Thread error handling, enviroment variable for thread count

src/utils/workerPool.ts

@@ -7,34 +7,46 @@ import logger from './logger'
 
 // ---------------------------------------------------------------------------
 
+const alertOnPendingCount = 10
 const workerFile = './src/utils/classes.ts'
 let pool: any = null
 let workers: any = null
 
 // ---------------------------------------------------------------------------
 
-// doALongTask(i, taskObj).then((res) => {
-//   msgAll(res)
-//   console.log('[MSGFROMCLIENT]', res)
-// })
+function handleWorkerError(client, err) {
+  logger.Log('resourcePromise error', logger.GetColor('redbg'))
+  console.error(err)
+  pool.destroy(client)
+}
 
 export function doALongTask(obj: any): Promise<any> {
+  if (pool.pending > alertOnPendingCount) {
+    logger.Log(
+      `More than ${alertOnPendingCount} callers waiting for free resource! (${pool.pending})`,
+      logger.GetColor('redbg')
+    )
+  }
+
   return new Promise((resolve) => {
+    let currClient
     pool
       .acquire()
       .then(function(client) {
-        doSomething(client, obj).then((res) => {
+        currClient = client
+        doSomething(client, obj)
+          .then((res) => {
             resolve(res)
             // TODO: check if result is really a result, and want to release port
             pool.release(client)
             // console.log('[RELEASE]: #' + client.index)
           })
+          .catch(function(err) {
+            handleWorkerError(currClient, err)
+          })
       })
       .catch(function(err) {
-        logger.Log('resourcePromise error', logger.GetColor('redbg'))
-        console.error(err)
-        // handle error - this is generally a timeout or maxWaitingClients
-        // error
+        handleWorkerError(currClient, err)
       })
   })
 }
@@ -62,15 +74,24 @@ export function initWorkerPool(initData: any): void {
     },
   }
 
+  const threadCount = process.env.NS_THREAD_COUNT || os.cpus().length - 1
+  if (process.env.NS_THREAD_COUNT) {
+    logger.Log(
+      `Setting thread count from enviroment variable NS_THREAD_COUNT: '${threadCount}'`,
+      logger.GetColor('red')
+    )
+  }
+
   const opts = {
-    min: os.cpus().length - 1, // minimum size of the pool
-    max: os.cpus().length - 1, // maximum size of the pool
+    min: threadCount, // minimum size of the pool
+    max: threadCount, // maximum size of the pool
     maxWaitingClients: 999,
   }
 
   pool = genericPool.createPool(factory, opts)
 }
 
+// TODO: accuire all workers here, and handle errors so they can be removed if threads exit
 export function msgAllWorker(data: any): void {
   workers.forEach((worker) => {
     worker.postMessage(data)
@@ -90,7 +111,8 @@ function getAWorker(i, initData) {
   worker.setMaxListeners(50)
 
   // worker.on('message', (msg) => {
-  //   logger.Log(`[MAIN]: Msg from worker #${i}`, msg)
+  //   logger.Log(`[MAIN]: Msg from worker #${i}`)
+  //   logger.Log(msg)
   // })
 
   // worker.on('online', () => {