compression with zilb options

1server.js

// iojs@1.0.4
// express@4.11.1
// compression@1.3.0

file = require('fs').readFileSync('s.cc') // 46Kb
zlib = require('zlib')
app = require('express')()
compression = require('compression')

app.get('/no_compression', function(req, res){

  res.setHeader('Content-Type','text/plain')
  res.send(file)
}).get('/with_compression', compression(), function(req, res){

  res.setHeader('Content-Type','text/plain')
  res.send(file)
}).get('/with_level_compression', compression({level: zlib.Z_BEST_SPEED, memLevel: zlib.Z_MAX_MEMLEVEL}), function(req, res){

  res.setHeader('Content-Type','text/plain')
  res.send(file)
}).listen(3000)

no_compression

$ ab -H "Accept-Encoding: gzip" -c 100 -n 5000 192.168.2.2:3000/no_compression
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Server Software:        
Server Hostname:        192.168.2.2
Server Port:            3000

Document Path:          /no_compression
Document Length:        46155 bytes

Concurrency Level:      100
Time taken for tests:   4.830 seconds
Complete requests:      5000
Failed requests:        0
Write errors:           0
Total transferred:      231690000 bytes
HTML transferred:       230775000 bytes
Requests per second:    1035.30 [#/sec] (mean)
Time per request:       96.590 [ms] (mean)
Time per request:       0.966 [ms] (mean, across all concurrent requests)
Transfer rate:          46849.52 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0   12  15.6      8     217
Processing:     3   79 140.7     42    1301
Waiting:        0   28  60.9     16     909
Total:          6   91 141.3     54    1308

with_compression

$ ab -H "Accept-Encoding: gzip" -c 100 -n 5000 192.168.2.2:3000/with_compression
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Server Software:        
Server Hostname:        192.168.2.2
Server Port:            3000

Document Path:          /with_compression
Document Length:        14105 bytes

Concurrency Level:      100
Time taken for tests:   6.635 seconds
Complete requests:      5000
Failed requests:        0
Write errors:           0
Total transferred:      71560000 bytes
HTML transferred:       70525000 bytes
Requests per second:    753.60 [#/sec] (mean)
Time per request:       132.697 [ms] (mean)
Time per request:       1.327 [ms] (mean, across all concurrent requests)
Transfer rate:          10532.67 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    4   5.0      2     146
Processing:    20  126 107.0    104     973
Waiting:        3   77  59.3     74     939
Total:         23  129 107.1    107     974

with_level_compression

$ ab -H "Accept-Encoding: gzip" -c 100 -n 5000 192.168.2.2:3000/with_level_compression
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Server Software:        
Server Hostname:        192.168.2.2
Server Port:            3000

Document Path:          /with_level_compression
Document Length:        16481 bytes

Concurrency Level:      100
Time taken for tests:   5.028 seconds
Complete requests:      5000
Failed requests:        0
Write errors:           0
Total transferred:      83440000 bytes
HTML transferred:       82405000 bytes
Requests per second:    994.36 [#/sec] (mean)
Time per request:       100.567 [ms] (mean)
Time per request:       1.006 [ms] (mean, across all concurrent requests)
Transfer rate:          16204.94 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    4   4.4      2      44
Processing:    13   96  81.1     80     575
Waiting:        7   51  28.1     49     484
Total:         23  100  81.5     83     593