Node.jsのメモリ使用量を監視してabで負荷テストしてみる

Node.jsのメモリ使用量を監視するスクリプト。アクセス数と同時に出力します。

var util = require('util');
var http = require('http');

var count = 0;
http.createServer(function(req,res) {
    count++;
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.end('\n');
}).listen(3000);

setInterval(function(){
    console.log("count="+count+", " + util.inspect(process.memoryUsage()));
}, 1000);

実行結果

$ node server.js 
count=0, { rss: 11026432, heapTotal: 4753920, heapUsed: 2512496 }
count=0, { rss: 11304960, heapTotal: 5030400, heapUsed: 2632336 }
count=0, { rss: 11317248, heapTotal: 5030400, heapUsed: 2649848 }
count=0, { rss: 11325440, heapTotal: 5030400, heapUsed: 2655384 }
count=0, { rss: 11329536, heapTotal: 5030400, heapUsed: 2660768 }
count=0, { rss: 11689984, heapTotal: 5030400, heapUsed: 2668688 }
count=1508, { rss: 17809408, heapTotal: 13507456, heapUsed: 6906912 }
count=6232, { rss: 29663232, heapTotal: 23399744, heapUsed: 9537744 }
count=10000, { rss: 32542720, heapTotal: 23602560, heapUsed: 10994144 }
count=10000, { rss: 32542720, heapTotal: 23602560, heapUsed: 11135688 }
count=10000, { rss: 32542720, heapTotal: 23602560, heapUsed: 11140888 }
count=10000, { rss: 32542720, heapTotal: 23602560, heapUsed: 11146088 }
count=10000, { rss: 32542720, heapTotal: 23602560, heapUsed: 11151288 }
count=10000, { rss: 32542720, heapTotal: 23602560, heapUsed: 11156488 }

負荷テストツールとしてapache付属のabコマンドを使ってみました。100クライアントから同時接続で、合計10000アクセスするようなコマンドはこんな感じ。

$ ab -n 10000 -c 100 http://127.0.0.1:3000/

実行結果(1回目)

$ ab -n 10000 -c 100 http://127.0.0.1:3000/
This is ApacheBench, Version 2.3 <$Revision: 1178079 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking 127.0.0.1 (be patient)
Completed 1000 requests
Completed 2000 requests
Completed 3000 requests
Completed 4000 requests
Completed 5000 requests
Completed 6000 requests
Completed 7000 requests
Completed 8000 requests
Completed 9000 requests
Completed 10000 requests
Finished 10000 requests


Server Software:        
Server Hostname:        127.0.0.1
Server Port:            3000

Document Path:          /
Document Length:        1 bytes

Concurrency Level:      100
Time taken for tests:   2.016 seconds
Complete requests:      10000
Failed requests:        0
Write errors:           0
Total transferred:      650000 bytes
HTML transferred:       10000 bytes
Requests per second:    4959.72 [#/sec] (mean)
Time per request:       20.162 [ms] (mean)
Time per request:       0.202 [ms] (mean, across all concurrent requests)
Transfer rate:          314.83 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    3   4.5      3      88
Processing:     0   17  15.9     13     123
Waiting:        0   15  15.4     11     119
Total:          1   20  16.5     17     123

Percentage of the requests served within a certain time (ms)
  50%     17
  66%     20
  75%     23
  80%     26
  90%     31
  95%     36
  98%     94
  99%    107
 100%    123 (longest request)

1秒間に約5000リクエストを処理しているようです。もう少しNode.jsをいじめてみようと思います。