The out of the box cache rules needs to be updated for WordPress running any ecommerce solution

Hi @eva2000 ,
on my VPS (I run a wordpress site) I used to be using ngx_pagespeed for months and recently I've turned off pagespeed and enabnled redis nxinx level caching + redis object caching.

Now after the setup, I saw some problem happening due to these caching and my sites are not performing well.

What are the problems you have seen?

• As I use Easy Digital Download as my eCommerce solution on my WP site, I saw that even if I add something in the cart; when I go to homepage, blog article or any other page, the cart gets to 0 instead of 1 (as I said I've added a test product in cart).
  
  So, when I digged more about it I find out that EDD uses a cookie named
  
  
  Code:

  edd_items_in_cart

  which is not in the whitelist list of out of the box setting centminmod setting. Neither for redis nor wpcache or any other cache settings - which is creating this entire mess.
  
  I'm pretty sure the same problem will happen with woocommerce sites, but I personally don't use woocommerce.
  
  
• The next problem I've faced is that any cache system of centminmod (as all use almost same caching rules) is caching the ecommerce related pages like checkout page, transaction complete, transaction failed etc. is getting cached as they aren't whitelisted in the config. EDD use the following slugs (by default)
  
  /checkout/ => for checkout page
  /checkout/purchase-confirmation/
  /checkout/purchase-history/
  /checkout/transaction-failed/
  /customer-dashboard/
  

  ---

  
  Now technically these pages are not supposed to be cached as it is different for all users.

Have you whitelisted them in the config?
No I haven't because what I looked into the rediscache_mysite.com.conf file, I saw the following config:

Code:

set $skip_cache 0;

# POST requests and urls with a query string should always go to PHP
if ($request_method = POST) {
  set $skip_cache 1;
}

if ($query_string != "") {
  set $skip_cache 1;
}

# Don't cache uris containing the following segments
if ($request_uri ~* "/wp-admin/|/xmlrpc.php|wp-.*.php|/feed/|index.php|sitemap(_index)?.xml") {
  set $skip_cache 1;
}

# Don't use the cache for logged in users or recent commenters
if ($http_cookie ~* "comment_author|wordpress_[a-f0-9]+|wp-postpass|wordpress_no_cache|wordpress_logged_in") {
  set $skip_cache 1;
}

location /redis-fetch {
  internal  ;
  set  $redis_key $args;
  redis_pass  redisbackend;
  redis_connect_timeout 60000;
  redis_read_timeout 60000;
  redis_send_timeout 60000;
}

location /redis-store {
  internal  ;
  set_unescape_uri $key $arg_key ;
  redis2_query set $key $echo_request_body;
  redis2_query expire $key 6h;
  redis2_pass  redisbackend;
  redis2_connect_timeout 60s;
  redis2_read_timeout 60s;
  redis2_send_timeout 60s;
}

Now here under the if block of cookie check I can easily add edd_items_in_cart within the check. But what I'm not sure of is how to add check for the above mentioned ecommerce pages?

should it be like this:

Code:

if ($request_uri ~* "/wp-admin/|/xmlrpc.php|wp-.*.php|/feed/|index.php|sitemap(_index)?.xml|/checkout/|/checkout/purchase-confirmation/|/checkout/purchase-history/|/checkout/transaction-failed/|/customer-dashboard/") {
  set $skip_cache 1;
}

If you can take a look and let me know it will be really help.

Also after I made the changes, should I make the same changes to any other file? And at last after the changes are made should I run just the following commands:

Code:

redis-cli flushall
service redis restart

or any other command along with it? Any help will be highly appriciated.

 

Hey @eva2000, I'm graciously looking forward to your reply on this matter.

 

Hi @eva2000,
Thanks a lot for your reply. I'm using v0.8 stable as it is a production site. I think you missed one thing in the above config, i.e. the sub checkout pages which will be like /checkout/* if I'm not wrong.

I'm talking about these pages:
/checkout/purchase-confirmation/
/checkout/purchase-history/
/checkout/transaction-failed/

So in the end the final config will look like this:

Code:

set $skip_cache 0;

# POST requests and urls with a query string should always go to PHP
if ($request_method = POST) {
  set $skip_cache 1;
}

if ($query_string != "") {
  set $skip_cache 1;
}

# Don't cache uris containing the following segments
if ($request_uri ~* "\?add-to-cart=|/cart/|/my-account/|/checkout/|/checkout/*|/shop/checkout/|/store/checkout/|/customer-dashboard/|/addons/|/wp-admin/|/xmlrpc.php|wp-.*.php|/feed/|index.php|sitemap(_index)?.xml") {
  set $skip_cache 1;
}

# Don't use the cache for logged in users or recent commenters
if ($http_cookie ~* "comment_author|wordpress_[a-f0-9]+|wp-postpass|wordpress_no_cache|wordpress_logged_in|edd_items_in_cart|woocommerce_items_in_cart") {
  set $skip_cache 1;
}

location /redis-fetch {
  internal  ;
  set  $redis_key $args;
  redis_pass  redisbackend;
  redis_connect_timeout 60000;
  redis_read_timeout 60000;
  redis_send_timeout 60000;
}

location /redis-store {
  internal  ;
  set_unescape_uri $key $arg_key ;
  redis2_query set $key $echo_request_body;
  redis2_query expire $key 6h;
  redis2_pass  redisbackend;
  redis2_connect_timeout 60s;
  redis2_read_timeout 60s;
  redis2_send_timeout 60s;
}

Let me know if I made any mistakes above.

Also thanks for the cache enabler config, but I guess I can't use it as I'm using both redis nginx level caching + redis object caching. So cache enabler will not work. Also I read on other threads here that using redis at negix level is far superior than cache enabler.

Also after I made these changes in my config, should I need to run any other commends besides the following:

Code:

npreload
redis-cli flushall
service redis restart

Please let me know. Looking forward to your reply.

 

Thank you very much. I'm doing this changes right now. Also as you mentioned above that you have added the cache enabler thing for everyone's help. Then I think you should also change the config code for wpcache, wpsupercache and fastcgi configs too. Just a thought.

 

@eva2000 Hey, I need another help.

I want all search bots to see non cache copy, so what should I put in the redis config? Can you please help?

 

@eva2000 you mean like this:

Code:

map $http_user_agent $redis_device {
    default                               'desktop';
    ~*bots                                        'bots';
}

and then do this:

Code:

# exclude mobile devices from redis caching
if ($redis_device = bots) {
  set $skip_cache 1;
}

Please let me know

 

like redis_bots ? My above code is right? WOW! didn't expected that.

 

Made the changes and restarted redis. Thank you for your help.

 

I kept it as desktop as it was. Hope that's not gonna create any issue.