Monday, January 22, 2018

Pi-Hole doused my Fire

Some time in late 2017 my nearly 2 year old Amazon Kindle Fire tablet took a performance nosedive. It was inexpensive and I never expected stellar performance which I do not get when web browsing. It's been a great simple device for my typical regular use of email and video consumption in the evening. I could usually go several days without a recharge.

Then one day it was dead (not atypical given my usage pattern), so I plugged it in. When I returned to it, expecting maybe a 10-15% battery level drop, it was dead again. Since then I've been charging it repeatedly but when I go to use it, it's again dead. Unfortunately, Fire O/S doesn't have any battery usage stats in it natively, and I just haven't taken the time to find an Amazon app that does, if there even is one.

Today I jumped onto my Pi-Hole (anti-ad DNS appliance) administration console and noticed a few very interesting things in the stats. First, of my first 5 "Top Clients", one is abnormally high in comparison:

"Top Clients" stats

That .124 address is the Fire tablet. Hmmm.
Then there are the "Top Blocked Domains". Again, a suspiciously high outlier:

"Top Blocked Domains" stats

Those numbers are pretty darn close, so the evidence is rather convincing that the tablet is attempting to report device metrics but failing and repeatedly retrying, killing the battery.

I haven't solved the issue yet. Part of the reason I set up the Pi-Hole in the first place was to improve the under powered performance of the Fire tablet so I don't want to just exclude it from using the Pi-Hole. I will likely just whitelist the offending domain and see what happens.

UPDATE: Clearly I didn't do much research online about this earlier. Other's have encountered very similar issues as I've found on the Pi-Hole forum.

UPDATE 2: I white listed the offending URL, put a full charge on the device and haven't touched it for about 6 hours. Battery check shows 100% still. On the Pi-Hole console, both relevant "Top Blocked Domains" and "Top Client" numbers are reduced and the overall "Percent Blocked" has fallen from about 74% to 54%.