fix: fix back pressure detection
[poolifier.git] / src / pools / abstract-pool.ts
index f89af5acf813afc18eeaaa1b9277039c6692e480..dceef6decb534f083510d90a947a05861c2ec2df 100644 (file)
@@ -118,7 +118,10 @@ export abstract class AbstractPool<
     this.executeTask = this.executeTask.bind(this)
     this.enqueueTask = this.enqueueTask.bind(this)
     this.dequeueTask = this.dequeueTask.bind(this)
-    this.checkAndEmitEvents = this.checkAndEmitEvents.bind(this)
+    this.checkAndEmitTaskExecutionEvents =
+      this.checkAndEmitTaskExecutionEvents.bind(this)
+    this.checkAndEmitTaskQueuingEvents =
+      this.checkAndEmitTaskQueuingEvents.bind(this)
 
     if (this.opts.enableEvents === true) {
       this.emitter = new PoolEmitter()
@@ -204,9 +207,10 @@ export abstract class AbstractPool<
       this.opts.workerChoiceStrategy =
         opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN
       this.checkValidWorkerChoiceStrategy(this.opts.workerChoiceStrategy)
-      this.opts.workerChoiceStrategyOptions =
-        opts.workerChoiceStrategyOptions ??
-        DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+      this.opts.workerChoiceStrategyOptions = {
+        ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
+        ...opts.workerChoiceStrategyOptions
+      }
       this.checkValidWorkerChoiceStrategyOptions(
         this.opts.workerChoiceStrategyOptions
       )
@@ -244,6 +248,22 @@ export abstract class AbstractPool<
         'Invalid worker choice strategy options: must be a plain object'
       )
     }
+    if (
+      workerChoiceStrategyOptions.choiceRetries != null &&
+      !Number.isSafeInteger(workerChoiceStrategyOptions.choiceRetries)
+    ) {
+      throw new TypeError(
+        'Invalid worker choice strategy options: choice retries must be an integer'
+      )
+    }
+    if (
+      workerChoiceStrategyOptions.choiceRetries != null &&
+      workerChoiceStrategyOptions.choiceRetries <= 0
+    ) {
+      throw new RangeError(
+        `Invalid worker choice strategy options: choice retries '${workerChoiceStrategyOptions.choiceRetries}' must be greater than zero`
+      )
+    }
     if (
       workerChoiceStrategyOptions.weights != null &&
       Object.keys(workerChoiceStrategyOptions.weights).length !== this.maxSize
@@ -283,7 +303,7 @@ export abstract class AbstractPool<
       tasksQueueOptions.concurrency <= 0
     ) {
       throw new Error(
-        `Invalid worker tasks concurrency '${tasksQueueOptions.concurrency}'`
+        `Invalid worker tasks concurrency '${tasksQueueOptions.concurrency}' is a negative integer or zero`
       )
     }
   }
@@ -351,6 +371,9 @@ export abstract class AbstractPool<
           0
         )
       }),
+      ...(this.opts.enableTasksQueue === true && {
+        backPressure: this.hasBackPressure()
+      }),
       failedTasks: this.workerNodes.reduce(
         (accumulator, workerNode) =>
           accumulator + workerNode.usage.tasks.failed,
@@ -566,7 +589,10 @@ export abstract class AbstractPool<
     workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
   ): void {
     this.checkValidWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
-    this.opts.workerChoiceStrategyOptions = workerChoiceStrategyOptions
+    this.opts.workerChoiceStrategyOptions = {
+      ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
+      ...workerChoiceStrategyOptions
+    }
     this.workerChoiceStrategyContext.setOptions(
       this.opts.workerChoiceStrategyOptions
     )
@@ -646,14 +672,15 @@ export abstract class AbstractPool<
 
   /** @inheritDoc */
   public listTaskFunctions (): string[] {
-    if (
-      Array.isArray(this.getWorkerInfo(0).taskFunctions) &&
-      (this.getWorkerInfo(0).taskFunctions as string[]).length > 0
-    ) {
-      return this.getWorkerInfo(0).taskFunctions as string[]
-    } else {
-      return []
+    for (const workerNode of this.workerNodes) {
+      if (
+        Array.isArray(workerNode.info.taskFunctions) &&
+        workerNode.info.taskFunctions.length > 0
+      ) {
+        return workerNode.info.taskFunctions
+      }
     }
+    return []
   }
 
   /** @inheritDoc */
@@ -712,7 +739,6 @@ export abstract class AbstractPool<
       } else {
         this.enqueueTask(workerNodeKey, task)
       }
-      this.checkAndEmitEvents()
     })
   }
 
@@ -778,12 +804,12 @@ export abstract class AbstractPool<
     const workerUsage = this.workerNodes[workerNodeKey].usage
     ++workerUsage.tasks.executing
     this.updateWaitTimeWorkerUsage(workerUsage, task)
-    if (this.canUpdateTaskWorkerUsage(workerNodeKey)) {
-      const taskWorkerUsage = this.workerNodes[
+    if (this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey)) {
+      const taskFunctionWorkerUsage = this.workerNodes[
         workerNodeKey
-      ].getTaskWorkerUsage(task.name as string) as WorkerUsage
-      ++taskWorkerUsage.tasks.executing
-      this.updateWaitTimeWorkerUsage(taskWorkerUsage, task)
+      ].getTaskFunctionWorkerUsage(task.name as string) as WorkerUsage
+      ++taskFunctionWorkerUsage.tasks.executing
+      this.updateWaitTimeWorkerUsage(taskFunctionWorkerUsage, task)
     }
   }
 
