feat: add new metrics and simple router cost fn (#88)

components/metrics/src/bin/mock_worker.rs

@@ -112,11 +112,17 @@ fn mock_stats_handler(_stats: Stats) -> serde_json::Value {
     let request_active_slots = rand::thread_rng().gen_range(0..=request_total_slots);
     let kv_total_blocks = 100;
     let kv_active_blocks = rand::thread_rng().gen_range(0..=kv_total_blocks);
+    let num_requests_waiting = rand::thread_rng().gen_range(0..=100);
+    let gpu_cache_usage_perc = rand::thread_rng().gen_range(0.0..=1.0);
+    let gpu_prefix_cache_hit_rate = rand::thread_rng().gen_range(0.0..=1.0);
     let stats = ForwardPassMetrics {
         request_active_slots,
         request_total_slots,
         kv_active_blocks,
         kv_total_blocks,
+        num_requests_waiting,
+        gpu_cache_usage_perc,
+        gpu_prefix_cache_hit_rate,
     };
     println!("stats out: {:?}", stats);
     serde_json::to_value(stats).unwrap()

container/deps/vllm/vllm_v0.7.2-dynamo-kv-disagg-patch.patch

@@ -2990,7 +2990,7 @@ index 3cf1850e..ae006579 100644
 +    gpu_cache_usage_perc: float
 +    gpu_prefix_cache_hit_rate: float
 diff --git a/vllm/engine/multiprocessing/client.py b/vllm/engine/multiprocessing/client.py
-index 85b5f31e..fe719642 100644
+index 85b5f31e..05030292 100644
 --- a/vllm/engine/multiprocessing/client.py
 +++ b/vllm/engine/multiprocessing/client.py
 @@ -8,6 +8,7 @@ from typing import (Any, AsyncGenerator, Dict, Iterator, List, Mapping,
@@ -3084,7 +3084,7 @@ index 85b5f31e..fe719642 100644
      @staticmethod
      def is_unsupported_config(engine_args: AsyncEngineArgs):
          # Pipeline parallel not yet supported
-@@ -180,6 +210,63 @@ class MQLLMEngineClient(EngineClient):
+@@ -180,6 +210,61 @@ class MQLLMEngineClient(EngineClient):
          except Exception as e:
              self._set_errored(e)
  
@@ -3118,8 +3118,9 @@ index 85b5f31e..fe719642 100644
 +                    # Metrics received- check the message
 +                    message: Frame = await self.metrics_socket.recv(copy=False)
 +                    metrics = pickle.loads(message.buffer)
-+                    if self.metrics_publisher is not None:
-+                        if isinstance(metrics, KvMetrics):
++                    if self.metrics_publisher is not None and isinstance(
++                        metrics, KvMetrics
++                    ):
 +                        self.metrics_publisher.publish(metrics.request_active_slots,
 +                                                    metrics.request_total_slots,
 +                                                    metrics.kv_active_blocks,
@@ -3127,13 +3128,10 @@ index 85b5f31e..fe719642 100644
 +                                                    metrics.num_requests_waiting, 
 +                                                    metrics.gpu_cache_usage_perc, 
 +                                                    metrics.gpu_prefix_cache_hit_rate)
-+                        if isinstance(metrics, Stats):
-+                            # TODO
-+                            # Send the whole stats to user
-+                            pass
-+
 +                        logger.debug("Metrics successful.")
 +
++                    # TODO: Investigate sending whole stats object
++
 +        except asyncio.CancelledError:
 +            logger.debug("Shutting down MQLLMEngineClient check metrics loop.")
 +
@@ -3148,7 +3146,7 @@ index 85b5f31e..fe719642 100644
      async def run_output_handler_loop(self):
          """Get RequestOutputs from Engine and stream to Request Queues"""
  
-@@ -278,12 +365,26 @@ class MQLLMEngineClient(EngineClient):
+@@ -278,12 +363,26 @@ class MQLLMEngineClient(EngineClient):
              # Wait until server is ready.
              response = await self._wait_for_server_rpc(socket)
  
@@ -3175,7 +3173,7 @@ index 85b5f31e..fe719642 100644
  
      def close(self):
          """Destroy the ZeroMQ Context."""
-@@ -293,6 +394,8 @@ class MQLLMEngineClient(EngineClient):
+@@ -293,6 +392,8 @@ class MQLLMEngineClient(EngineClient):
          # Cancel background tasks.
          if self.health_loop is not None:
              self.health_loop.cancel()
@@ -3184,7 +3182,7 @@ index 85b5f31e..fe719642 100644
          if self.output_loop is not None:
              self.output_loop.cancel()
  
-@@ -415,6 +518,9 @@ class MQLLMEngineClient(EngineClient):
+@@ -415,6 +516,9 @@ class MQLLMEngineClient(EngineClient):
          """
          if self._errored_with is not None:
              raise self._errored_with
@@ -3194,7 +3192,7 @@ index 85b5f31e..fe719642 100644
  
      @property
      def is_running(self) -> bool:
-@@ -473,6 +579,7 @@ class MQLLMEngineClient(EngineClient):
+@@ -473,6 +577,7 @@ class MQLLMEngineClient(EngineClient):
          trace_headers: Optional[Mapping[str, str]] = None,
          prompt_adapter_request: Optional[PromptAdapterRequest] = None,
          priority: int = 0,
@@ -3202,7 +3200,7 @@ index 85b5f31e..fe719642 100644
          *,
          inputs: Optional[PromptType] = None  # DEPRECATED
      ) -> AsyncGenerator[RequestOutput, None]:
-@@ -502,7 +609,8 @@ class MQLLMEngineClient(EngineClient):
+@@ -502,7 +607,8 @@ class MQLLMEngineClient(EngineClient):
  
          return self._process_request(prompt, sampling_params, request_id,
                                       lora_request, trace_headers,
@@ -3212,7 +3210,7 @@ index 85b5f31e..fe719642 100644
  
