feat: enable metrics polling

Signed-off-by: Meenakshi Sharma <163925564+nvda-mesharma@users.noreply.github.com>
Signed-off-by: Neelay Shah <neelays@nvidia.com>
Co-authored-by: Neelay Shah <neelays@nvidia.com>
Co-authored-by: Ryan Olson <ryanolson@users.noreply.github.com>
Co-authored-by: Meenakshi Sharma <163925564+nvda-mesharma@users.noreply.github.com>
Co-authored-by: Biswa Panda <biswapanda@users.noreply.github.com>
Co-authored-by: Ryan McCormick <rmccormick@nvidia.com>

examples/python_rs/llm/vllm/README.md

@@ -180,7 +180,7 @@ 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/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 prefix deepseek-ai/DeepSeek-R1-Distill-Llama-8B
 
 # List tmux sessions
 tmux ls
@@ -252,7 +252,7 @@ llmctl http add chat-models deepseek-ai/DeepSeek-R1-Distill-Llama-8B triton-init
 ```
 
 ```bash
-curl localhost:9992/v1/chat/completions   -H "Content-Type: application/json"   -d '{
+curl localhost:8080/v1/chat/completions   -H "Content-Type: application/json"   -d '{
     "model": "deepseek-ai/DeepSeek-R1-Distill-Llama-8B",
     "messages": [
     {

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

+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+import asyncio
+
+import uvloop
+from common.protocol import Request, Response
+from vllm.logger import logger as vllm_logger
+
+from triton_distributed.llm import KvRouter
+from triton_distributed.runtime import (
+    DistributedRuntime,
+    triton_endpoint,
+    triton_worker,
+)
+
+
+class Router:
+    """
+    Request handler for the generate endpoint
+    """
+
+    def __init__(
+        self,
+        router,
+        workers_client,
+    ):
+        self.router = router
+        self.workers_client = workers_client
+
+    @triton_endpoint(Request, Response)
+    async def generate(self, request):
+        lora_id = 0
+        worker_id = None
+        tokens = [3] * 64
+        try:
+            worker_id = await self.router.schedule(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"got exception of type {type(e)}: {e}")
+            worker_id = None
+            vllm_logger.exception(f"Error during worker selection: {e}")
+
+        vllm_logger.info(f"Scheduling to worker_id: {worker_id}")
+
+        if worker_id is None:
+            vllm_logger.info("randomly select worker")
+            engine_generator = await self.workers_client.random(
+                request.model_dump_json()
+            )
+        else:
+            vllm_logger.info(f"directly select worker: {worker_id}")
+            engine_generator = await self.workers_client.direct(
+                request.model_dump_json(), worker_id
+            )
+
+        async for resp in engine_generator:
+            resp = resp.data() if hasattr(resp, "data") else resp
+            yield resp
+
+    @triton_endpoint(Request, Response)
+    async def mock_generate(self, request):
+        print(f"Received request: {request}")
+        yield "Hello, World!"
+
+
+ROUTE_SELF = True
+
+
+@triton_worker()
+async def worker(runtime: DistributedRuntime):
+    workers_client = (
+        await runtime.namespace("triton-init")
+        .component("vllm")
+        .endpoint("generate")
+        .client()
+    )
+
+    vllm_logger.info(
+        f"Have number of workers ({len(workers_client.endpoint_ids())}) are ready:\n"
+        + "\n".join(f"id: {id}" for id in workers_client.endpoint_ids())
+    )
+
+    # [TODO] Collect endpoint implementation expects services to provide
+    # ForwardPassMetrics as part of stats handling and it will panic if
+    # otherwise. This needs to be fixed so that non-providing endpoints will
+    # simply be ignored, but before that, we will make sure that the services
+    # of the same namespace::component are created via KvMetricsPublisher,
+    # if it is also used to create endpoints.
+    kv_listener = runtime.namespace("triton-init").component("vllm")
+    await kv_listener.create_service()
+    router = KvRouter(runtime, kv_listener)
+    # i.e. below will cause panic
+    # endpoint = kv_listener.endpoint("generate")
+    # await endpoint.serve_endpoint(
+    #     Router(router, workers_client).mock_generate
+    # )
+
+    router_component = runtime.namespace("triton-init").component("frontend")
+    await router_component.create_service()
+
+    endpoint = router_component.endpoint("generate")
+    await endpoint.serve_endpoint(Router(router, workers_client).generate)
+
+
+if __name__ == "__main__":
+    uvloop.install()
+
+    asyncio.run(worker())

