import asyncio from collections import defaultdict from itertools import chain import os import random import time from dataclasses import dataclass, field from typing import Dict, Any, List, Optional, Tuple from uuid import uuid4, UUID from pydantic import BaseModel import ray import ray.cloudpickle as pickle from ray.serve.autoscaling_policy import BasicAutoscalingPolicy from ray.serve.backend_worker import create_backend_replica from ray.serve.constants import (ASYNC_CONCURRENCY, SERVE_PROXY_NAME, LongPollKey) from ray.serve.http_proxy import HTTPProxyActor from ray.serve.kv_store import RayInternalKVStore from ray.serve.exceptions import RayServeException from ray.serve.utils import (format_actor_name, get_random_letters, logger, try_schedule_resources_on_nodes, get_all_node_ids) from ray.serve.config import BackendConfig, ReplicaConfig from ray.serve.long_poll import LongPollHost from ray.actor import ActorHandle import numpy as np # Used for testing purposes only. If this is set, the controller will crash # after writing each checkpoint with the specified probability. _CRASH_AFTER_CHECKPOINT_PROBABILITY = 0 CHECKPOINT_KEY = "serve-controller-checkpoint" # Feature flag for controller resource checking. If true, controller will # error if the desired replicas exceed current resource availability. _RESOURCE_CHECK_ENABLED = True # How often to call the control loop on the controller. CONTROL_LOOP_PERIOD_S = 1.0 REPLICA_STARTUP_TIME_WARNING_S = 5 # TypeDefs BackendTag = str EndpointTag = str ReplicaTag = str NodeId = str GoalId = int class TrafficPolicy: def __init__(self, traffic_dict: Dict[str, float]) -> None: self.traffic_dict: Dict[str, float] = dict() self.shadow_dict: Dict[str, float] = dict() self.set_traffic_dict(traffic_dict) def set_traffic_dict(self, traffic_dict: Dict[str, float]) -> None: prob = 0 for backend, weight in traffic_dict.items(): if weight < 0: raise ValueError( "Attempted to assign a weight of {} to backend '{}'. " "Weights cannot be negative.".format(weight, backend)) prob += weight # These weights will later be plugged into np.random.choice, which # uses a tolerance of 1e-8. if not np.isclose(prob, 1, atol=1e-8): raise ValueError("Traffic dictionary weights must sum to 1, " "currently they sum to {}".format(prob)) self.traffic_dict = traffic_dict def set_shadow(self, backend: str, proportion: float): if proportion == 0 and backend in self.shadow_dict: del self.shadow_dict[backend] else: self.shadow_dict[backend] = proportion def __repr__(self) -> str: return f"" class BackendInfo(BaseModel): # TODO(architkulkarni): Add type hint for worker_class after upgrading # cloudpickle and adding types to RayServeWrappedReplica worker_class: Any backend_config: BackendConfig replica_config: ReplicaConfig class Config: # TODO(architkulkarni): Remove once ReplicaConfig is a pydantic # model arbitrary_types_allowed = True @dataclass class SystemState: backends: Dict[BackendTag, BackendInfo] = field(default_factory=dict) traffic_policies: Dict[EndpointTag, TrafficPolicy] = field( default_factory=dict) routes: Dict[BackendTag, Tuple[EndpointTag, Any]] = field( default_factory=dict) backend_goal_ids: Dict[BackendTag, GoalId] = field(default_factory=dict) traffic_goal_ids: Dict[EndpointTag, GoalId] = field(default_factory=dict) route_goal_ids: Dict[BackendTag, GoalId] = field(default_factory=dict) def get_backend_configs(self) -> Dict[BackendTag, BackendConfig]: return { tag: info.backend_config for tag, info in self.backends.items() } def get_backend(self, backend_tag: BackendTag) -> Optional[BackendInfo]: return self.backends.get(backend_tag) def add_backend(self, backend_tag: BackendTag, backend_info: BackendInfo, goal_id: GoalId = 0) -> None: self.backends[backend_tag] = backend_info self.backend_goal_ids = goal_id def get_endpoints(self) -> Dict[EndpointTag, Dict[str, Any]]: endpoints = {} for route, (endpoint, methods) in self.routes.items(): if endpoint in self.traffic_policies: traffic_policy = self.traffic_policies[endpoint] traffic_dict = traffic_policy.traffic_dict shadow_dict = traffic_policy.shadow_dict else: traffic_dict = {} shadow_dict = {} endpoints[endpoint] = { "route": route if route.startswith("/") else None, "methods": methods, "traffic": traffic_dict, "shadows": shadow_dict, } return endpoints @dataclass class ActorStateReconciler: controller_name: str = field(init=True) detached: bool = field(init=True) http_proxy_cache: