Locker keep refreshing lock by itself

batch/leader/locker.js

@@ -7,18 +7,51 @@ var debug = require('../util/debug')('leader-locker');
 
 function Locker(locker) {
     this.locker = locker;
+    this.intervalIds = {};
 }
 
 module.exports = Locker;
 
 Locker.prototype.lock = function(host, ttl, callback) {
+    var self = this;
     debug('Locker.lock(%s, %d)', host, ttl);
-    this.locker.lock(host, ttl, callback);
+    this.locker.lock(host, ttl, function (err, lock) {
+        self.startRenewal(host);
+        return callback(err, lock);
+    });
 };
 
 Locker.prototype.unlock = function(host, callback) {
+    var self = this;
     debug('Locker.unlock(%s)', host);
-    this.locker.unlock(host, callback);
+    this.locker.unlock(host, function(err) {
+        self.stopRenewal(host);
+        return callback(err);
+    });
+};
+
+Locker.prototype.startRenewal = function(host) {
+    var self = this;
+    if (!this.intervalIds.hasOwnProperty(host)) {
+        this.intervalIds[host] = setInterval(function() {
+            debug('Trying to extend lock host=%s', host);
+            self.locker.lock(host, 5000, function(err, _lock) {
+                if (err) {
+                    return self.stopRenewal(host);
+                }
+                if (_lock) {
+                    debug('Extended lock host=%s', host);
+                }
+            });
+        }, 1000);
+    }
+};
+
+Locker.prototype.stopRenewal = function(host) {
+    if (this.intervalIds.hasOwnProperty(host)) {
+        clearInterval(this.intervalIds[host]);
+        delete this.intervalIds[host];
+    }
 };
 
 module.exports.create = function createLocker(type, config) {