From 594a9e17da7f85d4866dd73d8ff6913f6a17339a Mon Sep 17 00:00:00 2001
From: calzoneman <calzoneman@gmail.com>
Date: Wed, 25 May 2016 18:52:17 -0700
Subject: [PATCH] Spread channel saves across the save interval

Since all channels were saved sequentially, this would cause huge lag
spikes every time the channel save interval fired.  This change adds a
delay between each channel so that the additional load is spread evenly
across the save interval.
---
 package.json  |  2 +-
 src/bgtask.js | 13 ++++++++-----
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/package.json b/package.json
index c7d7994a..b0405ab4 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
   "author": "Calvin Montgomery",
   "name": "CyTube",
   "description": "Online media synchronizer and chat",
-  "version": "3.16.0",
+  "version": "3.16.1",
   "repository": {
     "url": "http://github.com/calzoneman/sync"
   },
diff --git a/src/bgtask.js b/src/bgtask.js
index e2fb9e75..7cb6ab4c 100644
--- a/src/bgtask.js
+++ b/src/bgtask.js
@@ -62,12 +62,15 @@ function initChannelDumper(Server) {
     var CHANNEL_SAVE_INTERVAL = parseInt(Config.get("channel-save-interval"))
                                 * 60000;
     setInterval(function () {
+        var wait = CHANNEL_SAVE_INTERVAL / Server.channels.length;
         Promise.reduce(Server.channels, (_, chan) => {
-            if (!chan.dead && chan.users && chan.users.length > 0) {
-                return chan.saveState().catch(err => {
-                    Logger.errlog.log(`Failed to save /r/${chan.name}: ${err.stack}`);
-                });
-            }
+            return Promise.delay(wait).then(() => {
+                if (!chan.dead && chan.users && chan.users.length > 0) {
+                    return chan.saveState().catch(err => {
+                        Logger.errlog.log(`Failed to save /r/${chan.name}: ${err.stack}`);
+                    });
+                }
+            });
         }, 0);
     }, CHANNEL_SAVE_INTERVAL);
 }