Itcampro @ itcamp12 # Premium conference on Microsoft technologies Serving 10 million requests per...

itcampro@ itcamp12# Premium conference on Microsoft technologies

Serving 10 million requests per day

How to solve the architecture challenges of a high traffic ASP.NET website

Level 400

Dan Fizesan, Lead Developer, NetMatch – Travel Technology

Solutions


Private & Public CloudITCamp 2012 sponsors


Private & Public Cloud

• Dan Fizesan, 37 years old.

• 15 year experience with Progress / C# / ASP.NET / T-SQL.

• Technical Architect / Lead developer in NetMatch / Zoover project.

• NetMatch international company e-business provider for tourism industry

• Zoover is a website with reviews about trips on average 500.000 unique visitors per day

• Contact: [email protected]

Who am I



• Architecture of a web application

• Deep dive into the macro architecture

• Serving 10 million requests a day - final

view

• Demo

• Q & A

Agenda



• More and more users are using the online websites

• Applications on mobile devices are using data from the web data services

• The FOCUS in the presentation are on-premise applications that are also subject to above trends

Context



• Be online as much time as possible

• Serve as many users as possible

• Low cost of ownership

• Good performance

Architectural Goals



• We reach high availability when more than 90% of the time the website is working correctly

• 99% availability = the website is down 87,6 hours in a year (or 15 minutes every day)

• 99.99% availability = the system is down less then 1 hour per year

• Our systems go for 99.9% availability

Availability



How can we reach 99.9% availability?

• Through passive redundancy – failover

• Through active redundancy

• Through data sources replication

Challenge



• Hardware load balancers

• Software load balancers: Network Load Balancer, Ha Proxy, etc.

• Algorithms to spread the load

• Implementing failover is crucial

• Alternative: Producer-consumer pattern – used in IIS

Load Balancers + Failover



Web is stateless, what happens with the state when using a web farm?

Challenge

No sessions stickiness: • SQL (session) state

server, • distributed cache

session state, • use cookies

With session stickiness• performs worse• can lead to

overloaded servers




• How can we serve as many users as possible?Partly through using load balancersPartly through scalability of the website



Architectural Goals



• The ability of the website to grow the user base by adding more hardware

• The more linear the relation is, the more scalable the website is

• Vertical scalability

• Horizontal scalability, lower costs using commodity hardware

Scalability




• How can we serve as many users as possible?Partly through using load balancersPartly through scalability of the website



Architectural Goals



• Helps the backend (database/services)

• Advantage: brings consistency in an webfarm

• Disadvantages: latency

• Some of the free options: Windows Server AppFabric Caching,

memcached

• Some of the commercial options: NCache, Azure AppFabric caching

Distributed Caching



How can we protect the website in the case the distributed cache goes down or is not reachable?

• Through implementing failover caching mechanisms in the website

Challenge



• Be online as much time as possible Through high availability

• Serve as many users as possiblePartly through using load balancersPartly through scalability of the website



Architectural Goals



• Web code/ business layer performance

• Database queries performanceFlat databasesReplicated databases

• Distributed architecture splitting into sub-applications

• Parallelization of the code (demo)

Perceived good performance



How can we use distributed architecture and have a good performance?

• We should externalize the resource-intensive parts of the application into sub-applications

• Choosing wrong parts will only add (network) latency

Challenge


OUR ARCHITECTURE TO SERVE

10 MILLION REQUESTS PER DAY



300 requests

Demo Results

Approach % s

ThreadPool parallelism 1200% 21,6 s

Task Parallel Library parallelism 4200% 76 s

Simple Threads parallelism 155% 2,8 s

Custom ThreadPool parallelism 100% 1,8 s


Q & A

Contact: [email protected]/itcamp2012/challenges.pptxwww.netmatch.ro/itcamp2012/demo.zip

http://www.netmatch.ro/itcamp2012/challenges.pptx

http://www.netmatch.ro/itcamp2012/demo.zip



• Availability

• Redundancy

• Load balancer

• Scalability

• Distributed caching

• Performance

To Remember

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