Migrating Legacy Systems to Cloud Environments: A Case Study. Hong Wu Laboratory of Internet Technologies, Institute of Software, CAS

Transcription

1 Migrating Legacy Systems to Cloud Environments: A Case Study Hong Wu Laboratory of Internet Technologies, Institute of Software, CAS

2 Outline Introduction Case Study QONE Migration Future Work

3 Outline Introduction Background Migrating Legacy Systems to the Cloud Case Study QONE Migration Future Work

4 Background Legacy Systems Antiquated systems but have a serious effect on the day-today running of the business Legacy System Evolution/Crisis Outdated technology High maintenance costs Hard to embrace new needs.. Dismantling or Modernizing legacy systems?

5 Background (cont d) Cloud Computing leads new trends Shifting from client/server-based systems to the cloud New business models Software transform to Service Advantages of Cloud Computing Large economies of scale Save up-front purchase Elasticity Deal with burst of loads Migrating legacy systems to cloud environments

6 Migrating Legacy Systems to the Cloud We seek to better understand the software engineering process issues in migrating (Browser/Server structure based) legacy systems to the cloud Where to start? What tasks to carry out? How much effort is required? How to manage the overall process?

7 Outline Introduction Case Study QONE Migration QONE Overview Migration Process Summary Future Work

8 QONE Overview Software platform for project and process management In compliance with ISO9000/CMMI Main features Software project management Software measurement and analysis Organizational asset management System management More than 300 industry organizations More than 5 major releases, 10 minor releases since 2007 Browser/Server structure, MVC design pattern based on SSH, J2EE standards Shanxi Sichuan Henan Yunnan Hunan Beijing Hebei Guangxi Tianjin Hong Kong Guangdong Jiangsu Shanghai Fujian Liaoning Shandong Zhejiang

9 Motivations Problems Elastic capacity is required to meet ever-changing business needs Performance problems arise when the number of simultaneous accesses increases Leverage the cloud computing technologies to provide software process management services Elastic for business variability Multi-tenancy Self-service Reducing costs

10 Migration Process Migration Strategy Making Cloud Environments Construction QONE Migration Performance Testing According to Gatner, there re five options of migrating applications to cloud environments: rehost on infrastructure as a service (IaaS) refactor for platform as a service (PaaS) revise for IaaS or PaaS rebuild on PaaS replace with software as a service (SaaS) Our considerations: To minimize the changes on the legcy system (less efforts) No budget for commercial cloud platforms (less cost)

11 Migration Process (cont d) Migration Strategy Making Cloud Environments Construction QONE Migration Performance Testing Eucalyptus

12 Migration Process (cont d) Migration Strategy Making Cloud Environments Construction QONE Migration Performance Testing Create VM image CentOS linux Deploy QONE runtime environments Java runtime environment; Application server (Tomcat) Deploy QONE application install QONE in the VM image database is created separatly on a database server database connection is reconfigured

13 Migration Process (cont d) Service Setup Process Create a vm instance for one tenant Create a (logical) database and set up database configration for the tenant Start QONE in the vm instance The tenant can access the QONE application via selfservice portal

14 Migration Process (cont d) Migration Strategy Making Cloud Environments Construction 50% performance degradation QONE Migration Performance Testing Resources load is not very high in both environments of VM and PM Performance Metrics Environment No. of concurrent users Average response time Transactions per second Application Server Resources Load Database Server Linux OS Virtual Machine Physical Machine 50 (per instance) 100 (per machine) s s 4.24 CPU < 40% Memory < 40% Disk I/O < 5% CPU<80% Memory<45% Disk I/O<5% CPU < 30% Memory < 50% Disk I/O < 20% CPU<40% Memory<50% Disk I/O<20% Windows OS Physical Machine 100 (per machine) 2.08 s 4.85 CPU<85% Memory<55% Disk I/O<8% CPU<60% Memory<80% Disk I/O<60% Testing tool: LoadRunner Using same resources for each vm instance and physical machine respectively: 4*2.6Hz CPU, 3GB Memory, 20G Disk 100Mbps LAN, Linux Qone applications running on different OS have slight performance differences

15 Summary Based on the first step of cloud adoption, the legacy system reaps the benefits from the cloud No upfront investment in setting up and running infrastructure by customers Self-service portal Ongoing Work SLA-based dynamic resource scheduling on Eucalyptus platform: To supprt dynamic resrouce provision (scale up and down) to deploy and maintain QONE application for different customers according to their variable business needs To improve resource utilization so that the infrastructure can serve more custormers

16 Outline Introduction Case Study QONE Migration Future Work Cloud Migration Process Framework

17 Future Work Cloud Migration Process Framework Cloud Migration Process Framework of Legacy Systems Process Measurement Model G Q1 Q2 M1 M2 M3 M4 Cloud Migration Process Model Business Subprocess Process Model Technical Subprocess Organizationa l Subprocess Process Risk Management Model Soluti on Analy sis Identifi cation Monit oring Cloud Migration Process Management Platform

18 Thank You! Q&A Hong Wu PhD Candidate in Software Engineering