/build/source/nativelink-scheduler/src/api_worker_scheduler.rs

Source
// Copyright 2024 The NativeLink Authors. All rights reserved.
//
// 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.

use std::ops::{Deref, DerefMut};
use std::sync::Arc;

use async_lock::Mutex;
use lru::LruCache;
use nativelink_config::schedulers::WorkerAllocationStrategy;
use nativelink_error::{error_if, make_err, make_input_err, Code, Error, ResultExt};
use nativelink_metric::{
    group, MetricFieldData, MetricKind, MetricPublishKnownKindData, MetricsComponent,
    RootMetricsComponent,
};
use nativelink_util::action_messages::{OperationId, WorkerId};
use nativelink_util::operation_state_manager::{UpdateOperationType, WorkerStateManager};
use nativelink_util::platform_properties::PlatformProperties;
use nativelink_util::spawn;
use nativelink_util::task::JoinHandleDropGuard;
use tokio::sync::mpsc::{self, UnboundedSender};
use tokio::sync::Notify;
use tonic::async_trait;
use tracing::{event, Level};

use crate::platform_property_manager::PlatformPropertyManager;
use crate::worker::{ActionInfoWithProps, Worker, WorkerTimestamp, WorkerUpdate};
use crate::worker_scheduler::WorkerScheduler;

struct Workers(LruCache<WorkerId, Worker>);

impl Deref for Workers {
    type Target = LruCache<WorkerId, Worker>;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl DerefMut for Workers {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.0
    }
}

// Note: This could not be a derive macro because this derive-macro
// does n ot support LruCache and nameless field structs.
impl MetricsComponent for Workers {
    fn publish(
        &self,
        _kind: MetricKind,
        _field_metadata: MetricFieldData,
    ) -> Result<MetricPublishKnownKindData, nativelink_metric::Error> {
        let _enter = group!("workers").entered();
        for (worker_id, worker) in self.iter() {
            let _enter = group!(worker_id).entered();
            worker.publish(MetricKind::Component, MetricFieldData::default())?;
        }
        Ok(MetricPublishKnownKindData::Component)
    }
}

/// A collection of workers that are available to run tasks.
#[derive(MetricsComponent)]
struct ApiWorkerSchedulerImpl {
    /// A `LruCache` of workers availabled based on `allocation_strategy`.
    #[metric(group = "workers")]
    workers: Workers,

    /// The worker state manager.
    #[metric(group = "worker_state_manager")]
    worker_state_manager: Arc<dyn WorkerStateManager>,
    /// The allocation strategy for workers.
    allocation_strategy: WorkerAllocationStrategy,
    /// A channel to notify the matching engine that the worker pool has changed.
    worker_change_notify: Arc<Notify>,
    /// A channel to notify that an operation is still alive.
    operation_keep_alive_tx: UnboundedSender<(OperationId, WorkerId)>,
}

impl ApiWorkerSchedulerImpl {
    /// Refreshes the lifetime of the worker with the given timestamp.
    fn refresh_lifetime(
        &mut self,
        worker_id: &WorkerId,
        timestamp: WorkerTimestamp,
    ) -> Result<(), Error> {
        let worker = self.workers.0.peek_mut(worker_id).ok_or_else(|| {
            make_input_err!(
                "Worker not found in worker map in refresh_lifetime() {}",
                worker_id
            )
        })?0;
        error_if!(
            worker.last_update_timestamp > timestamp,
            "Worker already had a timestamp of {}, but tried to update it with {}",
            worker.last_update_timestamp,
            timestamp
        );
        worker.last_update_timestamp = timestamp;
        for operation_id0 in worker.running_action_infos.keys() {
            if self
                .operation_keep_alive_tx
                .send((operation_id.clone(), *worker_id))
                .is_err()
            {
                event!(
                    Level::ERROR,
                    ?operation_id,
                    ?worker_id,
                    "OperationKeepAliveTx stream closed"
                );
            }
        }
        Ok(())
    }

    /// Adds a worker to the pool.
    /// Note: This function will not do any task matching.
    fn add_worker(&mut self, worker: Worker) -> Result<(), Error> {
        let worker_id = worker.id;
        self.workers.put(worker_id, worker);

        // Worker is not cloneable, and we do not want to send the initial connection results until
        // we have added it to the map, or we might get some strange race conditions due to the way
        // the multi-threaded runtime works.
        let worker = self.workers.peek_mut(&worker_id).unwrap();
        let res = worker
            .send_initial_connection_result()
            .err_tip(|| "Failed to send initial connection result to worker"0);
        if let Err(err0) = &res {
            event!(
                Level::ERROR,
                ?worker_id,
                ?err,
                "Worker connection appears to have been closed while adding to pool"
            );
        }
        self.worker_change_notify.notify_one();
        res
    }

    /// Removes worker from pool.
    /// Note: The caller is responsible for any rescheduling of any tasks that might be
    /// running.
    fn remove_worker(&mut self, worker_id: &WorkerId) -> Option<Worker> {
        let result = self.workers.pop(worker_id);
        self.worker_change_notify.notify_one();
        result
    }

