Google Chrome sucking up your bandwidth?

[adamb]

After a recent Google Chrome update, I have found quite a big spike in my bandwidth usage. My allowance is 40GB per month at peak times and I have never gone over my allowance for the 12 months I have been with IDnet. By the 15th of this month I had already used 30+GB.
After trawling around the network looking for suspicous traffic nothing was apparent.

I downloaded Netlimiter ( download at: http://lop.im/2m6tR ) to see if there was anthing on my main PC consuming all this bandwidth. After a couple of minutes it was obvious that the culprit was Google Chrome browser. I generally leave Chrome running 24/7 with my homepage tabs on (all static pages) when I am not using it. I have never really messed about with the settings as it works perfectly on default settings. However, if you have "Prefetching" switched on then your browser will download fresh versions of all the most visited websites and your favourites etc in the cache so they load up instantly when you visit them.

This was confirmed when I watched the traffic via Netlimiter.

The first hour after installation, Chrome consumed 245MB (down) in 1 hour. The 2nd hour was roughly the same. After a couple of Google searches I found out how to disable prefetching.

1) Type: chrome://flags/ into the address bar and disable the option:
Prerender from omnibox Mac, Windows, Linux, Chrome OS. Enables prerendering of suggestions from the Omnibox and predicts appropriate network actions (prerendering, Instant, DNS preconnect) by calculating a confidence value for each Omnibox result.

2) Go to Chrome settings and click on "Under the Bonnet" and disable "Predict network actions to improve page load performance".

This is from Google:
===========================
Predictions for network actions.
When you visit a web page, Google Chrome can look up the IP addresses of all links on the web page. Browsers use the IP address to load a web page, so by looking up this information in advance, any links that you click on the web page will load faster. Websites can also use prerendering technology to preload the links that you might click next.
===========================

Whilst the above suggests that it's just caching DNS lookups it also seems to be downloading whole webpages and their contents. So basically when you open your browser it will look through your history and then look at which websites you visit most and then fetch them all to the browser cache for faster loading. Not only does it do this but it seems to follow links and do the same thing to those pages. After a while of being idle it starts all over again :/ This is what I have observed when starting the browser and watching traffic flow via Netlimiter 3. The most visited website IP addresses popped up and spawned lots of connections which peaked up to 200Kb /s and lasted for up to a minute each time. DNS prefetching would use bytes rather than MB's.

Upon further inspection of previous logs from another program, I found this from Networx ( download Networx at: http://lop.im/6oRRx ):

Click pic to enlarge




As you can see, for 10 hours Chrome was using tons of bandwidth without me even knowing. Then it suddenly stopped. The same thing happened today for 2 hours until I completed the steps above.

The moral of the story is to download both Netlimiter and Networx (Freeware) and monitor your own browser traffic if you use a browser that prefetches content. You could be wasting precious bandwidth. Netlimiter will also monitor all other processes so you can narrow down other suspect traffic.

I hope this helps anyone with the same problem. I'll be looking at a big excess bandwidth bill next month which will be a big blow to our budget.

[Rik]

Thanks for that, I'm sure others will benefit from you experience. Stickies.

[adamb]

No problem   My prefetch bandwidth usage seems quite excessive compared to other threads around the internet. Still not quite understanding why it's so high. All I know is that everything is back to normal now since disabling prefetch.

According to Google, prefetch is only used when you start to type in a URL, it will then predict which website you are entering and preload it in the background. What I was finding was that Chrome was connecting to lots of different IP addresses (my frequently visited websites) and fetching content and then following links and doing the same! I don't know how deep it was crawling. At one point there must have been about 50 threads running, each pulling in big chunks of data. I really don't want to ditch Chrome as I cannot export the 100's of passwords I have stored in it. I will be very wary when updates happen.

If anyone is more knowledgeable about this then I would love to hear your comments. It's very strange behaviour. It's also nothing to do with my extensions as I created all the extensions I use (4).

[Stevescat]

This is very interesting Adam. I've recently been bending my kids' ears about the amount of data we appear to be consuming. I've disabled the settings you suggest and will watch with interest if this has any impact on our usage! Many thanks for your post on this.

[pctech]

Sounds like a nasty pest to me and another good reason to avoid Chrome.

When you have your own network including submarine cables and links into all of the major and some smaller ISPs to enable you to hitch a free ride on their networks bandwidth use is no longer a consideration and Google forgets that the customers of quality ISPs pay for what they use.

Google can also harvest useful stats from this useful feature.


And people used to think Microsoft was evil.

[Baz]

so what is it actually doing that is using bandwidth.

