Merge pull request FormidableLabs#45 from FormidableLabs/bug-memoryleak

Bug memoryleak

Author: jasonwilson

README.md

@@ -92,16 +92,24 @@ Usage: nodejs-dashboard [options] -- [node] [script] [arguments]
 ```
 Options:
 
-  -h, --help             output usage information
-  -V, --version          output the version number
-  -p, --port [port]      Socket listener port
-  -e, --eventdelay [ms]  Minimum threshold for event loop reporting, default 10ms
+  -h, --help                 output usage information
+  -V, --version              output the version number
+  -p, --port [port]          Socket listener port
+  -r, --refreshinterval [ms] Metrics refresh interval, default 1000ms
+  -e, --eventdelay [ms]      Minimum threshold for event loop reporting, default 10ms
+  -s, --scrollback [count]   Maximum scroll history for log windows
 ```
 
 #####`--port`
 Under the hood the dashboard utilizes SocketIO with a default port of `9838`. If this conflicts with an existing service you can optionally change this value.
 
+#####`--refreshinterval`
+Specifies the interval in milliseconds that the metrics should be refreshed. The default is 1000 ms (1 second).
+
 #####`--eventdelay`
 This tunes the minimum threshold for reporting event loop delays. The default value is `10ms`. Any delay below this value will be reported at `0`.
 
+#####`--scrollback`
+Specifies the maximum number of lines that log windows (e.g. stdout, stderr) will buffer in order to scroll backwards and see the history. The default is 1000 lines.
+
 To gracefully exit and terminate the spawned process use one of:  `Ctrl + C`, `Q`, or `ESC`.

bin/nodejs-dashboard.js

@@ -16,7 +16,9 @@ var program = new commander.Command(pkg.name);
 
 program.version(pkg.version);
 program.option("-p, --port [port]", "Socket listener port");
+program.option("-r, --refreshinterval [ms]", "Metrics refresh interval, default 1000ms");
 program.option("-e, --eventdelay [ms]", "Minimum threshold for event loop reporting, default 10ms");
+program.option("-s, --scrollback [count]", "Maximum scroll history for log windows");
 program.usage("[options] -- [node] [script] [arguments]");
 program.parse(process.argv);
 
@@ -29,9 +31,12 @@ var command = program.args[0];
 var args = program.args.slice(1);
 
 var port = program.port || config.PORT;
+var refreshInterval = program.refreshinterval || config.REFRESH_INTERVAL;
 var eventDelay = program.eventdelay || config.BLOCKED_THRESHOLD;
+var scrollback = program.scrollback || config.SCROLLBACK;
 
 process.env[config.PORT_KEY] = port;
+process.env[config.REFRESH_INTERVAL_KEY] = refreshInterval;
 process.env[config.BLOCKED_THRESHOLD_KEY] = eventDelay;
 
 var child = spawn(command, args, {
@@ -44,7 +49,7 @@ console.log("Waiting for client connection on %d...", port); //eslint-disable-li
 
 var server = new SocketIO(port);
 
-var dashboard = new Dashboard({ appName: appName, program: program });
+var dashboard = new Dashboard({ appName: appName, program: program, scrollback: scrollback });
 
 server.on("connection", function (socket) {
   socket.on("metrics", function (data) {

lib/config.js

@@ -5,6 +5,9 @@ var pkg = require("../package.json");
 module.exports = {
   PORT: 9838,
   PORT_KEY: pkg.name + "_PORT",
+  REFRESH_INTERVAL: 1000,
+  REFRESH_INTERVAL_KEY: pkg.name + "_REFRESH_INTERVAL",
   BLOCKED_THRESHOLD: 10,
-  BLOCKED_THRESHOLD_KEY: pkg.name + "_BLOCKED_THRESHOLD"
+  BLOCKED_THRESHOLD_KEY: pkg.name + "_BLOCKED_THRESHOLD",
+  SCROLLBACK: 1000
 };

lib/dashboard-agent.js

@@ -8,37 +8,38 @@ var _ = require("lodash");
 var config = require("./config");
 
 var dashboardAgent = function () {
+
   var options = {
     port: process.env[config.PORT_KEY],
-    blockedThreshold: process.env[config.BLOCKED_THRESHOLD_KEY],
-    refreshInterval: 1000
+    refreshInterval: process.env[config.REFRESH_INTERVAL_KEY],
+    blockedThreshold: process.env[config.BLOCKED_THRESHOLD_KEY]
   };
 
-  var socket = new SocketIO("http://localhost:" + options.port);
-
-  var eventLoop = {
-    delay: 0,
-    high: 0
+  // check if the app was launched w/o the dashboard
+  // if so, don't start any of the monitoring
+  var enabled = options.port && options.refreshInterval && options.blockedThreshold;
+
+  var socket;
+
+  var metrics = {
+    eventLoop: {
+      delay: 0,
+      high: 0
+    },
+    mem: {
+      systemTotal: os.totalmem()
+    },
+    cpu: {
+      utilization: 0
+    }
   };
 
   var _delayed = function (delay) {
-    eventLoop.high = Math.max(eventLoop.high, delay);
-    eventLoop.delay = delay;
+    metrics.eventLoop.high = Math.max(metrics.eventLoop.high, delay);
+    metrics.eventLoop.delay = delay;
   };
 