    /// Sets if the worker is draining or not.
    async fn set_drain_worker(
        &mut self,
        worker_id: &WorkerId,
        is_draining: bool,
    ) -> Result<(), Error> {
        let worker = self
            .workers
            .get_mut(worker_id)
            .err_tip(|| format!("Worker {worker_id} doesn't exist in the pool")0)?0;
        worker.is_draining = is_draining;
        self.worker_change_notify.notify_one();
        Ok(())
    }

    fn inner_find_worker_for_action(
        &self,
        platform_properties: &PlatformProperties,
    ) -> Option<WorkerId> {
        let mut workers_iter = self.workers.iter();
        let workers_iter = match self.allocation_strategy {
            // Use rfind to get the least recently used that satisfies the properties.
            WorkerAllocationStrategy::least_recently_used => workers_iter.rfind(|(_, w)| {
                w.can_accept_work() && platform_properties.is_satisfied_by(&w.platform_properties)33
            }34),
            // Use find to get the most recently used that satisfies the properties.
            WorkerAllocationStrategy::most_recently_used => workers_iter.find(|(_, w)| {
                w.can_accept_work() && platform_properties.is_satisfied_by(&w.platform_properties)
            }),
        };
        workers_iter.map(|(_, w)| &w.id28).copied()
    }

    async fn update_action(
        &mut self,
        worker_id: &WorkerId,
        operation_id: &OperationId,
        update: UpdateOperationType,
    ) -> Result<(), Error> {
        let worker = self.workers.get_mut(worker_id).err_tip(|| {
            format!("Worker {worker_id} does not exist in SimpleScheduler::update_action")
        })?0;

        // Ensure the worker is supposed to be running the operation.
        if !worker.running_action_infos.contains_key(operation_id) {
            let err = make_err!(
                Code::Internal,
                "Operation {operation_id} should not be running on worker {worker_id} in SimpleScheduler::update_action"
            );
            return Result::<(), _>::Err(err.clone())
                .merge(self.immediate_evict_worker(worker_id, err).await);
        }

        let (is_finished, due_to_backpressure) = match &update {
            UpdateOperationType::UpdateWithActionStage(action_stage) => {
                (action_stage.is_finished(), false)
            }
            UpdateOperationType::KeepAlive => (false, false),
            UpdateOperationType::UpdateWithError(err) => {
                (true, err.code == Code::ResourceExhausted)
            }
        };

        // Update the operation in the worker state manager.
        {
            let update_operation_res = self
                .worker_state_manager
                .update_operation(operation_id, worker_id, update)
                .await
                .err_tip(|| "in update_operation on SimpleScheduler::update_action"0);
            if let Err(err0) = update_operation_res {
                event!(
                    Level::ERROR,
                    ?operation_id,
                    ?worker_id,
                    ?err,
                    "Failed to update_operation on update_action"
                );
                return Err(err);
            }
        }

        if !is_finished {
            return Ok(());
        }

        // Clear this action from the current worker if finished.
        let complete_action_res = {
            let was_paused = !worker.can_accept_work();

            // Note: We need to run this before dealing with backpressure logic.
            let complete_action_res = worker.complete_action(operation_id);

            // Only pause if there's an action still waiting that will unpause.
            if (was_paused || due_to_backpressure) && worker.has_actions()0 {
                worker.is_paused = true;
            }
            complete_action_res
        };

        self.worker_change_notify.notify_one();

        complete_action_res
    }

    /// Notifies the specified worker to run the given action and handles errors by evicting
    /// the worker if the notification fails.
    async fn worker_notify_run_action(
        &mut self,
        worker_id: WorkerId,
        operation_id: OperationId,
        action_info: ActionInfoWithProps,
    ) -> Result<(), Error> {
        if let Some(worker) = self.workers.get_mut(&worker_id) {
            let notify_worker_result =
                worker.notify_update(WorkerUpdate::RunAction((operation_id, action_info.clone())));

            if notify_worker_result.is_err() {
                event!(
                    Level::WARN,
                    ?worker_id,
                    ?action_info,
                    ?notify_worker_result,
                    "Worker command failed, removing worker",
                );

                let err = make_err!(
                    Code::Internal,
                    "Worker command failed, removing worker {worker_id} -- {notify_worker_result:?}",
                );

                return Result::<(), _>::Err(err.clone())
                    .merge(self.immediate_evict_worker(&worker_id, err).await);
            }
        } else {
            event!(
                Level::WARN,
                ?worker_id,
                ?operation_id,
                ?action_info,
                "Worker not found in worker map in worker_notify_run_action"
            );
        }
        Ok(())
    }

    /// Evicts the worker from the pool and puts items back into the queue if anything was being executed on it.
    async fn immediate_evict_worker(
        &mut self,
        worker_id: &WorkerId,
        err: Error,
    ) -> Result<(), Error> {
        let mut result = Ok(());
        if let Some(mut worker) = self.remove_worker(worker_id) {
            // We don't care if we fail to send message to worker, this is only a best attempt.
            let _ = worker.notify_update(WorkerUpdate::Disconnect);
            for (operation_id4, _) in worker.running_action_infos.drain() {
                result = result.merge(
                    self.worker_state_manager
                        .update_operation(
                            &operation_id,
                            worker_id,
                            UpdateOperationType::UpdateWithError(err.clone()),
                        )
                        .await,
                );
            }
        }
        // Note: Calling this many time is very cheap, it'll only trigger `do_try_match` once.
        // TODO(allada) This should be moved to inside the Workers struct.
        self.worker_change_notify.notify_one();
        result
    }
}

