Massive CPU usage of FTL since update to v6

[Blubberland]

Versions

pihole -v

Core version is v6.0 (Latest: N/A)
Web version is v6.0 (Latest: N/A)
FTL version is v6.0 (Latest: N/A)

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Platform

OS and version

cat /etc/os-release

PRETTY_NAME="Raspbian GNU/Linux 11 (bullseye)"
NAME="Raspbian GNU/Linux"
VERSION_ID="11"
VERSION="11 (bullseye)"
VERSION_CODENAME=bullseye

Platform

Raspberry Pi 2B

Expected behavior

Using 60% CPU at max (with idling websession) - like before the upgrade

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Actual behavior / bug

pihole-FTL 95% CPU usage on average constantly (even without a websession)

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Steps to reproduce

Steps to reproduce the behavior:

1. Upgrade to v6
2. ...

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Debug Token

pihole -d

[?] Would you like to upload the log? [y/N] y
    * Using curl for transmission.
    * curl failed, contact Pi-hole support for assistance.
    * Error message: curl: (6) Could not resolve host: tricorder.pi-hole.net

[✗] There was an error uploading your debug log.
   * Please try again or contact the Pi-hole team for assistance.

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Screenshots

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Additional context

Unbound running, but doesn't seem to work anymore, but wasn't able to troubleshoot, because system is completely unresponsive.
Set 8.8.8.8 for DNS on router temporarily, because pihole DNS did not respond anymore.

[0x41424142]

pi-hole/pi-hole#5894 (comment)

this help by chance?

[Blubberland]

Sorry for picking the wrong repo and thanks for moving the issue @yubiuser.

pi-hole/pi-hole#5894 (comment)

this help by chance?

Not really, I mean, because they're empty, it does actually get the chance to load the query graphs faster in the Webinterface.
Doesn't change anything else. And with "faster", I mean, it still takes several minutes display the nearly empty graphs.
I'll try to make a fresh install at the weekend when I have more time, and see if there might have been an issue in the upgrade process.

(edits: typos, formatting and clarification)

[yubiuser]

No problem. It's difficult for users to know which of our repos fits best.

[DL6ER]

Could you check if your database is okay? What is the output of

pihole-FTL sqlite3 /etc/pihole/pihole-FTL.db "pragma integrity_check;"

[pralor-bot]

This issue has been mentioned on Pi-hole Userspace. There might be relevant details there:

https://discourse.pi-hole.net/t/web-interface-slow-after-update-from-5-to-6/76280/17

[Blubberland]

Could you check if your database is okay? What is the output of

pihole-FTL sqlite3 /etc/pihole/pihole-FTL.db "pragma integrity_check;"

Again, I get resolve error, just like shown above, when I tried to get the debug token.

unable to resolve host raspi2: Temporary failure in name resolution

[yubiuser]

What resolver is set in /etc/resolv.conf?

[Blubberland]

Sorry, I ran out out of patience troubleshooting a nearly unresponsive system. I reflashed the whole system.
But to answer your question: it should've been unbound, if the pihole update didn't change anything.

[jfb-pihole]

But to answer your question: it should've been unbound, if the pihole update didn't change anything.

This would be unusual, to have a local instance of unbound specified as an upstream DNS server in /etc/resolv.conf.

Note that this is different than the upstream DNS server used by Pi-hole. /etc/resolv.conf is the DNS server used by the host OS.