From f92b2b6668e6895ebe68c39487ab951faafe1a6c Mon Sep 17 00:00:00 2001
From: shaharmor <shahar@peer5.com>
Date: Mon, 18 Jun 2018 18:10:47 +0300
Subject: [PATCH] refresh slots automatically every slotsRefreshInterval
 (default 5s)

---
 README.md                  |  1 +
 lib/cluster/index.js       | 24 ++++++++++++++++++++++--
 test/functional/cluster.js | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 831f9c19..9e68f5d9 100644
--- a/README.md
+++ b/README.md
@@ -744,6 +744,7 @@ but a few so that if one is unreachable the client will try the next one, and th
     will resend the commands rejected with `TRYAGAIN` error after the specified time (in ms).
     * `redisOptions`: Default options passed to the constructor of `Redis` when connecting to a node.
     * `slotsRefreshTimeout`: Milliseconds before a timeout occurs while refreshing slots from the cluster (default `1000`)
+    * `slotsRefreshInterval`: Milliseconds between every automatic slots refresh (default `5000`)
 
 ### Read-write splitting
 
diff --git a/lib/cluster/index.js b/lib/cluster/index.js
index c268c888..483d978d 100644
--- a/lib/cluster/index.js
+++ b/lib/cluster/index.js
@@ -37,6 +37,7 @@ var DelayQueue = require('./delay_queue');
  * if `retryDelayOnTryAgain` is valid delay time.
  * @param {number} [options.slotsRefreshTimeout=1000] - The milliseconds before a timeout occurs while refreshing
  * slots from the cluster.
+ * @param {number} [options.slotsRefreshInterval=5000] - The milliseconds between every automatic slots refresh.
  * @param {Object} [options.redisOptions] - Passed to the constructor of `Redis`.
  * @extends [EventEmitter](http://nodejs.org/api/events.html#events_class_events_eventemitter)
  * @extends Commander
@@ -106,7 +107,8 @@ Cluster.defaultOptions = {
   retryDelayOnFailover: 100,
   retryDelayOnClusterDown: 100,
   retryDelayOnTryAgain: 100,
-  slotsRefreshTimeout: 1000
+  slotsRefreshTimeout: 1000,
+  slotsRefreshInterval: 5000
 };
 
 util.inherits(Cluster, EventEmitter);
@@ -116,6 +118,15 @@ Cluster.prototype.resetOfflineQueue = function () {
   this.offlineQueue = new Deque();
 };
 
+Cluster.prototype.resetNodesRefreshInterval = function () {
+  if (this.slotsTimer) {
+    return;
+  }
+  this.slotsTimer = setInterval(function() {
+    this.refreshSlotsCache();
+  }.bind(this), this.options.slotsRefreshInterval);
+};
+
 /**
  * Connect to a cluster
  *
@@ -127,6 +138,7 @@ Cluster.prototype.connect = function () {
     this.setStatus('ready');
     this.retryAttempts = 0;
     this.executeOfflineCommands();
+    this.resetNodesRefreshInterval();
   }
 
   return new Promise(function (resolve, reject) {
@@ -219,6 +231,10 @@ Cluster.prototype.disconnect = function (reconnect) {
     clearTimeout(this.reconnectTimeout);
     this.reconnectTimeout = null;
   }
+  if (this.slotsTimer) {
+    clearInterval(this.slotsTimer);
+    this.slotsTimer = null;
+  }
 
   if (status === 'wait') {
     this.setStatus('close');
@@ -245,6 +261,10 @@ Cluster.prototype.quit = function (callback) {
     clearTimeout(this.reconnectTimeout);
     this.reconnectTimeout = null;
   }
+  if (this.slotsTimer) {
+    clearInterval(this.slotsTimer);
+    this.slotsTimer = null;
+  }
   if (status === 'wait') {
     var ret = Promise.resolve('OK').nodeify(callback);
 
@@ -346,7 +366,7 @@ Cluster.prototype.setStatus = function (status) {
 /**
  * Refresh the slot cache
  *
- * @param {function} callback
+ * @param {function} [callback]
  * @private
  */
 Cluster.prototype.refreshSlotsCache = function (callback) {
diff --git a/test/functional/cluster.js b/test/functional/cluster.js
index e2ef6fed..c85f0717 100644
--- a/test/functional/cluster.js
+++ b/test/functional/cluster.js
@@ -199,6 +199,41 @@ describe('cluster', function () {
       }
     });
 
+    it('should discover other nodes automatically every slotsRefreshInterval', function (done) {
+      var times = 0;
+      var argvHandler = function (argv) {
+        if (argv[0] === 'cluster' && argv[1] === 'slots') {
+          times++;
+          if (times === 1) {
+            return [
+              [0, 5460, ['127.0.0.1', 30001]],
+              [5461, 10922, ['127.0.0.1', 30001]],
+              [10923, 16383, ['127.0.0.1', 30001]]
+            ];
+          }
+
+          return [
+            [0, 5460, ['127.0.0.1', 30001]],
+            [5461, 10922, ['127.0.0.1', 30001]],
+            [10923, 16383, ['127.0.0.1', 30002]]
+          ];
+        }
+      };
+      var node1 = new MockServer(30001, argvHandler);
+      var node2 = new MockServer(30002, argvHandler);
+
+      node1.once('connect', function() {
+        node2.once('connect', function () {
+          cluster.disconnect();
+          disconnect([node1, node2], done);
+        });
+      });
+
+      var cluster = new Redis.Cluster([
+        { host: '127.0.0.1', port: '30001' }
+      ], { slotsRefreshInterval: 100, redisOptions: { lazyConnect: false } });
+    });
+
     it('should send command to the correct node', function (done) {
       var node1 = new MockServer(30001, function (argv) {
         if (argv[0] === 'cluster' && argv[1] === 'slots') {