#[derive(MetricsComponent)]
pub struct ApiWorkerScheduler {
    #[metric]
    inner: Mutex<ApiWorkerSchedulerImpl>,
    #[metric(group = "platform_property_manager")]
    platform_property_manager: Arc<PlatformPropertyManager>,

    #[metric(
        help = "Timeout of how long to evict workers if no response in this given amount of time in seconds."
    )]
    worker_timeout_s: u64,
    _operation_keep_alive_spawn: JoinHandleDropGuard<()>,
}

impl ApiWorkerScheduler {
    pub fn new(
        worker_state_manager: Arc<dyn WorkerStateManager>,
        platform_property_manager: Arc<PlatformPropertyManager>,
        allocation_strategy: WorkerAllocationStrategy,
        worker_change_notify: Arc<Notify>,
        worker_timeout_s: u64,
    ) -> Arc<Self> {
        let (operation_keep_alive_tx, mut operation_keep_alive_rx) = mpsc::unbounded_channel();
        Arc::new(Self {
            inner: Mutex::new(ApiWorkerSchedulerImpl {
                workers: Workers(LruCache::unbounded()),
                worker_state_manager: worker_state_manager.clone(),
                allocation_strategy,
                worker_change_notify,
                operation_keep_alive_tx,
            }),
            platform_property_manager,
            worker_timeout_s,
            _operation_keep_alive_spawn: spawn!(
                "simple_scheduler_operation_keep_alive",
                async move {22
                    const RECV_MANY_LIMIT: usize = 256;
                    let mut messages = Vec::with_capacity(RECV_MANY_LIMIT);
                    loop {
                        messages.clear();
                        operation_keep_alive_rx
                            .recv_many(&mut messages, RECV_MANY_LIMIT)
                            .await;
                        if messages.is_empty() {
                            return; // Looks like our sender has been dropped.
                        }
                        for (operation_id, worker_id) in messages.drain(..) {
                            let update_operation_res = worker_state_manager
                                .update_operation(
                                    &operation_id,
                                    &worker_id,
                                    UpdateOperationType::KeepAlive,
                                )
                                .await;
                            if let Err(err) = update_operation_res {
                                event!(Level::WARN, ?err, "Error while running worker_keep_alive_received, maybe job is done?");
                            }
                        }
                    }
                }0
            ),
        })
    }

    pub async fn worker_notify_run_action(
        &self,
        worker_id: WorkerId,
        operation_id: OperationId,
        action_info: ActionInfoWithProps,
    ) -> Result<(), Error> {
        let mut inner = self.inner.lock().await;
        inner
            .worker_notify_run_action(worker_id, operation_id, action_info)
            .await
    }

    /// Attempts to find a worker that is capable of running this action.
    // TODO(blaise.bruer) This algorithm is not very efficient. Simple testing using a tree-like
    // structure showed worse performance on a 10_000 worker * 7 properties * 1000 queued tasks
    // simulation of worst cases in a single threaded environment.
    pub async fn find_worker_for_action(
        &self,
        platform_properties: &PlatformProperties,
    ) -> Option<WorkerId> {
        let inner = self.inner.lock().await;
        inner.inner_find_worker_for_action(platform_properties)
    }

    /// Checks to see if the worker exists in the worker pool. Should only be used in unit tests.
    #[must_use]
    pub async fn contains_worker_for_test(&self, worker_id: &WorkerId) -> bool {
        let inner = self.inner.lock().await;
        inner.workers.contains(worker_id)
    }

    /// A unit test function used to send the keep alive message to the worker from the server.
    pub async fn send_keep_alive_to_worker_for_test(
        &self,
        worker_id: &WorkerId,
    ) -> Result<(), Error> {
        let mut inner = self.inner.lock().await;
        let worker = inner.workers.get_mut(worker_id).ok_or_else(|| {
            make_input_err!("WorkerId '{}' does not exist in workers map", worker_id)
        })?0;
        worker.keep_alive()
    }
}