Dict[NodeId, ActorHandle] = field(default_factory=dict) backend_replicas: Dict[BackendTag, Dict[ReplicaTag, ActorHandle]] = field( default_factory=lambda: defaultdict(dict)) backend_replicas_to_start: Dict[BackendTag, List[ReplicaTag]] = field( default_factory=lambda: defaultdict(list)) backend_replicas_to_stop: Dict[BackendTag, List[ReplicaTag]] = field( default_factory=lambda: defaultdict(list)) backends_to_remove: List[BackendTag] = field(default_factory=list) # NOTE(ilr): These are not checkpointed, but will be recreated by # `_enqueue_pending_scale_changes_loop`. currently_starting_replicas: Dict[asyncio.Future, Tuple[ BackendTag, ReplicaTag, ActorHandle]] = field(default_factory=dict) currently_stopping_replicas: Dict[asyncio.Future, Tuple[ BackendTag, ReplicaTag]] = field(default_factory=dict) def __getstate__(self): state = self.__dict__.copy() del state["currently_stopping_replicas"] del state["currently_starting_replicas"] return state def __setstate__(self, state): self.__dict__.update(state) self.currently_stopping_replicas = {} self.currently_starting_replicas = {} # TODO(edoakes): consider removing this and just using the names. def http_proxy_handles(self) -> List[ActorHandle]: return list(self.http_proxy_cache.values()) def get_replica_handles(self) -> List[ActorHandle]: return list( chain.from_iterable([ replica_dict.values() for replica_dict in self.backend_replicas.values() ])) def get_replica_tags(self) -> List[ReplicaTag]: return list( chain.from_iterable([ replica_dict.keys() for replica_dict in self.backend_replicas.values() ])) async def _start_backend_replica(self, current_state: SystemState, backend_tag: BackendTag, replica_tag: ReplicaTag) -> ActorHandle: """Start a replica and return its actor handle. Checks if the named actor already exists before starting a new one. Assumes that the backend configuration is already in the Goal State. """ # NOTE(edoakes): the replicas may already be created if we # failed after creating them but before writing a # checkpoint. replica_name = format_actor_name(replica_tag, self.controller_name) try: replica_handle = ray.get_actor(replica_name) except ValueError: logger.debug("Starting replica '{}' for backend '{}'.".format( replica_tag, backend_tag)) backend_info = current_state.get_backend(backend_tag) replica_handle = ray.remote(backend_info.worker_class).options( name=replica_name, lifetime="detached" if self.detached else None, max_restarts=-1, max_task_retries=-1, **backend_info.replica_config.ray_actor_options).remote( backend_tag, replica_tag, backend_info.replica_config.actor_init_args, backend_info.backend_config, self.controller_name) return replica_handle def _scale_backend_replicas(self, backends: Dict[BackendTag, BackendInfo], backend_tag: BackendTag, num_replicas: int) -> None: """Scale the given backend to the number of replicas. NOTE: this does not actually start or stop the replicas, but instead adds the intention to start/stop them to self.backend_replicas_to_start and self.backend_replicas_to_stop. The caller is responsible for then first writing a checkpoint and then actually starting/stopping the intended replicas. This avoids inconsistencies with starting/stopping a replica and then crashing before writing a checkpoint. """ logger.debug("Scaling backend '{}' to {} replicas".format( backend_tag, num_replicas)) assert (backend_tag in backends ), "Backend {} is not registered.".format(backend_tag) assert num_replicas >= 0, ("Number of replicas must be" " greater than or equal to 0.") current_num_replicas = len(self.backend_replicas[backend_tag]) delta_num_replicas = num_replicas - current_num_replicas backend_info = backends[backend_tag] if delta_num_replicas > 0: can_schedule = try_schedule_resources_on_nodes(requirements=[ backend_info.replica_config.resource_dict for _ in range(delta_num_replicas) ]) if _RESOURCE_CHECK_ENABLED and not all(can_schedule): num_possible = sum(can_schedule) raise RayServeException( "Cannot scale backend {} to {} replicas. Ray Serve tried " "to add {} replicas but the resources only allows {} " "to be added. To fix this, consider scaling to replica to " "{} or add more resources to the cluster. You can check " "avaiable resources with ray.nodes().".format( backend_tag, num_replicas, delta_num_replicas, num_possible, current_num_replicas + num_possible)) logger.debug("Adding {} replicas to backend {}".format( delta_num_replicas, backend_tag)) for _ in range(delta_num_replicas): replica_tag = "{}#{}".format(backend_tag, get_random_letters()) self.backend_replicas_to_start[backend_tag].append(replica_tag) elif delta_num_replicas < 0: logger.debug("Removing {} replicas from backend '{}'".format( -delta_num_replicas, backend_tag)) assert len( self.backend_replicas[backend_tag]) >= delta_num_replicas for _ in range(-delta_num_replicas): replica_tag, _ = self.backend_replicas[backend_tag].popitem() if len(self.backend_replicas[backend_tag]) == 0: del self.backend_replicas[backend_tag] self.backend_replicas_to_stop[backend_tag].append(replica_tag) async def _enqueue_pending_scale_changes_loop(self, current_state: SystemState): for backend_tag, replicas_to_create in self.backend_replicas_to_start.\ items(): for replica_tag in replicas_to_create: replica_handle = await self._start_backend_replica( current_state, backend_tag, replica_tag) ready_future = replica_handle.ready.remote().as_future() self.currently_starting_replicas[ready_future] = ( backend_tag, replica_tag, replica_handle) for backend_tag, replicas_to_stop in self.backend_replicas_to_stop.\ items(): for replica_tag in replicas_to_stop: replica_name = format_actor_name(replica_tag, self.controller_name) async def kill_actor(replica_name_to_use): # NOTE: the replicas may already be stopped if we failed # after stopping them but before writing a checkpoint. try: replica = ray.get_actor(replica_name_to_use) except ValueError: return # TODO(edoakes): this logic isn't ideal because there may # be pending tasks still executing on the replica. However, # if we use replica.__ray_terminate__, we may send it while # the replica is being restarted and there's no way to tell # if it successfully killed the worker or not. ray.kill(replica, no_restart=True) self.currently_stopping_replicas[asyncio.ensure_future( kill_actor(replica_name))] = (backend_tag, replica_tag) async def _check_currently_starting_replicas(self) -> bool: """Returns a boolean specifying if there are more replicas to start""" in_flight = list() if self.currently_starting_replicas: done, in_flight = await asyncio.wait( list(self.currently_starting_replicas.keys()), timeout=0) for fut in done: (backend_tag, replica_tag, replica_handle) = self.currently_starting_replicas.pop(fut) self.backend_replicas[backend_tag][ replica_tag] = replica_handle backend = self.backend_replicas_to_start.get(backend_tag) if backend: try: backend.remove(replica_tag) except ValueError: pass if len(backend) == 0: del self.backend_replicas_to_start[backend_tag] return len(in_flight) > 0 async def _check_currently_stopping_replicas(self) -> bool: """Returns a boolean specifying if there are more replicas to stop""" in_flight = list() if self.currently_stopping_replicas: done_stoppping, in_flight = await asyncio.wait( list(self.currently_stopping_replicas.keys()), timeout=0) for fut in done_stoppping: (backend_tag, replica_tag) = self.currently_stopping_replicas.pop(fut) backend = self.backend_replicas_to_stop.get(backend_tag) if backend: try: backend.remove(replica_tag) except ValueError: pass if len(backend) == 0: del self.backend_replicas_to_stop[backend_tag] return len(in_flight) > 0 async def backend_control_loop(self): start = time.time() prev_warning = start need_to_continue = True while need_to_continue: if time.time() - prev_warning > REPLICA_STARTUP_TIME_WARNING_S: prev_warning = time.time() logger.warning("Waited {:.2f}s for replicas to start up. Make " "sure there are enough resources to create the " "replicas.".format(time.time() - start)) need_to_continue = ( await self._check_currently_starting_replicas() or await self._check_currently_stopping_replicas()) asyncio.sleep(1) def _start_http_proxies_if_needed(self, http_host: str, http_port: str, http_middlewares: List[Any]) -> None: """Start an HTTP proxy on every node if it doesn't already exist.""" if http_host is None: return for node_id, node_resource in get_all_node_ids(): if node_id in self.http_proxy_cache: continue name = format_actor_name(SERVE_PROXY_NAME, self.controller_name, node_id) try: proxy = ray.get_actor(name) except ValueError: logger.info("Starting HTTP proxy with name '{}' on node '{}' " "listening on '{}:{}'".format( name, node_id, http_host, http_port)) proxy = HTTPProxyActor.options( name=name, lifetime="detached" if self.detached else None, max_concurrency=ASYNC_CONCURRENCY, max_restarts=-1, max_task_retries=-1, resources={ node_resource: 0.01 }, ).remote( http_host, http_port, controller_name=self.controller_name, http_middlewares=http_middlewares) self.http_proxy_cache[node_id] = proxy def _stop_http_proxies_if_needed(self) -> bool: """Removes HTTP proxy actors from any nodes that no longer exist. Returns whether or not any actors were removed (a checkpoint should be taken). """ actor_stopped = False all_node_ids = {node_id for node_id, _ in get_all_node_ids()} to_stop = [] for node_id in self.http_proxy_cache: if node_id not in all_node_ids: logger.info("Removing HTTP proxy on removed node '{}'.".format( node_id)) to_stop.append(node_id) for node_id in to_stop: proxy = self.http_proxy_cache.pop(node_id) ray.kill(proxy, no_restart=True) actor_stopped = True return actor_stopped def _recover_actor_handles(self) -> None: # Refresh the RouterCache for node_id in self.http_proxy_cache.keys(): name = format_actor_name(SERVE_PROXY_NAME, self.controller_name, node_id) self.http_proxy_cache[node_id] = ray.get_actor(name) # Fetch actor handles for all of the backend replicas in the system. # All of these backend_replicas are guaranteed to already exist because # they would not be written to a checkpoint in self.backend_replicas # until they were created. for backend_tag, replica_dict in self.backend_replicas.items(): for replica_tag in replica_dict.keys(): replica_name = format_actor_name(replica_tag, self.controller_name) self.backend_replicas[backend_tag][ replica_tag] = ray.get_actor(replica_name) async def _recover_from_checkpoint( self, current_state: SystemState, controller: "ServeController" ) -> Dict[BackendTag, BasicAutoscalingPolicy]: self._recover_actor_handles() autoscaling_policies = dict() for backend, info in current_state.backends.items(): metadata = info.backend_config.internal_metadata if metadata.autoscaling_config is not None: autoscaling_policies[backend] = BasicAutoscalingPolicy( backend, metadata.autoscaling_config) # Start/stop any pending backend replicas. await self._enqueue_pending_scale_changes_loop(current_state) await self.backend_control_loop() return autoscaling_policies @dataclass class FutureResult: # Goal requested when this future was created requested_goal: Dict[str, Any] @dataclass class Checkpoint: goal_state: SystemState current_state: SystemState reconciler: ActorStateReconciler # TODO(ilr) Rename reconciler to PendingState inflight_reqs: Dict[uuid4, FutureResult] @ray.remote class ServeController: """Responsible for managing the state of the serving system. The controller implements fault tolerance by persisting its state in a new checkpoint each time a state change is made. If the actor crashes, the latest checkpoint is loaded and the state is recovered. Checkpoints are written/read using a provided KV-store interface. All hard state in the system is maintained by this actor and persisted via these checkpoints. Soft state required by other components is fetched by those actors from this actor on startup and updates are pushed out from this actor. All other actors started by the controller are named, detached actors so they will not fate share with the controller if it crashes. The following guarantees are provided for state-changing calls to the controller: - If the call succeeds, the change was made and will be reflected in the system even if the controller or other actors die unexpectedly. - If the call fails, the change may have been made but isn't guaranteed to have been. The client should retry in this case. Note that this requires all implementations here to be idempotent. """ async def __init__(self, controller_name: str, http_host: str, http_port: str, http_middlewares: List[Any], detached: bool = False): # Used to read/write checkpoints. self.kv_store = RayInternalKVStore(namespace=controller_name) # Current State self.current_state = SystemState() # Goal State # TODO(ilr) This is currently *unused* until the refactor of the serve # controller. self.goal_state = SystemState() # ActorStateReconciler self.actor_reconciler = ActorStateReconciler(controller_name, detached) # backend -> AutoscalingPolicy self.autoscaling_policies = dict() # Dictionary of backend_tag -> proxy_name -> most recent queue length. self.backend_stats = defaultdict(lambda: defaultdict(dict)) # Used to ensure that only a single state-changing operation happens # at any given time. self.write_lock = asyncio.Lock() self.http_host = http_host self.http_port = http_port self.http_middlewares = http_middlewares # If starting the actor for the first time, starts up