hostwatch at 100% CPU

[tessus]

I've updated to 25.7.11_1 (from 25.7.10) 1 or 2 days ago. A few minutes ago the hostwatch process went haywire and stayed at 100%. I also saw that syslog-ng was at about 80%. Then I killed the hostwatch process and everything went back to normal.

What is this process and what does it do? Is it a new service and what could it make to jump to 100% CPU all of a sudden?

[tessus]

Ok, in the release notes I can see:

This release brings the new host discovery service which resolves and remembers MAC addresses for IPv4 and IPv6 hosts in your connected networks and provides this data for the firewall MAC aliases and captive portal clients. It is now enabled by default, but you can choose to opt out by disabling the automatic discovery option.

Well, my questions still remain. What could it make to jump to 100% CPU all of a sudden? Also, I am not sure what this actually does. MAC addresses are "remembered" in the ARP cache, so why do I need this service? What is going to be worse (perf, functionality, ...) when I do not use this service?

[Patrick M. Hausen]

Nothing is going to be worse, just disable it.

Interfaces: Neighbors: Automatic Discovery

It fills in a missing feature people coming from consumer routers like Fritzbox got used to and frequently demanded: show an overview of all devices in my network.

[bycarlsjr]

Nothing is going to be worse, just disable it.

Interfaces: Neighbors: Automatic Discovery

It fills in a missing feature people coming from consumer routers like Fritzbox got used to and frequently demanded: show an overview of all devices in my network.

More useless garbage that we didn't ask for..... Why can't this be a plugin that those folks can install separately and not brick our routers.... I have a 16Gig hostwatch log this morning, lose gui, forced to restart to recover...  Definitely not a professional group here....

[s1l3nce]

Nothing is going to be worse, just disable it.

Interfaces: Neighbors: Automatic Discovery

It fills in a missing feature people coming from consumer routers like Fritzbox got used to and frequently demanded: show an overview of all devices in my network.

More useless garbage that we didn't ask for..... Why can't this be a plugin that those folks can install separately and not brick our routers.... I have a 16Gig hostwatch log this morning, lose gui, forced to restart to recover...  Definitely not a professional group here....

Yep, that new feature broke my WebUI because it filled up the storage completely ( /var/log/hostwatch/hostwatch_20260116.log was more than 100 Gigs).

People reporting high CPU usage with this update is probably related to this also.
Here is the explanation -> https://github.com/opnsense/hostwatch/issues/8