Managing all fail overs correctly

sreeix · Feb 26, 2012 · 7ac73b1 · 7ac73b1
1 parent b45781d
commit 7ac73b1
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Showing 4 changed files with 51 additions and 21 deletions.
diff --git a/config/config.json b/config/config.json
@@ -9,5 +9,5 @@
   }
   ]
   ,"listen_port": 9999
-  ,"check_period": 5
+  ,"check_period": 5000
 }
diff --git a/lib/redis_proxy.js b/lib/redis_proxy.js
@@ -23,23 +23,49 @@ var RedisProxy = module.exports = function(o){
   }
 
   this.allServers = _.map(o.servers, function(server){
-    var s =new Server(server);
-    s.on('up', function(){
+    return new Server(server).on('up', function() {
       console.log("We have a server that went up");
-      console.log(this);
-    });
-    s.on('down', function(){
-      console.log("We have a server that went DOWN");
-      console.log(this);
+      if(_.isNull(self._active) || _.isUndefined(self._active)){
+        self._active = this;
+        console.log("setting up the active "+ self._active.options.port);
+        self.readyup(this);
+      }
+    }).on('down', function(){
+      if(_.isEqual(self._active.options, this.options)){
+        console.log("Main server down PANIC");
+        console.log("finding next active server.");
+        self.nextActive();
+      }
     });
   });
 };
+
 RedisProxy.prototype.readyup = function(server){
-  console.log("Creating the pool for active server"+ server.options.host);
+  console.log("Creating the pool for active server"+ server.options.port);
   this.connections = new Pool({create: function(){
-    return redis.createClient(server.options.port, server.options.host);
+    try {
+       var client = redis.createClient(server.options.port, server.options.host, {max_attempts: 1});
+       client.on('error', redis.print);
+    } catch(err) {
+      console.log(err);
+      console.log(">>>>>>>>>>>>>>>");
+    }
   }});
 };
+
+RedisProxy.prototype.nextActive = function() {
+  this._active = _.find(this.allServers, function(server) {
+    return server.isUp()
+  });
+
+  if(this._active){
+    this.readyup(this._active);
+    console.log("Setting up as active "+ this._active.options.port);
+  } else {
+    throw new Error("Expected to have atleast one redis to proxy");
+  }
+}
+
 RedisProxy.prototype.active = function(command, callback) {
   return this._active;
 }
@@ -48,16 +74,13 @@ RedisProxy.prototype.sendCommand = function(command, callback) {
   return this.connections.take().sendRaw(command, callback);
 };
 
-RedisProxy.prototype.findByClient = function(client){
-  return _.find(this.allServers, function(server){ 
-    return (server.client.port == client.port && server.client.host === client.host);
-  });
-};
-
 RedisProxy.prototype.watch = function(){
   var self = this;
   setInterval(function(){
-    _.each(this.allServers, function(server){
+    console.log("Timeout.....");
+    _.each(self.allServers, function(server){
+      console.log("Pinging ");
+      console.log(server.options.port);
       server.ping();
     });
   }, this.options.check_period);

diff --git a/lib/server.js b/lib/server.js
@@ -22,6 +22,8 @@ Server.prototype.setupClient = function(serverInfo){
       self.up();
     });
     this.client.on('error', function(data){
+      console.log("EEEEEEEERRRRRRRRRRRRROOOOOOOOOORRRRRRRR");
+      console.log(data);
       self.down();
     });
 
@@ -30,6 +32,7 @@ Server.prototype.setupClient = function(serverInfo){
       self.down();
     });
   } catch(err) {
+    console.log("-------------");
     console.log(err);
     self.down();
     // Its ok... we will bring this guy up some point in time
@@ -49,13 +52,17 @@ Server.prototype.ping = function(){
   if(!this.client){
     this.setupClient(this.options);
   } else {
-    this.client.ping(function(){
-      console.log("xxxxxxxxxx");
+    this.client.ping(function(err, data){
+      if(err){
+        return self.down();
+      }
       self.up();
     });
   }
 };
-
+Server.prototype.isUp = function(){
+  return this.status === 'up';
+}
 Server.prototype.down = function(){
   this.status = 'down';
   this.emit('down');

diff --git a/server.js b/server.js
@@ -26,6 +26,6 @@ var server = net.createServer(function (socket) {
     });
   });
 });
-
+redis_proxy.watch();
 server.listen(config.listen_port, "127.0.0.1");
 console.log("server is listening on 127.0.0.1:"+ config.listen_port);