the other system # components. If recovering, fetches their actor handles. self.actor_reconciler._start_http_proxies_if_needed( self.http_host, self.http_port, self.http_middlewares) # Map of awaiting results # TODO(ilr): Checkpoint this once this becomes asynchronous self.inflight_results: Dict[UUID, asyncio.Event] = dict() self._serializable_inflight_results: Dict[UUID, FutureResult] = dict() checkpoint = self.kv_store.get(CHECKPOINT_KEY) if checkpoint is None: logger.debug("No checkpoint found") else: await self._recover_from_checkpoint(checkpoint) # NOTE(simon): Currently we do all-to-all broadcast. This means # any listeners will receive notification for all changes. This # can be problem at scale, e.g. updating a single backend config # will send over the entire configs. In the future, we should # optimize the logic to support subscription by key. self.long_poll_host = LongPollHost() # The configs pushed out here get updated by # self._recover_from_checkpoint in the failure scenario, so that must # be run before we notify the changes. self.notify_backend_configs_changed() self.notify_replica_handles_changed() self.notify_traffic_policies_changed() self.notify_route_table_changed() asyncio.get_event_loop().create_task(self.run_control_loop()) async def wait_for_event(self, uuid: UUID) -> bool: if uuid not in self.inflight_results: return True event = self.inflight_results[uuid] await event.wait() self.inflight_results.pop(uuid) self._serializable_inflight_results.pop(uuid) async with self.write_lock: self._checkpoint() return True def _create_event_with_result( self, goal_state: Dict[str, any], recreation_uuid: Optional[UUID] = None) -> UUID: # NOTE(ilr) Must be called before checkpointing! event = asyncio.Event() event.result = FutureResult(goal_state) event.set() uuid_val = recreation_uuid or uuid4() self.inflight_results[uuid_val] = event self._serializable_inflight_results[uuid_val] = event.result return uuid_val async def _num_inflight_results(self) -> int: return len(self.inflight_results) def notify_replica_handles_changed(self): self.long_poll_host.notify_changed( LongPollKey.REPLICA_HANDLES, { backend_tag: list(replica_dict.values()) for backend_tag, replica_dict in self.actor_reconciler.backend_replicas.items() }) def notify_traffic_policies_changed(self): self.long_poll_host.notify_changed( LongPollKey.TRAFFIC_POLICIES, self.current_state.traffic_policies, ) def notify_backend_configs_changed(self): self.long_poll_host.notify_changed( LongPollKey.BACKEND_CONFIGS, self.current_state.get_backend_configs()) def notify_route_table_changed(self): self.long_poll_host.notify_changed(LongPollKey.ROUTE_TABLE, self.current_state.routes) async def listen_for_change(self, keys_to_snapshot_ids: Dict[str, int]): """Proxy long pull client's listen request. Args: keys_to_snapshot_ids (Dict[str, int]): Snapshot IDs are used to determine whether or not the host should immediately return the data or wait for the value to be changed. """ return await ( self.long_poll_host.listen_for_change(keys_to_snapshot_ids)) def get_http_proxies(self) -> Dict[str, ActorHandle]: """Returns a dictionary of node ID to http_proxy actor handles.""" return self.actor_reconciler.http_proxy_cache def _checkpoint(self) -> None: """Checkpoint internal state and write it to the KV store.""" assert self.write_lock.locked() logger.debug("Writing checkpoint") start = time.time() checkpoint = pickle.dumps( Checkpoint(self.goal_state, self.current_state, self.actor_reconciler, self._serializable_inflight_results)) self.kv_store.put(CHECKPOINT_KEY, checkpoint) logger.debug("Wrote checkpoint in {:.2f}".format(time.time() - start)) if random.random( ) < _CRASH_AFTER_CHECKPOINT_PROBABILITY and self.detached: logger.warning("Intentionally crashing after checkpoint") os._exit(0) async def _recover_from_checkpoint(self, checkpoint_bytes: bytes) -> None: """Recover the instance state from the provided checkpoint. This should be called in the constructor to ensure that the internal state is updated before any other operations run. After running this, internal state will be updated and long-poll clients may be notified. Performs the following operations: 1) Deserializes the internal state from the checkpoint. 