WordPress.org

1. antorome
   Member
   Posted 1 year ago #

   Hello,

   I just changed to a dedicated server and installed APC, configuring W3TotalCache for using APC when possible and I am also ussing Amazon CDN.

   I have been checking and is "Page Cache" the one not working fine. If I use APC the load time increase by 3 or 4 seconds. If I use Disk (enhanced) it works fine.

   I am using the configuration you propose in apc.ini

   The server is this one
   Fujitsu Siemens RX100
   Intel Pentium 3.4 GHz
   1GB RAM
   1x HD 80GB SATA
   Linux CentOS

   Do you think is a problem of configuration (need to adjust apc.ini parameters) or of the server?

   Thanks

2. Chris Olbekson
   Member
   Posted 1 year ago #

   @Antorome,

   With 1GB of RAM you should try increasing the apc_shm_size to around 256M or even 512M then test again.

   Using Apache Bench is a good way to test for best settings.

3. antorome
   Member
   Posted 1 year ago #

   @c3mdigital It worked fine for me that tweak. Thanks!
   Btw, how do you use Apache Bench? I've been looking in google, I saw how to run it but don't know too well how to read the data and adjust the shm_size accordingly.

   Thanks again

4. Chris Olbekson
   Member
   Posted 1 year ago #

   To run Apache Bench run this command from ssh:

   ab -n 1000 -c 10 http://example.org/

   The number after -n represents how many requests to make and the number after -c determines the concurrency level.

   I usually run multiple tests and increase the concurrency level each time till I get up to 100.

   This won't necessarily tell you how to adjust the shm_size but its good for testing the various caching methods like disk enhanced vs APC or APC vs Memcached for database and object caching.

   The number I use to determine best performance is requests per second.

   Here is a sample output from the a run with 5000 requests at a 100 concurrency level on a VPS running Apache with Nginx as a front end proxy.

   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/
   
   Benchmarking wp-performance.com (be patient)
   Completed 500 requests
   Completed 1000 requests
   Completed 1500 requests
   Completed 2000 requests
   Completed 2500 requests
   Completed 3000 requests
   Completed 3500 requests
   Completed 4000 requests
   Completed 4500 requests
   Completed 5000 requests
   Finished 5000 requests
   
   Server Software:        nginx/0.7.65
   Server Hostname:        wp-performance.com
   Server Port:            80
   
   Document Path:          /
   Document Length:        9348 bytes
   
   Concurrency Level:      100
   Time taken for tests:   0.607 seconds
   Complete requests:      5000
   Failed requests:        0
   Write errors:           0
   Total transferred:      49172298 bytes
   HTML transferred:       46870872 bytes
   Requests per second:    8242.83 [#/sec] (mean)
   Time per request:       12.132 [ms] (mean)
   Time per request:       0.121 [ms] (mean, across all concurrent requests)
   Transfer rate:          79163.82 [Kbytes/sec] received
   
   Connection Times (ms)
                 min  mean[+/-sd] median   max
   Connect:        0    1   0.9      1       9
   Processing:     3   11   1.8     11      61
   Waiting:        1    5   2.1      5      54
   Total:          5   12   1.7     12      61
   
   Percentage of the requests served within a certain time (ms)
     50%     12
     66%     12
     75%     13
     80%     13
     90%     14
     95%     15
     98%     15
     99%     16
    100%     61 (longest request

Topic Closed

This topic has been closed to new replies.