      @overload
      def encode(
-@@ -586,6 +694,7 @@ class MQLLMEngineClient(EngineClient):
+@@ -586,6 +692,7 @@ class MQLLMEngineClient(EngineClient):
          trace_headers: Optional[Mapping[str, str]] = None,
          prompt_adapter_request: Optional[PromptAdapterRequest] = None,
          priority: int = 0,
@@ -3220,7 +3218,7 @@ index 85b5f31e..fe719642 100644
      ) -> Union[AsyncGenerator[RequestOutput, None], AsyncGenerator[
              PoolingRequestOutput, None]]:
          """Send an RPCGenerateRequest to the RPCServer and stream responses."""
-@@ -630,6 +739,12 @@ class MQLLMEngineClient(EngineClient):
+@@ -630,6 +737,12 @@ class MQLLMEngineClient(EngineClient):
              else:
                  lp_bytes = None
  
@@ -3233,7 +3231,7 @@ index 85b5f31e..fe719642 100644
              request_bytes = pickle.dumps(
                  RPCProcessRequest(
                      prompt=prompt,
-@@ -639,11 +754,11 @@ class MQLLMEngineClient(EngineClient):
+@@ -639,11 +752,11 @@ class MQLLMEngineClient(EngineClient):
                      trace_headers=trace_headers,
                      prompt_adapter_request=prompt_adapter_request,
                      priority=priority,
@@ -3247,7 +3245,7 @@ index 85b5f31e..fe719642 100644
              await self.input_socket.send_multipart(parts, copy=False)
  
              # 4) Stream the RequestOutputs from the output queue. Note
-@@ -705,3 +820,6 @@ class MQLLMEngineClient(EngineClient):
+@@ -705,3 +818,6 @@ class MQLLMEngineClient(EngineClient):
          # Raise on error, otherwise happily return None
          if isinstance(request_output, BaseException):
              raise request_output
@@ -3255,7 +3253,7 @@ index 85b5f31e..fe719642 100644
 +    def set_metrics_publisher(self, metrics_publisher):
 +        self.metrics_publisher = metrics_publisher
 diff --git a/vllm/engine/multiprocessing/engine.py b/vllm/engine/multiprocessing/engine.py
-index a0dd7958..3204cfb8 100644
+index a0dd7958..c82bc15b 100644
 --- a/vllm/engine/multiprocessing/engine.py
 +++ b/vllm/engine/multiprocessing/engine.py
 @@ -3,35 +3,115 @@
@@ -3355,23 +3353,23 @@ index a0dd7958..3204cfb8 100644
 +            self.metrics_socket.send_multipart((metrics_bytes, ), copy=False)
 +
 +# TODO: Send entire stats object to the client
-+class StatLogger(StatLoggerBase):
-+    def __init__(
-+        self,
-+        metrics_socket
-+    ):
-+        self.metrics_socket = metrics_socket
++# class StatLogger(StatLoggerBase):
++#     def __init__(
++#         self,
++#         metrics_socket
++#     ):
++#         self.metrics_socket = metrics_socket
 +
-+    def log(self, stats: Stats) -> None:
-+        self._send_metrics(stats)
++#     def log(self, stats: Stats) -> None:
++#         self._send_metrics(stats)
 +
-+    def info(self, type: str, obj: SupportsMetricsInfo) -> None:
-+        pass
++#     def info(self, type: str, obj: SupportsMetricsInfo) -> None:
++#         pass
 +
-+    def _send_metrics(self, stats: Stats):
-+        if not self.metrics_socket.closed:
-+            metrics_bytes = pickle.dumps(stats)
-+            self.metrics_socket.send_multipart((metrics_bytes, ), copy=False)
++#     def _send_metrics(self, stats: Stats):
++#         if not self.metrics_socket.closed:
++#             metrics_bytes = pickle.dumps(stats)
++#             self.metrics_socket.send_multipart((metrics_bytes, ), copy=False)
 +
 +
 +
@@ -3379,7 +3377,7 @@ index a0dd7958..3204cfb8 100644
  
  class MQLLMEngine:
      """A multiprocessing wrapper for :class:`LLMEngine`.
-@@ -94,12 +174,35 @@ class MQLLMEngine:
+@@ -94,12 +174,37 @@ class MQLLMEngine:
          self.heartbeat_socket = self.ctx.socket(zmq.constants.PUSH)
          self.heartbeat_socket.bind(f"{ipc_path}{IPC_HEALTH_EXT}")
  