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

+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+import asyncio
+import ctypes
+from ctypes import c_char_p, c_int64, c_uint32
+
+import uvloop
+from common.protocol import Request, Response
+from vllm.logger import logger as vllm_logger
+
+from triton_distributed.llm import KvMetricsPublisher
+from triton_distributed.runtime import (
+    DistributedRuntime,
+    triton_endpoint,
+    triton_worker,
+)
+
+
+class TritonResult:
+    OK = 0
+    ERR = 1
+
+
+class MockEngine:
+    """
+    Request handler for the generate endpoint
+    """
+
+    def __init__(self, metrics_publisher, worker_id):
+        self.worker_id = worker_id
+        # KV events
+        self.lib = ctypes.CDLL("/opt/triton/llm_binding/lib/libtriton_llm_capi.so")
+        self.lib.triton_llm_init.argtypes = [c_char_p, c_char_p, c_int64]
+        self.lib.triton_llm_init.restype = c_uint32
+        result = self.lib.triton_llm_init(
+            "triton-init".encode(), "vllm".encode(), worker_id
+        )
+        if result == TritonResult.OK:
+            vllm_logger.info(
+                "KVCacheEventManager initialized successfully. Ready to publish KV Cache Events"
+            )
+        else:
+            vllm_logger.info("KVCacheEventManager initialization failed!")
+        self.lib.triton_kv_event_publish_stored.argtypes = [
+            ctypes.c_uint64,  # event_id
+            ctypes.POINTER(ctypes.c_uint32),  # token_ids
+            ctypes.POINTER(ctypes.c_size_t),  # num_block_tokens
+            ctypes.POINTER(ctypes.c_uint64),  # block_ids
+            ctypes.c_size_t,  # num_blocks
+            ctypes.POINTER(ctypes.c_uint64),  # parent_hash
+            ctypes.c_uint64,  # lora_id
+        ]
+        self.lib.triton_kv_event_publish_stored.restype = (
+            ctypes.c_uint32
+        )  # triton_llm_result_t
+
+        self.lib.triton_kv_event_publish_removed.argtypes = [
+            ctypes.c_uint64,  # event_id
+            ctypes.POINTER(ctypes.c_uint64),  # block_ids
+            ctypes.c_size_t,  # num_blocks
+        ]
+        self.lib.triton_kv_event_publish_removed.restype = (
+            ctypes.c_uint32
+        )  # triton_llm_result_t
+
+        # KV metrics
+        self.metrics_publisher = metrics_publisher
+
+        self.request_active_slots = 0
+        self.request_total_slots = 4
+        self.kv_active_block = 0
+        self.kv_total_blocks = 4
+        # [NOTE] Now that the component must has proper metrics reported
+        # to be properly selected by the router
+        self.metrics_publisher.publish(
+            self.request_active_slots,
+            self.request_total_slots,
+            self.kv_active_block,
+            self.kv_total_blocks,
+        )
+        self.event_id_counter = 0
+        self.tokens = [3] * 64
+
+    @triton_endpoint(Request, Response)
+    async def generate(self, request):
+        print(f"Received request: {request}")
+        self.request_active_slots = min(
+            self.request_active_slots + 1, self.request_total_slots
+        )
+        self.kv_active_block = min(self.kv_active_block + 1, self.kv_total_blocks)
+        self.metrics_publisher.publish(
+            self.request_active_slots,
+            self.request_total_slots,
+            self.kv_active_block,
+            self.kv_total_blocks,
+        )
+        self.store_event()
+        yield "Hello, World!"
+
+    def store_event(self):
+        parent_hash = (
+            (ctypes.c_uint64 * 1)(self.event_id_counter)
+            if self.event_id_counter > 0
+            else None
+        )
+        result = self.lib.triton_kv_event_publish_stored(
+            self.event_id_counter,  # uint64_t event_id
+            (ctypes.c_uint32 * len(self.tokens))(
+                *self.tokens
+            ),  # const uint32_t *token_ids
+            (ctypes.c_size_t * 1)(
+                len(self.tokens)
+            ),  # const uintptr_t *num_block_tokens
+            (ctypes.c_uint64 * 1)(self.event_id_counter),  # const uint64_t *block_ids
+            1,  # uintptr_t num_blocks
+            parent_hash,  # const uint64_t *parent_hash
+            0,  # uint64_t lora_id
+        )
+        self.event_id_counter += 1
+
+        if result == TritonResult.OK:
+            vllm_logger.debug(f"Store - Published KV Event: {self.event_id_counter}")
+        else:
+            vllm_logger.debug(
+                f"Store - Failed to Publish KV Event: {self.event_id_counter}"
+            )
+
+    async def cooldown(self):
+        while True:
+            await asyncio.sleep(5)
+            self.request_active_slots = max(0, self.request_active_slots - 1)
+            self.kv_active_block = max(0, self.kv_active_block - 1)
+            self.metrics_publisher.publish(
+                self.request_active_slots,
+                self.request_total_slots,
+                self.kv_active_block,
+                self.kv_total_blocks,
+            )
+
+
+@triton_worker()
+async def worker(runtime: DistributedRuntime):
+    """
+    Instantiate a `backend` component and serve the `generate` endpoint
+    A `Component` can serve multiple endpoints
+    """
+    component = runtime.namespace("triton-init").component("vllm")
+    metrics_publisher = KvMetricsPublisher()
+    await metrics_publisher.create_service(component)
+
+    endpoint = component.endpoint("generate")
+    engine = MockEngine(metrics_publisher, endpoint.lease_id())
+    await asyncio.gather(
+        engine.cooldown(),
+        endpoint.serve_endpoint(engine.generate),
+    )
+
+
+if __name__ == "__main__":
+    uvloop.install()
+    asyncio.run(worker())

