[serve] Remove SLO code and blist dependency (#10075)

python/ray/serve/router.py

@@ -5,8 +5,6 @@ import time
 from typing import DefaultDict, List
 import pickle
 
-import blist
-
 from ray.exceptions import RayTaskError
 
 import ray
@@ -24,7 +22,6 @@ class Query:
             request_args,
             request_kwargs,
             request_context,
-            request_slo_ms,
             call_method="__call__",
             shard_key=None,
             async_future=None,
@@ -36,10 +33,6 @@ class Query:
 
         self.async_future = async_future
 
-        # Service level objective in milliseconds. This is expected to be the
-        # absolute time since unix epoch.
-        self.request_slo_ms = request_slo_ms
-
         self.call_method = call_method
         self.shard_key = shard_key
         self.is_shadow_query = is_shadow_query
@@ -59,11 +52,6 @@ class Query:
         kwargs = pickle.loads(value)
         return Query(**kwargs)
 
-    # adding comparator fn for maintaining an
-    # ascending order sorted list w.r.t request_slo_ms
-    def __lt__(self, other):
-        return self.request_slo_ms < other.request_slo_ms
-
 
 def _make_future_unwrapper(client_futures: List[asyncio.Future],
                            host_future: asyncio.Future):
@@ -111,7 +99,7 @@ class Router:
         # backend_name -> worker replica tag queue
         self.worker_queues: DefaultDict[deque[str]] = defaultdict(deque)
         # backend_name -> worker payload queue
-        self.backend_queues = defaultdict(blist.sortedlist)
+        self.backend_queues = defaultdict(deque)
 
         # -- Metadata -- #
 
@@ -184,18 +172,11 @@ class Router:
         logger.debug("Received a request for endpoint {}".format(endpoint))
         self.num_router_requests.labels(endpoint=endpoint).add()
 
-        # check if the slo specified is directly the
-        # wall clock time
-        if request_meta.absolute_slo_ms is not None:
-            request_slo_ms = request_meta.absolute_slo_ms
-        else:
-            request_slo_ms = request_meta.adjust_relative_slo_ms()
         request_context = request_meta.request_context
         query = Query(
             request_args,
             request_kwargs,
             request_context,
-            request_slo_ms,
             call_method=request_meta.call_method,
             shard_key=request_meta.shard_key,
             async_future=asyncio.get_event_loop().create_future())
@@ -366,7 +347,7 @@ class Router:
                         backend, curr_queries))
                 continue
 
-            request = buffer_queue.pop(0)
+            request = buffer_queue.pop()
             self.queries_counter[backend][backend_replica_tag] += 1
             future = asyncio.get_event_loop().create_task(
                 self._do_query(backend, backend_replica_tag, request))