@@ -3406,16 +3404,18 @@ index a0dd7958..3204cfb8 100644
 +            self.engine.cache_config.num_gpu_blocks,
 +            self.metrics_socket
 +        )
-+        self.general_stat_logger = StatLogger(
-+            self.metrics_socket
-+        )
 +        self.engine.add_logger("kv_metrics", self.kv_stat_logger)
-+        self.engine.add_logger("general_metrics", self.general_stat_logger)
++        
++        # TODO investigate sending whole stats object
++        # self.general_stat_logger = StatLogger(
++        #     self.metrics_socket
++        # )
++        # self.engine.add_logger("general_metrics", self.general_stat_logger)
 +
      @property
      def dead_error(self) -> BaseException:
          if self._errored_with is not None:
-@@ -171,8 +274,17 @@ class MQLLMEngine:
+@@ -171,8 +276,17 @@ class MQLLMEngine:
                  # Handle the query from the Client.
                  if request == RPCStartupRequest.IS_SERVER_READY:
                      tracing_enabled = self.engine.is_tracing_enabled()
@@ -3435,7 +3435,7 @@ index a0dd7958..3204cfb8 100644
  
              except Exception as e:
                  response = e
-@@ -185,6 +297,7 @@ class MQLLMEngine:
+@@ -185,6 +299,7 @@ class MQLLMEngine:
  
          while True:
              if not self.engine.has_unfinished_requests():
@@ -3443,7 +3443,7 @@ index a0dd7958..3204cfb8 100644
                  # Poll until there is work to do.
                  while self.input_socket.poll(timeout=POLLING_TIMEOUT_MS) == 0:
                      # When there's no work, check on engine health and send
-@@ -220,6 +333,13 @@ class MQLLMEngine:
+@@ -220,6 +335,13 @@ class MQLLMEngine:
      def handle_new_input(self):
          """Handle new input from the socket"""
          try:
@@ -3457,7 +3457,7 @@ index a0dd7958..3204cfb8 100644
              while self.input_socket.poll(timeout=0) != 0:
                  frames = self.input_socket.recv_multipart(copy=False)
                  request = pickle.loads(frames[0].buffer)
-@@ -262,6 +382,11 @@ class MQLLMEngine:
+@@ -262,6 +384,11 @@ class MQLLMEngine:
              self._send_outputs(rpc_err)
  
          try:
@@ -3469,7 +3469,7 @@ index a0dd7958..3204cfb8 100644
              self.engine.add_request(
                  request_id=request_id,
                  prompt=request.prompt,
-@@ -269,7 +394,9 @@ class MQLLMEngine:
+@@ -269,7 +396,9 @@ class MQLLMEngine:
                  lora_request=request.lora_request,
                  trace_headers=request.trace_headers,
                  prompt_adapter_request=request.prompt_adapter_request,

