Add retry_max_delay option

README.md

@@ -202,6 +202,9 @@ connection to the redis server, commands are added to a queue and are executed
 once the connection has been established. Setting `enable_offline_queue` to
 `false` will disable this feature and the callback will be execute immediately
 with an error, or an error will be thrown if no callback is specified.
+* `retry_max_delay`: defaults to `null`. By default every time the client tries to connect and fails time before
+reconnection (delay) almost doubles. This delay normally grows infinitely, but setting `retry_max_delay` limits delay
+to maximum value, provided in miliseconds.
 
 ```js
     var redis = require("redis"),

index.js

@@ -51,11 +51,14 @@ function RedisClient(stream, options) {
     if (options.connect_timeout && !isNaN(options.connect_timeout) && options.connect_timeout > 0) {
         this.connect_timeout = +options.connect_timeout;
     }
-
     this.enable_offline_queue = true;
     if (typeof this.options.enable_offline_queue === "boolean") {
         this.enable_offline_queue = this.options.enable_offline_queue;
     }
+    this.retry_max_delay = null;
+    if (options.retry_max_delay !== undefined && !isNaN(options.retry_max_delay) && options.retry_max_delay > 0) {
+        this.retry_max_delay = options.retry_max_delay;
+    }
 
     this.initialize_retry_vars();
     this.pub_sub_mode = false;
@@ -429,7 +432,11 @@ RedisClient.prototype.connection_gone = function (why) {
         return;
     }
 
-    this.retry_delay = Math.floor(this.retry_delay * this.retry_backoff);
+    if (this.retry_max_delay !== null && this.retry_delay > this.retry_max_delay) {
+        this.retry_delay = this.retry_max_delay;
+    } else {
+        this.retry_delay = Math.floor(this.retry_delay * this.retry_backoff);
+    }
 
     if (exports.debug_mode) {
         console.log("Retry connection in " + this.retry_delay + " ms");

test.js

@@ -1798,6 +1798,28 @@ tests.auth = function () {
     });
 };
 
+tests.reconnectRetryMaxDelay = function() {
+    var time = new Date().getTime(),
+        name = 'reconnectRetryMaxDelay',
+        reconnecting = false;
+    var client = redis.createClient(PORT, HOST, {
+        retry_max_delay: 1
+    });
+    client.on('ready', function() {
+        if (!reconnecting) {
+            reconnecting = true;
+            client.retry_delay = 1000;
+            client.retry_backoff = 1;
+            client.stream.end();
+        } else {
+            client.end();
+            var lasted = new Date().getTime() - time;
+            assert.ok(lasted < 1000);
+            next(name);
+        }
+    });
+};
+
 all_tests = Object.keys(tests);
 all_start = new Date();
 test_count = 0;