intro to managed dns: load balancing

Intro To Managed DNS: Load Balancing @DynInc @Dotcom_Monitor

Intro To Managed DNS: Load Balancing


Today’s Discussion •  Why distribu?ng load even maAers •  The role of the DNS in distribu?ng load •  Different techniques •  Measuring success •  Where does load come from? •  Load distribu?on at other levels


Today’s Presenters Andrew Sullivan – Director of DNS Opera?ons, Dyn [email protected] Brad Canham – VP, Sales & Marke?ng, Dotcom-‐Monitor bradc@dotcom-‐monitor.com Vadim Mazo – CTO, Dotcom-‐Monitor vadimm@dotcom-‐monitor.com


“Balancing load”


Load distribuDon

•  Internet: a network of networks •  “Load balancing” is just a special case •  Align demand with resources •  Align resources with demand •  Be Goldilocks: strive to make demand just right


What’s DNS got to do with it?

•  Almost everything starts with the DNS •  Every web impression starts with DNS

– Every image – Every link – Every tweet

•  Browser vendors have started to play tricks


Load distribuDon in DNS 1

www.example.org. 300 A 192.0.2.1


www.example.org. 300 A 192.0.2.1 www.example.org. 300 A 192.0.2.2



The Pros/The Cons

• No special soYware/ service

• Exis?ng deployed soYware has bugs

• Standard DNS func?onality

• Totally dependent on clients

• Should work almost everywhere

• Insensi?ve to client’s loca?on

• All exis?ng tools should work


LocaDon?

•  On the Internet, everyone is local


LocaDon?

•  On the Internet everyone is local •  On the Internet, everyone is local


LocaDon?

•  On the Internet everyone is local •  On the Internet, everyone is local •  People don’t like slow performance, wherever they are


DNS lookup can go a long way


Long hops cause latency


Everything can go a long way


Instead of this…


…get this.


Closer means lower latency


The Pros/The Cons

• No special soYware/ service

• Maximum number of servers

• Standard DNS func?onality

• Depends on clients to pick one that performs best

• If current preference goes down, client ?mes out



Anycast!


Anycast


The Pros/The Cons

• Extremely scalable (no server limit)

• Requires significant exper?se

• Addi?onal benefits (more redundancy and so on

• High ini?al investment

• Somewhat more flexible than just using many name servers

• Sensi?ve to network changes

• Widely available through outsourcing

• Tricky debugging


Example measurements •  We set up two names

– dyn-‐dotcom-‐webinar-‐example-‐1.com – dyn-‐dotcom-‐webinar-‐example-‐2.com

•  The first is a standard, straight “unicast” system for DNS

•  The second is a standard, Dyn “anycast” system for DNS

•  Everything else the same


Heat map comparison


One locaDon


Page load effect


More than one variable


Other room for improvement


Everything can go a long way


Tailor answers per region


Keep Measuring!

•  DNS Traceroute Tool (Trace style>DNS)hAp://bit.ly/dctraceroute

•  Browser Test from 19 worldwide loca?onshAp://bit.ly/dcbrowsertest

•  Link for special monitoring access exclusive to Dyn webinar aAendees hAp://dotcom-‐monitor.com/dyn


What next? •  Get a baseline as of today from around the world:

hAp://bit.ly/dctraceroute •  Choose DNS to see DNS resolu?on ?mes •  Choose Network to see latency ?mes

•  Measure page load ?mes from around the world hAp://bit.ly/dcbrowsertest

•  Experiment (Dyn can help if you like!)

•  Monitor con?nuously to ensure it keeps working as expected

•  Special link for webinar aAendees: hAp://bit.ly/SpecialTrial


THANK YOU!


NEXT WEBINAR: Wednesday, April 3 with Joyent

Bit.ly/106Nxt9

“When is the right time for Managed DNS?”

Dyn CTO Cory von Wallenstein & Joyent CTO Jason Hoffman

intro to managed dns: load balancing

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