Warning when using RPC

wilhelm: <p>I’m following <a href="https://pytorch.org/tutorials/intermediate/rpc_tutorial.html" rel="noopener nofollow ugc">this tutorial</a> for RPC in PyTorch.<br>
The problem is that running that code I get the following warning:</p>
<blockquote>
<p>/opt/anaconda/anaconda3/envs/dl-gym/lib/python3.10/site-packages/torch/distributed/distributed_c10d.py:653: UserWarning: You are using a Backend &lt;class ‘torch.distributed.distributed_c10d.ProcessGroupGloo’&gt; as a ProcessGroup. This usage is deprecated since PyTorch 2.0. Please use a public API of PyTorch Distributed instead.</p>
</blockquote>
<p>How can I get rid of that warning?</p>
<p>By the way, I saw that that code is running using the CPU. Since I have 4 GPUs I would like them instead of the CPU. Is there any API to change the backend to “nccl” and using the GPUs?</p>
<p>Thanks</p>

vmoens: <p>Unfortunately, torch RPC is in a stale situation and mostly unmaintained.<br>
Using RPC with GPUs is currently broken.<br>
Feel free to upvote / comment on this issue to make yourself heard!</p><aside class="onebox githubissue" data-onebox-src="https://github.com/pytorch/pytorch/issues/95487#issuecomment-1983397846">
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      <a href="https://github.com/pytorch/pytorch/issues/95487#issuecomment-1983397846" target="_blank" rel="noopener nofollow ugc">Torch RPC on multiple nodes with GPU returns a EOF error</a>
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        opened <span class="discourse-local-date" data-format="ll" data-date="2023-02-24" data-time="17:23:46" data-timezone="UTC">05:23PM - 24 Feb 23 UTC</span>
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          <img alt="vmoens" src="https://avatars.githubusercontent.com/u/25529882?v=4" class="onebox-avatar-inline" width="20" height="20">
          vmoens
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    <div class="labels">
        <span style="display:inline-block;margin-top:2px;background-color: #B8B8B8;padding: 2px;border-radius: 4px;color: #fff;margin-left: 3px;">
          oncall: distributed
        </span>
        <span style="display:inline-block;margin-top:2px;background-color: #B8B8B8;padding: 2px;border-radius: 4px;color: #fff;margin-left: 3px;">
          triaged
        </span>
        <span style="display:inline-block;margin-top:2px;background-color: #B8B8B8;padding: 2px;border-radius: 4px;color: #fff;margin-left: 3px;">
          module: rpc
        </span>
        <span style="display:inline-block;margin-top:2px;background-color: #B8B8B8;padding: 2px;border-radius: 4px;color: #fff;margin-left: 3px;">
          module: tensorpipe
        </span>
    </div>
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  <div class="github-row">
    <p class="github-body-container">### 🐛 Describe the bug