-  blocked(_delayed, { threshold: options.blockedThreshold });
-
   var _getStats = function (cb) {
-    var metrics = {
-      eventLoop: eventLoop,
-      mem: {
-        systemTotal: os.totalmem()
-      },
-      cpu: {
-        utilization: 0
-      }
-    };
-
     _.merge(metrics.mem, process.memoryUsage());
 
     pusage.stat(process.pid, function (err, stat) {
@@ -54,29 +55,43 @@ var dashboardAgent = function () {
   };
 
   var resetEventMetrics = function () {
-    eventLoop.delay = 0;
+    metrics.eventLoop.delay = 0;
   };
 
   var _emitStats = function () {
+
     _getStats(function (err, newMetrics) {
       if (err) {
         console.error("Failed to load metrics: ", err); //eslint-disable-line
-        socket.emit("error", JSON.stringify(err));
-      } else {
+        if (socket && socket.connected) {
+          socket.emit("error", JSON.stringify(err));
+        }
+      } else if (socket && socket.connected) {
         socket.emit("metrics", JSON.stringify(newMetrics));
       }
 
       resetEventMetrics();
     });
+
   };
 
   var startPump = function () {
-    options.intervalId = setInterval(_emitStats, options.refreshInterval);
+    if (enabled) {
+      socket = new SocketIO("http://localhost:" + options.port);
+      blocked(_delayed, { threshold: options.blockedThreshold });
+      options.intervalId = setInterval(_emitStats, options.refreshInterval);
+    }
   };
 
   var destroy = function () {
-    socket.close();
-    clearInterval(options.intervalId);
+    if (socket) {
+      socket.close();
+      socket = null;
+    }
+    if (options.intervalId) {
+      clearInterval(options.intervalId);
+      options.intervalId = null;
+    }
   };
 
   startPump();

lib/dashboard.js

@@ -10,6 +10,8 @@ var CpuView = require("./views/cpu-view");
 var EventEmitter = require("events");
 
 var Dashboard = function Dashboard(options) {
+  this.options = options || {};
+
   this.screen = blessed.screen({
     smartCSR: true,
     title: options.appName
@@ -35,6 +37,7 @@ Dashboard.prototype._createView = function () {
 
   var stdoutView = new StreamView({
     parent: container,
+    scrollback: this.options.scrollback,
     label: "stdout",
     color: "green"
   });
@@ -43,6 +46,7 @@ Dashboard.prototype._createView = function () {
 
   var stderrView = new StreamView({
     parent: container,
+    scrollback: this.options.scrollback,
     label: "stderr",
     color: "red",
     top: "50%"

lib/views/stream-view.js

@@ -3,6 +3,8 @@
 var blessed = require("blessed");
 var util = require("util");
 
+var MAX_OBJECT_LOG_DEPTH = 20;
+
 var StreamView = function StreamView(options) {
 
   this.scrollBox = blessed.log({
@@ -11,6 +13,7 @@ var StreamView = function StreamView(options) {
     scrollable: true,
     input: true,
     alwaysScroll: true,
+    scrollback: options.scrollback,
     scrollbar: {
       ch: " ",
       inverse: true
@@ -40,4 +43,23 @@ StreamView.prototype.onEvent = function (data) {
   this.scrollBox.log(data);
 };
 
+// this is to fix the Log's log/add method
+// the original method calls shiftLine with two parameters (start, end)
+// when it should call it with just one (num lines to shift out)
+// blessed v0.1.81 - https://github.com/chjj/blessed/issues/255
+blessed.log.prototype.log =
+blessed.log.prototype.add = function add() {
+  var args = Array.prototype.slice.call(arguments);
+  if (typeof args[0] === "object") {
+    args[0] = util.inspect(args[0], { showHidden: true, depth: MAX_OBJECT_LOG_DEPTH });
+  }
+  var text = util.format.apply(util, args);
+  this.emit("log", text);
+  var ret = this.pushLine(text);
+  if (this.scrollback && this._clines.fake.length > this.scrollback) {
+    this.shiftLine(this._clines.fake.length - this.scrollback);
+  }
+  return ret;
+};
+
 module.exports = StreamView;

test/app/index.js

@@ -8,7 +8,7 @@ var _ = require("lodash");
 var slowFunc = function (count) {
   var begin = Date.now();
 
-  var values = _.times(count, _.random(0, count));
+  var values = _.times(count, function(n) { return _.random(0, count); });
   values = _.sortBy(values);
 
   return Date.now() - begin;

test/lib/dashboard-agent.spec.js

@@ -13,11 +13,12 @@ describe("dashboard-agent", function () {
   var server;
   var agent;
   var TEST_PORT = 12345;
-  var REPORTING_THRESHOLD = 1500;
+  var MAX_EVENT_LOOP_DELAY = 10;
 
   before(function () {
     process.env[config.PORT_KEY] = TEST_PORT;
     process.env[config.BLOCKED_THRESHOLD_KEY] = 1;
+    process.env[config.REFRESH_INTERVAL_KEY] = 10;
   });
 
   beforeEach(function () {
@@ -31,27 +32,18 @@ describe("dashboard-agent", function () {
   });
 
   describe("initialization", function () {
-    var clock;
-    before(function () {
-      clock = sinon.useFakeTimers();
-    });
-
-    after(function () {
-      clock.restore();
-    });
 
     it("should use environment variables for configuration", function (done) {
       var checkMetrics = function (metrics) {
         expect(metrics).to.be.exist;
-        expect(metrics.eventLoop.delay).to.equal(0);
+        expect(metrics.eventLoop.delay).to.be.at.most(MAX_EVENT_LOOP_DELAY);
       };
 
-      clock.tick(REPORTING_THRESHOLD);
-
       server.on("connection", function (socket) {
         expect(socket).to.be.defined;
         socket.on("error", done);
         socket.on("metrics", function (data) { //eslint-disable-line max-nested-callbacks
+          socket.removeAllListeners("metrics");
           checkMetrics(JSON.parse(data));
           done();
         });