kumpera, https://github.com/huydhn
Headers under torch/csrc/distributed may be referened with relative path, e.g., "<c10d/...>". However, relative path cannot be gracefully handled by Meta internal build when the NCCL PG is hipified to support AMD/RCCL because the "hipified" header files are generated in other directories. Moreover, using absolute path for header inclusion is the state-of-the-art in most components in Pytorch. Thus, this patch refactors all header paths in torch/csrc/distributed to be absolute.
See D39835774 for more details about Meta internal complication.
**How to test**: commit 9e5d199 removes -I./torch/csrc/distributed in compile options. Thus use it to verify we don't miss any relative path use of torch/csrc/distributed headers.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/85780
Approved by: https://github.com/kumpera
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/68310
Enable desync root cause analysis by recording the last footprint of collective calls. When timeout we parse the store trace and figure out the root cause of the desync issue. This feature is built based on async error handling.
Test Plan:
Standalone test
* Typical desync - P467288969
* Mismatched collectives - P467288916
* Mismatched broadcast size - P467288873
DDP benchmark
* DDP benchmark desync - P467433483, P467520195
No perf regression:
* w/o this diff https://www.internalfb.com/intern/fblearner/details/308379789?tab=Outputs
* w/ this diff https://www.internalfb.com/intern/fblearner/details/308534088?tab=Outputs
Reviewed By: mingzhe09088
Differential Revision: D32348647
fbshipit-source-id: 43e7e96e3fa2be0ac66c1325bceb639b461a8b3a
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/60543
Since now c10d is part of libtorch, it would also be nice if the sources lived all in one place.
ghstack-source-id: 132306292
Test Plan: It builds
Reviewed By: cbalioglu
Differential Revision: D29062002
fbshipit-source-id: d9e1301e9d73e1643fa0f0119cd2d618f1ad52e6