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

@@ -31,8 +31,8 @@ from vllm.logger import logger as vllm_logger
 from vllm.outputs import RequestOutput
 from vllm.transformers_utils.tokenizer import AnyTokenizer
 
-from triton_distributed._core import Client
 from triton_distributed.runtime import (
+    Client,
     DistributedRuntime,
     triton_endpoint,
     triton_worker,
@@ -126,7 +126,7 @@ class Processor(ProcessMixIn):
                     sampling_params=sampling_params,
                     request_id=request_id,
                 ).model_dump_json(),
-                uuid.UUID(worker_id).int,
+                int(worker_id),
             )
 
         output = self.generate_responses(engine_generator)

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

@@ -58,20 +58,21 @@ class Router:
     @triton_endpoint(Tokens, WorkerId)
     async def generate(self, request) -> AsyncIterator[WorkerId]:
         lora_id = 0
-        worker_id = ""
+        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}")
-                if "No worker found" in str(e):
-                    worker_id = ""
-                else:
+                worker_id = None
                 vllm_logger.exception(f"Error during worker selection: {e}")
 
             vllm_logger.info(f"Scheduling to worker_id: {worker_id}")
 
-            yield worker_id
+            yield str(worker_id)
 
         else:
             # TODO: Do we implement round_robin and random here?
@@ -113,8 +114,7 @@ async def worker(runtime: DistributedRuntime, args: Namespace):
         + "\n".join(f"id: {id}" for id in workers_client.endpoint_ids())
     )
 
-    # TODO Router is a fixed namespace separate from the others
-    kv_listener = runtime.namespace("router").component(args.model_name)
+    kv_listener = runtime.namespace("triton-init").component("vllm")
     await kv_listener.create_service()
 
     router_component = runtime.namespace("triton-init").component("router")

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

@@ -15,7 +15,6 @@
 
 import asyncio
 import os
-import uuid
 from typing import AsyncIterator
 
 import uvloop
@@ -26,6 +25,7 @@ from vllm.engine.arg_utils import AsyncEngineArgs
 from vllm.logger import logger as vllm_logger
 from vllm.sampling_params import RequestOutputKind
 
+from triton_distributed.llm import KvMetricsPublisher
 from triton_distributed.runtime import (
     DistributedRuntime,
     triton_endpoint,
@@ -40,10 +40,18 @@ class VllmEngine(BaseVllmEngine):
     vLLM Inference Engine
     """
 
-    def __init__(self, engine_args: AsyncEngineArgs):
+    def __init__(
+        self, engine_args: AsyncEngineArgs, metrics_publisher: KvMetricsPublisher
+    ):
+        self.metrics_publisher = metrics_publisher
         self.engine_args = engine_args
         super().__init__(engine_args)
 
+    async def initialize(self):
+        await super().initialize()
+        assert self.engine_client is not None, "engine_client was not initialized"
+        self.engine_client.set_metrics_publisher(self.metrics_publisher)
+
     @triton_endpoint(vLLMGenerateRequest, MyRequestOutput)
     async def generate(self, request) -> AsyncIterator:
         assert (
@@ -74,21 +82,32 @@ async def worker(runtime: DistributedRuntime, engine_args: AsyncEngineArgs):
     """
     Serve the triton-init.vllm.generate endpoint.
     """
+    metrics_publisher = KvMetricsPublisher()
     worker_component = runtime.namespace("triton-init").component("vllm")
-    await worker_component.create_service()
+    await metrics_publisher.create_service(worker_component)
 
     worker_endpoint = worker_component.endpoint("generate")
 
