CalendarAgent process is out of control - delegation may be causing problems?

I went in and disabled all accounts on Mac. I rarely use iCal on Mac, just iPad and iPhone.

They seem to be still working and have bee monitoring Activity Monitor for a few minutes and Calendaragent hasn't reared its ugly head again.

My late 2011 iMac crashes if it goes to sleep. I changed preferences to never sleep but darken screen. An ok workaround for a desktop but it would be unacceptable it I had a MBP.

Both solutions are crappy workarounds. Very unhappy with ML upgrade.

I lied it came back with a vengeance, not too much CPU but 2.0 gb real mem and 3.32 gb virtual mem. **** what a dog!

Similar experience here, but not as severe. Google Mail/Calendar accessed using Apple Mail and Calendar on OSX 10.8. Multiple accounts and delegations.

Occasionally, Calendaragent gets busy and consumes 90-100% of CPU (according to ActivityMonitor). I thought about killing it but didn't. In the end, I just quit Calendar, noted that Calendaregent continued to run but eventually spun down from 90% to ~0% CPU, then restarted Calendar.

I've not seen it grow beyond 130MB of real memory (140MB virtual).

Same problem here. Have two linked google accounts in Mail, Contacts & Calendars. CalendarAgent has been spiking to ~100% of new MBPr and eating ~400MB when doing so.

When CPU is spiked, lots of entries in system.log that look like:

Jul 31 11:53:20 xxxxxxxxx.local CalendarAgent[28267]: Unexpected EOF, returning last token as fallback

Update at the end of the day: No more spikes of activity that I've noticed. Memory use has actually shrunk - to around 120MB. I've made no attempt to prune my calendar.

I continually have to force quit it thru activity monitor or it just takes all memory. Just started it today and it started at 21 mb real and in 3 minutes it is up to 468 mb and rising.

Same here. Battery life has severly taken a hit since upgrading to ML the day it was released -- new MB Air (13") that used to get 7-8 hours battery life is down to 2-3. Like the above poster, I am able to alleviate the issue by killing the process, but I don't know of a way to permanently keep it off.

As soon as the laptop starts getting hot, I notice a sudden decrease in battery % and see the estimated time remaining at something crazy (like 1:20 when I have 63% battery left). Reliably, CalendarAgent is always eating most of my CPU in Activity Monitor. Once I kill the process, the estimated time remaining rebounds to about 3x what it was estimating previously.

Good call bchemel - I'm noticing the same console log entries when the CPU spikes.

The big mystery is: Why is this thread the only recent hit (and one of just three total) on a Google search for that error message? You'd think we were the only 6 people in the world with this problem 🙂

I can't believe it either that there only six people in Appleland that have this problem. It reached an all time onhigh of using 7.39 gb of virtual memory. I am not sure what delegations are but it happens no matter what I have running. I have to keep Activity Monitor running and visible at all times and have to force quit CalendarAgent whenever it gets over 100 Mb of real memory. What a pain.

I was wondering if I should just redownload and reinstall Mountain Lion. Not sure if I can even do that nor what the ramifications would be.

This is so frustrating.

I should point out I haven't seen memory spikes, only CPU spikes, and in my case I don't have delegations set. I even tried setting my non-iCloud accounts to check manually rather than every 15-60 minutes and that didn't help. Should probably try the same for iCould as well though ...

In addition to all the memory and CPU hogging, my screen keeps flickering until I forcefully kill the calendar agent 😟

Same pronblem here. After installing Mountain Lion on my MacBookAir the CalenderAgent Process grow up to 98% and the fan is working on very High Rotation. :-(

No solution yet...

Been waiting for "the answer" too. Here is what worked for my. I had three subscriptions that were located on my mac (not on icloud). I deleted those three calendars and calendar agent is behaving again. I kind of wonder if the calendar agent EOF error was waiting for a response from a calendar server that just wasn't giving responses . . . but calendar agent kept pinging it for a response. Hope this helps some.

I was able to get this to stop. Go to:

• System Preferences
• Notifications

Click the "Calendar" entry on the left. Un-Check everything on the right. The entry moves to the bottom (or below the line). After that, my CPU went straight down to a normal percentage, system temp dropped, etc.

This is a *bug*. Let's hope a fix comes out so we can enable notifications again!

Hope this helps.

-Steve