@@ -802,23 +828,29 @@ export abstract class AbstractPool<
     this.updateTaskStatisticsWorkerUsage(workerUsage, message)
     this.updateRunTimeWorkerUsage(workerUsage, message)
     this.updateEluWorkerUsage(workerUsage, message)
-    if (this.canUpdateTaskWorkerUsage(workerNodeKey)) {
-      const taskWorkerUsage = this.workerNodes[
+    if (this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey)) {
+      const taskFunctionWorkerUsage = this.workerNodes[
         workerNodeKey
-      ].getTaskWorkerUsage(
+      ].getTaskFunctionWorkerUsage(
         message.taskPerformance?.name ?? DEFAULT_TASK_NAME
       ) as WorkerUsage
-      this.updateTaskStatisticsWorkerUsage(taskWorkerUsage, message)
-      this.updateRunTimeWorkerUsage(taskWorkerUsage, message)
-      this.updateEluWorkerUsage(taskWorkerUsage, message)
+      this.updateTaskStatisticsWorkerUsage(taskFunctionWorkerUsage, message)
+      this.updateRunTimeWorkerUsage(taskFunctionWorkerUsage, message)
+      this.updateEluWorkerUsage(taskFunctionWorkerUsage, message)
     }
   }
 
-  private canUpdateTaskWorkerUsage (workerNodeKey: number): boolean {
+  /**
+   * Whether the worker node shall update its task function worker usage or not.
+   *
+   * @param workerNodeKey - The worker node key.
+   * @returns `true` if the worker node shall update its task function worker usage, `false` otherwise.
+   */
+  private shallUpdateTaskFunctionWorkerUsage (workerNodeKey: number): boolean {
     const workerInfo = this.getWorkerInfo(workerNodeKey)
     return (
       Array.isArray(workerInfo.taskFunctions) &&
-      workerInfo.taskFunctions.length > 1
+      workerInfo.taskFunctions.length > 2
     )
   }
 
@@ -827,7 +859,19 @@ export abstract class AbstractPool<
     message: MessageValue<Response>
   ): void {
     const workerTaskStatistics = workerUsage.tasks
-    --workerTaskStatistics.executing
+    if (
+      workerTaskStatistics.executing != null &&
+      workerTaskStatistics.executing > 0
+    ) {
+      --workerTaskStatistics.executing
+    } else if (
+      workerTaskStatistics.executing != null &&
+      workerTaskStatistics.executing < 0
+    ) {
+      throw new Error(
+        'Worker usage statistic for tasks executing cannot be negative'
+      )
+    }
     if (message.taskError == null) {
       ++workerTaskStatistics.executed
     } else {
@@ -1182,7 +1226,7 @@ export abstract class AbstractPool<
     }
   }
 
-  private checkAndEmitEvents (): void {
+  private checkAndEmitTaskExecutionEvents (): void {
     if (this.emitter != null) {
       if (this.busy) {
         this.emitter.emit(PoolEvents.busy, this.info)
@@ -1193,6 +1237,12 @@ export abstract class AbstractPool<
     }
   }
 
+  private checkAndEmitTaskQueuingEvents (): void {
+    if (this.hasBackPressure()) {
+      this.emitter?.emit(PoolEvents.backPressure, this.info)
+    }
+  }
+
   /**
    * Gets the worker information given its worker node key.
    *
@@ -1211,7 +1261,11 @@ export abstract class AbstractPool<
    * @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)
+    const workerNode = new WorkerNode<Worker, Data>(
+      worker,
+      this.worker,
+      this.maxSize
+    )
     // Flag the worker node as ready at pool startup.
     if (this.starting) {
       workerNode.info.ready = true
@@ -1237,6 +1291,23 @@ export abstract class AbstractPool<
     }
   }
 
+  /** @inheritDoc */
+  public hasWorkerNodeBackPressure (workerNodeKey: number): boolean {
+    return (
+      this.opts.enableTasksQueue === true &&
+      this.workerNodes[workerNodeKey].hasBackPressure()
+    )
+  }
+
+  private hasBackPressure (): boolean {
+    return (
+      this.opts.enableTasksQueue === true &&
+      this.workerNodes.findIndex(
+        (workerNode) => !workerNode.hasBackPressure()
+      ) === -1
+    )
+  }
+
   /**
    * Executes the given task on the worker given its worker node key.
    *
@@ -1246,10 +1317,13 @@ export abstract class AbstractPool<
   private executeTask (workerNodeKey: number, task: Task<Data>): void {
     this.beforeTaskExecutionHook(workerNodeKey, task)
     this.sendToWorker(workerNodeKey, task, task.transferList)
+    this.checkAndEmitTaskExecutionEvents()
   }
 
   private enqueueTask (workerNodeKey: number, task: Task<Data>): number {
-    return this.workerNodes[workerNodeKey].enqueueTask(task)
+    const tasksQueueSize = this.workerNodes[workerNodeKey].enqueueTask(task)
+    this.checkAndEmitTaskQueuingEvents()
+    return tasksQueueSize
   }
 
   private dequeueTask (workerNodeKey: number): Task<Data> | undefined {