When running torch rpc on multiple nodes with submitit (<span class="show-more-container"><a href="" rel="noopener" class="show-more">…</a></span><span class="excerpt hidden">through slurm) I get an EOF error _even if I'm not using the gpus and I'm not making them available to RPC_.
Here's a script to reproduce:
```python
import os
from torch.distributed import rpc
import torch
import submitit
import socket
import subprocess
import time

MAX_TIME_TO_CONNECT=1000

def rpc_init_node(
    rank,
    rank0_ip,
    tcp_port,
    world_size,
):
    DEVICES=[]  #list(range(torch.cuda.device_count()))
    os.environ["MASTER_ADDR"] = str(rank0_ip)
    os.environ["MASTER_PORT"] = "29500"
    # os.environ["TORCH_DISTRIBUTED_DEBUG"] = "DETAIL"
    # os.environ['TP_SOCKET_IFNAME']='lo'
    options = rpc.TensorPipeRpcBackendOptions(
        num_worker_threads=16,
        init_method=f"tcp://{rank0_ip}:{tcp_port}",
        rpc_timeout=MAX_TIME_TO_CONNECT,
        _transports=["uv"],
        # Currently fails when nodes have more than 0 gpus avail,
        # even when no device is made visible
        devices=DEVICES,
    )
    print(f"init rpc on {rank}")
    rpc.init_rpc(
        f"NODE_{rank}",
        rank=rank,
        backend=rpc.BackendType.TENSORPIPE,
        rpc_backend_options=options,
        world_size=world_size,
    )
    rpc.shutdown()

def rpc_init_master(
    tcp_port,
    world_size,
):
    hostname = socket.gethostname()
    rank0_ip = socket.gethostbyname(hostname)

    DEVICES=[]  # list(range(torch.cuda.device_count()))
    os.environ["MASTER_ADDR"] = str(rank0_ip)
    os.environ["MASTER_PORT"] = "29500"
    # os.environ["TORCH_DISTRIBUTED_DEBUG"] = "DETAIL"
    # os.environ['TP_SOCKET_IFNAME']='lo'
    options = rpc.TensorPipeRpcBackendOptions(
        num_worker_threads=16,
        init_method=f"tcp://{rank0_ip}:{tcp_port}",
        rpc_timeout=MAX_TIME_TO_CONNECT,
        _transports=["uv"],
        # Currently fails when nodes have more than 0 gpus avail,
        # even when no device is made visible
        devices=DEVICES,
    )
    print("init rpc on master")
    rpc.init_rpc(
        "TRAINER",
        rank=0,
        backend=rpc.BackendType.TENSORPIPE,
        rpc_backend_options=options,
        world_size=world_size,
    )
    # some dummy compute
    out = rpc.rpc_sync("NODE_1", torch.add, args=(torch.ones(()), torch.ones(())))
    rpc.shutdown()
    print("result", out)
    return out.item()

if __name__ == "__main__":
    slurm_conf = {
        "timeout_min": 100,
        "slurm_partition": "train",
        "slurm_cpus_per_task": 4, # works
        #"slurm_gpus_per_task": 1, "slurm_cpus_per_gpu": 8, # does not work
    }
    master_on_node = True
    num_nodes = 2
    executor = submitit.AutoExecutor(folder="log_test")
    executor.update_parameters(**slurm_conf)
    if not master_on_node:
        hostname = socket.gethostname()
        IPAddr = socket.gethostbyname(hostname)
    else:
        job = executor.submit(rpc_init_master, 1234, num_nodes+1)
        print("job id", job.job_id)
        time.sleep(2.0)
        cmd=f"squeue -j {job.job_id} -o %N | tail -1"
        node = subprocess.check_output(cmd, shell=True, text=True).strip()
        print("node", node)
        cmd=f'sinfo -n {node} -O nodeaddr | tail -1'
        print(cmd)
        IPAddr = subprocess.check_output(cmd, shell=True, text=True).strip()
    print("IP addr:", IPAddr)

    for i in range(num_nodes):
        _job = executor.submit(
                rpc_init_node, i + 1, IPAddr, 1234, num_nodes+1)
    if not master_on_node:
        out = rpc_init_master(1234, num_nodes+1)
    else:
        out = job.result()
    print("result", out)
```

I commented the line that makes the code break if uncommented (you should comment the line above tagged with `# works`).

###&nbsp;What does not matter
- If you tell which devices RPC should see using `devices=list_of_device`, or `devices=[]` the effect is the same.
- If you launch things from the master node or create a master node (see script for example) the error is the same
- The code runs using multiprocessing, presumably because I'm staying on the same node (?)

I had to set the `_transport` in the TensorPipe options because I'm running on AWS and without it it's not running