2) Starts/stops any replicas that are pending creation or deletion. """ start = time.time() logger.info("Recovering from checkpoint") restored_checkpoint: Checkpoint = pickle.loads(checkpoint_bytes) self.current_state = restored_checkpoint.current_state self.actor_reconciler = restored_checkpoint.reconciler self._serializable_inflight_results = restored_checkpoint.inflight_reqs for uuid, fut_result in self._serializable_inflight_results.items(): self._create_event_with_result(fut_result.requested_goal, uuid) # NOTE(edoakes): unfortunately, we can't completely recover from a # checkpoint in the constructor because we block while waiting for # other actors to start up, and those actors fetch soft state from # this actor. Because no other tasks will start executing until after # the constructor finishes, if we were to run this logic in the # constructor it could lead to deadlock between this actor and a child. # However, we do need to guarantee that we have fully recovered from a # checkpoint before any other state-changing calls run. We address this # by acquiring the write_lock and then posting the task to recover from # a checkpoint to the event loop. Other state-changing calls acquire # this lock and will be blocked until recovering from the checkpoint # finishes. This can be removed once we move to the async control loop. async def finish_recover_from_checkpoint(): assert self.write_lock.locked() self.autoscaling_policies = await self.actor_reconciler.\ _recover_from_checkpoint(self.current_state, self) self.write_lock.release() logger.info( "Recovered from checkpoint in {:.3f}s".format(time.time() - start)) await self.write_lock.acquire() asyncio.get_event_loop().create_task(finish_recover_from_checkpoint()) async def do_autoscale(self) -> None: for backend, info in self.current_state.backends.items(): if backend not in self.autoscaling_policies: continue new_num_replicas = self.autoscaling_policies[backend].scale( self.backend_stats[backend], info.backend_config.num_replicas) if new_num_replicas > 0: await self.update_backend_config( backend, BackendConfig(num_replicas=new_num_replicas)) async def reconcile_current_and_goal_backends(self): pass # backends_to_delete = set( # self.current_state.backends.keys()).difference( # self.goal_state.backends.keys()) async def run_control_loop(self) -> None: while True: await self.do_autoscale() async with self.write_lock: self.actor_reconciler._start_http_proxies_if_needed( self.http_host, self.http_port, self.http_middlewares) checkpoint_required = self.actor_reconciler.\ _stop_http_proxies_if_needed() if checkpoint_required: self._checkpoint() await asyncio.sleep(CONTROL_LOOP_PERIOD_S) def _all_replica_handles( self) -> Dict[BackendTag, Dict[ReplicaTag, ActorHandle]]: """Used for testing.""" return self.actor_reconciler.backend_replicas def get_all_backends(self) -> Dict[BackendTag, BackendConfig]: """Returns a dictionary of backend tag to backend config.""" return self.current_state.get_backend_configs() def get_all_endpoints(self) -> Dict[EndpointTag, Dict[BackendTag, Any]]: """Returns a dictionary of backend tag to backend config.""" return self.current_state.get_endpoints() async def _set_traffic(self, endpoint_name: str, traffic_dict: Dict[str, float]) -> UUID: if endpoint_name not in self.current_state.get_endpoints(): raise ValueError("Attempted to assign traffic for an endpoint '{}'" " that is not registered.".format(endpoint_name)) assert isinstance(traffic_dict, dict), "Traffic policy must be a dictionary." for backend in traffic_dict: if self.current_state.get_backend(backend) is None: raise ValueError( "Attempted to assign traffic to a backend '{}' that " "is not registered.".format(backend)) traffic_policy = TrafficPolicy(traffic_dict) self.current_state.traffic_policies[endpoint_name] = traffic_policy return_uuid = self._create_event_with_result({ endpoint_name: traffic_policy }) # NOTE(edoakes): we must write a checkpoint before pushing the # update to avoid inconsistent state if we crash after pushing the # update. self._checkpoint() self.notify_traffic_policies_changed() return return_uuid async def set_traffic(self, endpoint_name: str, traffic_dict: Dict[str, float]) -> UUID: """Sets the traffic policy for the specified endpoint.""" async with self.write_lock: return_uuid = await self._set_traffic(endpoint_name, traffic_dict) return return_uuid async def shadow_traffic(self, endpoint_name: str, backend_tag: BackendTag, proportion: float) -> UUID: """Shadow traffic from the endpoint to the backend.""" async with self.write_lock: if endpoint_name not in self.current_state.get_endpoints(): raise ValueError("Attempted to shadow traffic