(rendezvous-api)=

Rendezvous

{eval-rst}

.. automodule:: torch.distributed.elastic.rendezvous

Below is a state diagram describing how rendezvous works.

Registry

{eval-rst}

.. autoclass:: RendezvousParameters
   :members:

.. autoclass:: RendezvousHandlerRegistry

.. automodule:: torch.distributed.elastic.rendezvous.registry

.. autofunction:: torch.distributed.elastic.rendezvous.registry.get_rendezvous_handler

Handler

{eval-rst}

.. currentmodule:: torch.distributed.elastic.rendezvous

.. autoclass:: RendezvousHandler
   :members:

Dataclasses

{eval-rst}

.. autoclass:: RendezvousInfo

.. currentmodule:: torch.distributed.elastic.rendezvous.api

.. autoclass:: RendezvousStoreInfo

   .. automethod:: build(rank, store)

Exceptions

{eval-rst}

.. autoclass:: RendezvousError
.. autoclass:: RendezvousClosedError
.. autoclass:: RendezvousTimeoutError
.. autoclass:: RendezvousConnectionError
.. autoclass:: RendezvousStateError
.. autoclass:: RendezvousGracefulExitError

Implementations

Dynamic Rendezvous

{eval-rst}

.. currentmodule:: torch.distributed.elastic.rendezvous.dynamic_rendezvous

.. autofunction:: create_handler

.. autoclass:: DynamicRendezvousHandler()
   :members: from_backend

.. autoclass:: RendezvousBackend
   :members:

.. autoclass:: RendezvousTimeout
   :members:

C10d Backend

{eval-rst}

.. currentmodule:: torch.distributed.elastic.rendezvous.c10d_rendezvous_backend

.. autofunction:: create_backend

.. autoclass:: C10dRendezvousBackend
   :members:

Etcd Backend

{eval-rst}

.. currentmodule:: torch.distributed.elastic.rendezvous.etcd_rendezvous_backend

.. autofunction:: create_backend

.. autoclass:: EtcdRendezvousBackend
   :members:

Etcd Rendezvous (Legacy)

{warning}

The `DynamicRendezvousHandler` class supersedes the `EtcdRendezvousHandler`
class, and is recommended for most users. `EtcdRendezvousHandler` is in
maintenance mode and will be deprecated in the future.

{eval-rst}

.. currentmodule:: torch.distributed.elastic.rendezvous.etcd_rendezvous

.. autoclass:: EtcdRendezvousHandler

Etcd Store

The EtcdStore is the C10d Store instance type returned by next_rendezvous() when etcd is used as the rendezvous backend.

{eval-rst}

.. currentmodule:: torch.distributed.elastic.rendezvous.etcd_store

.. autoclass:: EtcdStore
   :members:

Etcd Server

The EtcdServer is a convenience class that makes it easy for you to start and stop an etcd server on a subprocess. This is useful for testing or single-node (multi-worker) deployments where manually setting up an etcd server on the side is cumbersome.

{warning}

For production and multi-node deployments please consider properly deploying
a highly available etcd server as this is the single point of failure for your
distributed jobs.

{eval-rst}

.. currentmodule:: torch.distributed.elastic.rendezvous.etcd_server

.. autoclass:: EtcdServer