I am testing my new site on the following setup
* 2 m1.large ec2 instances as web server behind a elastic load balancer
* both webserver has memcache/apc/nginx/php-fpm installed
* 1 m1.large ec2 instance for mongo db
when I run this from a remote server
ab -n 100 http://beta.domain.com/
I get the following results
Server Software: nginx/1.1.19
Server Hostname: beta.domain.com
Server Port: 80
Document Path: /
Document Length: 50817 bytes
Concurrency Level: 1
Time taken for tests: 127.032 seconds
Complete requests: 100
Failed requests: 0
Write errors: 0
Total transferred: 5117100 bytes
HTML transferred: 5081700 bytes
Requests per second: 0.79 [#/sec] (mean)
Time per request: 1270.322 [ms] (mean)
Time per request: 1270.322 [ms] (mean, across all concurrent requests)
Transfer rate: 39.34 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 21 42 100.4 26 1018
Processing: 1119 1228 69.4 1218 1488
Waiting: 941 1016 41.8 1015 1159
Total: 1144 1270 121.6 1246 2199
Percentage of the requests served within a certain time (ms)
50% 1246
66% 1271
75% 1281
80% 1295
90% 1364
95% 1483
98% 1547
99% 2199
100% 2199 (longest request)
APC hit rate is around 98%. Also I am checking the memcached log file as I do this test and I can see the ab is hitting both servers and hitting the values on memcached (All hit, no misses). But still RPS value is 0.79. Isn't this very low? Am I missing the point here?
EDIT
Also all static content (css, js, images) are being served from Amazon S3 in gz format and have 1 year expiration date.
*EDIT 2 *
I ran the same test with -c 50 parameter and here is the result
Concurrency Level: 50
Time taken for tests: 49.332 seconds
Complete requests: 100
Failed requests: 0
Write errors: 0
Total transferred: 5118200 bytes
HTML transferred: 5082800 bytes
Requests per second: 2.03 [#/sec] (mean)
Time per request: 24666.145 [ms] (mean)
Time per request: 493.323 [ms] (mean, across all concurrent requests)
Transfer rate: 101.32 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 20 33 10.0 30 58
Processing: 7656 20521 6139.1 21495 29328
Waiting: 7538 20415 6131.9 21407 29243
Total: 7687 20554 6140.3 21540 29380
Percentage of the requests served within a certain time (ms)
50% 21540
66% 23255
75% 25744
80% 26204
90% 27414
95% 28098
98% 29259
99% 29380
100% 29380 (longest request)
** Load Generation **
I guess ab does that, doesn't it? Sorry, I am quite new to benchmarking :) I also added -c 50 and ran the test again. See the results above.
** Testing page **
This page lists 20 products with image, description etc. Does some backend calculations but results are all cached in memcache, so it never actually hits the database (mongo). I can see this from memcache log file.
** What else **
Here is the result of vmstat on one of the servers during the ab test
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
0 0 0 7161224 21028 199896 0 0 26 16 29 30 1 0 99 0
and iostat
Linux 3.2.0-29-virtual 10/02/2012 _x86_64_ (2 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
0.67 0.00 0.31 0.15 0.34 98.54
Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
xvdap1 4.25 48.00 32.40 178001 120160
xvdb 0.17 0.54 0.00 1993 4