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

I use GMail/GCal for email and calendar. I had my GCal synced to iCal in Snow Leopard, but stopped using it in Lion. After upgrading to Mountain Lion I decided to give it a shot again, mostly to get my appointments in the notification center. However, I noticed that a process called "CalendarAgent" was using tons of CPU and memory: over 100% and 400 mb, respectively. It was slowing my computer down and killing my battery life.


After some investigation, it seems like Delegation (calendars that are shared to me by other GCal users) may be part of the problem. If I remove all of the calendars from the "Delegation" tab in the Preferences for Calendar, then CalendarAgent goes down to 0-1 % CPU and 156mb memory. It still seems a little high on the memory front, but at least the CPU isn't out of control now.


This is obviously not an optimal solution. I need to access the shared calendars to schedule meetings with my coworkers. Has anybody run into this issue? Any ideas for fixing this? Is it a Mountain Lion bug?

MacBook Pro (15-inch Mid 2010), OS X Mountain Lion

Posted on Jul 29, 2012 10:24 AM

Reply
82 replies

Jan 25, 2014 7:34 PM in response to bonzabuy

Thanks bonzabuy! I had the CalendarAgent memory consumption problem after upgrading to Mavericks on my late 2009 iMac. Your Calendar Cache file delete procedure appears to have solved the problem. Memory use stabilized at 22.0 MB. After I re-enabled my gmail calendars in Internet Account preferences, memory use rose to 26.7 MB and held. You have to be fairly quick about the restart. Otherwise the Calendar Cache file regenerates itself, I noticed. I don't know if that would prevent the fix from working.

Regards, davids11

Jan 26, 2014 12:59 PM in response to msl422004

This did it for me. Full credit to bonzabuy

on this thread: Re: CalendarAgent process is out of control - delegation may be causing problems?


Jul 15, 2013 12:53 AM (in response to msl422004)


I spent over an hour on the phone with Apple support. They tried a number of things - from disk permissions, disk repair, start up items, login items, new user account.


This did it for me.


The thing that seemed to do the trick instantly:


Delete the Calendar cache.


A rough procedure:

Open iCal

Full back up all calendars (full archive I think it's called)

Close iCal.



Go to Finder

'Go" menu

Hold down option key

Go to Library

In Library go to Calendar.

Delete Calendar Cache.


Restart machine.

Start iCal.


If all is well & all reminders / appointments restored then you can delete the backup.


Hope this helps some others - it worked for me

Feb 3, 2014 7:26 PM in response to Ola_M

My first fix was to simply quit the CalendarAgent using Activity Monitor. It started as 700K and slowly climbed back up to 59MB of Real RAM use. It seemed to stabilize there. I performed the suggestions posted here to uncheck the Calendar from the Internet Accounts preference (using Mavericks), deleted the Calendar itmes in the Library and CalendarAgent is stable at using 59MB of RAM, and 0% of my CPU. Thanks for the tips!

Aug 3, 2014 11:19 PM in response to Ola_M

This works much faster:


OSX’s CalendarAgent can cause issues with processor/memory hogging from time to time. If you want to disable it yo can do so from the command line:

launchctl unload -w /System/Library/LaunchAgents/com.apple.CalendarAgent.plist

You can re-enable it with the following:

launchctl load -w /System/Library/LaunchAgents/com.apple.CalendarAgent.plist

You can test to see if it’s running with the following command:

sudo launchctl list | grep CalendarAgent

Mar 2, 2015 10:23 PM in response to msl422004

I am using MacBook Pro 2014 Retina Display. Initially came with Mavericks and upgraded to Yosemite (10.10.2).

Had the same Problem. Calendar Agent took nearly 6 to 7 GB of the RAM and left me with 15MB ram. Got really irritated. But found this after a hard struggle. I tried the above solutions, think didn’t quite work for me.

Follow the steps you will get your problem solved.



  1. Backup all the calendar events to your iCloud by enabling calendar in the internet accounts from system preferences. (Do this step only if you need your events to be there).
  2. Then open TERMINAL and type.
  3. chflags nohidden /Users/*******/Library
  4. ******* represents your username or the name in which your mac is started with. This name can be seen from "Macintosh HD” then “Users” then the user which you are..
  5. After running the command then again type in TERMINAL
  6. chflags nohidden /Users/*******/Library/Containers
  7. Now close the TERMINAL after running it.
  8. Now, open finder and goto "Macintosh HD” then to “Users” then the user which you are then “Library” then “Calendars”.
  9. In “Calendars” you have got to delete some files.
  10. Those are:
  • Calendar Cache
  • Calendar Cache- shm
  • Calendar Cache- wal
  • Email Cache.plist


Actually after deleting it,restarting PC solves the problem.

Sometimes you can’t delete those files because the Calendar Agent uses them and is running in background.

For that you have got to open Activity Monitor and Force Quit Calendar Agent and delete.

Restart your PC. Then open Calendar. Nothing happens and is back to normal.

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

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