Perfect System Monitor Demo 简体中文

This project demonstrates how to use Perfect SysInfo library to monitor realtime performance of server.

Ensure you have installed and activated the latest Swift 3.1 tool chain.

Download, Build & Run

Use the following commands in terminal to quick install & run this demo:

$ git clone https://github.com/PerfectExamples/SystemMonitor-Demo.git
$ cd SystemMonitor-Demo
$ swift build
$ ./.build/debug/SystemMonitor

If success, the terminal should display something like [INFO] Starting HTTP server localhost on 0.0.0.0:8888.

Then you can check the server status by browsing http://localhost:8888:

Walk Through

This project is based on Perfect Template. If you are not familiar with Perfect server, please try Perfect Template Start Project first.

API Routes

This server contains two routes, /api for server JSON query of real time polling. /** is actually mapping to /index.html as homepage.

"routes":[
  ["method":"get", "uri":"/api", "handler":handler],
  ["method":"get", "uri":"/**", "handler":PerfectHTTPServer.HTTPHandler.staticFiles,
   "documentRoot":"./webroot"]
]

System Information

Considering that SysInfo has a rich set of system information so it is necessary to pick up those info which is really needed.

The following code filters out a few basic metrics to monitor and translate into a JSON string. Please note the OS differences:

• CPU usage: average idle time, system time and user time, in percentage.
• Free memory
• Network I/O
• Disk I/O

extension SysInfo {
  static var express: String? {
    get {
      #if os(Linux)
        guard
          let cpu = SysInfo.CPU["cpu"],
          let mem = SysInfo.Memory["MemAvailable"],
          let net = SysInfo.Net["enp0s3"],
          let dsk = SysInfo.Disk["sda"],
          let wr = dsk["writes_completed"],
          let rd = dsk["reads_completed"]
          else {
            return nil
        }
      #else
        guard
          let cpu = SysInfo.CPU["cpu"],
          let mem = SysInfo.Memory["free"],
          let net = SysInfo.Net["en0"],
          let dsk = SysInfo.Disk["disk0"],
          let wr = dsk["bytes_written"],
          let rd = dsk["bytes_read"]
          else {
            return nil
        }
      #endif
      guard
        let idl = cpu["idle"],
        let user = cpu["user"],
        let system = cpu["system"],
        let nice = cpu["nice"],
        let rcv = net["i"],
        let snd = net["o"]
        else {
          return nil
      }

      let total = (idl + user + system + nice) / 100
      let idle =  idl / total
      let usr = user / total
      let sys = system / total
      let MB = UInt64(1048576)
      let report : [String: Int]
          = ["idle": idle, "usr": usr, "sys": sys, "free": mem,
             "rcv": rcv, "snd": snd,
             "rd": Int(rd / MB), "wr": Int(wr / MB)]
      do {
        return try report.jsonEncodedString()
      }catch {
        return nil
      }//end do
    }
  }
}

Request / Response Handler

Once got the request, the server will immediately send back the JSON:

func handler(data: [String:Any]) throws -> RequestHandler {
	return {
		_ , res in
    guard let report = SysInfo.express else {
      res.status = .badGateway
      res.completed()
      return
    }//end
		res.setHeader(.contentType, value: "text/json")
    .appendBody(string: report)
    .completed()
	}
}

index.html

The homepage is very simple: use promises to download the data and render it by a certain chart framework, such as ChartJS:

/// setup a chart
function setup(api) {
  var ctx = document.getElementById(api).getContext("2d");
  return new Chart(ctx, {
    type: 'line',
    data: {  datasets: datagroups[api]   },
    options: {
        scales: {
            xAxes: [{
                type: 'linear',
                position: 'bottom'
            }]
        }
    }
  });
}//end setup

/// polling data from server api by promises, decode JSON and render in chart
function update(){
  fetch('http://' + window.location.host + '/api',{method: 'get'})
  .then( (resp) => { return resp.json() })
  .then( (obj) => {

    var chart = charts["cpu"];
    var dset = chart.chart.config.data.datasets;
    appendDataTo(dset, "CPU-idle", counter, obj.idle);
    appendDataTo(dset, "CPU-user", counter, obj.usr);
    appendDataTo(dset, "CPU-system", counter, obj.sys);
    chart.update();

    var chart = charts["mem"];
    var dset = chart.chart.config.data.datasets;
    appendDataTo(dset, "MEM-free", counter, obj.free);
    chart.update();

    var chart = charts["net"];
    var dset = chart.chart.config.data.datasets;
    appendDataTo(dset, "NET-recv", counter, obj.rcv);
    appendDataTo(dset, "NET-snd", counter, obj.snd);
    chart.update();

    var chart = charts["ios"];
    var dset = chart.chart.config.data.datasets;
    appendDataTo(dset, "DISK-read", counter, obj.rd);
    appendDataTo(dset, "DISK-write", counter, obj.wr);
    chart.update();

    counter += 1;

  });
}//end function

/// repeatedly polling data every second
window.setInterval(update, 1000);

Issues

We are transitioning to using JIRA for all bugs and support related issues, therefore the GitHub issues has been disabled.

If you find a mistake, bug, or any other helpful suggestion you'd like to make on the docs please head over to http://jira.perfect.org:8080/servicedesk/customer/portal/1 and raise it.

A comprehensive list of open issues can be found at http://jira.perfect.org:8080/projects/ISS/issues

Further Information

For more information on the Perfect project, please visit perfect.org.

Now WeChat Subscription is Available (Chinese)