examples/python_rs/llm/vllm/README.md

@@ -237,7 +237,7 @@ kv-router-run.sh <number_of_workers> <routing_strategy> Optional[<model_name>]
 Example:
 ```bash
 # Launch 8 workers with prefix routing strategy and use deepseek-ai/DeepSeek-R1-Distill-Llama-8B as the model
-bash /workspace/examples/python_rs/llm/vllm/scripts/kv-router-run.sh 8 prefix deepseek-ai/DeepSeek-R1-Distill-Llama-8B
+bash /workspace/examples/python_rs/llm/vllm/scripts/kv-router-run.sh 8 test deepseek-ai/DeepSeek-R1-Distill-Llama-8B
 
 # List tmux sessions
 tmux ls

examples/python_rs/llm/vllm/kv_router/router.py

@@ -15,98 +15,138 @@
 
 
 import asyncio
+import random
 from argparse import Namespace
-from enum import Enum
 from typing import AsyncIterator
 
 import uvloop
 from common.protocol import Tokens
 from vllm.logger import logger as vllm_logger
 
-from dynamo.llm import KvIndexer, KvMetricsAggregator, KvRouter
+from dynamo.llm import AggregatedMetrics, KvIndexer, KvMetricsAggregator, OverlapScores
 from dynamo.runtime import DistributedRuntime, dynamo_endpoint, dynamo_worker
 
 WorkerId = str
 
 
-class RoutingStrategy(Enum):
-    PREFIX = "prefix"
-    ROUND_ROBIN = "round_robin"
-    RANDOM = "random"
-
-
-class Router:
+class CustomRouter:
     """
     Request handler for the generate endpoint
     """
 
     def __init__(
         self,
-        router: KvRouter,
-        routing_strategy: RoutingStrategy = RoutingStrategy.PREFIX,
+        workers_client,
+        indexer: KvIndexer,
+        metrics_aggregator: KvMetricsAggregator,
     ):
-        vllm_logger.info(
-            f"Initializing KV Router with strategy: {routing_strategy.value}"
+        vllm_logger.info("Initializing Custom Router")
+        self.indexer = indexer
+        self.metrics_aggregator = metrics_aggregator
+        self.workers_client = workers_client
+
+    def _cost_function(
+        self,
+        scores: OverlapScores | None,
+        metrics: AggregatedMetrics | None,
+        token_length: int,
+    ):
+        worker_scores = {}
+        if scores:
+            for worker_id, score in scores.scores.items():
+                # score is number of matching blocks we multiply by block_size to get tokens
+                # and compare to token_length. The larger the cache hit the better
+                worker_scores[worker_id] = (
+                    score * self.indexer.block_size() / token_length
                 )
-        self.router = router
-        self.routing_strategy = routing_strategy
 
-    @dynamo_endpoint(Tokens, WorkerId)
-    async def generate(self, request) -> AsyncIterator[WorkerId]:
-        lora_id = 0
-        worker_id = None
-        if self.routing_strategy == RoutingStrategy.PREFIX:
-            try:
-                worker_id = await self.router.schedule(request.tokens, lora_id)
-            # [NOTE][TODO] Now that the scheduler may return more error messages,
-            # now we are catching all exceptions and logging them. Should have
-            # catch specific router exceptions once we have dedicated types.
-            except Exception as e:
-                vllm_logger.info(f"{e}")
-                worker_id = ""
-                vllm_logger.exception(f"Error during worker selection: {e}")
+        worker_metrics = {}
+        # pull metrics for each worker
+        max_waiting = 0.0
+        if metrics:
+            for endpoint in metrics.endpoints:
+                worker_id = endpoint.worker_id
+            worker_metrics[worker_id] = {
+                "gpu_cache_usage_perc": endpoint.gpu_cache_usage_perc
+                if hasattr(endpoint, "gpu_cache_usage_perc")
+                else 0.0,
+                "num_requests_waiting": endpoint.num_requests_waiting
+                if hasattr(endpoint, "num_requests_waiting")
+                else 0.0,
+                "gpu_prefix_cache_hit_rate": endpoint.gpu_prefix_cache_hit_rate
+                if hasattr(endpoint, "gpu_prefix_cache_hit_rate")
+                else 0.0,
+            }
+            max_waiting = max(
+                max_waiting, worker_metrics[worker_id]["num_requests_waiting"]
+            )
 
-            vllm_logger.info(f"Scheduling to worker_id: {worker_id}")
+        # Get all worker IDs from the client. This is needed because scores / metrics may not have values for all workers
+        # and we want all workers to be considered in the logit calculation
+        worker_ids = self.workers_client.endpoint_ids()
+
+        worker_logits = {}
+        for worker_id in worker_ids:
+            # Use default values if worker not in scores or metrics
+            score = worker_scores.get(worker_id, 0.0)
+            metrics_dict = worker_metrics.get(
+                worker_id,
+                {
+                    "gpu_cache_usage_perc": 0.0,
+                    "num_requests_waiting": 0.0,
+                    "gpu_prefix_cache_hit_rate": 0.0,
+                },
+            )
 
-            yield str(worker_id)
+            normalized_waiting = (
+                metrics_dict["num_requests_waiting"] / max_waiting
+                if max_waiting > 0
+                else 0.0
+            )
 
-        else:
-            # TODO: Do we implement round_robin and random here?
-            # or just skip this router and directly enable in preprocess?
-            raise NotImplementedError(
-                f"Routing strategy {self.routing_strategy} not implemented"
+            # Have 1 metric that weights towards cache hit
+            # 2 metrics that penalize overloaded worker and queuing
+            worker_logits[worker_id] = (
+                2 * score - metrics_dict["gpu_cache_usage_perc"] - normalized_waiting
+            )
+            vllm_logger.info(
