Support overrideable jax coordinator port and modify default port for Cloud TPU jax.distributed.initialize()

jax/_src/clusters/cloud_tpu_cluster.py

@@ -26,7 +26,7 @@
 
 # We use an arbitrarily chosen port for the coordinator since we cannot
 # rely on communication to choose one in real time.
-coordinator_port = '8476'
+coordinator_port = '8482'
 
 metadata_response_code_success = 200
 
@@ -95,7 +95,7 @@ def is_env_present(cls) -> bool:
     return False
 
   @classmethod
-  def get_coordinator_address(cls, timeout_secs: int | None) -> str:
+  def get_coordinator_address(cls, timeout_secs: int | None, override_coordinator_port: str | None) -> str:
     # For both GCE via QueuedResources and GKE via JobSet, the
     # Megascale coordinator address is set as the host with process id = 0,
     # so can be used as the jax distributed system coordinator.
@@ -108,7 +108,8 @@ def get_coordinator_address(cls, timeout_secs: int | None) -> str:
     coordinator_address = coordinator_address.split(':')[0]
     logger.debug("TPU Cluster using coordinator address: %s", coordinator_address)
     cls.wait_for_coordinator(coordinator_address, timeout_secs)
-    return f'{coordinator_address}:{coordinator_port}'
+    port = override_coordinator_port or coordinator_port
+    return f'{coordinator_address}:{port}'
 
   @classmethod
   def wait_for_coordinator(cls, coordinator_address, timeout_secs):

jax/_src/clusters/cluster.py

@@ -15,6 +15,7 @@
 from __future__ import annotations
 
 from collections.abc import Sequence
+import os
 import logging
 from jax._src.cloud_tpu_init import running_in_cloud_tpu_vm
 
@@ -69,7 +70,8 @@ def auto_detect_unset_distributed_params(cls,
     if env:
       logger.debug('Initializing distributed JAX environment via %s', env.__name__)
       if coordinator_address is None:
-        coordinator_address = env.get_coordinator_address(timeout_secs=initialization_timeout)
+        coordinator_port = os.environ.get("JAX_COORDINATOR_PORT")
+        coordinator_address = env.get_coordinator_address(timeout_secs=initialization_timeout, override_coordinator_port=coordinator_port)
       if num_processes is None:
         num_processes = env.get_process_count()
       if process_id is None:
@@ -95,7 +97,7 @@ def is_env_present(cls) -> bool:
     raise NotImplementedError("ClusterEnv subclasses must implement is_env_present")
 
   @classmethod
-  def get_coordinator_address(cls, timeout_secs: int | None) -> str:
+  def get_coordinator_address(cls, timeout_secs: int | None, override_coordinator_port: str | None) -> str:
     """Returns address and port used by JAX to bootstrap.
 
     Process id 0 will open a tcp socket at "hostname:port" where

jax/_src/clusters/k8s_cluster.py

@@ -173,7 +173,7 @@ def _controller(cls):
     )
 
   @classmethod
-  def get_coordinator_address(cls, timeout_secs: int | None) -> str:
+  def get_coordinator_address(cls, timeout_secs: int | None, override_coordinator_port: str | None) -> str:
     controller = cls._controller()
     job = cls._job()
     pod = cls._pod()
@@ -254,9 +254,10 @@ def wait_for_host(hostname):
 
           wait_for_host(coordinator_hostname)
 
+      port = override_coordinator_port or cls._coordinator_port
       return '{hostname}:{port}'.format(
         hostname=coordinator_hostname,
-        port=cls._coordinator_port
+        port=port
       )
 
     else:

jax/_src/clusters/mpi4py_cluster.py

@@ -33,7 +33,7 @@ def is_env_present(cls) -> bool:
     return find_spec("mpi4py") is not None
 
   @classmethod
-  def get_coordinator_address(cls, timeout_secs: int | None) -> str:
+  def get_coordinator_address(cls, timeout_secs: int | None, override_coordinator_port: str | None) -> str:
 
     # Using mpi4py, figure out rank 0 and it's hostname.
     # Then broadcast the hostname and port.
@@ -49,8 +49,11 @@ def get_coordinator_address(cls, timeout_secs: int | None) -> str:
         # Order all the hostnames, and find unique ones
         hostname = socket.gethostname()
 
-        # Apparently, we want to pick a port in an ephemeral range...
-        port_id = hash(hostname) % 2**12 + (65535 - 2**12 + 1)
+        if override_coordinator_port:
+            port_id = override_coordinator_port
+        else:
+            # Apparently, we want to pick a port in an ephemeral range...
+            port_id = str(hash(hostname) % 2**12 + (65535 - 2**12 + 1))
 
         hostname = f'{hostname}:{port_id}'
 

jax/_src/clusters/ompi_cluster.py

@@ -33,17 +33,20 @@ def is_env_present(cls) -> bool:
     return _ORTE_URI in os.environ
 
   @classmethod
-  def get_coordinator_address(cls, timeout_secs: int | None) -> str:
+  def get_coordinator_address(cls, timeout_secs: int | None, override_coordinator_port: str | None) -> str:
     # Examples of orte_uri:
     # 1531576320.0;tcp://10.96.0.1,10.148.0.1,10.108.0.1:34911
     # 1314521088.0;tcp6://[fe80::b9b:ac5d:9cf0:b858,2620:10d:c083:150e::3000:2]:43370
     orte_uri = os.environ[_ORTE_URI]
-    job_id_str = orte_uri.split('.', maxsplit=1)[0]
-    # The jobid is always a multiple of 2^12, let's divide it by 2^12
-    # to reduce likelihood of port conflict between jobs
-    job_id = int(job_id_str) // 2**12
-    # Pick port in ephemeral range [(65535 - 2^12 + 1), 65535]
-    port = job_id % 2**12 + (65535 - 2**12 + 1)
+    if override_coordinator_port:
+        port = override_coordinator_port
+    else:
+        job_id_str = orte_uri.split('.', maxsplit=1)[0]
+        # The jobid is always a multiple of 2^12, let's divide it by 2^12
+        # to reduce likelihood of port conflict between jobs
+        job_id = int(job_id_str) // 2**12
+        # Pick port in ephemeral range [(65535 - 2^12 + 1), 65535]
+        port = str(job_id % 2**12 + (65535 - 2**12 + 1))
     launcher_ip_match = re.search(r"tcp://(.+?)[,:]|tcp6://\[(.+?)[,\]]", orte_uri)
     if launcher_ip_match is None:
         raise RuntimeError('Could not parse coordinator IP address from Open MPI environment.')

jax/_src/clusters/slurm_cluster.py

@@ -34,9 +34,12 @@ def is_env_present(cls) -> bool:
                (_JOBID_PARAM, _NODE_LIST, _PROCESS_COUNT, _PROCESS_ID, _LOCAL_PROCESS_ID))
 
   @classmethod
-  def get_coordinator_address(cls, timeout_secs: int | None) -> str:
-    # Pick port in ephemeral range [(65535 - 2^12 + 1), 65535]
-    port = int(os.environ[_JOBID_PARAM]) % 2**12 + (65535 - 2**12 + 1)
+  def get_coordinator_address(cls, timeout_secs: int | None, override_coordinator_port: str | None) -> str:
+    if override_coordinator_port:
+        port = override_coordinator_port
+    else:
+        # Pick port in ephemeral range [(65535 - 2^12 + 1), 65535]
+        port = str(int(os.environ[_JOBID_PARAM]) % 2**12 + (65535 - 2**12 + 1))
 
     # Parse the first hostname of the job
     # If we are looking for 'node001',