fix: default api port and attention selector

aphrodite/attention/selector.py

@@ -12,7 +12,7 @@
                                     is_openvino, is_tpu, is_xpu)
 from aphrodite.platforms import current_platform
 
-APHRODITE_ATTENTION_BACKEND = "APHRODITE_ATTENTION_BACKEND"
+APHRODITE_ATTENTION_BACKEND = os.getenv("APHRODITE_ATTENTION_BACKEND", None)
 
 
 class _Backend(enum.Enum):
@@ -42,7 +42,9 @@ def get_env_variable_attn_backend() -> Optional[_Backend]:
     '''
     Get the backend override specified by the Aphrodite attention
     backend environment variable, if one is specified.
+
     Returns:
+
     * _Backend enum value if an override is specified
     * None otherwise
     '''
@@ -64,9 +66,12 @@ def get_env_variable_attn_backend() -> Optional[_Backend]:
 def global_force_attn_backend(attn_backend: Optional[_Backend]) -> None:
     '''
     Force all attention operations to use a specified backend.
+
     Passing `None` for the argument re-enables automatic
     backend selection.,
+
     Arguments:
+
     * attn_backend: backend selection (None to revert to auto)
     '''
     global forced_attn_backend
@@ -92,15 +97,14 @@ def get_attn_backend(
     block_size: int,
     is_blocksparse: bool = False,
 ) -> Type[AttentionBackend]:
+    """Selects which attention backend to use and lazily imports it."""
 
     if is_blocksparse:
         logger.info("Using BlocksparseFlashAttention backend.")
         from aphrodite.attention.backends.blocksparse_attn import (
             BlocksparseFlashAttentionBackend)
         return BlocksparseFlashAttentionBackend
-    """Determine which attention backend to use and only import
-    the selected backend module.
-    """
+
     backend = which_attn_to_use(num_heads, head_size, num_kv_heads,
                                 sliding_window, dtype, kv_cache_dtype,
                                 block_size)
@@ -120,12 +124,12 @@ def get_attn_backend(
         return ROCmFlashAttentionBackend
     elif backend == _Backend.TORCH_SDPA:
         assert is_cpu(), RuntimeError(
-            "Torch SDPA backend is only used for CPU devices.")
+            "Torch SDPA backend is only used for the CPU device.")
         logger.info("Using Torch SDPA backend.")
         from aphrodite.attention.backends.torch_sdpa import TorchSDPABackend
         return TorchSDPABackend
     elif backend == _Backend.OPENVINO:
-        logger.info("Using OpenVINO attention backend.")
+        logger.info("Using OpenVINO Attention backend.")
         from aphrodite.attention.backends.openvino import (
             OpenVINOAttentionBackend)
         return OpenVINOAttentionBackend
@@ -157,7 +161,6 @@ def which_attn_to_use(
     block_size: int,
 ) -> _Backend:
     """Returns which flash attention backend to use."""
-
     # Default case.
     selected_backend = _Backend.FLASH_ATTN
 
@@ -174,7 +177,8 @@ def which_attn_to_use(
         # Check the environment variable and override if specified
         backend_by_env_var: Optional[str] = APHRODITE_ATTENTION_BACKEND
         if backend_by_env_var is not None:
-            selected_backend = backend_name_to_enum(backend_by_env_var.upper())
+            selected_backend = backend_name_to_enum(backend_by_env_var)
+
     if is_cpu():
         if selected_backend != _Backend.TORCH_SDPA:
             logger.info(f"Cannot use {selected_backend} backend on CPU.")
@@ -266,9 +270,13 @@ def global_force_attn_backend_context_manager(
     context manager, reverting the global attention backend
     override to its prior state upon exiting the context
     manager.
+
     Arguments:
+
     * attn_backend: attention backend to force
+
     Returns:
+
     * Generator
     '''
 

aphrodite/common/utils.py

@@ -472,7 +472,8 @@ def get_distributed_init_method(ip: str, port: int) -> str:
 def get_open_port(port: Optional[int] = None) -> int:
     if port is None:
         # Default behavior here is to return a port for multi-gpu communication
-        port = int(os.getenv("APHRODITE_PORT", 2242))
+        port = int(os.getenv("APHRODITE_PORT", 0)
+                   ) if "APHRODITE_PORT" in os.environ else None
     if port is not None:
         while True:
             try: