perf: drastically reduce worker nodes array lookups
authorJérôme Benoit <jerome.benoit@sap.com>
Fri, 21 Jul 2023 11:48:12 +0000 (13:48 +0200)
committerJérôme Benoit <jerome.benoit@sap.com>
Fri, 21 Jul 2023 11:48:12 +0000 (13:48 +0200)
Signed-off-by: Jérôme Benoit <jerome.benoit@sap.com>
CHANGELOG.md
src/pools/abstract-pool.ts
src/pools/cluster/fixed.ts
src/pools/pool.ts
src/pools/selection-strategies/worker-choice-strategy-context.ts
src/pools/thread/fixed.ts
src/worker/abstract-worker.ts
tests/pools/selection-strategies/worker-choice-strategy-context.test.js

index 0ed0c9f64b66d20ea9175ce72ec959970bef2ccf..91530cd66fd3c9ed486a8ed6d2293c3a31bcead7 100644 (file)
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Drastically reduce lookup by worker in the worker nodes.
+
 ## [2.6.19] - 2023-07-20
 
 ### Added
index 00bfaf8eea87f991221664e7cea3059cca4f5457..086d7ee82550bc40c46781b83616c1639b32155b 100644 (file)
@@ -284,7 +284,7 @@ export abstract class AbstractPool<
         0
       ) < this.numberOfWorkers
     ) {
-      this.createAndSetupWorker()
+      this.createAndSetupWorkerNode()
     }
   }
 
@@ -425,6 +425,9 @@ export abstract class AbstractPool<
     }
   }
 
+  /**
+   * The pool readiness boolean status.
+   */
   private get ready (): boolean {
     return (
       this.workerNodes.reduce(
@@ -438,7 +441,7 @@ export abstract class AbstractPool<
   }
 
   /**
-   * Gets the approximate pool utilization.
+   * The approximate pool utilization.
    *
    * @returns The pool utilization.
    */
@@ -459,38 +462,27 @@ export abstract class AbstractPool<
   }
 
   /**
-   * Pool type.
+   * The pool type.
    *
    * If it is `'dynamic'`, it provides the `max` property.
    */
   protected abstract get type (): PoolType
 
   /**
-   * Gets the worker type.
+   * The worker type.
    */
   protected abstract get worker (): WorkerType
 
   /**
-   * Pool minimum size.
+   * The pool minimum size.
    */
   protected abstract get minSize (): number
 
   /**
-   * Pool maximum size.
+   * The pool maximum size.
    */
   protected abstract get maxSize (): number
 
-  /**
-   * Get the worker given its id.
-   *
-   * @param workerId - The worker id.
-   * @returns The worker if found in the pool worker nodes, `undefined` otherwise.
-   */
-  private getWorkerById (workerId: number): Worker | undefined {
-    return this.workerNodes.find(workerNode => workerNode.info.id === workerId)
-      ?.worker
-  }
-
   /**
    * Checks if the worker id sent in the received message from a worker is valid.
    *
@@ -500,7 +492,7 @@ export abstract class AbstractPool<
   private checkMessageWorkerId (message: MessageValue<Response>): void {
     if (
       message.workerId != null &&
-      this.getWorkerById(message.workerId) == null
+      this.getWorkerNodeKeyByWorkerId(message.workerId) == null
     ) {
       throw new Error(
         `Worker message received from unknown worker '${message.workerId}'`
@@ -514,12 +506,26 @@ export abstract class AbstractPool<
    * @param worker - The worker.
    * @returns The worker node key if found in the pool worker nodes, `-1` otherwise.
    */
-  protected getWorkerNodeKey (worker: Worker): number {
+  private getWorkerNodeKey (worker: Worker): number {
     return this.workerNodes.findIndex(
       workerNode => workerNode.worker === worker
     )
   }
 
+  /**
+   * Gets the worker node key given its worker id.
+   *
+   * @param workerId - The worker id.
+   * @returns The worker node key if the worker id is found in the pool worker nodes, `undefined` otherwise.
+   */
+  private getWorkerNodeKeyByWorkerId (workerId: number): number | undefined {
+    for (const [workerNodeKey, workerNode] of this.workerNodes.entries()) {
+      if (workerNode.info.id === workerId) {
+        return workerNodeKey
+      }
+    }
+  }
+
   /** @inheritDoc */
   public setWorkerChoiceStrategy (
     workerChoiceStrategy: WorkerChoiceStrategy,
@@ -533,9 +539,9 @@ export abstract class AbstractPool<
     if (workerChoiceStrategyOptions != null) {
       this.setWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
     }
-    for (const workerNode of this.workerNodes) {
+    for (const [workerNodeKey, workerNode] of this.workerNodes.entries()) {
       workerNode.resetUsage()
-      this.setWorkerStatistics(workerNode.worker)
+      this.sendWorkerStatisticsMessageToWorker(workerNodeKey)
     }
   }
 
@@ -654,18 +660,20 @@ export abstract class AbstractPool<
             resolve()
           })
         })
-        await this.destroyWorker(workerNode.worker)
+        await this.destroyWorkerNode(workerNodeKey)
         await workerExitPromise
       })
     )
   }
 
   /**
-   * Terminates the given worker.
+   * Terminates the worker node given its worker node key.
    *
-   * @param worker - A worker within `workerNodes`.
+   * @param workerNodeKey - The worker node key.
    */
-  protected abstract destroyWorker (worker: Worker): void | Promise<void>
+  protected abstract destroyWorkerNode (
+    workerNodeKey: number
+  ): void | Promise<void>
 
   /**
    * Setup hook to execute code before worker nodes are created in the abstract constructor.
@@ -802,15 +810,15 @@ export abstract class AbstractPool<
    *
    * The default worker choice strategy uses a round robin algorithm to distribute the tasks.
    *
-   * @returns The worker node key
+   * @returns The chosen worker node key
    */
   private chooseWorkerNode (): number {
     if (this.shallCreateDynamicWorker()) {
-      const worker = this.createAndSetupDynamicWorker()
+      const workerNodeKey = this.createAndSetupDynamicWorkerNode()
       if (
         this.workerChoiceStrategyContext.getStrategyPolicy().useDynamicWorker
       ) {
-        return this.getWorkerNodeKey(worker)
+        return workerNodeKey
       }
     }
     return this.workerChoiceStrategyContext.execute()
@@ -826,13 +834,13 @@ export abstract class AbstractPool<
   }
 
   /**
-   * Sends a message to the given worker.
+   * Sends a message to worker given its worker node key.
    *
-   * @param worker - The worker which should receive the message.
+   * @param workerNodeKey - The worker node key.
    * @param message - The message.
    */
   protected abstract sendToWorker (
-    worker: Worker,
+    workerNodeKey: number,
     message: MessageValue<Data>
   ): void
 
@@ -844,11 +852,11 @@ export abstract class AbstractPool<
   protected abstract createWorker (): Worker
 
   /**
-   * Creates a new worker and sets it up completely in the pool worker nodes.
+   * Creates a new, completely set up worker node.
    *
-   * @returns New, completely set up worker.
+   * @returns New, completely set up worker node key.
    */
-  protected createAndSetupWorker (): Worker {
+  protected createAndSetupWorkerNode (): number {
     const worker = this.createWorker()
 
     worker.on('message', this.opts.messageHandler ?? EMPTY_FUNCTION)
@@ -861,9 +869,9 @@ export abstract class AbstractPool<
       this.emitter?.emit(PoolEvents.error, error)
       if (this.opts.restartWorkerOnError === true && !this.starting) {
         if (workerInfo.dynamic) {
-          this.createAndSetupDynamicWorker()
+          this.createAndSetupDynamicWorkerNode()
         } else {
-          this.createAndSetupWorker()
+          this.createAndSetupWorkerNode()
         }
       }
       if (this.opts.enableTasksQueue === true) {
@@ -876,78 +884,102 @@ export abstract class AbstractPool<
       this.removeWorkerNode(worker)
     })
 
-    this.addWorkerNode(worker)
+    const workerNodeKey = this.addWorkerNode(worker)
 
-    this.afterWorkerSetup(worker)
+    this.afterWorkerNodeSetup(workerNodeKey)
 
-    return worker
+    return workerNodeKey
   }
 
   /**
-   * Creates a new dynamic worker and sets it up completely in the pool worker nodes.
+   * Creates a new, completely set up dynamic worker node.
    *
-   * @returns New, completely set up dynamic worker.
+   * @returns New, completely set up dynamic worker node key.
    */
-  protected createAndSetupDynamicWorker (): Worker {
-    const worker = this.createAndSetupWorker()
-    this.registerWorkerMessageListener(worker, message => {
-      const workerNodeKey = this.getWorkerNodeKey(worker)
+  protected createAndSetupDynamicWorkerNode (): number {
+    const workerNodeKey = this.createAndSetupWorkerNode()
+    this.registerWorkerMessageListener(workerNodeKey, message => {
+      const localWorkerNodeKey = this.getWorkerNodeKeyByWorkerId(
+        message.workerId
+      ) as number
+      const workerUsage = this.workerNodes[localWorkerNodeKey].usage
       if (
         isKillBehavior(KillBehaviors.HARD, message.kill) ||
         (message.kill != null &&
           ((this.opts.enableTasksQueue === false &&
-            this.workerNodes[workerNodeKey].usage.tasks.executing === 0) ||
+            workerUsage.tasks.executing === 0) ||
             (this.opts.enableTasksQueue === true &&
-              this.workerNodes[workerNodeKey].usage.tasks.executing === 0 &&
-              this.tasksQueueSize(workerNodeKey) === 0)))
+              workerUsage.tasks.executing === 0 &&
+              this.tasksQueueSize(localWorkerNodeKey) === 0)))
       ) {
         // Kill message received from the worker: no new tasks are submitted to that worker for a while ( > maxInactiveTime)
-        void (this.destroyWorker(worker) as Promise<void>)
+        void (this.destroyWorkerNode(localWorkerNodeKey) as Promise<void>)
       }
     })
-    const workerInfo = this.getWorkerInfoByWorker(worker)
+    const workerInfo = this.getWorkerInfo(workerNodeKey)
     workerInfo.dynamic = true
     if (this.workerChoiceStrategyContext.getStrategyPolicy().useDynamicWorker) {
       workerInfo.ready = true
     }
-    this.sendToWorker(worker, {
+    this.sendToWorker(workerNodeKey, {
       checkActive: true,
       workerId: workerInfo.id as number
     })
-    return worker
+    return workerNodeKey
   }
 
   /**
-   * Registers a listener callback on the given worker.
+   * Registers a listener callback on the worker given its worker node key.
    *
-   * @param worker - The worker which should register a listener.
+   * @param workerNodeKey - The worker node key.
    * @param listener - The message listener callback.
    */
   protected abstract registerWorkerMessageListener<
     Message extends Data | Response
-  >(worker: Worker, listener: (message: MessageValue<Message>) => void): void
+  >(
+    workerNodeKey: number,
+    listener: (message: MessageValue<Message>) => void
+  ): void
 
   /**
-   * Function that can be hooked up when a worker has been newly created and moved to the pool worker nodes.
+   * Method hooked up after a worker node has been newly created.
    * Can be overridden.
    *
-   * @param worker - The newly created worker.
+   * @param workerNodeKey - The newly created worker node key.
    */
-  protected afterWorkerSetup (worker: Worker): void {
+  protected afterWorkerNodeSetup (workerNodeKey: number): void {
     // Listen to worker messages.
-    this.registerWorkerMessageListener(worker, this.workerListener())
+    this.registerWorkerMessageListener(workerNodeKey, this.workerListener())
     // Send the startup message to worker.
-    this.sendStartupMessageToWorker(worker)
-    // Setup worker task statistics computation.
-    this.setWorkerStatistics(worker)
+    this.sendStartupMessageToWorker(workerNodeKey)
+    // Send the worker statistics message to worker.
+    this.sendWorkerStatisticsMessageToWorker(workerNodeKey)
   }
 
   /**
-   * Sends the startup message to the given worker.
+   * Sends the startup message to worker given its worker node key.
+   *
+   * @param workerNodeKey - The worker node key.
+   */
+  protected abstract sendStartupMessageToWorker (workerNodeKey: number): void
+
+  /**
+   * Sends the worker statistics message to worker given its worker node key.
    *
-   * @param worker - The worker which should receive the startup message.
+   * @param workerNodeKey - The worker node key.
    */
-  protected abstract sendStartupMessageToWorker (worker: Worker): void
+  private sendWorkerStatisticsMessageToWorker (workerNodeKey: number): void {
+    this.sendToWorker(workerNodeKey, {
+      statistics: {
+        runTime:
+          this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+            .runTime.aggregate,
+        elu: this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+          .elu.aggregate
+      },
+      workerId: this.getWorkerInfo(workerNodeKey).id as number
+    })
+  }
 
   private redistributeQueuedTasks (workerNodeKey: number): void {
     while (this.tasksQueueSize(workerNodeKey) > 0) {
@@ -980,7 +1012,7 @@ export abstract class AbstractPool<
   }
 
   /**
-   * This function is the listener registered for each worker message.
+   * This method is the listener registered for each worker message.
    *
    * @returns The listener function to execute when a message is received from a worker.
    */
@@ -998,8 +1030,8 @@ export abstract class AbstractPool<
   }
 
   private handleWorkerReadyResponse (message: MessageValue<Response>): void {
-    this.getWorkerInfoByWorker(
-      this.getWorkerById(message.workerId) as Worker
+    this.getWorkerInfo(
+      this.getWorkerNodeKeyByWorkerId(message.workerId) as number
     ).ready = message.ready as boolean
     if (this.emitter != null && this.ready) {
       this.emitter.emit(PoolEvents.ready, this.info)
@@ -1043,27 +1075,12 @@ export abstract class AbstractPool<
   }
 
   /**
-   * Gets the worker information from the given worker node key.
+   * Gets the worker information given its worker node key.
    *
    * @param workerNodeKey - The worker node key.
    * @returns The worker information.
    */
-  private getWorkerInfo (workerNodeKey: number): WorkerInfo {
-    return this.workerNodes[workerNodeKey].info
-  }
-
-  /**
-   * Gets the worker information from the given worker.
-   *
-   * @param worker - The worker.
-   * @returns The worker information.
-   * @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker is not found.
-   */
-  protected getWorkerInfoByWorker (worker: Worker): WorkerInfo {
-    const workerNodeKey = this.getWorkerNodeKey(worker)
-    if (workerNodeKey === -1) {
-      throw new Error('Worker not found')
-    }
+  protected getWorkerInfo (workerNodeKey: number): WorkerInfo {
     return this.workerNodes[workerNodeKey].info
   }
 
@@ -1071,7 +1088,8 @@ export abstract class AbstractPool<
    * Adds the given worker in the pool worker nodes.
    *
    * @param worker - The worker.
-   * @returns The worker nodes length.
+   * @returns The added worker node key.
+   * @throws {@link https://nodejs.org/api/errors.html#class-error} If the added worker node is not found.
    */
   private addWorkerNode (worker: Worker): number {
     const workerNode = new WorkerNode<Worker, Data>(worker, this.worker)
@@ -1079,7 +1097,12 @@ export abstract class AbstractPool<
     if (this.starting) {
       workerNode.info.ready = true
     }
-    return this.workerNodes.push(workerNode)
+    this.workerNodes.push(workerNode)
+    const workerNodeKey = this.getWorkerNodeKey(worker)
+    if (workerNodeKey === -1) {
+      throw new Error('Worker node not found')
+    }
+    return workerNodeKey
   }
 
   /**
@@ -1096,14 +1119,14 @@ export abstract class AbstractPool<
   }
 
   /**
-   * Executes the given task on the given worker.
+   * Executes the given task on the worker given its worker node key.
    *
-   * @param worker - The worker.
+   * @param workerNodeKey - The worker node key.
    * @param task - The task to execute.
    */
   private executeTask (workerNodeKey: number, task: Task<Data>): void {
     this.beforeTaskExecutionHook(workerNodeKey, task)
-    this.sendToWorker(this.workerNodes[workerNodeKey].worker, task)
+    this.sendToWorker(workerNodeKey, task)
   }
 
   private enqueueTask (workerNodeKey: number, task: Task<Data>): number {
@@ -1133,17 +1156,4 @@ export abstract class AbstractPool<
       this.flushTasksQueue(workerNodeKey)
     }
   }
-
-  private setWorkerStatistics (worker: Worker): void {
-    this.sendToWorker(worker, {
-      statistics: {
-        runTime:
-          this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
-            .runTime.aggregate,
-        elu: this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
-          .elu.aggregate
-      },
-      workerId: this.getWorkerInfoByWorker(worker).id as number
-    })
-  }
 }
index dbf1d470b7e7f36eb12dec0bba28c081fac60786..eadbfcfe4fa96af126629ab3a851d47c2b38e5d5 100644 (file)
@@ -60,8 +60,9 @@ export class FixedClusterPool<
   }
 
   /** @inheritDoc */
-  protected destroyWorker (worker: Worker): void {
-    this.sendToWorker(worker, { kill: true, workerId: worker.id })
+  protected destroyWorkerNode (workerNodeKey: number): void {
+    const worker = this.workerNodes[workerNodeKey].worker
+    this.sendToWorker(workerNodeKey, { kill: true, workerId: worker.id })
     worker.on('disconnect', () => {
       worker.kill()
     })
@@ -69,24 +70,27 @@ export class FixedClusterPool<
   }
 
   /** @inheritDoc */
-  protected sendToWorker (worker: Worker, message: MessageValue<Data>): void {
-    worker.send(message)
+  protected sendToWorker (
+    workerNodeKey: number,
+    message: MessageValue<Data>
+  ): void {
+    this.workerNodes[workerNodeKey].worker.send(message)
   }
 
   /** @inheritDoc */
-  protected sendStartupMessageToWorker (worker: Worker): void {
-    this.sendToWorker(worker, {
+  protected sendStartupMessageToWorker (workerNodeKey: number): void {
+    this.sendToWorker(workerNodeKey, {
       ready: false,
-      workerId: worker.id
+      workerId: this.workerNodes[workerNodeKey].worker.id
     })
   }
 
   /** @inheritDoc */
   protected registerWorkerMessageListener<Message extends Data | Response>(
-    worker: Worker,
+    workerNodeKey: number,
     listener: (message: MessageValue<Message>) => void
   ): void {
-    worker.on('message', listener)
+    this.workerNodes[workerNodeKey].worker.on('message', listener)
   }
 
   /** @inheritDoc */
index 4a0ab725adbaaa5cb08a5740ba195663b554270f..207a8598e3bb9d401ca653eee8b232b4f8f52ee7 100644 (file)
@@ -64,7 +64,7 @@ export interface PoolInfo {
   readonly strategy: WorkerChoiceStrategy
   readonly minSize: number
   readonly maxSize: number
-  /** Pool utilization ratio. */
+  /** Pool utilization. */
   readonly utilization?: number
   /** Pool total worker nodes. */
   readonly workerNodes: number
@@ -198,7 +198,7 @@ export interface IPool<
    */
   readonly execute: (data?: Data, name?: string) => Promise<Response>
   /**
-   * Terminates every current worker in this pool.
+   * Terminates all workers in this pool.
    */
   readonly destroy: () => Promise<void>
   /**
index 28e3af081db65595fb985f39e30a930a43d70620..122774dd0e48c157d5d7c7ce5bdc4ea590281087 100644 (file)
@@ -171,7 +171,7 @@ export class WorkerChoiceStrategyContext<
       ) as IWorkerChoiceStrategy
     ).choose()
     if (workerNodeKey == null) {
-      throw new Error('Worker node key chosen is null or undefined')
+      throw new TypeError('Worker node key chosen is null or undefined')
     }
     return workerNodeKey
   }
index bef82826350d772c146656d4676f942923d33165..f4f712dfd6cc6c720c5872291670c59cc4e3aef3 100644 (file)
@@ -56,23 +56,29 @@ export class FixedThreadPool<
   }
 
