[P/D] Support ipv6 in P/D scenario (#7858)

Co-authored-by: Shangming Cai <caishangming@linux.alibaba.com>

python/sglang/srt/disaggregation/common/conn.py

@@ -23,7 +23,14 @@ from sglang.srt.disaggregation.base.conn import (
 )
 from sglang.srt.disaggregation.utils import DisaggregationMode
 from sglang.srt.server_args import ServerArgs
-from sglang.srt.utils import get_free_port, get_ip, get_local_ip_by_remote
+from sglang.srt.utils import (
+    format_tcp_address,
+    get_free_port,
+    get_ip,
+    get_local_ip_by_remote,
+    is_valid_ipv6_address,
+    maybe_wrap_ipv6_address,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -65,11 +72,18 @@ class CommonKVManager(BaseKVManager):
     def _register_to_bootstrap(self):
         """Register KVSender to bootstrap server via HTTP POST."""
         if self.dist_init_addr:
-            ip_address = socket.gethostbyname(self.dist_init_addr.split(":")[0])
+            if self.dist_init_addr.startswith("["):  # [ipv6]:port or [ipv6]
+                if self.dist_init_addr.endswith("]"):
+                    host = self.dist_init_addr
+                else:
+                    host, _ = self.dist_init_addr.rsplit(":", 1)
+            else:
+                host = socket.gethostbyname(self.dist_init_addr.rsplit(":", 1)[0])
         else:
-            ip_address = get_ip()
+            host = get_ip()
+            host = maybe_wrap_ipv6_address(host)
 
-        bootstrap_server_url = f"{ip_address}:{self.bootstrap_port}"
+        bootstrap_server_url = f"{host}:{self.bootstrap_port}"
         url = f"http://{bootstrap_server_url}/route"
         payload = {
             "role": "Prefill",
@@ -92,8 +106,10 @@ class CommonKVManager(BaseKVManager):
             logger.error(f"Prefill Failed to register to bootstrap server: {e}")
 
     @cache
-    def _connect(self, endpoint: str):
+    def _connect(self, endpoint: str, is_ipv6: bool = False):
         socket = zmq.Context().socket(zmq.PUSH)
+        if is_ipv6:
+            socket.setsockopt(zmq.IPV6, 1)
         socket.connect(endpoint)
         return socket
 
@@ -263,15 +279,27 @@ class CommonKVReceiver(BaseKVReceiver):
             return None
 
     @classmethod
-    def _connect(cls, endpoint: str):
+    def _connect(cls, endpoint: str, is_ipv6: bool = False):
         with cls._global_lock:
             if endpoint not in cls._socket_cache:
                 sock = cls._ctx.socket(zmq.PUSH)
+                if is_ipv6:
+                    sock.setsockopt(zmq.IPV6, 1)
                 sock.connect(endpoint)
                 cls._socket_cache[endpoint] = sock
                 cls._socket_locks[endpoint] = threading.Lock()
             return cls._socket_cache[endpoint], cls._socket_locks[endpoint]
 
+    @classmethod
+    def _connect_to_bootstrap_server(cls, bootstrap_info: dict):
+        ip_address = bootstrap_info["rank_ip"]
+        port = bootstrap_info["rank_port"]
+        is_ipv6_address = is_valid_ipv6_address(ip_address)
+        sock, lock = cls._connect(
+            format_tcp_address(ip_address, port), is_ipv6=is_ipv6_address
+        )
+        return sock, lock
+
     def _register_kv_args(self):
         pass
 

python/sglang/srt/disaggregation/mini_lb.py

@@ -17,6 +17,7 @@ from fastapi import FastAPI, HTTPException
 from fastapi.responses import ORJSONResponse, Response, StreamingResponse
 
 from sglang.srt.disaggregation.utils import PDRegistryRequest
+from sglang.srt.utils import maybe_wrap_ipv6_address
 
 AIOHTTP_STREAM_READ_CHUNK_SIZE = (
     1024 * 64
@@ -271,7 +272,7 @@ async def handle_generate_request(request_data: dict):
 