#[async_trait]
impl WorkerScheduler for ApiWorkerScheduler {
    fn get_platform_property_manager(&self) -> &PlatformPropertyManager {
        self.platform_property_manager.as_ref()
    }

    async fn add_worker(&self, worker: Worker) -> Result<(), Error> {
        let mut inner = self.inner.lock().await;
        let worker_id = worker.id;
        let result = inner
            .add_worker(worker)
            .err_tip(|| "Error while adding worker, removing from pool"0);
        if let Err(err0) = result {
            return Result::<(), _>::Err(err.clone())
                .merge(inner.immediate_evict_worker(&worker_id, err).await);
        }
        Ok(())
    }

    async fn update_action(
        &self,
        worker_id: &WorkerId,
        operation_id: &OperationId,
        update: UpdateOperationType,
    ) -> Result<(), Error> {
        let mut inner = self.inner.lock().await;
        inner.update_action(worker_id, operation_id, update).await
    }

    async fn worker_keep_alive_received(
        &self,
        worker_id: &WorkerId,
        timestamp: WorkerTimestamp,
    ) -> Result<(), Error> {
        let mut inner = self.inner.lock().await;
        inner
            .refresh_lifetime(worker_id, timestamp)
            .err_tip(|| "Error refreshing lifetime in worker_keep_alive_received()"0)
    }

    async fn remove_worker(&self, worker_id: &WorkerId) -> Result<(), Error> {
        let mut inner = self.inner.lock().await;
        inner
            .immediate_evict_worker(
                worker_id,
                make_err!(Code::Internal, "Received request to remove worker"),
            )
            .await
    }

    async fn remove_timedout_workers(&self, now_timestamp: WorkerTimestamp) -> Result<(), Error> {
        let mut inner = self.inner.lock().await;

        let mut result = Ok(());
        // Items should be sorted based on last_update_timestamp, so we don't need to iterate the entire
        // map most of the time.
        let worker_ids_to_remove: Vec<WorkerId> = inner
            .workers
            .iter()
            .rev()
            .map_while(|(worker_id, worker)| {
                if worker.last_update_timestamp <= now_timestamp - self.worker_timeout_s {
                    Some(*worker_id)
                } else {
                    None
                }
            })
            .collect();
        for worker_id2 in &worker_ids_to_remove {
            event!(
                Level::WARN,
                ?worker_id,
                "Worker timed out, removing from pool"
            );
            result = result.merge(
                inner
                    .immediate_evict_worker(
                        worker_id,
                        make_err!(
                            Code::Internal,
                            "Worker {worker_id} timed out, removing from pool"
                        ),
                    )
                    .await,
            );
        }

        result
    }

    async fn set_drain_worker(&self, worker_id: &WorkerId, is_draining: bool) -> Result<(), Error> {
        let mut inner = self.inner.lock().await;
        inner.set_drain_worker(worker_id, is_draining).await
    }
}

impl RootMetricsComponent for ApiWorkerScheduler {}

Coverage Report

Created: 2024-12-19 04:04

Line	Count	Source
1		// Copyright 2024 The NativeLink Authors. All rights reserved.
2		//
3		// Licensed under the Apache License, Version 2.0 (the "License");
4		// you may not use this file except in compliance with the License.
5		// You may obtain a copy of the License at
6		//
7		// http://www.apache.org/licenses/LICENSE-2.0
8		//
9		// Unless required by applicable law or agreed to in writing, software
10		// distributed under the License is distributed on an "AS IS" BASIS,
11		// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12		// See the License for the specific language governing permissions and
13		// limitations under the License.
14
15		use std::ops::{Deref, DerefMut};
16		use std::sync::Arc;
17
18		use async_lock::Mutex;
19		use lru::LruCache;
20		use nativelink_config::schedulers::WorkerAllocationStrategy;
21		use nativelink_error::{error_if, make_err, make_input_err, Code, Error, ResultExt};
22		use nativelink_metric::{
23		group, MetricFieldData, MetricKind, MetricPublishKnownKindData, MetricsComponent,
24		RootMetricsComponent,
25		};
26		use nativelink_util::action_messages::{OperationId, WorkerId};
27		use nativelink_util::operation_state_manager::{UpdateOperationType, WorkerStateManager};
28		use nativelink_util::platform_properties::PlatformProperties;
29		use nativelink_util::spawn;
30		use nativelink_util::task::JoinHandleDropGuard;
31		use tokio::sync::mpsc::{self, UnboundedSender};
32		use tokio::sync::Notify;
33		use tonic::async_trait;
34		use tracing::{event, Level};
35
36		use crate::platform_property_manager::PlatformPropertyManager;
37		use crate::worker::{ActionInfoWithProps, Worker, WorkerTimestamp, WorkerUpdate};
38		use crate::worker_scheduler::WorkerScheduler;
39
40		struct Workers(LruCache<WorkerId, Worker>);
41
42		impl Deref for Workers {
43		type Target = LruCache<WorkerId, Worker>;
44
45	54	fn deref(&self) -> &Self::Target {
46	54	&self.0
47	54	}
48		}
49
50		impl DerefMut for Workers {
51	109	fn deref_mut(&mut self) -> &mut Self::Target {
52	109	&mut self.0
53	109	}
54		}
55
56		// Note: This could not be a derive macro because this derive-macro
57		// does n ot support LruCache and nameless field structs.
58		impl MetricsComponent for Workers {
59	0	fn publish(
60	0	&self,
61	0	_kind: MetricKind,
62	0	_field_metadata: MetricFieldData,
63	0	) -> Result<MetricPublishKnownKindData, nativelink_metric::Error> {
64	0	let _enter = group!("workers").entered();
65	0	for (worker_id, worker) in self.iter() {
66	0	let _enter = group!(worker_id).entered();
67	0	worker.publish(MetricKind::Component, MetricFieldData::default())?;
68		}
69	0	Ok(MetricPublishKnownKindData::Component)
70	0	}
71		}
72
73		/// A collection of workers that are available to run tasks.
74		#[derive(MetricsComponent)]
75		struct ApiWorkerSchedulerImpl {
76		/// A `LruCache` of workers availabled based on `allocation_strategy`.
77		#[metric(group = "workers")]
78		workers: Workers,
79
80		/// The worker state manager.
81		#[metric(group = "worker_state_manager")]
82		worker_state_manager: Arc<dyn WorkerStateManager>,
83		/// The allocation strategy for workers.
84		allocation_strategy: WorkerAllocationStrategy,
85		/// A channel to notify the matching engine that the worker pool has changed.
86		worker_change_notify: Arc<Notify>,
87		/// A channel to notify that an operation is still alive.
88		operation_keep_alive_tx: UnboundedSender<(OperationId, WorkerId)>,
89		}
90
91		impl ApiWorkerSchedulerImpl {
92		/// Refreshes the lifetime of the worker with the given timestamp.
93	2	fn refresh_lifetime(
94	2	&mut self,
95	2	worker_id: &WorkerId,
96	2	timestamp: WorkerTimestamp,
97	2	) -> Result<(), Error> {
98	2	let worker = self.workers.0.peek_mut(worker_id).ok_or_else(\|\| {
99	0	make_input_err!(
100	0	"Worker not found in worker map in refresh_lifetime() {}",
101	0	worker_id
102	0	)
103	2	}) ?0 ;
104	0	error_if!(
105	2	worker.last_update_timestamp > timestamp, Branch (105:13): [True: 0, False: 2] Branch (105:13): [Folded - Ignored]
106		"Worker already had a timestamp of {}, but tried to update it with {}",
107		worker.last_update_timestamp,
108		timestamp
109		);
110	2	worker.last_update_timestamp = timestamp;
111	2	for operation_id0 in worker.running_action_infos.keys() {
112	0	if self Branch (112:16): [True: 0, False: 0] Branch (112:16): [Folded - Ignored]
113	0	.operation_keep_alive_tx
114	0	.send((operation_id.clone(), *worker_id))
115	0	.is_err()
116		{
117	0	event!(
118	0	Level::ERROR,
119		?operation_id,
120		?worker_id,
121	0	"OperationKeepAliveTx stream closed"
122		);
123	0	}
124		}
125	2	Ok(())
126	2	}
127
128		/// Adds a worker to the pool.
129		/// Note: This function will not do any task matching.
130	31	fn add_worker(&mut self, worker: Worker) -> Result<(), Error> {
131	31	let worker_id = worker.id;
132	31	self.workers.put(worker_id, worker);
133	31
134	31	// Worker is not cloneable, and we do not want to send the initial connection results until
