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Googlebot Cannot Access CSS and JS on your WordPress Site?

In the past couple of days, many client sites have gotten notices from Google Webmaster Tools about being unable to access CSS and JS files.

The most widespread issue was blocking of wp-content, wp-includes and wp-admin in the robots.txt file. Googlebot is now smart enough to not crawl these items by default, so they can be removed.

The second issue we found was related to the Wordfence plugin. As of version 6.0.12 Wordfence includes a call to a dynamic script located in wp-admin, which is a default “Disallow” entry in the WordPress robots.txt file. Upgrading to Wordfence 6.0.14 or later will fix this issue.

Users of WPCmdCtrl are already covered and have the update 🙂

WordPress Caching Comparision – W3 Total Cache vs. WP Super Cache vs. WP Cache

Updated June 14. Added results for W3 Total Cache using Disk Enhanced caching only at the request of Frederick Townes, author of W3 Total Cache. I ran tests with both “gzip” and “gzip and deflate” settings.

I’ve seen a lot of discussion lately about the various WordPress caching plugins. Here’s a quick comparison using Apache Bench. First some background on the test platform.

This is a 512mb VPS from prgmr.com

Fresh install of Ubuntu 10.04

NginX, PHP, MySQL installed via APT (PHP 5.3.2-1ubuntu4.2ppa3~lucid1 (FPM/FastCGI), NginX 0.7.65, MySQL (5.1.41-3ubuntu12.3))

WordPress 2.9.2, standard Kubrick theme, nginx Compatibility plug-in installed.

Plugin Versions:

WP-Cache 2.12
WP Super Cache 0.9.9
W3 Total Cache 0.8.5.2

The following command line was used. The -c and -n flags were modified during different runs as illustrated below.

ab -k -n XXX -c XXX http://testingserver/wordpress/2010/06/hello-world/
-n flag is the total number of requests (this is 1000 unless noted)
-c flag is for the number of concurrent requests
The Results

Click for full version
There was no -n 10000 -c 250 run for WordPress with no cache, as it would’ve taken very long and no further information would be gained.. Updated
Raw Data
50 Concurrent Requests

cache method time taken total transferred html transferred req/sec transfer rate

none 42.631 7025688 6786210 23.46 160.94

wp-cache 9.567 7157000 6872000 104.53 730.58

wp super cache (half on) 7.636 7184084 6905065 130.96 918.8

wp super cache (full) 7.411 7180000 6901000 134.93 946.07

w3 total cache (quick) 8.228 6427618 6039371 121.53 762.84

w3 total cache (APC for all) 8.384 6554037 6087793 119.28 763.44

w3 total cache (DE only) 7.787 7419504 7032408 128.41 930.43

w3 total cache (DE only gzip+deflate) 7.518 7393440 7008630 133.01 960.33

100 Concurrent Requests

cache method time taken total transferred html transferred req/sec transfer rate

none 41.277 7025688 6786210 24.23 166.22

wp-cache 7.942 7229988 6940603 125.91 888.98

wp super cache (half on) 4.711 7353500 7063600 212.28 1524.42

wp super cache (full) 4.598 7316282 7013904 217.49 1553.89

w3 total cache (quick) 4.619 6483320 6090890 216.5 1370.77

w3 total cache (APC for all) 5.326 6571413 6103337 187.76 1204.91

w3 total cache (DE only) 5.213 7467288 7076001 191.83 1398.88

w3 total cache (DE only gzip+deflate) 4.503 7458600 7068075 222.07 1617.52

250 Concurrent Requests

cache method time taken total transferred html transferred req/sec transfer rate

none 45.112 6694982 6459715 22.17 144.93

wp-cache 5.001 7370444 7067664 199.95 1439.19

wp super cache (half on) 4.782 7479736 7181764 209.11 1527.41

wp super cache (full) 3.436 7513840 7197120 291.02 2135.43

w3 total cache (quick) 5.341 6384178 5999741 187.24 1167.33

w3 total cache (APC for all) 7.17 6579256 6110264 139.46 896.05

w3 total cache (DE only) 4.648 7532448 7135446 215.14 1582.52

w3 total cache (DE only gzip+deflate) 5.265 7462944 7072038 189.93 1384.21

250 Concurrent Requests – 10000 Total Requests

cache method time taken total transferred html transferred req/sec transfer rate

none 384.545 64628053 62311067 26 164.12

wp-cache 34.552 71599548 68748013 289.42 2023.66

wp super cache (half on) 29.075 72047348 69241705 343.94 2419.91

wp super cache (full) 28.534 72337968 69365832 350.46 2475.77

w3 total cache (quick) 42.432 63564752 59751704 235.67 1462.91

w3 total cache (APC for all) 43.688 64968473 60366489 228.9 1452.25

w3 total cache (DE only gzip) 42.674 73695480 69868335 234.34 1686.48

w3 total cache (DE only gzip+deflate) 42.391 73612944 69793038 235.9 1695.81