+                f"Formula for {worker_id}: {worker_logits[worker_id]:.3f} = 2.0 * {score:.3f} - {metrics_dict['gpu_cache_usage_perc']:.3f} - {normalized_waiting:.3f}"
             )
 
+        if not worker_logits or all(logit == 0 for logit in worker_logits.values()):
+            return ""
 
-class CustomRouter:
-    """
-    Request handler for the generate endpoint
-    """
+        # Select the worker with the highest logit
+        if worker_logits:
+            max_logit = max(worker_logits.values())
+            best_workers = [
+                wid for wid, logit in worker_logits.items() if logit == max_logit
+            ]
+            best_worker_id = random.choice(best_workers)
+        else:
+            best_worker_id = ""
 
-    def __init__(
-        self,
-        indexer: KvIndexer,
-        metrics_aggregator: KvMetricsAggregator,
-    ):
-        self.indexer = indexer
-        self.metrics_aggregator = metrics_aggregator
+        # Log the metrics for the selected worker
+        if best_worker_id:
+            vllm_logger.info(
+                f"Selected worker: {best_worker_id}, logit: {worker_logits[best_worker_id]:.3f}"
+            )
+            vllm_logger.info(
+                f"Score: {scores.scores.get(best_worker_id, 0.0) if scores else 0.0:.3f}"
+            )
 
-    def _cost_function(self, scores, metrics):
-        # naive cost function for demonstration purposes
-        current_best = ("", 0)
-        for worker_id, score in scores.scores.items():
-            if score > current_best[1]:
-                current_best = (worker_id, score)
-        for endpoint in metrics.endpoints:
-            if endpoint.worker_id == current_best[0]:
-                print(f"Metrics of endpoint: {endpoint.worker_id}")
-                print(
-                    f"request slot usage: {endpoint.request_active_slots} / {endpoint.request_total_slots}"
+            metrics_dict = worker_metrics.get(best_worker_id, {})
+            vllm_logger.info(
+                f"GPU Cache Hit Rate: {metrics_dict.get('gpu_prefix_cache_hit_rate', 0.0):.3f}"
             )
-                print(
-                    f"KV block usage: {endpoint.kv_active_blocks} / {endpoint.kv_total_blocks}"
+            vllm_logger.info(
+                f"GPU Cache Usage: {metrics_dict.get('gpu_cache_usage_perc', 0.0):.3f}"
+            )
+            vllm_logger.info(
+                f"Requests Waiting: {metrics_dict.get('num_requests_waiting', 0.0) / max_waiting if max_waiting > 0 else 0.0:.3f}"
             )
-        return current_best[0]
+
+        return best_worker_id
 
     @dynamo_endpoint(Tokens, WorkerId)
     async def generate(self, request) -> AsyncIterator[WorkerId]:
@@ -116,18 +156,16 @@ class CustomRouter:
             scores = await self.indexer.find_matches_for_request(
                 request.tokens, lora_id
             )
-            metrics = await self.metrics_aggregator.get_metrics()
-            worker_id = self._cost_function(scores, metrics)
-
-        # [NOTE][TODO] Now that the scheduler may return more error messages,
-        # now we are catching all exceptions and logging them. Should have
-        # catch specific router exceptions once we have dedicated types.
         except Exception as e:
-            vllm_logger.info(f"{e}")
-            worker_id = ""
-            vllm_logger.exception(f"Error during worker selection: {e}")
+            scores = {}
+            vllm_logger.exception(f"Error finding matches: {e}")
+
+        token_length = len(request.tokens)
+        metrics = await self.metrics_aggregator.get_metrics()
+        worker_id = self._cost_function(scores, metrics, token_length)
 
         vllm_logger.info(f"Scheduling to worker_id: {worker_id}")
+        vllm_logger.info("########")
 
         yield str(worker_id)
 
@@ -144,14 +182,6 @@ async def worker(runtime: DistributedRuntime, args: Namespace):
         .endpoint("generate")
         .client()
     )
-    wait_task = workers_client.wait_for_endpoints()
-    await asyncio.sleep(1)
-
-    while not wait_task.done():
-        vllm_logger.info("Waiting for workers to be ready...")
-        await asyncio.sleep(5)
-
-    wait_task.result()
 
     while len(workers_client.endpoint_ids()) < args.min_workers:
         vllm_logger.info(
@@ -172,23 +202,11 @@ async def worker(runtime: DistributedRuntime, args: Namespace):
 
     endpoint = router_component.endpoint("generate")
 
-    if args.custom_router:
-        # @REVIEWER - I'm not currently checking if block size matches that of the engine
-        # If they don't match things will silently fail
-        # The preferred solution would be for the KV Indexer to read from the MDC in etcd and not bother the user at all
-        # The second solution would be to do KvIndexer(kv_listener, MDC.block_size)
-        # as this ensures block size matches that of the engine
-        # In this case we need to do some sort of handshake or check in case a user just puts in a random block size
-
     indexer = KvIndexer(kv_listener, args.block_size)
     metrics_aggregator = KvMetricsAggregator(kv_listener)
     await endpoint.serve_endpoint(
-            CustomRouter(indexer, metrics_aggregator).generate
+        CustomRouter(workers_client, indexer, metrics_aggregator).generate
     )
-    else:
-        # TODO Read block_size from MDC
-        router = KvRouter(runtime, kv_listener, args.block_size)
-        await endpoint.serve_endpoint(Router(router, args.routing_strategy).generate)
 
 
 if __name__ == "__main__":
@@ -197,35 +215,18 @@ if __name__ == "__main__":
     import argparse
 
     parser = argparse.ArgumentParser()
-    parser.add_argument(
-        "--routing-strategy",
-        type=RoutingStrategy,