-    # KV Publisher and Aggregator requires a UUID (str)
-    # KV Router requires a lease_id (int)
-    # This allows us to please both, until they are unified
-    # If VLLM_WORKER_ID is not set, KV Routing will fail
-    VLLM_WORKER_ID = uuid.UUID(int=worker_endpoint.lease_id())
+    VLLM_WORKER_ID = worker_endpoint.lease_id()
     os.environ["VLLM_WORKER_ID"] = str(VLLM_WORKER_ID)
     vllm_logger.info(f"Generate endpoint ID: {VLLM_WORKER_ID}")
 
-    vllm_engine = VllmEngine(engine_args)
+    VLLM_KV_NAMESPACE = "triton-init"
+    os.environ["VLLM_KV_NAMESPACE"] = str(VLLM_KV_NAMESPACE)
+
+    VLLM_KV_COMPONENT = "vllm"
+    os.environ["VLLM_KV_COMPONENT"] = str(VLLM_KV_COMPONENT)
+
+    vllm_engine = VllmEngine(engine_args, metrics_publisher)
     await vllm_engine.initialize()
+    # Initially send dummy metrics to kick start,
+    # vLLM will not update stat until forward pass is triggered
+    metrics_publisher.publish(
+        0,
+        1024,
+        0,
+        1024,
+    )
 
     await worker_endpoint.serve_endpoint(vllm_engine.generate)
 

lib/bindings/c/src/lib.rs

@@ -22,13 +22,13 @@ use tracing as log;
 use uuid::Uuid;
 
 use triton_distributed_llm::kv_router::{
-    indexer::compute_block_hash_for_seq, protocols::*, publisher::KvPublisher,
+    indexer::compute_block_hash_for_seq, protocols::*, publisher::KvEventPublisher,
 };
 use triton_distributed_runtime::{DistributedRuntime, Worker};
 static WK: OnceCell<Worker> = OnceCell::new();
 static DRT: AsyncOnceCell<DistributedRuntime> = AsyncOnceCell::new();
 // [FIXME] shouldn't the publisher be instance passing between API calls?
-static KV_PUB: OnceCell<KvPublisher> = OnceCell::new();
+static KV_PUB: OnceCell<KvEventPublisher> = OnceCell::new();
 
 fn initialize_tracing() {
     // Sets up RUST_LOG environment variable for logging while KV Publishing
@@ -49,11 +49,12 @@ pub enum TritonLlmResult {
 }
 
 /// # Safety
-/// the model_name_c_str and worker_id_c_str are passed as pointers to C strings
+/// the namespace_c_str and component_c_str are passed as pointers to C strings
 #[no_mangle]
 pub unsafe extern "C" fn triton_llm_init(
-    model_name_c_str: *const c_char,
-    worker_id_c_str: *const c_char,
+    namespace_c_str: *const c_char,
+    component_c_str: *const c_char,
+    worker_id: i64,
 ) -> TritonLlmResult {
     initialize_tracing();
     let wk = match WK.get_or_try_init(Worker::from_settings) {
@@ -78,7 +79,7 @@ pub unsafe extern "C" fn triton_llm_init(
             }
         }
     });
-    let model_name = match unsafe { CStr::from_ptr(model_name_c_str) }.to_str() {
+    let namespace = match unsafe { CStr::from_ptr(namespace_c_str) }.to_str() {
         Ok(s) => s.to_string(),
         Err(e) => {
             eprintln!("Failed to convert C string to Rust string: {:?}", e);
@@ -86,24 +87,17 @@ pub unsafe extern "C" fn triton_llm_init(
         }
     };
 
-    let worker_id_str = match unsafe { CStr::from_ptr(worker_id_c_str) }.to_str() {
-        Ok(s) => s,
+    let component = match unsafe { CStr::from_ptr(component_c_str) }.to_str() {
+        Ok(s) => s.to_string(),
         Err(e) => {
             eprintln!("Failed to convert C string to Rust string: {:?}", e);
             return TritonLlmResult::ERR;
         }
     };
 
