Building Scalable Applications with Azure Cloud Services and Service Bus

Building Scalable Applications with Azure Cloud Services and Service Bus

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Goals

VS 2013 Azure integration and ease of useCloud Services and Service Bus FeaturesLoosely Coupled designScale Out (not up)Easy to scale, resistant to failurePerformant (serialization, caching, batching, efficient code/frameworks)


Execution Models

Web sitesMobile servicesVirtual machinesCloud services


Cloud Services

Platform as a Service (PaaS)Platform infrastructure managed by AzureUser provides configurationConsist of 1-n worker/web roles


Roles

Two Types of Roles–Web Role: IIS enabled–Worker Role: IIS disabled

A role consists of 1-n identical instancesA deployment contains 1-n RolesEach role has an agent


Cloud Service Project


Instances

Non-durable virtual machine (VM)New instances can be created by a roles agent– Failure in VM– Scaling


Demo

Create Cloud Service and debug in Visual StudioEnvironment– Visual Studio 2013 Update 2– Windows Azure SDK 2.3– Node V0.10.26– Node.Js Tools for VS 2013 Beta


Windows Azure Scalability Posterhttp://msdn.microsoft.com/library/azure/xx130451.aspx

http://msdn.microsoft.com/library/azure/xx130451.aspx

http://msdn.microsoft.com/library/azure/xx130451.aspx


Azure Service Bus

Queues– reliable, persistent FIFO guaranteed– 1-n competing consumers

Topics– Publish/subscribe messaging (fan out)– Component exchange messages through topic– Supports filter registration


Queue Design

Receiving messages– Polling (pull based)– Queue listeners (push based)

Scale role instances to handle workloadBatch put/get itemsUse multiple queues for higher throughput


Sample Queue

Providers Consumers

N+2

NN+1


Sample Topic

Providers Consumers

Topic


Queue Receive Modes

PeekLock– Default mode– After message received, request sent back

ReceiveAndDelete– Both steps in single request– Less throughput– Can lose messages


Using Service Bus

Do not create and close queue/topic clientsBatch items and prefetchingUser asynchronous requestsPartitioning


Brokered Message


Demo Time!

BrokeredMessage, Serialization and Send/Receive

Requirement: Service Bus Namespace Connection StringGo to www.manage.windowsazure.com


Easy to Scale, Resistant to Failure

Avoid single point of failureScale-out not scale-upBe statelessHandle failure gracefully


Error Handling

Handle dropped connectionsHandle transient failures (retry/reconnect)Other failures (log, report, and notify user)If possible, fall back to a different service or workflow


Loosely Coupled Architecture

TestingEasier transition in switching implementationEasier migration to another platform


Useful Design Patterns

Isolate APIs with interfaceFaçade PatternDependency Injection ContainerFactories


Bang for Your Buck!

Batch network calls if appropriateProper serializationChoose frameworks wiselyDon’t server static content from website/web role


Blob Storage

Less load on serverFaster IO than SQLCheapest Azure storageUser for static content >100 kB


Azure Cache Service

Distributed In-memoryPersists during application restartsExpiration: never, absolute, slidingNotifications: AddItem, ReplaceItem, RemoveItemBuilt in back-up


Scaling

ConfigurationManualAPIAuto Scale


Scale by CPU


Scale by Queue


Demo Time

Node.js web roleC# worker role


Questions?

[email protected]

Slides and code available at www.kcode.me