-        default=RoutingStrategy.PREFIX,
-        choices=list(RoutingStrategy),
-        help="Routing strategy to use",
-    )
     parser.add_argument(
         "--min-workers",
         type=int,
         default=1,
         help="Minimum number of workers required before proceeding",
     )
-    parser.add_argument(
-        "--model-name",
-        type=str,
-        default="deepseek-ai/DeepSeek-R1-Distill-Llama-8B",
-        help="Model that is being served",
-    )
+    # TODO: Read block size
     parser.add_argument(
         "--block-size",
         type=int,
-        help="KV block size",
-    )
-    parser.add_argument(
-        "--custom-router",
-        type=bool,
-        default=False,
-        help="Whether to use custom router or not",
+        default=64,
+        help="Block size for the KV Indexer",
     )
     args = parser.parse_args()
 

examples/python_rs/llm/vllm/kv_router/worker.py

@@ -99,10 +99,13 @@ async def worker(runtime: DistributedRuntime, engine_args: AsyncEngineArgs):
     # Initially send dummy metrics to kick start,
     # vLLM will not update stat until forward pass is triggered
     metrics_publisher.publish(
-        0,
-        1024,
-        0,
-        1024,
+        0,  # request_active_slots
+        1024,  # request_total_slots
+        0,  # kv_active_blocks
+        1024,  # kv_total_blocks
+        0,  # num_requests_waiting
+        0.0,  # gpu_cache_usage_perc
+        0.0,  # gpu_prefix_cache_hit_rate
     )
 
     await asyncio.gather(

examples/python_rs/llm/vllm/scripts/kv-router-run.sh

@@ -18,53 +18,78 @@
 # - Must use a single GPU for workers as CUDA_VISIBLE_DEVICES is set to a fixed value
 # - Must use a single node
 
-if [ $# -lt 2 ]; then
-    echo "Usage: $0 <number_of_workers> <routing_strategy> [model_name] [endpoint_name]"
-    echo "Error: Must specify at least number of workers and routing strategy"
+if [ $# -lt 3 ]; then
+    echo "Usage: $0 <number_of_workers> <log_dir_name> [model_name] [model_args] [chat_endpoint_name] [completions_endpoint_name]"
+    echo "Error: Must specify at least number of workers, log_dir_name"
     echo "Optional: model_name (default: deepseek-ai/DeepSeek-R1-Distill-Llama-8B)"
-    echo "Optional: endpoint_name (default: dynamo.process.chat/completions)"
+    echo "Optional: model_args (quoted string with model arguments)"
+    echo "Optional: chat_endpoint_name (default: dynamo.process.chat/completions)"
+    echo "Optional: completions_endpoint_name (default: dynamo.process.completions)"
     exit 1
 fi
 
+# Uncomment if using Cache
+# export HF_HUB_OFFLINE=1
+
+# https://github.com/vllm-project/vllm/issues/10734#issuecomment-2507201353
+# Fix for:torch.distributed.DistBackendError: File name too long
+# export GLOO_SOCKET_IFNAME=lo
+
+
 NUM_WORKERS=$1
-ROUTING_STRATEGY=$2
+LOG_DIR_NAME=$2
 MODEL_NAME=${3:-"deepseek-ai/DeepSeek-R1-Distill-Llama-8B"}
-ENDPOINT_NAME=${4:-"dynamo.process.chat/completions"}
-VALID_STRATEGIES=("prefix")
+CUSTOM_MODEL_ARGS=$4
+CHAT_ENDPOINT_NAME=${5:-"dynamo.process.chat/completions"}
+COMPLETIONS_ENDPOINT_NAME=${6:-"dynamo.process.completions"}
 SESSION_NAME="v"
 WORKDIR="/workspace/examples/python_rs/llm/vllm"
 INIT_CMD="cd $WORKDIR"
 
-if [[ ! " ${VALID_STRATEGIES[@]} " =~ " ${ROUTING_STRATEGY} " ]]; then
-    echo "Error: Invalid routing strategy. Must be one of: ${VALID_STRATEGIES[*]}"
-    exit 1
+
+# Default model args
+DEFAULT_MODEL_ARGS="--model $MODEL_NAME \
+    --tokenizer $MODEL_NAME \
+    --enable-prefix-caching \
+    --block-size 64"
+
+# Use custom model args if provided, otherwise use default
+if [ -n "$CUSTOM_MODEL_ARGS" ]; then
+    MODEL_ARGS="$CUSTOM_MODEL_ARGS"
+    echo "Using custom model arguments"
+else
+    MODEL_ARGS="$DEFAULT_MODEL_ARGS"
+    echo "Using default model arguments"
 fi
+
+# Create logs directory if it doesn't exist
+LOGS_DIR="/logs/$LOG_DIR_NAME"
+mkdir -p $LOGS_DIR
+chmod -R 775 $LOGS_DIR
+
 ########################################################
 # HTTP Server
 ########################################################
-HTTP_CMD="DYN_LOG=DEBUG http"
+HTTP_CMD="DYN_LOG=DEBUG http |& tee $LOGS_DIR/http.log"
 tmux new-session -d -s "$SESSION_NAME-http"
 tmux send-keys -t "$SESSION_NAME-http" "$INIT_CMD && $HTTP_CMD" C-m
 
 ########################################################
 # LLMCTL
 ########################################################
-LLMCTL_CMD="sleep 5 && llmctl http remove chat-model $MODEL_NAME && \
-    llmctl http add chat-model $MODEL_NAME $ENDPOINT_NAME && \
-    llmctl http list chat-model"
+LLMCTL_CMD="sleep 5 && \
+    llmctl http remove chat $MODEL_NAME && \
+    llmctl http remove completions $MODEL_NAME && \
+    llmctl http add chat $MODEL_NAME $CHAT_ENDPOINT_NAME && \
+    llmctl http add completions $MODEL_NAME $COMPLETIONS_ENDPOINT_NAME && \
+    llmctl http list |& tee $LOGS_DIR/llmctl.log"
 tmux new-session -d -s "$SESSION_NAME-llmctl"
 tmux send-keys -t "$SESSION_NAME-llmctl" "$INIT_CMD && $LLMCTL_CMD" C-m
 
 ########################################################
 # Processor
 ########################################################
-# For now processor gets same args as worker, need to have them communicate over etcd
-PROCESSOR_CMD="RUST_LOG=info python3 -m kv_router.processor \
-    --model $MODEL_NAME \
-    --tokenizer $MODEL_NAME \
-    --enable-prefix-caching \
-    --block-size 32 \
-    --max-model-len 16384 "
+PROCESSOR_CMD="RUST_LOG=info python3 -m kv_router.processor $MODEL_ARGS |& tee $LOGS_DIR/processor.log"
 tmux new-session -d -s "$SESSION_NAME-processor"
 tmux send-keys -t "$SESSION_NAME-processor" "$INIT_CMD && $PROCESSOR_CMD" C-m
 
@@ -72,10 +97,7 @@ tmux send-keys -t "$SESSION_NAME-processor" "$INIT_CMD && $PROCESSOR_CMD" C-m