I have two laptops that use it and am now wondering if its the same for me

[Steve]

Chrome is prefetching web pages and storing them in cache, any web page contains multiple html links and chrome downloads these additional web pages whilst your viewing the website. If you then subsequently visit one of the prefetched pages you'll get an instantaneous load, if however you don't, the bandwidth used is wasted.

[Simon]

Useful to know. 

[armadillo]

Interesting thread.

I have an oldish version of Chrome (which I don't use as I don't like Chrome) and it does not recognise chrome://flags/ typed into the address bar.

But the post does serve to explain why Chrome kept starting downloading all by itself for no obvious reason. That was one of the reasons I stopped ever using it. I found that Safari does even more spontaneous downloading that I could not understand so I stopped using that too. I wonder if there are similar things going on there.

I have never encountered this with Firefox but I am still on version 3.6 and perhaps this was introduced in later versions.

[Technical Ben]

If it is they can get lost!

[JB]

I have an oldish version of Chrome (which I don't use as I don't like Chrome) and it does not recognise chrome://flags/ typed into the address bar.

I use Chromium, upon which Google Chrome is based. It does not recognise chrome://flags/ or chromium://flags/ or about:flags. However it does have a setting option to disable "Predict network actions to improve page load performance".

[armadillo]

I use Chromium, upon which Google Chrome is based. It does not recognise chrome://flags/ or chromium://flags/ or about:flags. However it does have a setting option to disable "Predict network actions to improve page load performance".

My Google Chrome has a setting:
"use DNS prefetching to improve page load performance"
which is not selected.

I could find nothing similar in Safari. Safari has various settings for auto-updating things such as browser updates, RSS feeds etc. They are all turned off, as they are for all other software and for Windows itself.

As well as periods of random downloading, Safari also has periods of frantic HDD activity, which stop as soon as it is closed.

This leaves Firefox as the only fully colour-managed browser which does not do weird self-initiated stuff - at least not in version 3.6.

[Monk]

Thank you for this information. I've been paying £4 extra each month for going over my allowance and blamed the kids... Hopefully it's going to get sorted now.

[foreversummer]

Thank you.  I've disabled mine as well.  In this house I am the only one who uses Chrome and I always blame my kids for our high usage.  Perhaps its me!

[Rik]

Of course it's you. 

[pctech]

If you think you aren't addicted to the Internet I challenge you to try a dial-up.

Our test ADSL connection was down at work on Friday last week so I had to resort to a dial-up modem to test external connectivity.


After enjoying a 2.9 Meg connection at home and a desktop LAN connection at work which averages 50 Meg it was painful.

[Lance]

Being addicted is different to wanting to do something quickly though! You might only want to do one thing on the Internet all month and given a choice you'd do it over a quick connection rather than a dial up one.

[jane]

There is something similar in Firefox I believe but maybe not as evil -

http://antivirus.about.com/od/securitytips/ht/disableprefetch.htm

Basically, in about:config, set the network.prefetch-next flag to false

[pctech]

Always be wary of a company whose slogan is 'don't be evil'

[jane]

The more you delve into what they do, the more paranoid you get. I have switched to startpage for my home page and searches as I was fed up with finding workarounds in IE and extensions in Firefox to curb the beast. Using Chrome is just asking for trouble but you could switch to SRWare Iron, a safer alternative based on Chrome.

[Technical Ben]

Always be wary of a company whose slogan is 'don't be evil'

Actually I'm less worried about them because of that. Only a small amount though, and with the likes of Apple and MS it's already sky high! 

[kerrso05]

adamb  this is really good advice but maybe you could update the advice as I think you will find that instead of "under the Hood" it now appears as:-

Settings

Click on + Show Advanced Settings

and then untick "Predict network actions to improve page load performance"

Also can you check about the information regarding
1) Type: chrome://flags/ into the address bar and disable the option:
Prerender from omnibox Mac, Windows, Linux, Chrome OS. Enables prerendering of suggestions from the Omnibox and predicts appropriate network actions (prerendering, Instant, DNS preconnect) by calculating a confidence value for each Omnibox result..........for the life of me, that doesn't seem to be there or maybe it is under something else now

Thanks again for this information.....it has really put me off using Chrome but then again I wasn't a big user of it anyway but my two daughters are and as others know I have been contemplating jumping ship lately because of the Idnets (stingy) caps in FTTP.....I'm going to try this in the meantime to see if this improves things.....it can't do any harm

Thanks again

[pctech]

Google are going one step further and offering Internet access via fibre in the States

http://fiber.google.com/about/

And people thought Phorm was bad.

[Steve]

I hope Google will do something similar here, we need the competition and not the hope that the last few yards of copper will just have to do the job. We really are a country sitting before the bronze age with regards the speed of an internet connection.

[pctech]

Are you happy to have your browsing history sold in exchange for that Steve?