fix: OptimalBits#1893

lib/queue.js

@@ -210,7 +210,8 @@ const Queue = function Queue(name, url, opts) {
     guardInterval: 5000,
     retryProcessDelay: 5000,
     drainDelay: 5,
-    backoffStrategies: {}
+    backoffStrategies: {},
+    maxWaitingLimit: Number.MAX_VALUE
   });
 
   this.settings.lockRenewTime =
@@ -907,14 +908,22 @@ Queue.prototype.updateDelayTimer = function() {
       ]);
 
       // Schedule next processing of the delayed jobs
-      if (delay <= 0) {
-        // Next set of jobs are due right now, process them also
-        this.updateDelayTimer();
-      } else {
-        // Update the delay set when the next job is due
-        // or the next guard time
-        this.delayTimer = setTimeout(() => this.updateDelayTimer(), delay);
-      }
+      this.getWaitingCount().then(cnt => {
+        if (cnt < this.settings.maxWaitingLimit) {
+          // limit the waiting queue grows too quickly
+          this.delayTimer = setTimeout(
+            () => this.updateDelayTimer(),
+            this.settings.guardInterval
+          );
+        } else if (delay <= 0) {
+          // Next set of jobs are due right now, process them also
+          this.updateDelayTimer();
+        } else {
+          // Update the delay set when the next job is due
+          // or the next guard time
+          this.delayTimer = setTimeout(() => this.updateDelayTimer(), delay);
+        }
+      });
 
       // Silence warnings about promise created but not returned.
       // This isn't an issue since we emit errors.