   /** @inheritDoc */
-  protected async destroyWorker (worker: Worker): Promise<void> {
-    this.sendToWorker(worker, { kill: true, workerId: worker.threadId })
-    this.workerNodes[this.getWorkerNodeKey(worker)].closeChannel()
+  protected async destroyWorkerNode (workerNodeKey: number): Promise<void> {
+    const workerNode = this.workerNodes[workerNodeKey]
+    const worker = workerNode.worker
+    this.sendToWorker(workerNodeKey, { kill: true, workerId: worker.threadId })
+    workerNode.closeChannel()
     await worker.terminate()
   }
 
   /** @inheritDoc */
-  protected sendToWorker (worker: Worker, message: MessageValue<Data>): void {
+  protected sendToWorker (
+    workerNodeKey: number,
+    message: MessageValue<Data>
+  ): void {
     (
-      this.getWorkerInfoByWorker(worker).messageChannel as MessageChannel
+      this.getWorkerInfo(workerNodeKey).messageChannel as MessageChannel
     ).port1.postMessage(message)
   }
 
   /** @inheritDoc */
-  protected sendStartupMessageToWorker (worker: Worker): void {
+  protected sendStartupMessageToWorker (workerNodeKey: number): void {
+    const worker = this.workerNodes[workerNodeKey].worker
     const port2: MessagePort = (
-      this.getWorkerInfoByWorker(worker).messageChannel as MessageChannel
+      this.getWorkerInfo(workerNodeKey).messageChannel as MessageChannel
     ).port2
     worker.postMessage(
       {
@@ -86,11 +92,11 @@ export class FixedThreadPool<
 
   /** @inheritDoc */
   protected registerWorkerMessageListener<Message extends Data | Response>(
-    worker: Worker,
+    workerNodeKey: number,
     listener: (message: MessageValue<Message>) => void
   ): void {
     (
-      this.getWorkerInfoByWorker(worker).messageChannel as MessageChannel
+      this.getWorkerInfo(workerNodeKey).messageChannel as MessageChannel
     ).port1.on('message', listener)
   }
 
index 0f1d442a6f242ef2a25068f8e212f2fbff686a37..0f0e0a393053b76bae28df789efe0b435ce36572 100644 (file)
@@ -373,7 +373,7 @@ export abstract class AbstractWorker<
   }
 
   /**
-   * Sends a message to the main worker.
+   * Sends a message to main worker.
    *
    * @param message - The response message.
    */
index 2070f8e03301aca85ac8215c52e96e11bb065acd..808a44cb096b77894b0ad34fd3a1c865091c0722 100644 (file)
@@ -115,14 +115,14 @@ describe('Worker choice strategy context test suite', () => {
       WorkerChoiceStrategyUndefinedStub
     )
     expect(() => workerChoiceStrategyContext.execute()).toThrowError(
-      new Error('Worker node key chosen is null or undefined')
+      new TypeError('Worker node key chosen is null or undefined')
     )
     workerChoiceStrategyContext.workerChoiceStrategies.set(
       workerChoiceStrategyContext.workerChoiceStrategy,
       WorkerChoiceStrategyNullStub
     )
     expect(() => workerChoiceStrategyContext.execute()).toThrowError(
-      new Error('Worker node key chosen is null or undefined')
+      new TypeError('Worker node key chosen is null or undefined')
     )
   })