Slow load times for admin only when plugin is active

[lordmatt]

Quick summary

The front page of one of a couple of very similar blogs (same host) takes about 27 to 30 seconds to respond. When plugin is disabled, load time is a fraction of a second.

Update note: Logged in or not turns out not to be a factor.

• PHP 8.4

Steps to reproduce

1. Be me.
2. Visit my blog
3. wait for half a minute
4. reload to check it was not a fluke
5. wait another 30 seconds
6. disable plugin
7. refresh
8. nice and fast website

Site owner impact

100% of the total website/platform users

Severity

Moderate

What other impact(s) does this issue have?

No revenue impact

[Jiwoon-Kim]

WordPress.com hosting responds quite quickly, whereas it used to be somewhat slow on Café24 hosting. It’s probably not a bug, but rather a combination of the hosting server’s computing performance and plugin optimization issues.

[obenland]

Thanks for the report @lordmatt. This might be something that was fixed with #2327. Could install the latest trunk version and see if it's still reproducible with that?

[lordmatt]

I'll give that a go.

BTW: The blog that is slow seems to be slow mostly on front page load, but for logged out too. Others that are near identical seem fine (or at least not as bad). The worst offender (30 seconds to load subscribes to more (mostly ActivityPub) than the others, if that is useful info (friends plugin installed too).

[lordmatt]

Sadly, no change.

[pfefferle]

Can you share the link to the blog? Do you have a custom front page or simply the default blog-post list?

[lordmatt]

The slow one is on https://node.lordmatt.co.uk running almost exactly the same stuff as https://iamthedj.lordmatt.co.uk/

Edit: subdomain miss-type

[lordmatt]

Huh? Well, call me a liar. It seems to only happen when I am logged in now.

[obenland]

It does't look like there's an activitypub profile at mode.lordmatt.co.uk, and it redirects me to https://authorbuzz.co.uk/register/.

Maybe Debug Bar could help with debugging slow queries or hooks? It would need WP_DEBUG enabled to work properly.

[lordmatt]

I'm not sure why no obvious profile might be the case. I'll take a look and try to figure that one out. I'll check in with Debug Bar and get back to you. I've started seeing this on some of my other blogs too, so I can test against various setups.

[lordmatt]

The reason for the profile not being there is that I missed typed node and typed mode instead. node.lordmatt.co.uk is the blog with the problem.

I went ahead and ran the debug bar with mixed results. After a bunch of profiling, nothing was jumping out at me. I did speed up the database query time for another plugin.

28 HTTP requests in 12,647.8 ms, which run after the primary document is already loaded. That's about 12 seconds (I think) which is hardly ideal but - unless I missed something - is a separate issue.

In this screen grab, you can see that all the delay is before anything is sent: https://node.lordmatt.co.uk/2025/10/28/posts/i-promise-that-im-not-fibbing/

Cache Hits: 7382
Cache Misses: 365

109 queries in 3,371.2 ms

most are under 1ms

I saw one that took 17.3 ms And some for friends plugin that took 574.6 ms another at 397.6 ms others: 599.3 ms and 451.3 ms that accounts for only 2 seconds of the 30ish.

I also added an index to each of the columns that friends plugin was searching via. This didn't seem to change much. Except that the SQL runs much faster - 114 queries in 88.8 ms.

Wait time is still 16.7 to 23.1 seconds. I filed an issue with the friends plugin to suggest adding indexes.

[obenland]

Are any of the HTTP requests that make up the 12 seconds related to the ActivityPub plugin?