-    let worker_id_uuid = match Uuid::parse_str(worker_id_str) {
-        Ok(uuid) => uuid,
-        Err(e) => {
-            eprintln!("Failed to parse worker_id as UUID: {:?}", e);
-            return TritonLlmResult::ERR;
-        }
-    };
     match result {
         Ok(_) => match KV_PUB
-            .get_or_try_init(move || triton_create_kv_publisher(model_name, worker_id_uuid))
+            .get_or_try_init(move || triton_create_kv_publisher(namespace, component, worker_id))
         {
             Ok(_) => TritonLlmResult::OK,
             Err(e) => {
@@ -143,17 +137,18 @@ pub extern "C" fn triton_llm_load_publisher_create() -> TritonLlmResult {
 // c++ executor api
 
 fn triton_create_kv_publisher(
-    model_name: String,
-    worker_id: Uuid,
-) -> Result<KvPublisher, anyhow::Error> {
-    log::info!("Creating KV Publisher for model: {}", model_name);
+    namespace: String,
+    component: String,
+    worker_id: i64,
+) -> Result<KvEventPublisher, anyhow::Error> {
+    log::info!("Creating KV Publisher for model: {}", component);
     match DRT
         .get()
         .ok_or(anyhow::Error::msg("Could not get Distributed Runtime"))
     {
         Ok(drt) => {
-            let backend = drt.namespace("router")?.component(model_name)?;
-            KvPublisher::new(drt.clone(), backend, worker_id)
+            let backend = drt.namespace(namespace)?.component(component)?;
+            KvEventPublisher::new(drt.clone(), backend, worker_id)
         }
         Err(e) => Err(e),
     }

lib/bindings/python/rust/lib.rs

@@ -64,6 +64,7 @@ fn _core(m: &Bound<'_, PyModule>) -> PyResult<()> {
     m.add_class::<Client>()?;
     m.add_class::<AsyncResponseStream>()?;
     m.add_class::<llm::kv::KvRouter>()?;
+    m.add_class::<llm::kv::KvMetricsPublisher>()?;
 
     engine::add_to_module(m)?;
 

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

@@ -23,6 +23,7 @@ pub(crate) struct KvRouter {
 #[pymethods]
 impl KvRouter {
     #[new]
+    // [FXIME] 'drt' can be obtained from 'component'
     fn new(drt: DistributedRuntime, component: Component) -> PyResult<Self> {
         let runtime = pyo3_async_runtimes::tokio::get_runtime();
         runtime.block_on(async {
@@ -44,11 +45,64 @@ impl KvRouter {
     ) -> PyResult<Bound<'p, PyAny>> {
         let router = self.inner.clone();
         pyo3_async_runtimes::tokio::future_into_py(py, async move {
-            let uuid = router
+            let worker_id = router
                 .schedule(&token_ids, lora_id)
                 .await
                 .map_err(to_pyerr)?;
-            Ok(uuid.to_string())
+            Ok(worker_id)
         })
     }
 }
+
+#[pyclass]
+pub(crate) struct KvMetricsPublisher {
+    inner: Arc<llm_rs::kv_router::publisher::KvMetricsPublisher>,
+}
+
+#[pymethods]
+impl KvMetricsPublisher {
+    #[new]
+    fn new() -> PyResult<Self> {
+        let inner = llm_rs::kv_router::publisher::KvMetricsPublisher::new().map_err(to_pyerr)?;
+        Ok(Self {
+            inner: inner.into(),
+        })
+    }
+
+    fn create_service<'p>(
+        &self,
+        py: Python<'p>,
+        component: Component,
+    ) -> PyResult<Bound<'p, PyAny>> {
+        let rs_publisher = self.inner.clone();
+        let rs_component = component.inner.clone();
+        pyo3_async_runtimes::tokio::future_into_py(py, async move {
+            let _ = rs_publisher
+                .create_service(rs_component)
+                .await
+                .map_err(to_pyerr)?;
+            Ok(())
+        })
+    }
+
+    fn publish<'p>(
+        &self,
+        py: Python<'p>,
+        request_active_slots: u64,
+        request_total_slots: u64,
+        kv_active_blocks: u64,
+        kv_total_blocks: u64,
+    ) -> PyResult<()> {
+        self.inner
+            .publish(
+                llm_rs::kv_router::protocols::ForwardPassMetrics {
+                    request_active_slots,
+                    request_total_slots,
+                    kv_active_blocks,
+                    kv_total_blocks,
+                }
+                .into(),
+            )
+            .map_err(to_pyerr)
+    }
+}

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

@@ -128,7 +128,7 @@ class Client:
 
 class KvRouter:
     """
-    The runtime object for a distributed NOVA applications
+    A router will determine which worker should handle a given request.
     """
 
