_prime_comment_caches() is using too much memory

I don’t know what to say.

I found the problem in wp-includes/comment.php #L2490:

wp_cache_add($comment->comment_ID, $comment, 'comment');

The data($comment) could not be set to memcache.

Maybe need apply some filters like update_option()?

Thank you.

Anyone here?

the problem is the memcache group bypass to set.

i change the
wp_cache_add($comment->comment_ID, $comment, 'comment');
to
wp_cache_add($comment->comment_ID, $comment, 'comments');

it’s work, memcache can set&get all the value, but if want to change all the comment group was so confusing.

so, any idea to fix it?

i check the object-cache.php, $no_mc_groups was a empty array.

i add ‘comment’ to $global_groups, but it’s still not work.

i test this follow code in memcache/redis obj-cache :
`
<?php var_dump(wp_cache_add(‘test’, ‘test’, ‘comment’));?>
<?php var_dump(wp_cache_get(‘test’, ‘comment’));?>
<?php var_dump(wp_cache_set(‘test’, ‘test’, ‘comment’));?>
<?php var_dump(wp_cache_get(‘test’, ‘comment’));?>
`
return
bool(true)
string(4) “test”
bool(true)
string(4) “test”

but it could not find in memcache/redis.

so, how it work when the group is comment?

i saw the wordpress define $no_mc_groups
[“no_mc_groups”]=>
array(3) {
[0]=>
string(7) “comment”
[1]=>
string(6) “counts”
[2]=>
string(7) “plugins”
}

but i cannot find the code to define this. Where is it?

WTF, when i do this, my site only can see the parent(=0) comments, the children comments cannot see.

why!?