135	31	// we have added it to the map, or we might get some strange race conditions due to the way
136	31	// the multi-threaded runtime works.
137	31	let worker = self.workers.peek_mut(&worker_id).unwrap();
138	31	let res = worker
139	31	.send_initial_connection_result()
140	31	.err_tip(\|\| "Failed to send initial connection result to worker"0 );
141	31	if let Err( err0 ) = &res { Branch (141:16): [True: 0, False: 31] Branch (141:16): [Folded - Ignored]
142	0	event!(
143	0	Level::ERROR,
144		?worker_id,
145		?err,
146	0	"Worker connection appears to have been closed while adding to pool"
147		);
148	31	}
149	31	self.worker_change_notify.notify_one();
150	31	res
151	31	}
152
153		/// Removes worker from pool.
154		/// Note: The caller is responsible for any rescheduling of any tasks that might be
155		/// running.
156	6	fn remove_worker(&mut self, worker_id: &WorkerId) -> Option<Worker> {
157	6	let result = self.workers.pop(worker_id);
158	6	self.worker_change_notify.notify_one();
159	6	result
160	6	}
161
162		/// Sets if the worker is draining or not.
163	2	async fn set_drain_worker(
164	2	&mut self,
165	2	worker_id: &WorkerId,
166	2	is_draining: bool,
167	2	) -> Result<(), Error> {
168	2	let worker = self
169	2	.workers
170	2	.get_mut(worker_id)
171	2	.err_tip(\|\| format!("Worker {worker_id} doesn't exist in the pool")0 ) ?0 ;
172	2	worker.is_draining = is_draining;
173	2	self.worker_change_notify.notify_one();
174	2	Ok(())
175	2	}
176
177	42	fn inner_find_worker_for_action(
178	42	&self,
179	42	platform_properties: &PlatformProperties,
180	42	) -> Option<WorkerId> {
181	42	let mut workers_iter = self.workers.iter();
182	42	let workers_iter = match self.allocation_strategy {
183		// Use rfind to get the least recently used that satisfies the properties.
184	42	WorkerAllocationStrategy::least_recently_used => workers_iter.rfind(\|(_, w)\| {
185	34	w.can_accept_work() && platform_properties.is_satisfied_by(&w.platform_properties)33 Branch (185:17): [True: 33, False: 1] Branch (185:17): [Folded - Ignored]
186	42	}34 ),
187		// Use find to get the most recently used that satisfies the properties.
188	0	WorkerAllocationStrategy::most_recently_used => workers_iter.find(\|(_, w)\| {
189	0	w.can_accept_work() && platform_properties.is_satisfied_by(&w.platform_properties) Branch (189:17): [True: 0, False: 0] Branch (189:17): [Folded - Ignored]
190	0	}),
191		};
192	42	workers_iter.map(\|(_, w)\| &w.id28 ).copied()
193	42	}
194
195	10	async fn update_action(
196	10	&mut self,
197	10	worker_id: &WorkerId,
198	10	operation_id: &OperationId,
199	10	update: UpdateOperationType,
200	10	) -> Result<(), Error> {
201	10	let worker = self.workers.get_mut(worker_id).err_tip(\|\| {
202	0	format!("Worker {worker_id} does not exist in SimpleScheduler::update_action")
203	10	}) ?0 ;
204
205		// Ensure the worker is supposed to be running the operation.
206	10	if !worker.running_action_infos.contains_key(operation_id) { Branch (206:12): [True: 1, False: 9] Branch (206:12): [Folded - Ignored]
207	1	let err = make_err!(
208	1	Code::Internal,
209	1	"Operation {operation_id} should not be running on worker {worker_id} in SimpleScheduler::update_action"
210	1	);
211	1	return Result::<(), _>::Err(err.clone())
212	1	.merge(self.immediate_evict_worker(worker_id, err).await);
213	9	}
214
215	9	let (is_finished, due_to_backpressure) = match &update {
216	6	UpdateOperationType::UpdateWithActionStage(action_stage) => {
217	6	(action_stage.is_finished(), false)
218		}
219	0	UpdateOperationType::KeepAlive => (false, false),
220	3	UpdateOperationType::UpdateWithError(err) => {
221	3	(true, err.code == Code::ResourceExhausted)
222		}
223		};
224
225		// Update the operation in the worker state manager.
226		{
227	9	let update_operation_res = self
228	9	.worker_state_manager
229	9	.update_operation(operation_id, worker_id, update)
230	9	.await
231	9	.err_tip(\|\| "in update_operation on SimpleScheduler::update_action"0 );
232	9	if let Err( err0 ) = update_operation_res { Branch (232:20): [True: 0, False: 9] Branch (232:20): [Folded - Ignored]
233	0	event!(
234	0	Level::ERROR,
235		?operation_id,
236		?worker_id,
237		?err,
238	0	"Failed to update_operation on update_action"
239		);
240	0	return Err(err);
241	9	}
242	9	}
243	9
244	9	if !is_finished { Branch (244:12): [True: 0, False: 9] Branch (244:12): [Folded - Ignored]
245	0	return Ok(());
246	9	}
247
248		// Clear this action from the current worker if finished.
249	9	let complete_action_res = {
250	9	let was_paused = !worker.can_accept_work();
251	9
252	9	// Note: We need to run this before dealing with backpressure logic.
253	9	let complete_action_res = worker.complete_action(operation_id);
254	9
255	9	// Only pause if there's an action still waiting that will unpause.
256	9	if (was_paused \|\| due_to_backpressure) && worker.has_actions()0 { Branch (256:17): [True: 0, False: 9] Branch (256:31): [True: 0, False: 9] Branch (256:55): [True: 0, False: 0] Branch (256:17): [Folded - Ignored] Branch (256:31): [Folded - Ignored] Branch (256:55): [Folded - Ignored]