     ...
@@ -138,9 +138,36 @@ class KvRouter:
         Create a `KvRouter` object that is associated with the `component`
         """
 
-    def schedule(self, token_ids: List[int], lora_id: int) -> str:
+    def schedule(self, token_ids: List[int], lora_id: int) -> int:
         """
         Return the worker id that should handle the given token ids,
         exception will be raised if there is no worker available.
         """
         ...
+
+class KvMetricsPublisher:
+    """
+    A metrics publisher will provide KV metrics to the router.
+    """
+
+    ...
+
+    def __init__(self) -> None:
+        """
+        Create a `KvMetricsPublisher` object
+        """
+
+    def create_service(self, component: Component) -> None:
+        """
+        Similar to Component.create_service, but only service created through
+        this method will interact with KV router of the same component.
+        """
+
+    def publish(self, request_active_slots: int,
+        request_total_slots: int,
+        kv_active_blocks: int,
+        kv_total_blocks: int) -> None:
+        """
+        Update the KV metrics being reported.
+        """
+        ...

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

@@ -13,4 +13,5 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from triton_distributed._core import KvMetricsPublisher as KvMetricsPublisher
 from triton_distributed._core import KvRouter as KvRouter

lib/bindings/python/src/triton_distributed/runtime/__init__.py

@@ -20,7 +20,8 @@ from typing import Any, AsyncGenerator, Callable, Type
 
 from pydantic import BaseModel, ValidationError
 
-from triton_distributed._core import DistributedRuntime
+from triton_distributed._core import Client as Client
+from triton_distributed._core import DistributedRuntime as DistributedRuntime
 
 
 def triton_worker():

lib/llm/src/kv_router.rs

@@ -23,14 +23,11 @@ use triton_distributed_runtime::{component::Component, DistributedRuntime};
 pub mod indexer;
 pub mod protocols;
 pub mod publisher;
-// [WIP] enable service_builder() through worker for metrics reporting
-// pub mod worker;
 mod scheduler;
 mod scoring;
 
 use crate::kv_router::{
     indexer::{KvIndexer, KvIndexerInterface, RouterEvent},
-    protocols::KV_BLOCK_SIZE,
     scheduler::{Endpoint, KvScheduler, Service},
     scoring::ProcessedEndpoints,
 };
@@ -113,7 +110,7 @@ impl KvRouter {
     }
 
     // [TODO] indexer needs to take 'lora_id' as parameter
-    pub async fn schedule(&self, token_ids: &Vec<u32>, _lora_id: u64) -> Result<String> {
+    pub async fn schedule(&self, token_ids: &Vec<u32>, _lora_id: u64) -> Result<i64> {
         // Extracting part of the code in KvRouter::generate() for only
         // the decision making part, routing is done by the caller
         let isl_tokens = token_ids.len();
@@ -122,25 +119,8 @@ impl KvRouter {
             .find_matches_for_request(token_ids.as_slice())
             .await?;
         log::debug!("KV router overlap_scores: {:?}", overlap_scores);
-        // [FIXME] Python binding results in "endpoint subscriber shutdown" error,
-        // need to investigate whether it happens in pure rust as well and then
-        // root cause it. Before that, not doing intelligent scheduling for rapid
-        // development..
-        // [FIXME] also need to fix that scheduler returns worker subject which is not
-        // the same as worker id (uuid). Seems like it adds additional annotation on top of uuid.
-        // Need to double check
-        // 'worker_subject' should be the same as worker id used for direct routing
-        // let worker_subject = self.scheduler.schedule(overlap_scores, isl_tokens).await?;
-        let mut selected_worker_subject = Option::<String>::None;
-        for (worker_subject, overlap_score) in &overlap_scores.scores {
-            if ((*overlap_score as usize * KV_BLOCK_SIZE) as f64 / isl_tokens as f64) >= 0.5 {
-                selected_worker_subject = Some(worker_subject.to_string());
-            }
-        }
-        match selected_worker_subject {
-            None => Err(anyhow::anyhow!("No worker found")),
-            Some(worker_subject) => Ok(worker_subject),
-        }
+        let worker_id = self.scheduler.schedule(overlap_scores, isl_tokens).await?;
+        Ok(worker_id)
     }
 }
 
@@ -167,7 +147,7 @@ async fn collect_endpoints(
             .unwrap();
 
