From 2d4df88629c4cab5795579b4ac248cf98fd59a2d Mon Sep 17 00:00:00 2001
From: Ian Bicking <ianb@colorstudy.com>
Date: Tue, 13 Dec 2016 13:19:07 -0600
Subject: [PATCH] Fix #1978, add a $CONTROLLER_SINGLETON variable that controls
 if this server instance should handle database upgrades and periodic tasks

---
 .env.dev                           | 1 +
 server/src/config.js               | 7 +++++++
 server/src/jobs.js                 | 4 ++++
 server/src/pages/metrics/server.js | 9 ++++++---
 server/src/server.js               | 4 ++++
 5 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/.env.dev b/.env.dev
index 5f079ccf3d..9197ea7903 100644
--- a/.env.dev
+++ b/.env.dev
@@ -3,5 +3,6 @@ CLIENT_SECRET=efde5874713abf2a8ec9d8af8488fae7c7e0a933dba08208f644fa93b5622dab
 SHOW_STACK_TRACES=true
 LOG_LINT=true
 LOG_LEVEL=debug
+CONTROLLER_SINGLETON=true
 # To test caching locally:
 #SET_CACHE=true
diff --git a/server/src/config.js b/server/src/config.js
index fc8ca38d3b..965b0f7d64 100644
--- a/server/src/config.js
+++ b/server/src/config.js
@@ -268,6 +268,13 @@ var conf = convict({
     default: true,
     env: "SET_CACHE",
     arg: "set-cache"
+  },
+  controllerSingleton: {
+    doc: "If true, then this ONE server should be the one that runs migrations and periodic tasks",
+    format: Boolean,
+    default: false,
+    env: "CONTROLLER_SINGLETON",
+    arg: "controller-singleton"
   }
 });
 
diff --git a/server/src/jobs.js b/server/src/jobs.js
index 08d65b7440..d66092a6e2 100644
--- a/server/src/jobs.js
+++ b/server/src/jobs.js
@@ -9,6 +9,10 @@ const ua = require("universal-analytics");
 let checkDeletedInterval = config.checkDeletedInterval * 1000;
 
 exports.start = function () {
+  if (! config.controllerSingleton) {
+    console.info("Note: not performing periodic tasks in this server");
+    return;
+  }
 
   //setInterval(require("./exporter").cleanExports, keepTime / 10);
 
diff --git a/server/src/pages/metrics/server.js b/server/src/pages/metrics/server.js
index 6a46471cd1..bac01f18e3 100644
--- a/server/src/pages/metrics/server.js
+++ b/server/src/pages/metrics/server.js
@@ -29,7 +29,7 @@ function safeStoreQueries() {
   });
 }
 
-if (config.refreshMetricsTime) {
+if (config.refreshMetricsTime && config.controllerSingleton) {
   // Randomize each worker +-30 seconds interval
   let interval = config.refreshMetricsTime * 1000 + Math.floor(Math.random()*60000 - 30000);
   if (interval < 10000) {
@@ -39,5 +39,8 @@ if (config.refreshMetricsTime) {
 } else {
   console.info("Not running periodic metrics updating");
 }
-// Also run immediately on startup:
-setTimeout(safeStoreQueries, 1000);
+
+if (config.controllerSingleton) {
+  // Also run immediately on startup:
+  setTimeout(safeStoreQueries, 1000);
+}
diff --git a/server/src/server.js b/server/src/server.js
index a788e99a24..566c6f24f6 100644
--- a/server/src/server.js
+++ b/server/src/server.js
@@ -120,6 +120,10 @@ if (config.useS3) {
 
 
 function initDatabase() {
+  if (! config.controllerSingleton) {
+    console.info("Note: this server will not perform database initialization");
+    return Promise.resolve();
+  }
   dbschema.createTables().then(() => {
     return dbschema.createKeygrip();
   }).then(() => {