Here's the error:
```
Traceback (most recent call last):
  File "/data/home/vmoens/dump/dummy.py", line 109, in &lt;module&gt;
    out = job.result()
  File "/fsx/users/vmoens/conda/envs/compile/lib/python3.9/site-packages/submitit/core/core.py", line 266, in result
    r = self.results()
  File "/fsx/users/vmoens/conda/envs/compile/lib/python3.9/site-packages/submitit/core/core.py", line 294, in results
    raise job_exception  # pylint: disable=raising-bad-type
submitit.core.utils.FailedJobError: Job (task=0) failed during processing with trace:
----------------------
Traceback (most recent call last):
  File "/fsx/users/vmoens/conda/envs/compile/lib/python3.9/site-packages/submitit/core/submission.py", line 54, in process_job
    result = delayed.result()
  File "/fsx/users/vmoens/conda/envs/compile/lib/python3.9/site-packages/submitit/core/utils.py", line 133, in result
    self._result = self.function(*self.args, **self.kwargs)
  File "/data/home/vmoens/dump/dummy.py", line 63, in rpc_init_master
    rpc.init_rpc(
  File "/fsx/users/vmoens/conda/envs/compile/lib/python3.9/site-packages/torch/distributed/rpc/__init__.py", line 199, in init_rpc
    _init_rpc_backend(backend, store, name, rank, world_size, rpc_backend_options)
  File "/fsx/users/vmoens/conda/envs/compile/lib/python3.9/site-packages/torch/distributed/rpc/__init__.py", line 234, in _init_rpc_backend
    rpc_agent = backend_registry.init_backend(
  File "/fsx/users/vmoens/conda/envs/compile/lib/python3.9/site-packages/torch/distributed/rpc/backend_registry.py", line 104, in init_backend
    return backend.value.init_backend_handler(*args, **kwargs)
  File "/fsx/users/vmoens/conda/envs/compile/lib/python3.9/site-packages/torch/distributed/rpc/backend_registry.py", line 363, in _tensorpipe_init_backend_handler
    api._all_gather(None, timeout=rpc_backend_options.rpc_timeout)
  File "/fsx/users/vmoens/conda/envs/compile/lib/python3.9/site-packages/torch/distributed/rpc/api.py", line 82, in wrapper
    return func(*args, **kwargs)
  File "/fsx/users/vmoens/conda/envs/compile/lib/python3.9/site-packages/torch/distributed/rpc/api.py", line 224, in _all_gather
    rpc_sync(
  File "/fsx/users/vmoens/conda/envs/compile/lib/python3.9/site-packages/torch/distributed/rpc/api.py", line 82, in wrapper
    return func(*args, **kwargs)
  File "/fsx/users/vmoens/conda/envs/compile/lib/python3.9/site-packages/torch/distributed/rpc/api.py", line 809, in rpc_sync
    return fut.wait()
RuntimeError: EOF: end of file (this error originated at tensorpipe/transport/uv/connection_impl.cc:132)
```