         // [FIXME] Endpoint is parsed from nats stats handler which may not include 'data' field
-        // if the service hasn't registered the handler.
+        // if the service hasn't registered the handler. Need to be tolerant to this.
         // Another option is to make sure the router is configured properly that
         // it listens to the right subject (where other publisher has stats).
         let services: Vec<Service> = values

lib/llm/src/kv_router/indexer.rs

@@ -79,7 +79,7 @@ pub enum KvRouterError {
 }
 
 /// Identifier of a LLM worker which emits events to the router.
-pub type WorkerId = uuid::Uuid;
+pub type WorkerId = i64;
 
 /// A shared reference to a [`RadixBlock`].
 type SharedRadixBlock = Rc<RefCell<RadixBlock>>;

lib/llm/src/kv_router/publisher.rs

@@ -13,20 +13,20 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use crate::kv_router::{indexer::RouterEvent, protocols::KvCacheEvent, KV_EVENT_SUBJECT};
+use crate::kv_router::{indexer::RouterEvent, protocols::*, KV_EVENT_SUBJECT};
+use std::sync::Arc;
 use tokio::sync::mpsc;
 use tracing as log;
 use triton_distributed_runtime::{component::Component, DistributedRuntime, Result};
-use uuid::Uuid;
 
-pub struct KvPublisher {
+pub struct KvEventPublisher {
     tx: mpsc::UnboundedSender<KvCacheEvent>,
 }
 
-impl KvPublisher {
-    pub fn new(drt: DistributedRuntime, backend: Component, worker_id: Uuid) -> Result<Self> {
+impl KvEventPublisher {
+    pub fn new(drt: DistributedRuntime, backend: Component, worker_id: i64) -> Result<Self> {
         let (tx, rx) = mpsc::unbounded_channel::<KvCacheEvent>();
-        let p = KvPublisher { tx };
+        let p = KvEventPublisher { tx };
 
         start_publish_task(drt, backend, worker_id, rx);
         Ok(p)
@@ -41,12 +41,10 @@ impl KvPublisher {
 fn start_publish_task(
     drt: DistributedRuntime,
     backend: Component,
-    worker_id: Uuid,
+    worker_id: i64,
     mut rx: mpsc::UnboundedReceiver<KvCacheEvent>,
 ) {
     let client = drt.nats_client().client().clone();
-    // [FIXME] service name is for metrics polling?
-    // let service_name = backend.service_name();
     let kv_subject = backend.event_subject(KV_EVENT_SUBJECT);
     log::info!("Publishing KV Events to subject: {}", kv_subject);
 
@@ -61,3 +59,37 @@ fn start_publish_task(
         }
     });
 }
+
+pub struct KvMetricsPublisher {
+    tx: tokio::sync::watch::Sender<Arc<ForwardPassMetrics>>,
+    rx: tokio::sync::watch::Receiver<Arc<ForwardPassMetrics>>,
+}
+
+impl KvMetricsPublisher {
+    pub fn new() -> Result<Self> {
+        let (tx, rx) = tokio::sync::watch::channel(Arc::new(ForwardPassMetrics::default()));
+        Ok(KvMetricsPublisher { tx, rx })
+    }
+
+    pub fn publish(
+        &self,
+        metrics: Arc<ForwardPassMetrics>,
+    ) -> Result<(), tokio::sync::watch::error::SendError<Arc<ForwardPassMetrics>>> {
+        log::debug!("Publish metrics: {:?}", metrics);
+        self.tx.send(metrics)
+    }
+
+    pub async fn create_service(&self, component: Component) -> Result<()> {
+        let mut metrics_rx = self.rx.clone();
+        let _ = component
+            .service_builder()
+            .stats_handler(Some(Box::new(move |name, stats| {
+                log::debug!("[IN worker?] Stats for service {}: {:?}", name, stats);
+                let metrics = metrics_rx.borrow_and_update().clone();
+                serde_json::to_value(&*metrics).unwrap()
+            })))
+            .create()
+            .await?;
+        Ok(())
+    }
+}

lib/llm/src/kv_router/scheduler.rs

@@ -17,8 +17,6 @@ use serde::{Deserialize, Serialize};
 use std::borrow::BorrowMut;
 use std::cmp::min;
 
-use uuid::Uuid;
-
 use crate::kv_router::indexer::OverlapScores;
 pub use crate::kv_router::protocols::{ForwardPassMetrics, KV_BLOCK_SIZE};
 use crate::kv_router::scoring::ProcessedEndpoints;
@@ -44,16 +42,17 @@ pub struct Endpoint {
 }
 
 impl Endpoint {
-    pub fn worker_id(&self) -> Uuid {
-        Uuid::parse_str(
+    pub fn worker_id(&self) -> i64 {
+        i64::from_str_radix(
             self.subject
-                .split(".")
+                .split("-")
                 .last()
                 .expect("invalid subject")
                 .to_string()
                 .as_str(),
+            16,
         )
-        .expect("invalid uuid")
+        .expect("invalid worker id")
     }
 }
 