     # Parse and transform prefill_server for bootstrap data
     parsed_url = urllib.parse.urlparse(prefill_server)
-    hostname = parsed_url.hostname
+    hostname = maybe_wrap_ipv6_address(parsed_url.hostname)
     modified_request = request_data.copy()
 
     batch_size = _get_request_batch_size(modified_request)
@@ -309,7 +310,7 @@ async def _forward_to_backend(request_data: dict, endpoint_name: str):
 
     # Parse and transform prefill_server for bootstrap data
     parsed_url = urllib.parse.urlparse(prefill_server)
-    hostname = parsed_url.hostname
+    hostname = maybe_wrap_ipv6_address(parsed_url.hostname)
     modified_request = request_data.copy()
     modified_request.update(
         {

python/sglang/srt/disaggregation/mooncake/conn.py

@@ -35,7 +35,15 @@ from sglang.srt.disaggregation.common.utils import (
 from sglang.srt.disaggregation.mooncake.transfer_engine import MooncakeTransferEngine
 from sglang.srt.disaggregation.utils import DisaggregationMode
 from sglang.srt.server_args import ServerArgs
-from sglang.srt.utils import get_free_port, get_int_env_var, get_ip, get_local_ip_auto
+from sglang.srt.utils import (
+    format_tcp_address,
+    get_free_port,
+    get_int_env_var,
+    get_ip,
+    get_local_ip_auto,
+    is_valid_ipv6_address,
+    maybe_wrap_ipv6_address,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -148,6 +156,9 @@ class MooncakeKVManager(BaseKVManager):
         self.request_status: Dict[int, KVPoll] = {}
         self.rank_port = None
         self.server_socket = zmq.Context().socket(zmq.PULL)
+        if is_valid_ipv6_address(self.local_ip):
+            self.server_socket.setsockopt(zmq.IPV6, 1)
+
         self.register_buffer_to_engine()
         if self.disaggregation_mode == DisaggregationMode.PREFILL:
             self.transfer_infos: Dict[int, Dict[str, TransferInfo]] = {}
@@ -240,8 +251,10 @@ class MooncakeKVManager(BaseKVManager):
             self.engine.register(aux_data_ptr, aux_data_len)
 
     @cache
-    def _connect(self, endpoint: str):
+    def _connect(self, endpoint: str, is_ipv6: bool = False):
         socket = zmq.Context().socket(zmq.PUSH)
+        if is_ipv6:
+            socket.setsockopt(zmq.IPV6, 1)
         socket.connect(endpoint)
         return socket
 
@@ -471,9 +484,9 @@ class MooncakeKVManager(BaseKVManager):
     def sync_status_to_decode_endpoint(
         self, remote: str, dst_port: int, room: int, status: int, prefill_rank: int
     ):
-        if ":" in remote:
+        self._connect(
-            remote = remote.split(":")[0]
+            format_tcp_address(remote, dst_port), is_ipv6=is_valid_ipv6_address(remote)
-        self._connect("tcp://" + remote + ":" + str(dst_port)).send_multipart(
+        ).send_multipart(
             [
                 str(room).encode("ascii"),
                 str(status).encode("ascii"),
@@ -616,9 +629,12 @@ class MooncakeKVManager(BaseKVManager):
                     f"Transfer thread failed because of {e}. Prefill instance with bootstrap_port={self.bootstrap_port} is dead."
                 )
 
+    def _bind_server_socket(self):
+        self.server_socket.bind(format_tcp_address(self.local_ip, self.rank_port))
+
     def start_prefill_thread(self):
         self.rank_port = get_free_port()
-        self.server_socket.bind(f"tcp://{self.local_ip}:{self.rank_port}")
+        self._bind_server_socket()
 
         def bootstrap_thread():
             """This thread recvs pre-alloc notification from the decode engine"""
@@ -657,7 +673,7 @@ class MooncakeKVManager(BaseKVManager):
 
     def start_decode_thread(self):
         self.rank_port = get_free_port()
-        self.server_socket.bind(f"tcp://{self.local_ip}:{self.rank_port}")
+        self._bind_server_socket()
 
