If You're Programming a Cell Phone Like a Server, You're Doing it Wrong • Hacker News Board

Re: If You're Programming a Cell Phone Like a Server, You're Doing it Wrong

#41

Post by kintamanimatt » Thu, Sep 19, 2013, 10:27 PM UTC

DougWebb wrote: post #11

The last thing I'd want is for my apps to each be downloading several MB of data they think I might need in the next few minutes. I can easily control how much battery life is remaining on my phone by plugging it in. I can't control how much of my data plan an app is using, except by uninstalling the app. Besides, in my experience the biggest drains on battery life aren't data transfers, they're (a) having the screen…

> I can easily control how much battery life is remaining on my phone by plugging it in.

Except when you can't. Are you really always near a power outlet? There have been plenty cases where I just haven't been able to charge my phone and have had to turn it off rather than use it for what I want.

> I can't control how much of my data plan an app is using, except by uninstalling the app.

Depending on where you are, get an unlimited data plan. I know not every country has these, but most do.

Re: If You're Programming a Cell Phone Like a Server, You're Doing it Wrong

#42

Post by kintamanimatt » Thu, Sep 19, 2013, 10:32 PM UTC

minimax wrote: post #32

How does the power usage of the wifi radio compare to the cell radio? Does it use more or less power?

Vastly less. I can save a few percent of battery life an hour just by using wifi instead of the mobile radio for data.

Re: If You're Programming a Cell Phone Like a Server, You're Doing it Wrong

#43

Post by kintamanimatt » Thu, Sep 19, 2013, 10:40 PM UTC

AsymetricCom wrote: post #29

Just another bugle call for developers and users to forfeit more of their rights to our mighty big data and cloud land owners. Is your app ready for the "Internet of Things"?

A few months ago I'd have been happily hitting the downvote button along with everyone else, mumbling to myself about how crazy you sound. Today, however, I wish you weren't being downvoted because you're half way to being right.

I strongly doubt the intent of things like Google Cloud Messaging is to intercept all your data and siphon it off to the NSA, GHCQ, and others. GCM is an incredibly useful service that has been designed to make it easier to write apps that use less power by eliminating polling. When you don't have to poll you can keep the mobile radio in a low power state. But the trouble is, you are indeed passing data (possibly even sensitive data!) through Google data centers when you're using GCM and it's equivalents.

The tech industry seems to trust Google less today than it did this time last year in light of the Snowden leaks, and quite rightly so.

Re: If You're Programming a Cell Phone Like a Server, You're Doing it Wrong

#44

Post by DougWebb » Thu, Sep 19, 2013, 10:43 PM UTC

kintamanimatt wrote: post #41

DougWebb wrote: post #11

The last thing I'd want is for my apps to each be downloading several MB of data they think I might need in the next few minutes. I can easily control how much battery life is remaining on my phone by plugging it in. I can't control how much of my data plan an app is using, except by uninstalling the app. Besides, in my experience the biggest drains on battery life aren't data transfers, they're (a) having the screen…

> I can easily control how much battery life is remaining on my phone by plugging it in. Except when you can't. Are you really always near a power outlet? There have been plenty cases where I just haven't been able to charge my phone and have had to turn it off rather than use it for what I want. > I can't control how much of my data plan an app is using, except by uninstalling the app. Depending on where you are, ge…

I'm in the US. My data plan is capped when I'm on my carrier's network, and unlimited (and much more expensive) when I'm roaming. Typical US carrier.

This highlights a good point: it's not just the number of bytes of data, it's the cost per byte. Many data plans have an explicit cost per byte, but even ones that don't will have an opportunity cost: if your app is sucking up a portion of my bandwidth, you're preventing my other apps from retrieving data. Even if my data was free, my bandwidth is limited.

Re: If You're Programming a Cell Phone Like a Server, You're Doing it Wrong

#45

Post by DougWebb » Thu, Sep 19, 2013, 10:46 PM UTC

levosmetalo wrote: post #30

DougWebb wrote: post #11

The last thing I'd want is for my apps to each be downloading several MB of data they think I might need in the next few minutes. I can easily control how much battery life is remaining on my phone by plugging it in. I can't control how much of my data plan an app is using, except by uninstalling the app. Besides, in my experience the biggest drains on battery life aren't data transfers, they're (a) having the screen…

> (b) being slightly out of range of a cell tower, and constantly dropping and reacquiring a 3G connection. The latter turns my phone into a hand-warmer and chews up my power. For this reason I'm pretty happy that my Android has an option to force 2G network for battery savings. Gives me 50% better battery life with no noticeable speed difference.

Yeah, most of the time my Android is on a WiFi network (office or home) and the cell data connection is turned off. My battery can last a pretty long time if I'm not away from my WiFis much and I don't have the screen on full brightness.

Re: If You're Programming a Cell Phone Like a Server, You're Doing it Wrong

#46

Post by DougWebb » Thu, Sep 19, 2013, 10:52 PM UTC

tjohns wrote: post #18

DougWebb wrote: post #11

The last thing I'd want is for my apps to each be downloading several MB of data they think I might need in the next few minutes. I can easily control how much battery life is remaining on my phone by plugging it in. I can't control how much of my data plan an app is using, except by uninstalling the app. Besides, in my experience the biggest drains on battery life aren't data transfers, they're (a) having the screen…

Foreground prefetching aside, there are controls that let users disable background data prefetching/syncing. In fact, it's even one of the buttons on the standard "power control" widget. While the screen is definitely a huge power drain, it's easily controlled by the user. Poorly behaved apps will drain battery regardless of what the user does, and definitely _can_ be a huge drain. These used to be a lot more common…

That control, like the permissions approval dialog, is a blunt tool. Sure, I can turn background data completely off, or I can let my apps run wild with it. There's no middle ground and no per-app control (unless the app developer provides one.)