@@ -69,11 +68,11 @@ pub struct Service {
 pub struct SchedulingRequest {
     isl_tokens: usize,
     overlap: OverlapScores,
-    resp_tx: tokio::sync::oneshot::Sender<String>,
+    resp_tx: tokio::sync::oneshot::Sender<i64>,
 }
 
 impl SchedulingRequest {
-    pub fn respond(self, worker_id: String) {
+    pub fn respond(self, worker_id: i64) {
         if self.resp_tx.send(worker_id).is_err() {
             tracing::trace!("failed to send response to requestor");
         }
@@ -174,7 +173,7 @@ impl KvScheduler {
         &self,
         overlap: OverlapScores,
         isl_tokens: usize,
-    ) -> Result<String, KvSchedulerError> {
+    ) -> Result<i64, KvSchedulerError> {
         let (resp_tx, resp_rx) = tokio::sync::oneshot::channel();
         let request = SchedulingRequest {
             isl_tokens,
@@ -199,7 +198,7 @@ impl KvScheduler {
 pub fn select_worker(
     workers: &mut ProcessedEndpoints,
     request: &SchedulingRequest,
-) -> Result<String, KvSchedulerError> {
+) -> Result<i64, KvSchedulerError> {
     // balance mode prioritizes balancing load across workers
     let balance_threshold: f64 = 0.1;
     let balance_mode = workers.load_std > balance_threshold * workers.load_avg;
@@ -227,6 +226,7 @@ pub fn select_worker(
         let kv_load_ratio = w.data.kv_active_blocks as f64 / w.data.kv_total_blocks as f64;
         let load_deviation = kv_load_ratio - workers.load_avg;
 
+        // [FIXME] multiple endpoints of the same worker cause out of bound error
         let worker_id = workers.worker_ids[i];
         let overlap_score = request.overlap.scores.get(&worker_id).map_or(0, |x| *x);
         let overlap_score = overlap_score as usize * KV_BLOCK_SIZE;
@@ -267,10 +267,10 @@ pub fn select_worker(
         Some(i) => {
             tracing::info!(
                 "selected worker: {}; cost: {}",
-                workers.endpoints[i].subject,
+                workers.endpoints[i].worker_id(),
                 best_cost
             );
-            Ok(workers.endpoints[i].subject.clone())
+            Ok(workers.endpoints[i].worker_id())
         }
         None => {
             tracing::debug!("all workers busy");

lib/llm/src/kv_router/scoring.rs

@@ -18,12 +18,11 @@
 use std::collections::HashSet;
 
 use crate::kv_router::scheduler::Endpoint;
-use uuid::Uuid;
 
 #[derive(Debug, Default)]
 pub struct ProcessedEndpoints {
     pub endpoints: Vec<Endpoint>,
-    pub worker_ids: Vec<Uuid>,
+    pub worker_ids: Vec<i64>,
     pub load_avg: f64,
     pub load_std: f64,
 }
@@ -43,8 +42,8 @@ impl ProcessedEndpoints {
             / load_values.len() as f64;
         let load_std = variance.sqrt();
 
-        let worker_ids: HashSet<Uuid> = endpoints.iter().map(|x| x.worker_id()).collect();
-        let worker_ids: Vec<Uuid> = worker_ids.into_iter().collect();
+        let worker_ids: HashSet<i64> = endpoints.iter().map(|x| x.worker_id()).collect();
+        let worker_ids: Vec<i64> = worker_ids.into_iter().collect();
 
         ProcessedEndpoints {
             endpoints,

lib/llm/src/protocols/common.rs

@@ -34,7 +34,6 @@ use std::time::SystemTime;
 
 use super::TokenIdType;
 
-pub mod kv_routing;
 pub mod llm_backend;
 pub mod postprocessor;
 pub mod preprocessor;

pyproject.toml

@@ -74,9 +74,6 @@ addopts = [
     "--mypy",
     "--ignore-glob=*model.py",
     # FIXME: Get relative/generic blob paths to work here
-    # Ignore rust<->python bindings until python package is built/installed in environment
-    "--ignore-glob=/workspace/python-wheel/python/triton_distributed_rs/*.py",
-    "--ignore-glob=/workspace/python-wheel/python/triton_distributed_rs/*.pyi",
 ]
 xfail_strict = true
 log_cli_level = "INFO"