257	0	worker.is_paused = true;
258	9	}
259	9	complete_action_res
260	9	};
261	9
262	9	self.worker_change_notify.notify_one();
263	9
264	9	complete_action_res
265	10	}
266
267		/// Notifies the specified worker to run the given action and handles errors by evicting
268		/// the worker if the notification fails.
269	28	async fn worker_notify_run_action(
270	28	&mut self,
271	28	worker_id: WorkerId,
272	28	operation_id: OperationId,
273	28	action_info: ActionInfoWithProps,
274	28	) -> Result<(), Error> {
275	28	if let Some(worker) = self.workers.get_mut(&worker_id) { Branch (275:16): [True: 0, False: 0] Branch (275:16): [Folded - Ignored] Branch (275:16): [True: 27, False: 0] Branch (275:16): [True: 1, False: 0]
276	28	let notify_worker_result =
277	28	worker.notify_update(WorkerUpdate::RunAction((operation_id, action_info.clone())));
278	28
279	28	if notify_worker_result.is_err() { Branch (279:16): [True: 0, False: 0] Branch (279:16): [Folded - Ignored] Branch (279:16): [True: 1, False: 26] Branch (279:16): [True: 0, False: 1]
280	1	event!(
281	1	Level::WARN,
282		?worker_id,
283		?action_info,
284		?notify_worker_result,
285	1	"Worker command failed, removing worker",
286		);
287
288	1	let err = make_err!(
289	1	Code::Internal,
290	1	"Worker command failed, removing worker {worker_id} -- {notify_worker_result:?}",
291	1	);
292	1
293	1	return Result::<(), _>::Err(err.clone())
294	1	.merge(self.immediate_evict_worker(&worker_id, err).await);
295	27	}
296		} else {
297	0	event!(
298	0	Level::WARN,
299		?worker_id,
300		?operation_id,
301		?action_info,
302	0	"Worker not found in worker map in worker_notify_run_action"
303		);
304		}
305	27	Ok(())
306	28	}
307
308		/// Evicts the worker from the pool and puts items back into the queue if anything was being executed on it.
309	6	async fn immediate_evict_worker(
310	6	&mut self,
311	6	worker_id: &WorkerId,
312	6	err: Error,
313	6	) -> Result<(), Error> {
314	6	let mut result = Ok(());
315	6	if let Some(mut worker) = self.remove_worker(worker_id) { Branch (315:16): [True: 5, False: 0] Branch (315:16): [Folded - Ignored] Branch (315:16): [True: 1, False: 0] Branch (315:16): [True: 0, False: 0]
316		// We don't care if we fail to send message to worker, this is only a best attempt.
317	6	let _ = worker.notify_update(WorkerUpdate::Disconnect);
318	6	for ( operation_id4 , _) in worker.running_action_infos.drain() {
319	4	result = result.merge(
320	4	self.worker_state_manager
321	4	.update_operation(
322	4	&operation_id,
323	4	worker_id,
324	4	UpdateOperationType::UpdateWithError(err.clone()),
325	4	)
326	4	.await,
327		);
328		}
329	0	}
330		// Note: Calling this many time is very cheap, it'll only trigger `do_try_match` once.
331		// TODO(allada) This should be moved to inside the Workers struct.
332	6	self.worker_change_notify.notify_one();
333	6	result
334	6	}
335		}
336
337		#[derive(MetricsComponent)]
338		pub struct ApiWorkerScheduler {
339		#[metric]
340		inner: Mutex<ApiWorkerSchedulerImpl>,
341		#[metric(group = "platform_property_manager")]
342		platform_property_manager: Arc<PlatformPropertyManager>,
343
344		#[metric(
345		help = "Timeout of how long to evict workers if no response in this given amount of time in seconds."
346		)]
347		worker_timeout_s: u64,
348		_operation_keep_alive_spawn: JoinHandleDropGuard<()>,
349		}
350
351		impl ApiWorkerScheduler {
352	27	pub fn new(
353	27	worker_state_manager: Arc<dyn WorkerStateManager>,
354	27	platform_property_manager: Arc<PlatformPropertyManager>,
355	27	allocation_strategy: WorkerAllocationStrategy,
356	27	worker_change_notify: Arc<Notify>,
357	27	worker_timeout_s: u64,
358	27	) -> Arc<Self> {
359	27	let (operation_keep_alive_tx, mut operation_keep_alive_rx) = mpsc::unbounded_channel();
360	27	Arc::new(Self {
361	27	inner: Mutex::new(ApiWorkerSchedulerImpl {
362	27	workers: Workers(LruCache::unbounded()),
363	27	worker_state_manager: worker_state_manager.clone(),
364	27	allocation_strategy,
365	27	worker_change_notify,
366	27	operation_keep_alive_tx,
367	27	}),
368	27	platform_property_manager,
369	27	worker_timeout_s,
370	27	_operation_keep_alive_spawn: spawn!(
371	27	"simple_scheduler_operation_keep_alive",
372	27	async move {22
373		const RECV_MANY_LIMIT: usize = 256;
374	22	let mut messages = Vec::with_capacity(RECV_MANY_LIMIT);
375		loop {
376	22	messages.clear();
377	22	operation_keep_alive_rx
378	22	.recv_many(&mut messages, RECV_MANY_LIMIT)
379	22	.await;
380	0	if messages.is_empty() { Branch (380:28): [True: 0, False: 0] Branch (380:28): [Folded - Ignored]
381	0	return; // Looks like our sender has been dropped.
382	0	}
383	0	for (operation_id, worker_id) in messages.drain(..) {
384	0	let update_operation_res = worker_state_manager
385	0	.update_operation(
386	0	&operation_id,
387	0	&worker_id,
388	0	UpdateOperationType::KeepAlive,
389	0	)
390	0	.await;
391	0	if let Err(err) = update_operation_res { Branch (391:36): [True: 0, False: 0] Branch (391:36): [Folded - Ignored]
