W3 Total Cache: what is considered to be “good” performance?

Because they are based on WP data, they would normally be taxing the system every time they appear in the templates, even if the data itself would change only once a day or week. Even if you cache the DB queries, it seems much slower than saving those block of data to the disk with a cron and use a phpinclude. Am I being too paranoid?

This would be a perfect case for using WordPress’s built in Transient API

Transients are small pieces of data that you set to expire. WordPress will cache the data in MySQL. If you have Memcached and Memcached server installed WordPress will serve the data directly from memory. It wouldn’t help any if you were serving a cached page but it would help for logged in users.

The only reason transients are not always a fit is because a database call is slower than checking the disk even when comparing mysql’s query cache to the operating systems memory cache for frequently accessed files. Instead it would be better if the Object Cache API was used for widgets so that the behavior of the cached objects could be predictable and transparently supported by W3TC and the supported caching engines.

Anyway, fragment caching in W3TC or WPSC currently uses a different policy, where everything is cached except the things that need to be executed each page view. The policy for caching the output of those objects and using that cache file to build templates until they’ve expired is not logic I’ve implemented yet.

@c3mdigital: I’m new to WP and did not know about this. Thanks for pointing out.

@frederick: yes, I’d rather check the disk if possible.

Ok.

Hi, to enter the fairly old posting here.
I had very bad results running on my VPS. Foir the initial base test, before starting caching.

Failed requests 9 out of ten.

And all so slow.

Is there anything which should be adjusted, before starting to use caching?
The AB test:

[Test results moderated as per the Forum Rules. Please use the pastebin]

But now, when I have the plugin Total Cache installed and save the cache to disk.
I have better results.

Server Software:        Apache
Server Hostname:        www.zukunftszone.de
Server Port:            80

Document Path:          /
Document Length:        55177 bytes

Concurrency Level:      2
Time taken for tests:   1.28341 seconds
Complete requests:      10
Failed requests:        1
   (Connect: 0, Length: 1, Exceptions: 0)
Write errors:           0
Total transferred:      556269 bytes
HTML transferred:       551787 bytes
Requests per second:    9.72 [#/sec] (mean)
Time per request:       205.668 [ms] (mean)
Time per request:       102.834 [ms] (mean, across all concurrent requests)
Transfer rate:          528.03 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.0      0       0
Processing:     1  198 416.5      1    1028
Waiting:        1  189 396.9      1     975
Total:          1  198 416.5      1    1028

Percentage of the requests served within a certain time (ms)
  50%      1
  66%      1
  75%      2
  80%    948
  90%   1028
  95%   1028
  98%   1028
  99%   1028
 100%   1028 (longest request)

Now my questions:
I have memcached installed and it gives out this result with everycache run through memcache:

Server Software:        Apache
Server Hostname:        www.zukunftszone.de
Server Port:            80

Document Path:          /
Document Length:        55316 bytes

Concurrency Level:      2
Time taken for tests:   1.943700 seconds
Complete requests:      10
Failed requests:        9
   (Connect: 0, Length: 9, Exceptions: 0)
Write errors:           0
Total transferred:      555391 bytes
HTML transferred:       551189 bytes
Requests per second:    5.14 [#/sec] (mean)
Time per request:       388.740 [ms] (mean)
Time per request:       194.370 [ms] (mean, across all concurrent requests)
Transfer rate:          278.85 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.0      0       0
Processing:    19  387 773.7     20    1856
Waiting:       18  378 756.2     19    1813
Total:         19  387 773.7     20    1856

Percentage of the requests served within a certain time (ms)
  50%     20
  66%     21
  75%     26
  80%   1855
  90%   1856
  95%   1856
  98%   1856
  99%   1856
 100%   1856 (longest request)

Might it be, that my memcache is not correctly configured?
Or isnt it mandatory, that the memcached cache will be better then to disc?

My memcache config output by server info:
memcache

memcache support enabled
Active persistent connections 0
Revision $Revision: 1.80 $

Directive Local Value Master Value
memcache.allow_failover 1 1
memcache.chunk_size 8192 8192
memcache.default_port 11211 11211
memcache.max_failover_attempts 20 20

I have the feeling I did anything wrong, while I didnt configure memcache.