Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/60558
Fixes 1/2 flaky tests as described in: https://github.com/pytorch/pytorch/issues/60260
`test_create_store_timeout_on_server` tests whether trying to create a `c10d::TCPStore` server on an already taken port actually fails with an `IOError`. Prior to this change the `utils.get_socket_with_port()` util method was used to synthetically reserve a port, then try creating the `TCPStore` on that port to validate the `IOError`. The issue with this is that on a dual stack ip setup, `get_socket_with_port()` (since it uses `socket.AF_UNSPEC`) reserves an ipv6 port, while `TCPStore` will try binding to an ipv4 port, so an `IOError` is not observed.
Changing the logic of the test to create two `TCPStore` servers. The first chooses a free port (by passing `server_port=0`) while the second tries to create a `TCPStore` server on the port that the first store is already running on. This would induce an `IOError` on the second store's constructor.
NOTE: this change does not solve another broader issue with `TCPStore` where the server and workers can listen and connect on ipv4 vs ipv6 when they are running on dual-stak ip hosts without ipv4 DNS entry and/or a `/etc/gai.conf` specifying the preferred bind ordering. See: https://github.com/pytorch/pytorch/pull/49124
Test Plan:
```
buck test //caffe2/test/distributed/elastic/utils:distributed_test
```
Reviewed By: cbalioglu
Differential Revision: D29334947
fbshipit-source-id: 76b998c59082cb04c0e86b7a1f3b509367fa0136
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53172
Pull Request resolved: https://github.com/pytorch/elastic/pull/141
Upstreams two modules to torch:
1. `torchelastic.rendezvous`
2. `torchelastic.utils`
These modules were chosen as `[1/n]` since they are the leaf modules in torchelastic.
==== NOTES: ====
1. I'm disabling etcd_rendezvous and etcd_server tests in CIRCLECI for the moment since I need to edit the test dockers to contain the etcd server binary (there's 4-5 test dockers - one for each platform so this is going to take some time for me to set up the environments and test) - T85992919.
2. I've fixed all lint errors on python files but there are ones on the cpp files on the ZeusRendezvous. I took a look at them, and I don't want to fix the linter errors right now for 2 major reasons:
1. Some of them are more than formatting changes (e.g. std::move vs pass by value) and I don't want to introduce bundled changes with the move
1. The old rendezvous code (the one we forked from in caffe2/fb) has the same problems and I think its better for us to deal with this when we deprecate caffe2/fb/rendezvous in favor of the one in torchelastic -T86012579.
Test Plan:
```
buck test mode/dev-nosan //caffe2/torch/distributed/elastic/utils/test/...
buck test mode/dev-nosan //caffe2/torch/distributed/elastic/utils/data/test/...
buck test mode/dev-nosan //caffe2/torch/distributed/elastic/rendezvous/test/...
buck test mode/dev-nosan //caffe2/torch/distributed/elastic/rendezvous/fb/...
buck test mode/dev-nosan //pytorch/elastic/torchelastic/...
```
\+ Sandcastle
Reviewed By: H-Huang
Differential Revision: D26718746
fbshipit-source-id: 67cc0350c3d847221cb3c3038f98f47915362f51
