From 29742d6a87829b7736007282e344fd2aee27b4ed Mon Sep 17 00:00:00 2001
From: Jakob Ackermann <das7pad@outlook.com>
Date: Sat, 3 Oct 2020 19:40:46 +0200
Subject: [PATCH 1/3] [misc] register the metrics sweeping interval handle for
 later cleanup

---
 libraries/metrics/index.js        |  1 +
 libraries/metrics/prom_wrapper.js | 12 +++++++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/libraries/metrics/index.js b/libraries/metrics/index.js
index 03357da193..238cf5ab81 100644
--- a/libraries/metrics/index.js
+++ b/libraries/metrics/index.js
@@ -30,6 +30,7 @@ function initialize(appName, opts = {}) {
   appName = appName || DEFAULT_APP_NAME
   configure({ ...opts, appName })
   collectDefaultMetrics({ timeout: 5000, prefix: '' })
+  promWrapper.setupSweeping()
 
   console.log(`ENABLE_TRACE_AGENT set to ${process.env.ENABLE_TRACE_AGENT}`)
   if (process.env.ENABLE_TRACE_AGENT === 'true') {
diff --git a/libraries/metrics/prom_wrapper.js b/libraries/metrics/prom_wrapper.js
index 57ddf0e2ac..9fe3407346 100644
--- a/libraries/metrics/prom_wrapper.js
+++ b/libraries/metrics/prom_wrapper.js
@@ -138,12 +138,15 @@ class MetricWrapper {
   }
 }
 
-if (!PromWrapper.sweepRegistered) {
+let sweepingInterval
+PromWrapper.setupSweeping = function() {
+  if (sweepingInterval) {
+    clearInterval(sweepingInterval)
+  }
   if (process.env.DEBUG_METRICS) {
     console.log('Registering sweep method')
   }
-  PromWrapper.sweepRegistered = true
-  setInterval(function() {
+  sweepingInterval = setInterval(function() {
     if (PromWrapper.ttlInMinutes) {
       if (process.env.DEBUG_METRICS) {
         console.log('Sweeping metrics')
@@ -153,6 +156,9 @@ if (!PromWrapper.sweepRegistered) {
       })
     }
   }, 60000)
+
+  const Metrics = require('./index')
+  Metrics.registerDestructor(() => clearInterval(sweepingInterval))
 }
 
 module.exports = PromWrapper

From 20223d865f26a83a1b132ccfbfc7ab84a3d3446d Mon Sep 17 00:00:00 2001
From: Jakob Ackermann <das7pad@outlook.com>
Date: Sat, 3 Oct 2020 19:42:24 +0200
Subject: [PATCH 2/3] [misc] do not register a noop sweeping interval

---
 libraries/metrics/prom_wrapper.js | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/libraries/metrics/prom_wrapper.js b/libraries/metrics/prom_wrapper.js
index 9fe3407346..7ec65547c2 100644
--- a/libraries/metrics/prom_wrapper.js
+++ b/libraries/metrics/prom_wrapper.js
@@ -143,18 +143,22 @@ PromWrapper.setupSweeping = function() {
   if (sweepingInterval) {
     clearInterval(sweepingInterval)
   }
+  if (!PromWrapper.ttlInMinutes) {
+    if (process.env.DEBUG_METRICS) {
+      console.log('Not registering sweep method -- empty ttl')
+    }
+    return
+  }
   if (process.env.DEBUG_METRICS) {
     console.log('Registering sweep method')
   }
   sweepingInterval = setInterval(function() {
-    if (PromWrapper.ttlInMinutes) {
-      if (process.env.DEBUG_METRICS) {
-        console.log('Sweeping metrics')
-      }
-      return metrics.forEach((metric, key) => {
-        return metric.sweep()
-      })
+    if (process.env.DEBUG_METRICS) {
+      console.log('Sweeping metrics')
     }
+    return metrics.forEach((metric, key) => {
+      return metric.sweep()
+    })
   }, 60000)
 
   const Metrics = require('./index')

From e1650616b853d73f6c7381e720ab30d9a1fd02a7 Mon Sep 17 00:00:00 2001
From: Jakob Ackermann <das7pad@outlook.com>
Date: Sat, 3 Oct 2020 19:42:24 +0200
Subject: [PATCH 3/3] [misc] version bump to 3.5.1

---
 libraries/metrics/package-lock.json | 2 +-
 libraries/metrics/package.json      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/libraries/metrics/package-lock.json b/libraries/metrics/package-lock.json
index bd63f72688..56fc668bdb 100644
--- a/libraries/metrics/package-lock.json
+++ b/libraries/metrics/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "@overleaf/metrics",
-  "version": "3.5.0",
+  "version": "3.5.1",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/libraries/metrics/package.json b/libraries/metrics/package.json
index 134bccfaba..be8ff08387 100644
--- a/libraries/metrics/package.json
+++ b/libraries/metrics/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@overleaf/metrics",
-  "version": "3.5.0",
+  "version": "3.5.1",
   "description": "A drop-in metrics and monitoring module for node.js apps",
   "repository": {
     "type": "git",