2. Creating highly available and resilient Microservices on Microsoft Azure Service Fabric
Mahesh Krishnan
CLD334

3. Agenda Why use microservices?
Azure Service Fabric Platform – An introduction
Service Fabric Programming model
Reliable Actors
Reliable Services
Wrap up

4. Traditional Monolithic approach
A monolithic application has most of its functionality within a single process that is commonly componentized with libraries
Scales by cloning the app on multiple servers/VMs/ containers

5. Microservices approach
Separates functionality into separate smaller services
Uses a standard communication protocol
Scales out be deploying each service independently creating instances of these services across servers/VMs containers

6. Why use microservices?
Can be versioned, deployed and scaled independently
Allows use of different technologies
Loose coupling of services
Faster delivery of features
Facilitates small, focused teams
Improves fault isolation

7. Microsoft Azure Service Fabric A platform for reliable, hyperscale, microservice-based applications
microservices
Service Fabric
Health Monitoring
Container Orchestration & lifecycle management
High Availability
Hybrid Operations
Data Partitioning
Self-healing
Simple programming models
High Density
Rolling Upgrades
Low Latency
Placement Constraints
Fast startup & shutdown
Replication & Failover
Load balancing
Hyper-Scale
Automated Rollback
Stateful services
Private Clouds
Windows
Server
Linux
Azure
Windows
Server
Linux
Hosted Clouds
Windows
Server
Linux

8. Service Fabric cluster with microservices
App1
App2

9. Types of Microservices
Stateless microservice
Stateful microservices

10. Stateless Microservices
Has either no state or state is persisted externally (such as Azure database or Azure storage)
There can be multiple instances of the services
e.g. Existing ASP.NET web apps, Azure cloud services

11. Stateful Microservices
State is maintained within the microservice
Allows for hot data to be next to the compute
State is partitioned for scale
Each partition state is replicated for reliability
e.g. Database, documents, user profile, shopping cart, etc

12. Cloud Services vs Service Fabric
Azure Cloud services
Service Fabric
One service instance/VM
Multiple microservices/VM
Lower compute density
High microservice density
Slow in deployment and upgrades
Faster
Slower scaling and DR
Fast scaling across the cluster

13. Programming models

14. Service fabric applications

15. Reliable Actors API

16. Actor programming model
Introduced in 1973!
An actor is the fundamental unit of computation
Does some processing
Holds state
Communicates with other actors
Similar to objects in OOP

17. Reliable Actors API
Build reliable stateless and stateful objects using a virtual Actor programming model
Suitable for applications with multiple independent units of scale and compute
Automatic state management and turn based concurrency

18. Reliable Actors Actors have an lD that maps to an object
Service Fabric manages nodes and can transparently move actors amongst them (provides HA and scale)
Actor methods run via turn based concurrency

19. Getting started Download the Service Fabric Download
Ensure PowerShell is installed and right execution policies set up
Run the DevClusterSetup.ps1script to start local cluster

20. Server side code - Interface
public interface IMyActor : IActor {
Task<string> DoWorkAsync(); }

21. Server side code - Implementation
public class MyActor : Actor, IMyActor {
public async Task<string> DoWorkAsync() …
return await Task.FromResult("result"); }

22. Client side code var app = "fabric:/HelloWorld";
var proxy = ActorProxy.Create<IMyActor>
(ActorId.NewId(), app);
var result = proxy.DoWorkAsync().Result;

23. Demo Reliable Actors Microsoft Ignite 2015 4/26/2017 8:23 AM
© 2015 Microsoft Corporation. All rights reserved. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

24. Actor Lifecycle

25. Actor lifecycle - Activation
If actor is not active, a new actor is created
Its state is then loaded (for stateful actors)
OnActivateSync method is called
Added to Active Actors table

26. Actor lifecycle - Deactivation
Unused actors removed from the Active Actors table
OnDeactivateSync method is called on Actor
Once deactivated, objects are garbage collected by CLR

27. Actor lifecycle – more concepts
Scan interval – Time interval between successive scans by Actor runtime for inactive actors (Default: 60 seconds)
Idle timeout – Time an actor can be idle before it is deactivated (Default: 60 seconds)
ActorGarbageCollection attribute used to change defaults

28. Reliable Services API

29. Reliable Services API
Write services that are reliable, available, scalable and provide consistency
Use Reliable Collections to persist state
Communicate using tech of your choice (WCF, WebAPI, ..)

30. Reliable Collection Can be used to create Stateful services. Features:
Multi-machine
Replicated (HA)
Persistance (durable)
Asynchrounous
Transactional

31. Getting started…
Only two methods you need to implement to get started.
CreateCommunicationListener – Method where the communication stack for the service is defined
RunAsync – This is where the Service runs the business logic – similar to WorkerRole’s Run method

32. Server side code - Implementation
public class MyStatelessService : StatelessService {
protected override ICommunicationListener
CreateCommunicationListener() { …}
protected override async Task
RunAsync(CancellationToken cancellationToken) { … } }

33. Reliable Collection
var myDictionary = await this.StateManager.GetOrAddAsync
<IReliableDictionary<string, long>>("myDictionary");
using (var tx = this.StateManager.CreateTransaction()) { …
await myDictionary.AddOrUpdateAsync(tx, "counter", 0,
(k, v) => ++v);
await tx.CommitAsync(); }

34. Scalability Can be partitioned for scalability – you choose scheme S
Node 1
Node 2
Node 3
Node 4
Node 5
Node 6 S P2 P1 S S S S P3 P4 S S S

35. Demo
Reliable Services

36. Demo
Service Fabric in the portal

37. Wrap up…
Service Fabric is the next generation of PaaS that can be used to create microservices
Has 2 programming models:
Reliable Actor API
Reliable Service API
Can create either stateful or stateless services
Availability, Scalability, load balancing, etc comes OOB

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39. Continue your Ignite learning path
Microsoft Ignite 2015
4/26/2017 8:23 AM
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© 2015 Microsoft Corporation. All rights reserved. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.