1. Auto-scaling Axis2 Web Services on Amazon EC2 By Afkham Azeez

2. 2 Overview The Problem A Solution Some Concepts Design & Implementation Details

3. 3 The Problem Fault tolerance, high availability & scalability are essential prerequisites for any enterprise application deployment One of the major concerns is avoiding single points of failure There is a high cost associated with achieving high availability & scalability.

4. 4 Solutions Traditional solution – Buying safety-net capacity Better solution – Scale-up the system when the load increases – Scale-down the system when the load decreases – Should not have idling nodes – Virtualization – Pay only for the actual computing power & bandwidth utilized

5. 5 Project Objective Building a framework which will auto-scale the number of Axis2 nodes on Amazon EC2, depending on the load This is a PoC Project

6. 6 Amazon EC2 Amazon EC2 provides resizable compute capacity in the cloud Provides a simple Web service interface & tooling that allows one to obtain and configure capacity with ease & to build failure resilient applications

7. 7 Apache Axis2 Axis2 is a middleware platform which enables hosting of Web service applications and supports some of the major Web services standards Can host Web services written in Java as well as various scripting languages Can be deployed in a clustered configuration Uses Apache Tribes for clustering Axis2 clustering has been adopted to work on EC2

8. 8 Apache Synapse Apache Synapse is designed to be a simple, lightweight and high performance ESB Supports load balancing with or without failover Supports static & dynamic load balancing Uses Apache Axis2

9. 9 Apache Tribes A messaging framework with group communication abilities Allows you to send and receive messages over a network, it also allows for dynamic discovery of other nodes in the network. Used by Apache Tomcat & Apache Axis2

10. 10 Deploying a Service on the Cloud AMI Instances

11. 11 Deploying a Service on the Cloud

12. 12 Deploying a Service on the Cloud

13. 13 Deploying a Service on the Cloud Service is available now

14. 14 Auto-scaling

15. 15 Auto-scaling Load Increases

16. 16 Auto-scaling Startup new instances

17. 17 Auto-scaling New instances join group

18. 18 Auto-scaling Load Decreases

19. 19 Auto-scaling Terminate instances

20. 20 Auto-scaling Terminate instances

21. 21 Deployment Architecture

22. 22 Membership Aware Dynamic Load Balancing (1/2)

23. 23 Membership Aware Dynamic Load Balancing (2/2)

24. 24 Membership Schemes Static Dynamic Hybrid (WKA based)

25. 25 WKA Based Membership (1/3) Application member joins. The load balancer is also a well-known member

26. 26 WKA Based Membership (2/3) A non-WK load balancer joins

27. 27 WKA Based Membership (3/3) A well-known load balancer rejoins after crashing

28. 28 Membership Channel Architecture

29. 29 Initialization Channel Architecture

30. 30 Synapse Configuration - axis2.xml

31. 31 Synapse Configuration - synapse.xml

32. 32 Synapse Configuration AutoscaleInMediator AutoscaleOutMediator Autoscale Task

33. 33 Synapse Configuration AutoscaleInMediator AutoscaleOutMediator MessageID List LoadAnalyzer Task SendMediator DynamicLoadbalanceEndpoint SendMediator EC2 Client Synapse From client To client To Axis2 From Axis2 To EC2 WS Get length Invoke IN OUT Normal Flow

34. 34 Synapse Configuration AutoscaleInMediator AutoscaleOutMediator MessageID List LoadAnalyzer Task SendMediator DynamicLoadbalanceEndpoint MakeFaultMediator EC2 Client Synapse From client To client To Axis2 From Axis2 To EC2 WS Get length Invoke IN ErrorHandler SendMediator Fault Flow

35. 35 Synapse Autoscale Task

36. 36 Axis2 Configuration - axis2.xml

37. 37 Synapse Autoscale Task Sanity Check Autoscaling –Scale up –Scale down

38. 38 Implementation Details Single AMI – autoscalews Start –ec2-run-instances ami-a03fdbc9 -k autoscale -f payload.zip -g autoscale-lb Payload –Extract params from payload –Env variables Axis2 & Synapse Configuration files & Repositories –Maintained on S3 Fault Tolerance –Monitoring cron job –Java Service Wrapper daemons –Future: Use monit –Future: Axis2/Synapse agent to check process status

39. 39 Implementation Details Start Initial Instance LB Group Axis2 App Group synapse.xml S3 Bucket Load configuration

40. 40 Implementation Details Repo Conf Axis2 Instance S3 Bucket Load repo Load configuration

41. 41 Questions Suggestions Improvements

42. 42 Thank You