         def decode_thread():
             while True:
@@ -776,7 +792,7 @@ class MooncakeKVManager(BaseKVManager):
         # requests with the same dst_sessions will be added into the same
         # queue, which enables early abort with failed sessions.
         dst_infos = self.transfer_infos[bootstrap_room].keys()
-        session_port_sum = sum(int(session.split(":")[1]) for session in dst_infos)
+        session_port_sum = sum(int(session.rsplit(":", 1)[1]) for session in dst_infos)
         shard_idx = session_port_sum % len(self.transfer_queues)
 
         self.transfer_queues[shard_idx].put(
@@ -814,11 +830,18 @@ class MooncakeKVManager(BaseKVManager):
     def _register_to_bootstrap(self):
         """Register KVSender to bootstrap server via HTTP POST."""
         if self.dist_init_addr:
-            ip_address = socket.gethostbyname(self.dist_init_addr.split(":")[0])
+            if self.dist_init_addr.startswith("["):  # [ipv6]:port or [ipv6]
+                if self.dist_init_addr.endswith("]"):
+                    host = self.dist_init_addr
+                else:
+                    host, _ = self.dist_init_addr.rsplit(":", 1)
+            else:
+                host = socket.gethostbyname(self.dist_init_addr.rsplit(":", 1)[0])
         else:
-            ip_address = get_ip()
+            host = get_ip()
+            host = maybe_wrap_ipv6_address(host)
 
-        bootstrap_server_url = f"{ip_address}:{self.bootstrap_port}"
+        bootstrap_server_url = f"{host}:{self.bootstrap_port}"
         url = f"http://{bootstrap_server_url}/route"
         payload = {
             "role": "Prefill",
@@ -1163,9 +1186,6 @@ class MooncakeKVReceiver(BaseKVReceiver):
 
     def _register_kv_args(self):
         for bootstrap_info in self.bootstrap_infos:
-            self.prefill_server_url = (
-                f"{bootstrap_info['rank_ip']}:{bootstrap_info['rank_port']}"
-            )
             packed_kv_data_ptrs = b"".join(
                 struct.pack("Q", ptr) for ptr in self.kv_mgr.kv_args.kv_data_ptrs
             )
@@ -1179,7 +1199,7 @@ class MooncakeKVReceiver(BaseKVReceiver):
             dst_tp_size = str(tp_size).encode("ascii")
             dst_kv_item_len = str(kv_item_len).encode("ascii")
 
-            sock, lock = self._connect("tcp://" + self.prefill_server_url)
+            sock, lock = self._connect_to_bootstrap_server(bootstrap_info)
             with lock:
                 sock.send_multipart(
                     [
@@ -1196,23 +1216,32 @@ class MooncakeKVReceiver(BaseKVReceiver):
                 )
 
     @classmethod
-    def _connect(cls, endpoint: str):
+    def _connect(cls, endpoint: str, is_ipv6: bool = False):
         with cls._global_lock:
             if endpoint not in cls._socket_cache:
                 sock = cls._ctx.socket(zmq.PUSH)
+                if is_ipv6:
+                    sock.setsockopt(zmq.IPV6, 1)
                 sock.connect(endpoint)
                 cls._socket_cache[endpoint] = sock
                 cls._socket_locks[endpoint] = threading.Lock()
             return cls._socket_cache[endpoint], cls._socket_locks[endpoint]
 
+    @classmethod
+    def _connect_to_bootstrap_server(cls, bootstrap_info: dict):
+        ip_address = bootstrap_info["rank_ip"]
+        port = bootstrap_info["rank_port"]
+        is_ipv6_address = is_valid_ipv6_address(ip_address)
+        sock, lock = cls._connect(
+            format_tcp_address(ip_address, port), is_ipv6=is_ipv6_address
+        )
+        return sock, lock
+
     def init(self, kv_indices: npt.NDArray[np.int32], aux_index: Optional[int] = None):
         for bootstrap_info in self.bootstrap_infos:
-            self.prefill_server_url = (
+            sock, lock = self._connect_to_bootstrap_server(bootstrap_info)
-                f"{bootstrap_info['rank_ip']}:{bootstrap_info['rank_port']}"
-            )
             is_dummy = bootstrap_info["is_dummy"]
 
