Just ran into this fix from Sebastian Shack if your mac has a lot of processor activity that you can’t track down/stop. ?The problem is that the “mds” and “mdworker” processes (which control and index your hard drive for Spotlight searches) get stuck consistently using ~100% CPU time (on a quad core, that’s out of 400%). ?In this case, the reason is because I’ve been using Backblaze, and online backup solution, though this fix may work for other online backup software or general apps.
The problem is that Backblaze is constantly creating and uploading files in the /Library/backblaze folder, and Spotlight sees that and is constantly trying to index those files even though they’re temporary. It’d be like trying to conduct a survey of New York City residents on a Saturday in Times Square — there’s a whole bunch, they’re constantly changing, and lots of them aren’t NYC residents. ?Or it’d be like if your doorbell rang every time someone walked by your house — you’d be up and down all the time, and none of those people are sticking around to talk to you anyway.
The solution is to block Spotlight from searching in Backblaze’s folder. ?Open up Spotlight preferences (System Preferences -> Spotlight) and click on “Privacy”. ?Now we need to find the folder Backblaze uses and drag it over. ?Go to Finder, click Go -> Go To Folder in the menu bar, and type in “/Library”. ?Select the “Backblaze” folder and drag it into the Spotlight preferences “Privacy” tab, and voila!