[BugFix][EPD] fix embedding req_id transfer error (#23481)

python/sglang/srt/disaggregation/encode_receiver.py

@@ -343,7 +343,12 @@ class MultiModalEmbeddingData(EmbeddingData):
         return kwargs
 
     def add(self, embedding_data: EmbeddingData):
-        assert self.req_id == embedding_data.req_id
+        if self.req_id != embedding_data.req_id:
+            logger.warning(
+                f"Dropping embedding data with mismatched req_id: "
+                f"expected {self.req_id}, got {embedding_data.req_id}"
+            )
+            return False
         assert not self.ready_list[embedding_data.part_idx]
         pid = embedding_data.part_idx
         self.ready_list[pid] = True
@@ -521,6 +526,17 @@ class WaitingImageRequest:
                 self.recv_socket.close()
                 return
 
+            # Extract original req_id from part_req_id and drop stale payloads
+            # that may arrive on a reused ZMQ port after a prior request aborted.
+            original_req_id = extract_original_req_id(recv_obj.req_id)
+            if original_req_id != self.recv_req.rid:
+                logger.warning(
+                    f"Dropping stale embedding data: expected rid={self.recv_req.rid}, "
+                    f"got rid={recv_obj.req_id} (likely from ZMQ port reuse)"
+                )
+                continue
+            recv_obj.req_id = original_req_id
+
             buffer = parts[1].buffer if hasattr(parts[1], "buffer") else parts[1]
             recv_obj.embedding = (
                 torch.frombuffer(buffer, dtype=recv_obj.dtype)
@@ -528,12 +544,6 @@ class WaitingImageRequest:
                 .clone()
             )
 
-            # Extract original req_id from part_req_id
-            part_req_id = recv_obj.req_id
-            original_req_id = extract_original_req_id(part_req_id)
-            # Update recv_obj.req_id to original for aggregation
-            recv_obj.req_id = original_req_id
-
             if self.recv_embedding_data is None:
                 self.recv_embedding_data = MultiModalEmbeddingData.from_embedding_data(
                     recv_obj