 # Router
 ########################################################
 ROUTER_CMD="RUST_LOG=info python3 -m kv_router.router \
-    --model $MODEL_NAME \
-    --routing-strategy $ROUTING_STRATEGY \
-    --min-workers $NUM_WORKERS \
-    --block-size 32"
+    --min-workers $NUM_WORKERS |& tee $LOGS_DIR/router.log"
 
 tmux new-session -d -s "$SESSION_NAME-router"
 tmux send-keys -t "$SESSION_NAME-router" "$INIT_CMD && $ROUTER_CMD" C-m
@@ -83,17 +105,12 @@ tmux send-keys -t "$SESSION_NAME-router" "$INIT_CMD && $ROUTER_CMD" C-m
 ########################################################
 # Workers
 ########################################################
-WORKER_CMD="RUST_LOG=info python3 -m kv_router.worker \
-    --model $MODEL_NAME \
-    --tokenizer $MODEL_NAME \
-    --enable-prefix-caching \
-    --block-size 64 \
-    --max-model-len 16384 "
+WORKER_CMD="RUST_LOG=info python3 -m kv_router.worker $MODEL_ARGS"
 
 for i in $(seq 1 $NUM_WORKERS); do
     tmux new-session -d -s "$SESSION_NAME-$i"
 done
 
 for i in $(seq 1 $NUM_WORKERS); do
-        tmux send-keys -t "$SESSION_NAME-$i" "$INIT_CMD && CUDA_VISIBLE_DEVICES=$((i-1)) $WORKER_CMD" C-m
+    tmux send-keys -t "$SESSION_NAME-$i" "$INIT_CMD && CUDA_VISIBLE_DEVICES=$((i-1)) $WORKER_CMD |& tee $LOGS_DIR/worker-$i.log" C-m
 done
\ No newline at end of file

examples/rust/llmctl/src/main.rs

@@ -228,6 +228,10 @@ async fn add_model(
         endpoint_name
     );
 
+    if model_name.starts_with('/') {
+        raise!("Model name '{}' cannot start with a slash", model_name);
+    }
+
     let parts: Vec<&str> = endpoint_name.split('.').collect();
 
     if parts.len() < 2 {

lib/bindings/python/rust/llm/kv.rs

@@ -90,6 +90,7 @@ impl KvMetricsPublisher {
         })
     }
 
+    #[allow(clippy::too_many_arguments)]
     fn publish(
         &self,
         _py: Python,
@@ -97,6 +98,9 @@ impl KvMetricsPublisher {
         request_total_slots: u64,
         kv_active_blocks: u64,
         kv_total_blocks: u64,
+        num_requests_waiting: u64,
+        gpu_cache_usage_perc: f32,
+        gpu_prefix_cache_hit_rate: f32,
     ) -> PyResult<()> {
         self.inner
             .publish(
@@ -105,6 +109,9 @@ impl KvMetricsPublisher {
                     request_total_slots,
                     kv_active_blocks,
                     kv_total_blocks,
+                    num_requests_waiting,
+                    gpu_cache_usage_perc,
+                    gpu_prefix_cache_hit_rate,
                 }
                 .into(),
             )
@@ -180,6 +187,10 @@ impl KvIndexer {
         })
     }
 
+    fn block_size(&self) -> usize {
+        self.inner.block_size()
+    }
+
     fn find_matches_for_request<'p>(
         &self,
         py: Python<'p>,
@@ -212,6 +223,12 @@ pub(crate) struct EndpointKvMetrics {
     pub kv_active_blocks: u64,
     #[pyo3(get, set)]
     pub kv_total_blocks: u64,
+    #[pyo3(get, set)]
+    pub num_requests_waiting: u64,
+    #[pyo3(get, set)]
+    pub gpu_cache_usage_perc: f32,
+    #[pyo3(get, set)]
+    pub gpu_prefix_cache_hit_rate: f32,
 }
 
 #[pyclass]
@@ -258,6 +275,9 @@ impl KvMetricsAggregator {
                 request_total_slots: x.data.request_total_slots,
                 kv_active_blocks: x.data.kv_active_blocks,
                 kv_total_blocks: x.data.kv_total_blocks,
+                num_requests_waiting: x.data.num_requests_waiting,
+                gpu_cache_usage_perc: x.data.gpu_cache_usage_perc,
+                gpu_prefix_cache_hit_rate: x.data.gpu_prefix_cache_hit_rate,
             })
             .collect();
         pyo3_async_runtimes::tokio::future_into_py(py, async move {

lib/bindings/python/src/dynamo/_core.pyi

@@ -242,7 +242,11 @@ class KvMetricsPublisher:
     def publish(self, request_active_slots: int,
         request_total_slots: int,
         kv_active_blocks: int,
-        kv_total_blocks: int) -> None:
+        kv_total_blocks: int,
+        num_requests_waiting: int,
+        gpu_cache_usage_perc: float,
+        gpu_prefix_cache_hit_rate: float
+    ) -> None:
         """
         Update the KV metrics being reported.
         """
@@ -298,7 +302,7 @@ class KvIndexer:
 
     ...
 
-    def __init__(self, component: Component) -> None:
+    def __init__(self, component: Component, block_size: int) -> None:
         """
         Create a `KvIndexer` object
         """
@@ -309,6 +313,12 @@ class KvIndexer:
         """
         ...
 
+    def block_size(self) -> int:
+        """
+        Return the block size of the KV Indexer.
+        """
+        ...
+
 class AggregatedMetrics:
     """
     A collection of metrics of the endpoints

lib/bindings/python/src/dynamo/llm/__init__.py

@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from dynamo._core import AggregatedMetrics as AggregatedMetrics
 from dynamo._core import DisaggregatedRouter as DisaggregatedRouter
 from dynamo._core import HttpAsyncEngine as HttpAsyncEngine
 from dynamo._core import HttpError as HttpError
@@ -21,3 +22,4 @@ from dynamo._core import KvIndexer as KvIndexer
 from dynamo._core import KvMetricsAggregator as KvMetricsAggregator
 from dynamo._core import KvMetricsPublisher as KvMetricsPublisher
 from dynamo._core import KvRouter as KvRouter
+from dynamo._core import OverlapScores as OverlapScores

lib/bindings/python/tests/test_kv_bindings.py

@@ -193,6 +193,9 @@ async def test_metrics_aggregator(distributed_runtime):
         "request_total_slots": 1024,
         "kv_active_blocks": 523,
         "kv_total_blocks": 777,
+        "num_requests_waiting": 10,
+        "gpu_cache_usage_perc": 0.5,
+        "gpu_prefix_cache_hit_rate": 0.75,
     }
 
     # need 'create_task' to put publisher task in the background
@@ -222,5 +225,8 @@ async def metrics_publisher_task(kv_listener, expected_metrics):
