WP-FFPC stopped caching

I thought it might be helpful if I post my nginx config for whatsthatbug.com:

server {
    # URL: Correct way to redirect URL's
    server_name whatsthatbug.com test.whatsthatbug.com;
    rewrite ^/(.*)$ https://www.whatsthatbug.com/$1 permanent;
}

server {
    server_name www.whatsthatbug.com;
    root /www/htdocs/wtb.com;
    access_log /var/log/nginx/whatsthatbug.com.access.log;
    error_log /var/log/nginx/whatsthatbug.com.error.log;
    include templates/common.conf;

 location ~* \.(?:js|css|png|jpg|jpeg|gif|ico)$ {
        expires 1m;
        add_header Pragma public;
        add_header Cache-Control "public, must-revalidate, proxy-revalidate";
 }

# SECURITY : Deny all attempts to access PHP Files in the uploads directory
location ~* /(?:uploads|files)/.*\.php$ {
    deny all;
}

    location ~ \.php$ {
        try_files $uri =404;
        include /etc/nginx/fastcgi_params;
        fastcgi_index index.php;
        fastcgi_pass php5-fpm-sock;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_buffers 16 16k;
        fastcgi_buffer_size 32k;
    }

location / {
                        try_files $uri $uri/ @memcached;
                }

                # try to get result from memcached
                location @memcached {
                                default_type text/html;
                                set $memcached_key data-$scheme://$host$request_uri;
                                set $memcached_request 1;

                                # exceptions
                                # avoid cache serve of POST requests
                                if ($request_method = POST ) {
                                                set $memcached_request 0;
                                }

                                # avoid cache serve of wp-admin-like pages, starting with "wp-"
                                if ( $uri ~ "/wp-" ) {
                                                set $memcached_request 0;
                                }

                                # avoid cache serve of any URL with query strings
                                if ( $args ) {
                                        set $memcached_request 0;
                                }

                                if ($http_cookie ~* "comment_author_|wordpressuser_|wp-postpass_|wordpress_logged_in_" ) {
                                        set $memcached_request 0;
                                }

                                if ( $memcached_request = 1) {
                                                add_header X-Cache-Engine "WP-FFPC with apc via nginx";
                                                memcached_pass memcached-servers;
                                                error_page 404 = @rewrites;
                                }

                                if ( $memcached_request = 0) {
                                                rewrite ^ /index.php last;
                                }
                }

                ## rewrite rules
                location @rewrites {
                                add_header X-Cache-Engine "";
                                rewrite ^ /index.php last;
                }
# PLUGINS : Enable Rewrite Rules for Yoast SEO SiteMap
rewrite ^/sitemap_index\.xml$ /index.php?sitemap=1 last;
rewrite ^/([^/]+?)-sitemap([0-9]+)?\.xml$ /index.php?sitemap=$1&sitemap_n=$2 last;

}

I WP_CACHE defined and set to true in wp-config.php?

It is:

define(‘WP_CACHE’, true);

Could this have any relevance? This is scrolling in my php-fpm error logs:

[10-Sep-2014 13:36:01 UTC] PHP Warning:  wp-ffpc clearing scheduled hook wp-ffpc-precache-task in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126
[10-Sep-2014 13:36:08 UTC] PHP Warning:  wp-ffpc clearing scheduled hook wp-ffpc-precache-task in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126
[10-Sep-2014 13:36:11 UTC] PHP Warning:  wp-ffpc clearing scheduled hook wp-ffpc-precache-task in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126
[10-Sep-2014 13:36:11 UTC] PHP Warning:  wp-ffpc clearing scheduled hook wp-ffpc-precache-task in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126
[10-Sep-2014 13:36:12 UTC] PHP Warning:  wp-ffpc clearing scheduled hook wp-ffpc-precache-task in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126
[10-Sep-2014 13:36:12 UTC] PHP Warning:  wp-ffpc clearing scheduled hook wp-ffpc-precache-task in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126

could you please check the contents of wp-content/advanced-cache.php?
wp-ffpc stores the variables based on the site url, which, in case it changed, might be out of date.

advanced-cache.php has 2 sections that are identical except for the server name. One is test.whatsthatbug.com and one is https://www.whatsthatbug.com.

I swapped the position of those 2 entries in advanced-cache.php, and pages are being cached – if I telnet localhost 11211, stats and stats cachedump show that there is relevant data. But they are not being served.

These lines are still filling up the php-fpm error log:
[10-Sep-2014 15:13:20 UTC] PHP Warning: wp-ffpc clearing scheduled hook wp-ffpc-precache-task in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126

Any thoughts on why the cached pages aren’t being served now?

Well, it looks like it *is* serving cached pages. Something is screwy with my browser cache. Not being logged in wasn’t good enough, but an incognito window showed me the truth. Thank you for taking a stab at it, and for writing the plugin!

Any idea on the PHP Warnings? They are still coming fast and furious.

I’ve been bitten by that with Chromium as well. I have a feeling one of the cookies is not removed once logged out and due to it’s presence, there is no caching.

I’ll take a look into this, it looks like it’s not just me ??

About this cookie thing… I never logged in my site using IE.

But, using IE11, sometimes it dont cache the page. It always give the no cached. There is not the debug comment in source code of page. And the ab test is a total fail… (I use ab to test if it is all OK with cache)
If I clear the cache/cookies and reload the page, the page is fully cached.

Chrome always cache the page if I am not logged. However, I cant be 100% sure because I dont like to use Chrome, I still use Firefox.

Peter, do you have any idea why php-fpm is logging so may warnings like this?

[10-Sep-2014 15:13:20 UTC] PHP Warning: wp-ffpc clearing scheduled hook wp-ffpc-precache-task in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126

I’d really like to be able to get that to stop!

@whatsthatbug.com please update to 1.6.3, it should have changed this to NOTICE level.

@leokesler
These are the cookies I look for: https://github.com/petermolnar/wp-ffpc/blob/master/wp-ffpc-backend.php#L57. Could you please list what cookies IE stores about your site when you’re not logged in?

After a clear history/cookie and a reload, these are the cookies:

[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected] (only have google analytics info)

For now it is working. Like I said, it happens sometimes. I only use IE to check if the cache is working or if the layout is OK.

Off topic: the time showed in comments (at source page) dont show the correct time. Its showing, I think, the UTC time and not the timezone configured in WordPress (for me, UTC-3).

Thank you. That did stop the “clearing scheduled hook” error. However, I’m now seeing these – not quite as fast and furious, but still at a decent clip:

[13-Sep-2014 00:02:55 UTC] PHP Warning:  wp-ffpc unable to determine path from Post Permalink, post ID: 2165860 in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126
[13-Sep-2014 00:02:55 UTC] PHP Warning:  wp-ffpc unable to determine path from Post Permalink, post ID: 2165860 in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126
[13-Sep-2014 00:03:03 UTC] PHP Warning:  wp-ffpc unable to determine path from Post Permalink, post ID: 2165861 in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126
[13-Sep-2014 00:03:03 UTC] PHP Warning:  wp-ffpc unable to determine path from Post Permalink, post ID: 2165861 in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126
[13-Sep-2014 00:03:07 UTC] PHP Warning:  wp-ffpc unable to determine path from Post Permalink, post ID: 2165862 in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126
[13-Sep-2014 00:03:07 UTC] PHP Warning:  wp-ffpc unable to determine path from Post Permalink, post ID: 2165862 in /var/www/html/wtb.com/wp-content/plugins/wp-ffpc/wp-common/plugin_utils.php on line 126

Is this anything to be concerned about? Or should it be Notice instead of Warning?