-            sock, lock = self._connect("tcp://" + self.prefill_server_url)
             with lock:
                 sock.send_multipart(
                     [

python/sglang/srt/disaggregation/mooncake/transfer_engine.py

@@ -1,7 +1,7 @@
 import logging
 from typing import List, Optional
 
-from sglang.srt.utils import get_bool_env_var, get_free_port
+from sglang.srt.utils import get_bool_env_var, get_free_port, maybe_wrap_ipv6_address
 
 logger = logging.getLogger(__name__)
 
@@ -27,7 +27,9 @@ class MooncakeTransferEngine:
             hostname=self.hostname,
             device_name=self.ib_device,
         )
-        self.session_id = f"{self.hostname}:{self.engine.get_rpc_port()}"
+        self.session_id = (
+            f"{maybe_wrap_ipv6_address(self.hostname)}:{self.engine.get_rpc_port()}"
+        )
 
     def register(self, ptr, length):
         try:

python/sglang/srt/disaggregation/nixl/conn.py

@@ -27,7 +27,11 @@ from sglang.srt.disaggregation.common.conn import (
 from sglang.srt.disaggregation.common.utils import group_concurrent_contiguous
 from sglang.srt.disaggregation.utils import DisaggregationMode
 from sglang.srt.server_args import ServerArgs
-from sglang.srt.utils import get_local_ip_by_remote
+from sglang.srt.utils import (
+    format_tcp_address,
+    get_local_ip_auto,
+    is_valid_ipv6_address,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -124,7 +128,10 @@ class NixlKVManager(CommonKVManager):
                 "to run SGLang with NixlTransferEngine."
             ) from e
         self.agent = nixl_agent(str(uuid.uuid4()))
+        self.local_ip = get_local_ip_auto()
         self.server_socket = zmq.Context().socket(zmq.PULL)
+        if is_valid_ipv6_address(self.local_ip):
+            self.server_socket.setsockopt(zmq.IPV6, 1)
         self.register_buffer_to_engine()
 
         if self.disaggregation_mode == DisaggregationMode.PREFILL:
@@ -337,8 +344,11 @@ class NixlKVManager(CommonKVManager):
             return False
         return self.transfer_statuses[room].is_done()
 
+    def _bind_server_socket(self):
+        self.server_socket.bind(format_tcp_address(self.local_ip, self.rank_port))
+
     def _start_bootstrap_thread(self):
-        self.server_socket.bind(f"tcp://{get_local_ip_by_remote()}:{self.rank_port}")
+        self._bind_server_socket()
 
         def bootstrap_thread():
             """This thread recvs transfer info from the decode engine"""
@@ -452,23 +462,20 @@ class NixlKVReceiver(CommonKVReceiver):
 
     def init(self, kv_indices: npt.NDArray[np.int32], aux_index: Optional[int] = None):
         for bootstrap_info in self.bootstrap_infos:
-            self.prefill_server_url = (
-                f"{bootstrap_info['rank_ip']}:{bootstrap_info['rank_port']}"
-            )
             logger.debug(
                 f"Fetched bootstrap info: {bootstrap_info} for engine rank: {self.kv_mgr.kv_args.engine_rank}"
             )
+            sock, lock = self._connect_to_bootstrap_server(bootstrap_info)
             is_dummy = bootstrap_info["is_dummy"]
             logger.debug(
-                f"Sending to {self.prefill_server_url} with bootstrap room {self.bootstrap_room} {is_dummy=}"
+                f"Sending to prefill server with bootstrap room {self.bootstrap_room} {is_dummy=}"
             )
-            sock, lock = self._connect("tcp://" + self.prefill_server_url)
             with lock:
                 sock.send_multipart(
                     [
                         GUARD,
                         str(self.bootstrap_room).encode("ascii"),
-                        get_local_ip_by_remote().encode("ascii"),
+                        self.kv_mgr.local_ip.encode("ascii"),
                         str(self.kv_mgr.rank_port).encode("ascii"),
                         self.kv_mgr.agent.name.encode("ascii"),
                         kv_indices.tobytes() if not is_dummy else b"",
@@ -494,9 +501,7 @@ class NixlKVReceiver(CommonKVReceiver):
 
