After 10.10.3/sleep discoveryd runs 100% CPU

enjoy. 😁

I updated from 10.9.5 to 10.10.3 and got this problem. The solution was to clean out

/Library/Preferences/SystemConfiguration/

pretty much as recommended by Jerry36. I took the precaution of switching off networking, unloading discoveryd, deleting the old plists, reboot, load discoveryd, switch on networking. It's been working fine for more than 4 days.

C.

guitarbruc wrote:

I haven't determined what software uses discoverd but when I quit it, no currently open software seems to be affected.

discoveryd is essential to the running of the OS (at least if you want any networking).

It is responsible for handling domain lookups - turning domains into IP addresses across the system. It also is required to make bonjour work (you may see the shared items in the Finder sidebar disappear when you kill it).

Killing the process will cause it to respawn, just give Activity Monitor a few seconds to refresh.

Unloading it with launchctl is risky it you forget to reload it.

I know this looks like it is helping, but it isn't the solution, its just causing the process to flush its caches & start over - eventually I think the issue will reappear.

Genius!!

Does anyone trying this want to keep copies of the old files to compare to the new ones that are recreated on reboot?

It may allow users to compare & find actual values to edit if the config files are activating settings that trigger this issue. If common settings can be found, it could help (assuming this is the root cause).

I'm not sure how essential discoveryd is for my particular setup. I've got 3 computers in the house on an Airport Extreme base station with a printer using the wireless network.

You are correct discoveryd does re-spawn after quitting. However, nothing appears to be affected by quitting discoveryd except that I can hold the laptop in my lap without it burning me and the battery life is extended by not having the fans spooling above 4,000rpm.

After it has been quit and it re-spawns it doesn't cause the fans to run overtime or overheat the system. I don't know what's causing the initial problem with it but killing it and letting it restart seems to stop the issue, at least temporarily. The laptop has been running for over 12 hours since I did it. I'm a fairly heavy system user and have put the system through its paces this morning with no obvious deleterious effects.

By the way, this issue only started with the 10.10.3 update 2 days ago. I expect others will be reporting it and am anxious for Apple to issue a fix.

I clean SystemConfiguration directory and it seems to solve the problem without creating new ones. Thanks !

There where also very old files in this directory, such as a "com.apple.airport.preferences.plist-orig" last modified in 2009 !

(my MacBookPro has a few weeks but inherits several generations of time capsule migrations).

Thank you! This helped. I also have the 100% discovered problem upon resuming from sleep. I've an early 2011 Macbook Pro, 13".

I followed Jerry36's suggestion, but went on file by file — removing one file, rebooting, putting the computer to sleep, waking back up, checking discoveryd, then removing the next file, and so on. When I removed "preferences.plist", the problem was solved.

Some of the files he mentioned did not exist on my computer, and I had some others he didn't mention. But since preferences.plist should be common to all installations, I think there's a good chance it should be the culprit.

I diff'd the old and the new preferences.plist (recreated automatically when I rebooted) and noticed I had some configs related to my Thunderbolt Ethernet adapter and to using my iPhone as an access point. Maybe this may help someone spotting the problem.

Thanks again Jerry, and good luck to all.

Rafael

That is some good sleuthing Rafael 🙂

Anyone else reading along should try the preferences.plist first too & report if it helps.

I have been having the discoveryd 100% processor utilization issue basically since installing Yosemite 10.10 although I can't pin point it exactly. it may have been in an interim update however it was happening for me BEFORE the 10.10.3 update. It would cause my late 2011 MBP 17" CPU temp to read between 90-95C and the fans were running at full 5500 RPM. The only solution, before reading this thread, was to reboot which would fix it temporarily. Now I am using the unload/load technique which is working and drops the temp down to 56C and fans at 3200 RPM.

I should also point out that after unloading and re-loading discoveryd it will not over-heat my mac for many hours at least. so far its the best way for me to deal with the issue since Apple is in typical fashion, not dealing with it and likely won't.

<Edited By Host>

Hey Rafael

I read your post after I fixed my MacBook, but I think you might have found the culprit.

I disabled the Thunderbolt Ethernet Adapter (Make Service Inactive in Network Preferences). I also disabled the Firewire network adapter.

discoveryd is now behaving.

Would be interesting to know if someone else gets results by just disabling the Thunderbolt Ethernet Adapter.

Thanks

Dr Honeydew

Take 2

A reboot and a bit of time and the problem reappeared.

I then deleted preferences.plist and rebooted a couple of times and slept a few times and there is no sign of the problem.

Rafael, your solution worked for me. My Network Preferences are back to the defaults and discoveryd is behaving.

Thank you

Dr Honeydew

Rafael, your suggestion worked wonderfully on my old 2009 MacBook Pro. All I did was delete preferences.plist, and hey! presto, discoveryd is fine. Drew, I have the original files, as well as the new ones, although I'm far too ignorant to draw any useful inferences from them.

Thanks,

Captain Dim

Just a gentle warning that although your discoverd issues might look like they have been solved after trying one of the many proposed solutions, most have had the issue come back. This is based on reading numerous threads on the net about this problem. the issue may not arise for days or weeks and then suddenly it's back.

I don't think there is a defacto solution. a solution that can claim to actually solve the problem. so beware.

My "solution" is just to unload it and re-load it. I haven't been having any networking issues so far, only issues with CPU usage. when that happens, I unload/reload and move on.