synchrony driver benchmarking

gistfile1.txt

So using the synchrony driver I get the following with concurrency level of 1:


Server Software:        thin
Server Hostname:        0.0.0.0
Server Port:            5000

Document Path:          /vsync/sync
Document Length:        3002 bytes

Concurrency Level:      1
Time taken for tests:   15.843 seconds
Complete requests:      1000
Failed requests:        0
Write errors:           0
Keep-Alive requests:    1000
Total transferred:      3151000 bytes
Total POSTed:           379379
HTML transferred:       3002000 bytes
Requests per second:    63.12 [#/sec] (mean)
Time per request:       15.843 [ms] (mean)
Time per request:       15.843 [ms] (mean, across all concurrent requests)
Transfer rate:          194.22 [Kbytes/sec] received
                        23.38 kb/s sent
                        217.61 kb/s total

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.0      0       0
Processing:     9   16   9.1     11      41
Waiting:        9   16   9.1     11      41
Total:          9   16   9.1     11      41

Percentage of the requests served within a certain time (ms)
  50%     11
  66%     12
  75%     13
  80%     31
  90%     32
  95%     34
  98%     35
  99%     37
 100%     41 (longest request)

Increasing concurrency doesn't seem to improve throughput:

Server Software:        thin
Server Hostname:        0.0.0.0
Server Port:            5000

Document Path:          /vsync/sync
Document Length:        3733 bytes

Concurrency Level:      2
Time taken for tests:   15.333 seconds
Complete requests:      1000
Failed requests:        999
   (Connect: 0, Receive: 0, Length: 999, Exceptions: 0)
Write errors:           0
Keep-Alive requests:    1000
Total transferred:      3151731 bytes
Total POSTed:           379758
HTML transferred:       3002731 bytes
Requests per second:    65.22 [#/sec] (mean)
Time per request:       30.666 [ms] (mean)
Time per request:       15.333 [ms] (mean, across all concurrent requests)
Transfer rate:          200.74 [Kbytes/sec] received
                        24.19 kb/s sent
                        224.92 kb/s total

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.0      0       0
Processing:     6   15   9.0     11      44
Waiting:        6   15   9.0     11      44
Total:          6   15   9.0     11      44

Percentage of the requests served within a certain time (ms)
  50%     11
  66%     11
  75%     12
  80%     31
  90%     32
  95%     33
  98%     35
  99%     37
 100%     44 (longest request)

Compare that with the hiredis connection:

Server Software:        thin
Server Hostname:        0.0.0.0
Server Port:            5000

Document Path:          /vsync/sync
Document Length:        3002 bytes

Concurrency Level:      1
Time taken for tests:   7.830 seconds
Complete requests:      1000
Failed requests:        0
Write errors:           0
Keep-Alive requests:    1000
Total transferred:      3151000 bytes
Total POSTed:           379379
HTML transferred:       3002000 bytes
Requests per second:    127.71 [#/sec] (mean)
Time per request:       7.830 [ms] (mean)
Time per request:       7.830 [ms] (mean, across all concurrent requests)
Transfer rate:          393.00 [Kbytes/sec] received
                        47.32 kb/s sent
                        440.31 kb/s total

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.0      0       0
Processing:     6    8   5.0      7      44
Waiting:        6    8   5.0      7      44
Total:          6    8   5.0      7      44

Percentage of the requests served within a certain time (ms)
  50%      7
  66%      7
  75%      7
  80%      7
  90%      8
  95%      9
  98%     31
  99%     32
 100%     44 (longest request)

With hiredis I'm not benefiting from increasing concurrency but that's expected as hiredis is blocking:

Server Software:        thin
Server Hostname:        0.0.0.0
Server Port:            5000

Document Path:          /vsync/sync
Document Length:        3002 bytes

Concurrency Level:      2
Time taken for tests:   7.950 seconds
Complete requests:      1000
Failed requests:        0
Write errors:           0
Keep-Alive requests:    1000
Total transferred:      3151000 bytes
Total POSTed:           379758
HTML transferred:       3002000 bytes
Requests per second:    125.79 [#/sec] (mean)
Time per request:       15.899 [ms] (mean)
Time per request:       7.950 [ms] (mean, across all concurrent requests)
Transfer rate:          387.08 [Kbytes/sec] received
                        46.65 kb/s sent
                        433.73 kb/s total

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.0      0       0
Processing:     6   16   8.6     14      82
Waiting:        6   16   8.6     14      82
Total:          6   16   8.6     14      82

Percentage of the requests served within a certain time (ms)
  50%     14
  66%     14
  75%     16
  80%     19
  90%     22
  95%     38
  98%     44
  99%     45
 100%     82 (longest request)

I switch between the 2 connections by alternating between these 2 code blocks in the Gemfile:

    # use these linse for the synchrony driver
    gem "hiredis", "~> 0.3.1"
    gem 'em-synchrony'
    gem "redis", "~> 2.2.0", :require => ["redis/connection/synchrony", "redis"]

    # use these lines for the hiredis driver
    gem "hiredis", "~> 0.3.1"
    gem "redis", "~> 2.2.0" , :require => ["redis/connection/hiredis", "redis"]