392	0	event!(Level::WARN, ?err, "Error while running worker_keep_alive_received, maybe job is done?");
393	0	}
394		}
395		}
396	27	}0
397	27	),
398		})
399	27	}
400
401	28	pub async fn worker_notify_run_action(
402	28	&self,
403	28	worker_id: WorkerId,
404	28	operation_id: OperationId,
405	28	action_info: ActionInfoWithProps,
406	28	) -> Result<(), Error> {
407	28	let mut inner = self.inner.lock().await;
408	28	inner
409	28	.worker_notify_run_action(worker_id, operation_id, action_info)
410	28	.await
411	28	}
412
413		/// Attempts to find a worker that is capable of running this action.
414		// TODO(blaise.bruer) This algorithm is not very efficient. Simple testing using a tree-like
415		// structure showed worse performance on a 10_000 worker * 7 properties * 1000 queued tasks
416		// simulation of worst cases in a single threaded environment.
417	42	pub async fn find_worker_for_action(
418	42	&self,
419	42	platform_properties: &PlatformProperties,
420	42	) -> Option<WorkerId> {
421	42	let inner = self.inner.lock().await;
422	42	inner.inner_find_worker_for_action(platform_properties)
423	42	}
424
425		/// Checks to see if the worker exists in the worker pool. Should only be used in unit tests.
426		#[must_use]
427	7	pub async fn contains_worker_for_test(&self, worker_id: &WorkerId) -> bool {
428	7	let inner = self.inner.lock().await;
429	7	inner.workers.contains(worker_id)
430	7	}
431
432		/// A unit test function used to send the keep alive message to the worker from the server.
433	1	pub async fn send_keep_alive_to_worker_for_test(
434	1	&self,
435	1	worker_id: &WorkerId,
436	1	) -> Result<(), Error> {
437	1	let mut inner = self.inner.lock().await;
438	1	let worker = inner.workers.get_mut(worker_id).ok_or_else(\|\| {
439	0	make_input_err!("WorkerId '{}' does not exist in workers map", worker_id)
440	1	}) ?0 ;
441	1	worker.keep_alive()
442	1	}
443		}
444
445		#[async_trait]
446		impl WorkerScheduler for ApiWorkerScheduler {
447	1	fn get_platform_property_manager(&self) -> &PlatformPropertyManager {
448	1	self.platform_property_manager.as_ref()
449	1	}
450
451	31	async fn add_worker(&self, worker: Worker) -> Result<(), Error> {
452	31	let mut inner = self.inner.lock().await;
453	31	let worker_id = worker.id;
454	31	let result = inner
455	31	.add_worker(worker)
456	31	.err_tip(\|\| "Error while adding worker, removing from pool"0 );
457	31	if let Err( err0 ) = result { Branch (457:16): [True: 0, False: 31] Branch (457:16): [Folded - Ignored]
458	0	return Result::<(), _>::Err(err.clone())
459	0	.merge(inner.immediate_evict_worker(&worker_id, err).await);
460	31	}
461	31	Ok(())
462	62	}
463
464		async fn update_action(
465		&self,
466		worker_id: &WorkerId,
467		operation_id: &OperationId,
468		update: UpdateOperationType,
469	10	) -> Result<(), Error> {
470	10	let mut inner = self.inner.lock().await;
471	10	inner.update_action(worker_id, operation_id, update).await
472	20	}
473
474		async fn worker_keep_alive_received(
475		&self,
476		worker_id: &WorkerId,
477		timestamp: WorkerTimestamp,
478	2	) -> Result<(), Error> {
479	2	let mut inner = self.inner.lock().await;
480	2	inner
481	2	.refresh_lifetime(worker_id, timestamp)
482	2	.err_tip(\|\| "Error refreshing lifetime in worker_keep_alive_received()"0 )
483	4	}
484
485	2	async fn remove_worker(&self, worker_id: &WorkerId) -> Result<(), Error> {
486	2	let mut inner = self.inner.lock().await;
487	2	inner
488	2	.immediate_evict_worker(
489	2	worker_id,
490	2	make_err!(Code::Internal, "Received request to remove worker"),
491	2	)
492	2	.await
493	4	}
494
495	5	async fn remove_timedout_workers(&self, now_timestamp: WorkerTimestamp) -> Result<(), Error> {
496	5	let mut inner = self.inner.lock().await;
497
498	5	let mut result = Ok(());
499	5	// Items should be sorted based on last_update_timestamp, so we don't need to iterate the entire
500	5	// map most of the time.
501	5	let worker_ids_to_remove: Vec<WorkerId> = inner
502	5	.workers
503	5	.iter()
504	5	.rev()
505	6	.map_while(\|(worker_id, worker)\| {
506	6	if worker.last_update_timestamp <= now_timestamp - self.worker_timeout_s { Branch (506:20): [True: 2, False: 4] Branch (506:20): [Folded - Ignored]
507	2	Some(*worker_id)
508		} else {
509	4	None
510		}
511	6	})
512	5	.collect();
513	7	for worker_id2 in &worker_ids_to_remove {
514	2	event!(
515	2	Level::WARN,
516		?worker_id,
517	2	"Worker timed out, removing from pool"
518		);
519	2	result = result.merge(
520	2	inner
521	2	.immediate_evict_worker(
522	2	worker_id,
523	2	make_err!(
524	2	Code::Internal,
525	2	"Worker {worker_id} timed out, removing from pool"
526	2	),
527	2	)
528	2	.await,
529		);
530		}
531
532	5	result
533	10	}
534
535	2	async fn set_drain_worker(&self, worker_id: &WorkerId, is_draining: bool) -> Result<(), Error> {
536	2	let mut inner = self.inner.lock().await;
537	2	inner.set_drain_worker(worker_id, is_draining).await
538	4	}
539		}
540
541		impl RootMetricsComponent for ApiWorkerScheduler {}