     def _register_kv_args(self):
         for bootstrap_info in self.bootstrap_infos:
-            self.prefill_server_url = (
+            sock, lock = self._connect_to_bootstrap_server(bootstrap_info)
-                f"{bootstrap_info['rank_ip']}:{bootstrap_info['rank_port']}"
-            )
             packed_kv_data_ptrs = b"".join(
                 struct.pack("Q", ptr) for ptr in self.kv_mgr.kv_args.kv_data_ptrs
             )
@@ -504,13 +509,12 @@ class NixlKVReceiver(CommonKVReceiver):
                 struct.pack("Q", ptr) for ptr in self.kv_mgr.kv_args.aux_data_ptrs
             )
 
-            sock, lock = self._connect("tcp://" + self.prefill_server_url)
             with lock:
                 sock.send_multipart(
                     [
                         GUARD,
                         "None".encode("ascii"),
-                        get_local_ip_by_remote().encode("ascii"),
+                        self.kv_mgr.local_ip.encode("ascii"),
                         str(self.kv_mgr.rank_port).encode("ascii"),
                         self.kv_mgr.agent.name.encode("ascii"),
                         self.kv_mgr.agent.get_agent_metadata(),

python/sglang/srt/distributed/device_communicators/shm_broadcast.py

@@ -16,7 +16,12 @@ from torch.distributed import ProcessGroup
 from zmq import IPV6  # type: ignore
 from zmq import SUB, SUBSCRIBE, XPUB, XPUB_VERBOSE, Context  # type: ignore
 
-from sglang.srt.utils import get_ip, get_open_port, is_valid_ipv6_address
+from sglang.srt.utils import (
+    format_tcp_address,
+    get_ip,
+    get_open_port,
+    is_valid_ipv6_address,
+)
 
 # SGLANG_RINGBUFFER_WARNING_INTERVAL can be set to 60
 SGLANG_RINGBUFFER_WARNING_INTERVAL = int(
@@ -225,9 +230,9 @@ class MessageQueue:
             remote_subscribe_port = get_open_port()
             if is_valid_ipv6_address(connect_ip):
                 self.remote_socket.setsockopt(IPV6, 1)
-                connect_ip = f"[{connect_ip}]"
+            self.remote_socket.bind(
-            socket_addr = f"tcp://{connect_ip}:{remote_subscribe_port}"
+                format_tcp_address(connect_ip, remote_subscribe_port)
-            self.remote_socket.bind(socket_addr)
+            )
 
         else:
             remote_subscribe_port = None
@@ -288,7 +293,9 @@ class MessageQueue:
             self.remote_socket.setsockopt_string(SUBSCRIBE, "")
             if is_valid_ipv6_address(handle.connect_ip):
                 self.remote_socket.setsockopt(IPV6, 1)
-            socket_addr = f"tcp://{handle.connect_ip}:{handle.remote_subscribe_port}"
+            socket_addr = format_tcp_address(
+                handle.connect_ip, handle.remote_subscribe_port
+            )
             logger.debug("Connecting to %s", socket_addr)
             self.remote_socket.connect(socket_addr)
 

python/sglang/srt/utils.py

@@ -2065,6 +2065,16 @@ def is_valid_ipv6_address(address: str) -> bool:
         return False
 
 
+def maybe_wrap_ipv6_address(address: str) -> str:
+    if is_valid_ipv6_address(address):
+        return f"[{address}]"
+    return address
+
+
+def format_tcp_address(ip: str, port: int) -> str:
+    return f"tcp://{maybe_wrap_ipv6_address(ip)}:{port}"
+
+
 def configure_ipv6(dist_init_addr):
     addr = dist_init_addr
     end = addr.find("]")