High CPU Usage and Excessive Server Processes Caused by ActivityPub Plugin

[lautfunk]

Quick summary

I am reaching out to report a critical issue I've encountered with your ActivityPub plugin on my WordPress installation. After thorough observation and analysis, I have discovered that the plugin is causing unusually high CPU usage on my server and generating an excessive number of processes. This has led to a significant degradation in the performance of my website.

Steps to reproduce

Occurs every 5 to 10 minutes.

What you expected to happen

Run

What actually happened

Not reachable.

Impact

All

Available workarounds?

No and the platform is unusable

Logs or notes

No response

[alecmuffett]

I don't have a fix for this, but I can confirm that I was suffering it on my standalone WordPress instance on an old RaspberryPi running an older version of PHP, where I was using the Friends plugin and following a couple of users who had very noisy and frequently updated feeds. All of the CPU burning was attributable to these two users who I was following, I am not sure why other than the observations that they both had very frequently updated timelines..

[pfefferle]

I am sorry, but ActivityPub is a very noise protocol in general, that means every time one of your posts will be shared it could cause quite some http traffic.

[pfefferle]

The plugin itself does not do a lot more than sending new posts to the fediverse and receiving/processing reactions.

[pfefferle]

An interesting article that explains the general problem really good https://ar.al/2022/11/09/is-the-fediverse-about-to-get-fryed-or-why-every-toot-is-also-a-potential-denial-of-service-attack/

[janboddez]

Probably related: #522.

[EricaHargreave]

Same thing is happening on my sites. Frustrating as I like the plugin otherwise.

[github-actions[bot]]

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