         expected_metrics["request_total_slots"],
         expected_metrics["kv_active_blocks"],
         expected_metrics["kv_total_blocks"],
+        expected_metrics["num_requests_waiting"],
+        expected_metrics["gpu_cache_usage_perc"],
+        expected_metrics["gpu_prefix_cache_hit_rate"],
     )
     await metrics_publisher.create_endpoint(kv_listener)

lib/llm/src/kv_router.rs

@@ -16,7 +16,7 @@
 use anyhow::Result;
 use dynamo_runtime::{component::Component, component::Namespace, DistributedRuntime};
 use futures::stream::StreamExt;
-use std::{sync::Arc, time::Duration};
+use std::sync::Arc;
 use tokio_util::sync::CancellationToken;
 use tracing;
 
@@ -29,7 +29,8 @@ pub mod scoring;
 
 use crate::kv_router::{
     indexer::{KvIndexer, KvIndexerInterface, RouterEvent},
-    scheduler::{Endpoint, KvScheduler, Service},
+    metrics_aggregator::collect_endpoints,
+    scheduler::KvScheduler,
     scoring::ProcessedEndpoints,
 };
 
@@ -148,73 +149,3 @@ impl KvRouter {
         Ok(worker_id)
     }
 }
-
-async fn collect_endpoints(
-    nats_client: dynamo_runtime::transports::nats::Client,
-    service_name: String,
-    ep_tx: tokio::sync::mpsc::Sender<ProcessedEndpoints>,
-    cancel: CancellationToken,
-) {
-    loop {
-        tokio::select! {
-            _ = cancel.cancelled() => {
-                tracing::debug!("cancellation token triggered");
-                break;
-            }
-            _ = tokio::time::sleep(Duration::from_secs(1)) => {
-                tracing::trace!("collecting endpoints for service: {}", service_name);
-            }
-        }
-
-        let values = match nats_client
-            .get_endpoints(&service_name, Duration::from_secs(1))
-            .await
-        {
-            Ok(v) => v,
-            Err(e) => {
-                tracing::warn!("Failed to retrieve endpoints for {}: {:?}", service_name, e);
-                continue;
-            }
-        };
-
-        tracing::debug!("values: {:?}", values);
-        let services: Vec<Service> = values
-            .into_iter()
-            .filter(|v| !v.is_empty())
-            .filter_map(|v| match serde_json::from_slice::<Service>(&v) {
-                Ok(service) => Some(service),
-                Err(e) => {
-                    tracing::warn!("For value: {:?} \nFailed to parse service: {:?}", v, e);
-                    None
-                }
-            })
-            .collect();
-        tracing::debug!("services: {:?}", services);
-
-        let endpoints: Vec<Endpoint> = services
-            .into_iter()
-            .flat_map(|s| s.endpoints)
-            .filter(|s| s.data.is_some())
-            .map(|s| Endpoint {
-                name: s.name,
-                subject: s.subject,
-                data: s.data.unwrap(),
-            })
-            .collect();
-        tracing::debug!("endpoints: {:?}", endpoints);
-
-        tracing::trace!(
-            "found {} endpoints for service: {}",
-            endpoints.len(),
-            service_name
-        );
-
-        let processed = ProcessedEndpoints::new(endpoints);
-
-        // process endpoints into
-        if ep_tx.send(processed).await.is_err() {
-            tracing::trace!("failed to send processed endpoints; shutting down");
-            break;
-        }
-    }
-}

lib/llm/src/kv_router/indexer.rs

@@ -588,6 +588,10 @@ impl KvIndexer {
         }
     }
 
+    pub fn block_size(&self) -> usize {
+        self.kv_block_size
+    }
+
     pub fn new(token: CancellationToken, kv_block_size: usize) -> Self {
         Self::new_with_frequency(token, None, kv_block_size)
     }
@@ -775,6 +779,10 @@ impl KvIndexerSharded {
         }
     }
 
+    pub fn block_size(&self) -> usize {
+        self.kv_block_size
+    }
+
     pub fn new(token: CancellationToken, num_shards: usize, kv_block_size: usize) -> Self {
         Self::new_with_frequency(token, num_shards, None, kv_block_size)
     }

lib/llm/src/kv_router/metrics_aggregator.rs

@@ -80,25 +80,24 @@ impl KvMetricsAggregator {
     }
 }
 
-async fn collect_endpoints(
+pub async fn collect_endpoints(
     nats_client: dynamo_runtime::transports::nats::Client,
     service_name: String,
     ep_tx: tokio::sync::mpsc::Sender<ProcessedEndpoints>,
     cancel: CancellationToken,
 ) {
+    let backoff_delay = Duration::from_millis(100);
+
     loop {
         tokio::select! {
             _ = cancel.cancelled() => {
                 tracing::debug!("cancellation token triggered");
                 break;
             }
-            _ = tokio::time::sleep(Duration::from_secs(1)) => {
+            _ = tokio::time::sleep(backoff_delay) => {
                 tracing::trace!("collecting endpoints for service: {}", service_name);
-            }
-        }
-
                 let values = match nats_client
-            .get_endpoints(&service_name, Duration::from_secs(1))
+                    .get_endpoints(&service_name, Duration::from_millis(300))
                     .await
                 {
                     Ok(v) => v,
@@ -146,4 +145,6 @@ async fn collect_endpoints(
                     break;
                 }
             }
+        }
+    }
 }

lib/llm/src/kv_router/protocols.rs

@@ -21,6 +21,12 @@ pub struct ForwardPassMetrics {
     pub request_total_slots: u64,
     pub kv_active_blocks: u64,
     pub kv_total_blocks: u64,
+    // integer from 0 to large number
+    pub num_requests_waiting: u64,
+    // percentage represented as a float from 0 to 1
+    pub gpu_cache_usage_perc: f32,
+    // percentage represented as a float from 0 to 1
+    pub gpu_prefix_cache_hit_rate: f32,
 }
 
 /// A [`BlockHash`] is a hash computed from the tokens_ids, extra_token_ids and the optional