Cloud concepts
0 likes768 views
This document discusses concepts related to scalability, availability, and autoscaling in cloud computing. It defines key terms like scalability, availability, and high availability. It describes techniques for vertical and horizontal scaling as well as load balancing. The document discusses capacity planning and choosing the required scale based on factors like throughput and cost of downtime. It also covers autoscaling and how systems can dynamically scale based on load. Finally, it compares different architecture patterns for availability from single node to multi-region deployments.
Cloud concepts
- 1. Last Updated: May. 2014 Committer and PMC member of Apache Stratos Senior Software Engineer, WSO2 Lahiru Sandaruwan Cloud Concepts
- 2. * Agenda • Some core concepts • Vertical/horizontal scaling techniques • Capacity planning • SLA Awareness • Autoscaling • Fault tolerance • Q&A, Discussion
- 3. * Scalability "The ability of the of a system to continue to operate correctly even when it is scaled to a larger size”
- 6. * High Availability A system that is designed for continuous operation in the event of a failure of one or more components. However, the system may display some degradation of service, but will continue to perform correctly. High Availability: The proportion of time during which the service is accessible with reasonable response times should be close to 100%.
- 7. * How to decide required scale (capacity) & availability? • Average throughput (TPS) • Max throughput (TPS) • Monetary value of a transaction • Average loss & max loss per second of downtime • Decide on how much to invest based on cost vs. benefit tradeoff
- 8. * Vertical Scaling • Get the maximum out of each allocated JVM or resource • Increase CPU size • Increase memory
- 10. * Load Balancing • Load balancing algorithms • Round robin • Weighted • Response based • Health check • Failover-only
- 12. * Clustering for availability Group Communication Channel/State replication
- 14. * Capacity Planning Throughput = number of completed requests / time to complete the requests No. of servers = (projected max load * 1.3) / max throughput of one server max throughput of one server = max throughput of that server for the slowest scenario in the set of use cases
- 15. * Static membership • Predefined members • Other (non-predefined) nodes cannot join M2 M1 M3 M4 Static group N
- 16. * Dynamic membership • No predefined members • Nodes can join & leave M2 M1 M3 M4 Dynamic group N Join
- 17. * Hybrid membership • Some predefined (well-known) members, and some dynamic members • Nodes can join & leave • Membership revolves around the static members Hybrid group N M2 M1 M3 M4 Static members M6M5 M7 Dynamic members Join (IP, Port)
- 18. * Multicast based membership management N M2 M1 M3 M4 Join (IP, Port)
- 19. * Well-known Address (WKA) based membership management Hybrid group N WK 2 WK 1 WK 3 WK 4 Static members M6 M5 M 7 Dynamic members Join (IP, Port) Notify
- 20. * Multicast vs. WKA Multicast WKA All nodes should be in the same subnet Nodes can be in different networks All nodes should be in the same multicast domain No multicasting requirement Multicasting should not be blocked No fixed IP addresses or hosts required At least one well-known IP address or host required Failure of any member does not affect membership discovery New members can join with some WKA nodes down, but not if all WKA nodes are down Does not work on IaaSs such as Amazon EC2 IaaS-friendly Requires keepalived, elastic IPs or some other mechanism for remapping IP addresses of WK members in cases of failure
- 21. * ● Solves performance, availability, and economic costs issues ● Currently the customer needs a considerable capacity planning ● Reduce cost of cloud: reduce economic cost and energy footprint SLA Awareness
- 22. * ● Monitoring the cloud parameters ● Trigger an event if a SLA violation happened ● Acting upon the events SLA Awareness: Solution
- 23. * Auto-scaling • Scale-out when load increases • Scale-in when load decreases • Always use the optimum amount of resources • Try out • AWS ELB • Apache Stratos Load Balancer • WSO2 ELB
- 24. * Auto-scaling – steady load
- 25. * Auto-scaling – load increasing
- 26. * Auto-scaling – load increasing
- 27. * Auto-scaling – steady load
- 28. * Auto-scaling – decreased load
- 29. * Auto-scaling – decreased load
- 30. * Auto-scaling – steady load
- 31. * Autoscaling - Analysis & Results
- 32. * Autoscaling - Analysis & Results
- 35. * Primary-secondary, multiple LB Primary Secondary keepalived Availability Cost LOWEST HIGHEST
- 36. * Active cluster, multiple LB Active Active keepalived Active Availability Cost LOWEST HIGHEST
- 37. * Multi-zone or multi-datacenter Deployment Region X Zone 1 Zone 2 Cloud Controller Availability Cost LOWEST HIGHEST
- 38. * Multi-region deployment Region X Zone 1 Zone 2 Region Y Zone 1 Zone 2 Availability Cost LOWEST HIGHEST
- 39. * Multiple IaaS (hybrid) DeploymentAvailability Cost LOWEST HIGHEST Private cloud (data center) Zone 1 Zone 2 Amazon EC2 Zone 1 Zone 2 Rackspace Cloud Zone 1 Zone 2
- 42. * References ๏ http://www.cari-info.org/cari-2012/session%201/1B3.pdf ๏ http://domino.research.ibm.com/library/cyberdig. nsf/papers/16D9BBF221540A0785257784004FC33D ๏ http://ieeexplore.ieee.org/xpl/login.jsp? tp=&arnumber=5452504&url=http%3A%2F%2Fieeexplore.ieee. org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5452504 ๏ http://ieeexplore.ieee.org/xpl/login.jsp? tp=&arnumber=5990687&url=http%3A%2F%2Fieeexplore.ieee. org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5990687 ๏ http://www.slideshare.net/afkham_azeez/java-colombo-developing- highly-scalable-apps - Azeez’s talk at Java Colombo
- 43. * DISCUSSION
- 44. * Thanks!