### Versions

Latest torch nightly, locally built

```
PyTorch version: 2.0.0.dev20230220+cu118
Is debug build: False
CUDA used to build PyTorch: 11.8
ROCM used to build PyTorch: N/A

OS: Ubuntu 18.04.6 LTS (x86_64)
GCC version: (Ubuntu 9.4.0-1ubuntu1~18.04) 9.4.0
Clang version: 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
CMake version: version 3.25.0
Libc version: glibc-2.27

Python version: 3.9.15 | packaged by conda-forge | (main, Nov 22 2022, 15:55:03)  [GCC 10.4.0] (64-bit runtime)
Python platform: Linux-5.4.0-1069-aws-x86_64-with-glibc2.27
Is CUDA available: True
CUDA runtime version: 11.6.112
CUDA_MODULE_LOADING set to: LAZY
GPU models and configuration:
GPU 0: NVIDIA A100-SXM4-40GB
GPU 1: NVIDIA A100-SXM4-40GB
GPU 2: NVIDIA A100-SXM4-40GB
GPU 3: NVIDIA A100-SXM4-40GB
GPU 4: NVIDIA A100-SXM4-40GB
GPU 5: NVIDIA A100-SXM4-40GB
GPU 6: NVIDIA A100-SXM4-40GB
GPU 7: NVIDIA A100-SXM4-40GB

Nvidia driver version: 510.47.03
cuDNN version: Probably one of the following:
/usr/local/cuda-11.0/targets/x86_64-linux/lib/libcudnn.so.8.0.5
/usr/local/cuda-11.0/targets/x86_64-linux/lib/libcudnn_adv_infer.so.8.0.5
/usr/local/cuda-11.0/targets/x86_64-linux/lib/libcudnn_adv_train.so.8.0.5
/usr/local/cuda-11.0/targets/x86_64-linux/lib/libcudnn_cnn_infer.so.8.0.5
/usr/local/cuda-11.0/targets/x86_64-linux/lib/libcudnn_cnn_train.so.8.0.5
/usr/local/cuda-11.0/targets/x86_64-linux/lib/libcudnn_ops_infer.so.8.0.5
/usr/local/cuda-11.0/targets/x86_64-linux/lib/libcudnn_ops_train.so.8.0.5
/usr/local/cuda-11.1/targets/x86_64-linux/lib/libcudnn.so.8.0.5
/usr/local/cuda-11.1/targets/x86_64-linux/lib/libcudnn_adv_infer.so.8.0.5
/usr/local/cuda-11.1/targets/x86_64-linux/lib/libcudnn_adv_train.so.8.0.5
/usr/local/cuda-11.1/targets/x86_64-linux/lib/libcudnn_cnn_infer.so.8.0.5
/usr/local/cuda-11.1/targets/x86_64-linux/lib/libcudnn_cnn_train.so.8.0.5
/usr/local/cuda-11.1/targets/x86_64-linux/lib/libcudnn_ops_infer.so.8.0.5
/usr/local/cuda-11.1/targets/x86_64-linux/lib/libcudnn_ops_train.so.8.0.5
/usr/local/cuda-11.2/targets/x86_64-linux/lib/libcudnn.so.8.1.1
/usr/local/cuda-11.2/targets/x86_64-linux/lib/libcudnn_adv_infer.so.8.1.1
/usr/local/cuda-11.2/targets/x86_64-linux/lib/libcudnn_adv_train.so.8.1.1
/usr/local/cuda-11.2/targets/x86_64-linux/lib/libcudnn_cnn_infer.so.8.1.1
/usr/local/cuda-11.2/targets/x86_64-linux/lib/libcudnn_cnn_train.so.8.1.1
/usr/local/cuda-11.2/targets/x86_64-linux/lib/libcudnn_ops_infer.so.8.1.1                                                                                                                                                                                     /usr/local/cuda-11.2/targets/x86_64-linux/lib/libcudnn_ops_train.so.8.1.1                                                                                                                                                                                     HIP runtime version: N/A
MIOpen runtime version: N/A
Is XNNPACK available: True

CPU:
Architecture:        x86_64
CPU op-mode(s):      32-bit, 64-bit
Byte Order:          Little Endian
CPU(s):              96
On-line CPU(s) list: 0-95
Thread(s) per core:  2
Core(s) per socket:  24
Socket(s):           2
NUMA node(s):        2
Vendor ID:           GenuineIntel
CPU family:          6
Model:               85
Model name:          Intel(R) Xeon(R) Platinum 8275CL CPU @ 3.00GHz
Stepping:            7
CPU MHz:             1369.306
BogoMIPS:            5999.99
Hypervisor vendor:   KVM
Virtualization type: full
L1d cache:           32K
L1i cache:           32K
L2 cache:            1024K
L3 cache:            36608K
NUMA node0 CPU(s):   0-23,48-71
NUMA node1 CPU(s):   24-47,72-95
Flags:               fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl xtopology nonstop_tsc cpuid aperfmperf tsc_known_freq pni pclmulqdq monitor ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single pti fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves ida arat pku ospke

Versions of relevant libraries:
[pip3] numpy==1.24.1
[pip3] pytorch-triton==2.0.0+c8bfe3f548
[pip3] torch==2.0.0.dev20230220+cu118
[pip3] torchaudio==2.0.0.dev20230222+cu118
[pip3] torchrl==0.0.4+46ec988
[pip3] torchsnapshot==0.1.0
[pip3] torchvision==0.15.0.dev20230221+cu118
[conda] magma-cuda110             2.5.2                         1    pytorch
[conda] mkl                       2022.1.0           hc2b9512_224
[conda] mkl-include               2023.0.0         h84fe81f_26648    conda-forge
[conda] numpy                     1.24.1                   pypi_0    pypi
[conda] pytorch-triton            2.0.0+c8bfe3f548          pypi_0    pypi
[conda] torch                     2.0.0a0+gitd677432           dev_0    &lt;develop&gt;
[conda] torchaudio                2.0.0.dev20230222+cu118          pypi_0    pypi
[conda] torchrl                   0.0.4+46ec988            pypi_0    pypi
[conda] torchsnapshot             0.1.0                    pypi_0    pypi
[conda] torchvision               0.15.0.dev20230221+cu118          pypi_0    pypi
```

cc @mrshenli @pritamdamania87 @zhaojuanmao @satgera @rohan-varma @gqchen @aazzolini @osalpekar @jiayisuse @H-Huang @kwen2501 @awgu @pietern @jjlilley @mrzzd @lw @beauby</span></p>
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