KB of data could be reasonable, depending on how often its being fetched. But the OA specifically mentioned retrieving several MB of data for use "during the next few minutes." If that's an app that doing some kind of news feed to an always-running widget, and it's grabbing images and stories in case I might want to read them, it can really add up.

Re: If You're Programming a Cell Phone Like a Server, You're Doing it Wrong

#47

Post by AsymetricCom » Thu, Sep 19, 2013, 10:52 PM UTC

kintamanimatt wrote: post #43

AsymetricCom wrote: post #29

Just another bugle call for developers and users to forfeit more of their rights to our mighty big data and cloud land owners. Is your app ready for the "Internet of Things"?

A few months ago I'd have been happily hitting the downvote button along with everyone else, mumbling to myself about how crazy you sound. Today, however, I wish you weren't being downvoted because you're half way to being right. I strongly doubt the intent of things like Google Cloud Messaging is to intercept all your data and siphon it off to the NSA, GHCQ, and others. GCM is an incredibly useful service that has b…

I'm not even considering that perspective. I'm just wary of the neofuedalist movement of technology in the last ten years or so, fueled by the mobile platforms being subject to regulatory capture.

The fact that data being captured by intelligence communities already shows you who owns this "land" and considers the "natural resources" theirs for the pillaging, this is a great example of the kind of neofeudalism this proposed platform is building. We just rent the internet, the data that it generates is for the kings and gods.

The fact that these so called mobile platforms leave so much complexity to be managed by the developer just goes to show that these so called platforms are simply land grabs and don't actually offer anything to the developer except his software locked down to a single platform. They don't need to offer any service, just a rent collecting system for their captured land.

Re: If You're Programming a Cell Phone Like a Server, You're Doing it Wrong

#48

Post by dllthomas » Thu, Sep 19, 2013, 11:21 PM UTC

kintamanimatt wrote: post #39

canthonytucci wrote: post #5

> Every decision you make should be based on minimizing the number of times the radio powers up. This is lunacy. Ok, lunacy is a bit strong. But I disagree with this and am throwing a "premature optimization" flag. Modern phone batteries last plenty long, and the radio being on is nothing compared to the big bright screen. /edit Given the opportunity to chose, I know I would gladly sacrifice a few minutes per charge…

Respecting known limitations and working within best practices is absolutely not premature optimization. If you know that using the mobile radio in a certain way is a source of excessive battery usage, it's silly to just disregard this information. It's not premature optimization if you know where the performance issues are from the outset, and these performance issues are so incredibly common that the Android team p…

It's premature optimization if you're caring about this in your prototype. It's not at all premature optimization to look at battery life before you ship.

Re: If You're Programming a Cell Phone Like a Server, You're Doing it Wrong

#49

Post by cbhl » Thu, Sep 19, 2013, 11:33 PM UTC

droopybuns wrote: post #14

canthonytucci wrote: post #5

> Every decision you make should be based on minimizing the number of times the radio powers up. This is lunacy. Ok, lunacy is a bit strong. But I disagree with this and am throwing a "premature optimization" flag. Modern phone batteries last plenty long, and the radio being on is nothing compared to the big bright screen. /edit Given the opportunity to chose, I know I would gladly sacrifice a few minutes per charge…

Lunacy is too strong! I think the average mobile app developer has no business thinking about radio optimization. They should however be spending lots of time thinking about cacheing and minimizing interaction with servers. Developers in general have gotten too comfortable with unnecessary traffic on Desktop machines. There are too many devs who have been focused on speed as the limiting factor for mobile apps, when…

It seems like lunacy to me to use a smartphone on a connection where you're charged using usage-based billing. My provider throttles me when I'm over my "cap"...

Re: If You're Programming a Cell Phone Like a Server, You're Doing it Wrong

#50

Post by vacri » Thu, Sep 19, 2013, 11:43 PM UTC

miratrix wrote: post #27

canthonytucci wrote: post #5

> Every decision you make should be based on minimizing the number of times the radio powers up. This is lunacy. Ok, lunacy is a bit strong. But I disagree with this and am throwing a "premature optimization" flag. Modern phone batteries last plenty long, and the radio being on is nothing compared to the big bright screen. /edit Given the opportunity to chose, I know I would gladly sacrifice a few minutes per charge…

The difference between DCH (the full-on high power state) and PCH (the lowest power, waiting-for-paging state) is about 2-orders of magnitude. Last time I measured, it was about ~100mA vs ~1mA (at ~3.7V) used by the radio. So, it's not couple of minutes of battery life, but rather _many_ hours of standby life instead. People usually aren't very happy when a fully charged phone dies overnight. I've seen apps do some c…

Anecdata: I turn my phone's wifi off when not required because it has a significant effect on the battery life - particularly when I'm not in range of a wifi signal. I've had a full charge die on an 8-hour country drive because wifi was on. On the return trip, wifi was turned off and it behaved as expected.

Go for a long walk in the park? All that time your phone's wifi is straining to find a wifi signal. It's not as big a power sap as the screen, however it's constantly, silently in use and the screen isn't.