marcopolo8888

Hello Jason,
thanks for coming back.
In the meanwhile I had heavily logged microtimes and tracked woocommerce status and save functions. trying to backtrace in runtime does not work with POST requests like ?wc-ajax=checkout.
That led to isolating the delay to
do_action( 'wp_insert_comment', $id, $comment );
Commenting this hook in the core file /wp-includes/comment.php eliminated the delay right away, but no order email either.
ok finding the actions hooking into “wp_insert_comment” is best done with ssh in wordpress root:
grep -Ril "add_action( 'wp_insert_comment" *

result:

wp-content/plugins/woocommerce/includes/class-wc-comments.php
wp-content/plugins/sitepress-multilingual-cms-master/inc/translation-management/translation-management.class.php
wp-content/plugins/nginx-helper/nginx-helper.php

first one commented and checked out out, still 20 sec
second add_action commented and checked out out, still 20 sec
in third files the same commented and checked out in only 642ms !

ok identified the source, but commenting out permanently does not makes sense

			if (!strpos($_SERVER['REQUEST_URI'], "checkout")) 
			{
				add_action( 'wp_insert_comment', array( &$rt_wp_nginx_purger, 'purgePostOnComment' ), 200, 2 );
			
				add_action( 'transition_comment_status', array( &$rt_wp_nginx_purger, 'purgePostOnCommentChange' ), 200, 3 );
			}

added the condition just for this checkout use case, so that comments somewhere else still get purged

my guess is, i could be wrong
as the woocommerce save order normally adds an order comment the purge mechanism is called, however as this is backend wp-admin, no cache is created anyway
my guess is that nginx cannot find any comment to purge in fastcgi and therefore (wild guess) takes a long time until the search times out after 17-18 sec or so.

Jason, if you dont use this nginx helper then just use the grep command to find the plugin.
Hope this helps