from an " "endpoint '{}' that is not registered." .format(endpoint_name)) if self.current_state.get_backend(backend_tag) is None: raise ValueError( "Attempted to shadow traffic to a backend '{}' that " "is not registered.".format(backend_tag)) self.current_state.traffic_policies[endpoint_name].set_shadow( backend_tag, proportion) traffic_policy = self.current_state.traffic_policies[endpoint_name] return_uuid = self._create_event_with_result({ endpoint_name: traffic_policy }) # NOTE(edoakes): we must write a checkpoint before pushing the # update to avoid inconsistent state if we crash after pushing the # update. self._checkpoint() self.notify_traffic_policies_changed() return return_uuid # TODO(architkulkarni): add Optional for route after cloudpickle upgrade async def create_endpoint(self, endpoint: str, traffic_dict: Dict[str, float], route, methods) -> UUID: """Create a new endpoint with the specified route and methods. If the route is None, this is a "headless" endpoint that will not be exposed over HTTP and can only be accessed via a handle. """ async with self.write_lock: # If this is a headless endpoint with no route, key the endpoint # based on its name. # TODO(edoakes): we should probably just store routes and endpoints # separately. if route is None: route = endpoint # TODO(edoakes): move this to client side. err_prefix = "Cannot create endpoint." if route in self.current_state.routes: # Ensures this method is idempotent if self.current_state.routes[route] == (endpoint, methods): return else: raise ValueError( "{} Route '{}' is already registered.".format( err_prefix, route)) if endpoint in self.current_state.get_endpoints(): raise ValueError( "{} Endpoint '{}' is already registered.".format( err_prefix, endpoint)) logger.info( "Registering route '{}' to endpoint '{}' with methods '{}'.". format(route, endpoint, methods)) self.current_state.routes[route] = (endpoint, methods) # NOTE(edoakes): checkpoint is written in self._set_traffic. return_uuid = await self._set_traffic(endpoint, traffic_dict) self.notify_route_table_changed() return return_uuid async def delete_endpoint(self, endpoint: str) -> UUID: """Delete the specified endpoint. Does not modify any corresponding backends. """ logger.info("Deleting endpoint '{}'".format(endpoint)) async with self.write_lock: # This method must be idempotent. We should validate that the # specified endpoint exists on the client. for route, (route_endpoint, _) in self.current_state.routes.items(): if route_endpoint == endpoint: route_to_delete = route break else: logger.info("Endpoint '{}' doesn't exist".format(endpoint)) return # Remove the routing entry. del self.current_state.routes[route_to_delete] # Remove the traffic policy entry if it exists. if endpoint in self.current_state.traffic_policies: del self.current_state.traffic_policies[endpoint] return_uuid = self._create_event_with_result({ route_to_delete: None, endpoint: None }) # NOTE(edoakes): we must write a checkpoint before pushing the # updates to the proxies to avoid inconsistent state if we crash # after pushing the update. self._checkpoint() self.notify_route_table_changed() return return_uuid async def create_backend(self, backend_tag: BackendTag, backend_config: BackendConfig, replica_config: ReplicaConfig) -> UUID: """Register a new backend under the specified tag.""" async with self.write_lock: # Ensures this method is idempotent. backend_info = self.current_state.get_backend(backend_tag) if backend_info is not None: if (backend_info.backend_config == backend_config and backend_info.replica_config == replica_config): return backend_replica = create_backend_replica( replica_config.func_or_class) # Save creator that starts replicas, the arguments to be passed in, # and the configuration for the backends. backend_info = BackendInfo( worker_class=backend_replica, backend_config=backend_config, replica_config=replica_config) self.current_state.add_backend(backend_tag, backend_info) metadata = backend_config.internal_metadata if metadata.autoscaling_config is not None: self.autoscaling_policies[ backend_tag] = BasicAutoscalingPolicy( backend_tag, metadata.autoscaling_config) try: # This call should be to run control loop self.actor_reconciler._scale_backend_replicas( self.current_state.backends, backend_tag, backend_config.num_replicas) except RayServeException as e: del self.current_state.backends[backend_tag] raise e return_uuid = self._create_event_with_result({ backend_tag: backend_info }) # NOTE(edoakes): we must write a checkpoint before starting new # or pushing the updated config to avoid inconsistent state if we # crash while making the change. self._checkpoint() await self.actor_reconciler._enqueue_pending_scale_changes_loop( self.current_state) await self.actor_reconciler.backend_control_loop() self.notify_replica_handles_changed() # Set the backend config inside routers # (particularly for max_concurrent_queries). self.notify_backend_configs_changed() return return_uuid async def delete_backend(self, backend_tag: BackendTag) -> UUID: async with self.write_lock: # This method must be idempotent. We should validate that the # specified backend exists on the client. if self.current_state.get_backend(backend_tag) is None: return # Check that the specified backend isn't used by any endpoints. for endpoint, traffic_policy in self.current_state.\ traffic_policies.items(): if (backend_tag in traffic_policy.traffic_dict or backend_tag in traffic_policy.shadow_dict): raise ValueError("Backend '{}' is used by endpoint '{}' " "and cannot be deleted. Please remove " "the backend from all endpoints and try " "again.".format(backend_tag, endpoint)) # Scale its replicas down to 0. This will also remove the backend # from self.current_state.backends and # self.actor_reconciler.backend_replicas. self.goal_state.backends[backend_tag] = None # This should be a call to the control loop self.actor_reconciler._scale_backend_replicas( self.current_state.backends, backend_tag, 0) # Remove the backend's metadata. del self.current_state.backends[backend_tag] if backend_tag in self.autoscaling_policies: del self.autoscaling_policies[backend_tag] # Add the intention to remove the backend from the routers. self.actor_reconciler.backends_to_remove.append(backend_tag) return_uuid = self._create_event_with_result({backend_tag: None}) # NOTE(edoakes): we must write a checkpoint before removing the # backend from the routers to avoid inconsistent state if we crash # after pushing the update. self._checkpoint() await self.actor_reconciler._enqueue_pending_scale_changes_loop( self.current_state) await self.actor_reconciler.backend_control_loop() self.notify_replica_handles_changed() return return_uuid async def update_backend_config(self, backend_tag: BackendTag, config_options: BackendConfig) -> UUID: """Set the config for the specified backend.""" async with self.write_lock: assert (self.current_state.get_backend(backend_tag) ), "Backend {} is not registered.".format(backend_tag) assert isinstance(config_options, BackendConfig) stored_backend_config = self.current_state.get_backend( backend_tag).backend_config backend_config = stored_backend_config.copy( update=config_options.dict(exclude_unset=True)) backend_config._validate_complete() self.current_state.get_backend( backend_tag).backend_config = backend_config backend_info = self.current_state.get_backend(backend_tag) # Scale the replicas with the new configuration. # This should be to run the control loop self.actor_reconciler._scale_backend_replicas( self.current_state.backends, backend_tag, backend_config.num_replicas) return_uuid = self._create_event_with_result({ backend_tag: backend_info }) # NOTE(edoakes): we must write a checkpoint before pushing the # update to avoid inconsistent state if we crash after pushing the # update. self._checkpoint() # Inform the routers about change in configuration # (particularly for setting max_batch_size). await self.actor_reconciler._enqueue_pending_scale_changes_loop( self.current_state) await self.actor_reconciler.backend_control_loop() self.notify_replica_handles_changed() self.notify_backend_configs_changed() return return_uuid def get_backend_config(self, backend_tag: BackendTag) -> BackendConfig: """Get the current config for the specified backend.""" assert (self.current_state.get_backend(backend_tag) ), "Backend {} is not registered.".format(backend_tag) return self.current_state.get_backend(backend_tag).backend_config def get_http_config(self): """Return the HTTP proxy configuration.""" return self.http_host, self.http_port async def shutdown(self) -> None: """Shuts down the serve instance completely.""" async with self.write_lock: for http_proxy in self.actor_reconciler.http_proxy_handles(): ray.kill(http_proxy, no_restart=True) for replica in self.actor_reconciler.get_replica_handles(): ray.kill(replica, no_restart=True) self.kv_store.delete(CHECKPOINT_KEY)