Google Public DNS: 70 billion requests a day and counting

http://googleblog.blogspot.com/2012/02/google-public-dns-70-billion-requests.html

by abraham • 14 years ago

105 45 14 years ago

googleblog.blogspot.com

jasoncartwright• 14 years ago

For comparison, OpenDNS does ~37bn http://www.opendns.com/technology/traffic-stats/

davidu4• 14 years ago

Just to add a couple data points:

  1) Tons of random indy web crawlers, mail cannons, etc. use Google Public DNS.
  2) We actively discourage large machine-based usage of our service.

Even with some aggressive handling of large machine-based users, we still grow at a crazy clip.

Our growth: http://i.imgur.com/znfu9.png

brador• 14 years ago

Any idea on the limit for "large" machine based usage?

For examples, I use it with a PHP script that hits it a few hundred times and have not yet had a problem. Should I be expecting one?

davidu4• 14 years ago

We had a 500 cluster web crawler using us. Probably doing about a billion queries a day. They had the option to pay us or switch to Google Public DNS. Guess which they did? :-)

A few hundred, even if a few hundred per minute, is not a problem.

tonfa5• 14 years ago

Took me a while to figure out who the "we" is (OpenDNS). Might be worth stating it in your comment.

st3fan• 14 years ago

This is all on PowerDNS?

davidu4• 14 years ago

Nope... but we like Bert (the author).

51Cards• 14 years ago

That's a little over 800,000 requests a second on average. That's some serious traffic.

TomGullen• 14 years ago

I just switched to Google DNS. Before I switched I got a 38ms response time when I ping google.com, now I get 285ms? I'm in the UK. Is this why it's slow?

zacgarrett• 14 years ago

DNS has nothing to do with ping response times. A ping requests the IP address from the DNS server and then does the ping. On most systems the DNS is cached locally, so multiple requests will use the same information.

icebraining• 14 years ago

DNS has nothing to do with ping response times.

Not true, the feature is called GeoDNS and gives you different IP addresses for the same domain based on your DNS server. See Locke1689's reply.

pyre• 14 years ago

I don't think that DNS lookup time is included in ping's latency numbers. It probably does the lookup once per run, and then caches the IP. It wouldn't make sense to to the DNS lookup once per ping.

Locke1689• 14 years ago

It's possible that you are suffering from mistaken redirection to a different CDN.

You should read up on how CDNs work (http://en.wikipedia.org/wiki/Content_delivery_network) but the gist is essentially that your DNS server determines which content node you're routed to. If your DNS server is your ISP's DNS server it's very likely that you're geographically close.

However, public DNS is usually anycasted to more general regions. In this case, you may be then routed to a content node which is close to the DNS node, but farther from you.

Google actually does support the EDNS extension in order to help solve this problem, but I find it unlikely that ping supports the extension.

This is a big problem with public DNS services. My research group will be releasing a project soon which seeks to alleviate the problem and dynamically choose DNS based on what provides you the best performance.

Edit: Actually I think I may be wrong about one point: IIRC the actual DNS clients don't need to support EDNS-client-subnet in order for it to be used. Only the DNS and authoritative DNS/CDN need to support it. Usually that's a problem because most of the major CDNs don't support it yet, but Google actually does support it on both their CDN and public DNS. Therefore you should be routed based on your prefix when talking to google.com, not the anycasted 8.8.8.8 node. Thus, I have no idea what's going wrong.

tonfa5• 14 years ago

The DNS is probably resolving google.com to an IP that is further away network-wise. You could check to which IP it resolves depending on your DNS.

skeletonjelly• 14 years ago

Seconding zacgarrett. Try using nslookup or dig to get a more accurate measurement on how the change in DNS has affected response times.

freehunter• 14 years ago

Being in the information security world, I have to wonder what percentage of these requests are based in malware? I know at least the latest version of ZeroAccess/Max++/Sirefef (which we managed to get before the AV vendors released definitions for it) uses it quite heavily. That's one of the symptoms we used to diagnose computers from a strictly network-level standpoint. No one on our network should be using Google DNS, so any computers who were making requests to 8.8.8.8 were likely infected (confirmed using other signatures).

That amounted to about 100 requests every day per infected computer just from us, and ZeroAccess isn't the only one doing it (and isn't a rare trojan).

quux• 14 years ago

Glad they're doing something about the CDN issue. This is the main thing that keeps me from switching to Google DNS.

nuttendorfer• 14 years ago

I used to use this but switched off over security concerns (Mainly because I didn't want Google everywhere)

I haven't noticed any difference in load times so I guess it didn't do any harm.

re_todd• 14 years ago

It would be funny if they suddenly dropped the service because it wasn't generating a good "revenue stream". It would be chaos for awhile.

c1sc0• 14 years ago

I'm wondering if there's a detectable peak in people switching to Google DNS because of censorship in countries like .be & .nl

sellandb• 14 years ago

I would be interested if statistical data gleaned from DNS makes it's way into any other service areas. DNS would seem like a useful way to rank the popularity of web sites, I am sure there are some interesting enhancements that could be made using that data.

tonfa5• 14 years ago

I think their privacy policy disallows it: http://code.google.com/speed/public-dns/privacy.html

> We don't correlate or combine your information from the temporary or permanent logs with any other data that Google might have about your use of other services, such as data from Web Search and data from advertising on the Google content network.

And they say that the logs are only used for debugging, DoS protection and abuse.

aw3c22• 14 years ago

The quote from the policy says nothing about using or not using the information about what DNS queries are made for data mining or ranking.

cowmixtoo• 14 years ago

It seems like Google's DNS servers are always MANY hops away from me, no matter where I am. The ping times range from 8ms to 45ms.

How is that faster than using a local DNS server?

secure• 14 years ago

Obviously it cannot be faster than a local DNS cache/server (for the RTT). What can be significantly faster is forwarding queries to Google Public DNS instead of your ISP. At least in my experience, ISPs often have slow and overloaded servers which are not well maintained. Recursively resolving completely on your own is often even slower than either of those two choices.

a1k0n• 14 years ago

ISPs often also have abusive DNSes that redirect unresolved domains to ad-ridden landing pages, which is why I switched.

j-kidd• 14 years ago

I have been running unbound for a month, and there is no noticeable difference in resolving time. This article provides a good read: http://linuxmafia.com/~rick/googledns.html

handelaar• 14 years ago

45ms beats the hell out of the hundreds, or thousands, that crappy Irish ISPs deliver from their own 'local' name servers. When they're working at all.

seancron• 14 years ago

For those thinking about changing their DNS servers, you might want to take a look at http://code.google.com/p/namebench/

It benchmarks global (like Google Public DNS and OpenDNS) and regional DNS providers to show which DNS servers would be fastest for you.

Codhisattva2• 14 years ago

What an enormous data mine.

Codhisattva2• 14 years ago

Down votes for pointing out that Google DNS is an enormous data mine? Why?

xiaoma• 14 years ago

I for one am very thankful for this DNS. Ever since moving to China, 8.8.8.8 has useful for getting around various flaws of the internet experience here. Even with a paid VPN, it's nice to have an always working DNS server.

Google Public DNS: 70 billion requests a day and counting

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