Migration of an On-Premise Single-Tenant Enterprise Application to the Azure Cloud: The Multi-Tenancy Case Study

Kokkuvõte Pilvearvutuse edu muudab radikaalselt tavasid kuidas edaspidi infotehnoloogia teenuseid arendatakse, juurutatakse ja hallatakse. Sellest tulenevalt on sõnakõlks „pilve migratsioon“ vägagi aktuaalne paljudes ettevõtetes. Tänu sellele tehnoloogiale on paljud suured ja väikesed ettevõtted huvitatud enda tarkvara, andmebaasi süsteemide ja infrastruktuuri üleviimisest pilve keskkonda. Olemasolevate süsteemide migreerimine pilve võib vähendada kulutusi, mis on seotud vajamineva riistvara, tarkvara paigaldamise ning litsentseerimisega ja samuti selle kõige haldamiseks vajaminevate inimeste palkamisega. Rakenduse ja selle andmete hoidmine pilves, mis teenindab mitmeid üürnike (ik. tenants) võib osutuda kalliks kui ei kasutada jagatud lähenemist üürnike vahel. Sellest tulenevalt on teadlikult disainitud rakenduse ning andme arhitektuur äärmiselt oluline organisatsioonile, mis kasutab mitme-üürniku (ik. multi-tenant) lähenemist. Käesolevas magistritöös kirjeldatakse juhtumiuuringut (ik. case study) ning saadud kogemusi eraldiseiseva majasiseselt paigaldatava rakenduse migreerimisel Azure pilve keskkonda. Töö kirjeldab juristidele mõeldud tootlikkuse mõõtmise tarkvara andmekihi migreerimist Azure pilvekeskkonda. Majasisese ühe tarbijaga tarkvara andmekihi üleviimine efektiivsele mitme-üürniku andmekandja süsteemi pilve keskkonnas nõuab lisaks ka kõrgetasemelise autentimis-mehhanismi disainimist ning realiseerimist. Töö põhirõhk on turvalise skaleeruva ning mitme-üürniku efektiivse andmekandja süsteemi arhitektuuri disainimine ning realiseerimine pilve-keskkonda. Projektis kasutatakse SQL Database’i (endine SQL Azure) poolt pakutavat sisse ehitatud võimekust (SQL Federations) selleks, et tagada turvaline andmete eraldatus erinevate üürnike vahel ja andmebaasi skaleeruvus. Tarkvara andmekihi migreerimine pilve keskkonda toob kaasa kulude vähenemis, mis on seotud tarkvara tarnimisega, paigaldamise ning haldamisega. Lisaks aitab see ettevõttel laieneda uutele turgudele, mis enne migreerimist oli takistatud kohapeal teostava tarkvara paigaldamisega. Tänu pilves olevale andmekihile nõuab uuele kliendile süsteemi paigaldamine väga väikest kulutust.The success of cloud computing is changing the way how information technology services are developed, deployed, maintained and scaled. This makes the ‘migration to the cloud’ a buzzword in the industry for most of the enterprises today. Observing so many advantages of this phenomenon technology, enterprises from small to large scales are interested in migrating their software applications, database systems or infrastructures to cloud scale solutions. Migrating existing systems to a cloud scale solution can reduce the expenses related to costs of the necessary hardware for servers, installation of the operating system environment, license costs of the operating system and database products, deployment of the database products and hiring professional staff for keeping the system up and running. However, storing the application data to a back-end that serves multiple tenants on the cloud will be also costly if the resources on the cloud platform are not shared fairly among tenants. Thus, a carefully designed multi-tenant architecture is essential for an organization that serves multiple tenants. In this master thesis, we will describe a case study and lessons learned on the migration of an enterprise application from an on-premise deployment backend to the Azure Cloud. More specifically, the thesis describes the migration of a productivity tool specialized for legal professionals to a multi-tenant data storage back-ends on Azure Cloud. Moving an on-premise, single-tenant software backend to a multi-tenant data storage system on the cloud will also require design and implementation of authentication mechanisms. The core focus of the work consists of the design and implementation of a secure, scalable and multi-tenant efficient data storage system and application architecture on the cloud. SQL Database (formerly SQL Azure) offers native features (SQL Federations) for the secure isolation of the data among tenants and database scalability which has been used inside the project. Furthermore, the basic application authentication mechanism is enhanced with identity providers such as Google Account and Windows Live ID by embedding native functionality of Windows Azure called Azure Access Control Service to the login mechanism. Migration of the software backend to a cloud scale solution is expected to reduce the costs related to delivery, deployment, maintenance and operation of the software for the business. Furthermore, it will help the business to target new markets since it is a cloud based solution and requires very little initial effort to deliver the software to the new customers

Securing multi-tenancy systems through multi DB instances and multiple databases on different physical servers

Use of the same application by multiple users through internet as a service is supported by cloud computing system. Both the user and attacker stay in the same machine as both of them are users of the same application creating an in-secure environment. Service must ensure secrecy both at the application and data layer level. Data isolation and Application isolation are two basic aspects that must be ensured to cater for security as desired by the clients that accesses the service. In this paper a more secured mechanism has been presented that help ensuring data isolation and security when Multi-tenancy of the users to the same service has been implemented

A Survey of Security and Privacy Challenges in Cloud Computing: Solutions and Future Directions

While cloud computing is gaining popularity, diverse security and privacy issues are emerging that hinder the rapid adoption of this new computing paradigm. And the development of defensive solutions is lagging behind. To ensure a secure and trustworthy cloud environment it is essential to identify the limitations of existing solutions and envision directions for future research. In this paper, we have surveyed critical security and privacy challenges in cloud computing, categorized diverse existing solutions, compared their strengths and limitations, and envisioned future research directions

A Review Of Multi-Tenant Database And Factors That Influence Its Adoption.

A Multi-tenant database (MTD) is a way of deploying a Database as a Service (DaaS). This is gaining momentum with significant increase in the number of organizations ready to take advantage of the technology. A multi-tenant database refers to a principle where a single instance of a Database Management System (DBMS) runs on a server, serving multiple clients organizations (tenants). This is a database which provides database support to a number of separate and distinct groups of users or tenants. This concept spreads the cost of hardware, software and other services to a large number of tenants, therefore significantly reducing per tenant cost. Three different approaches of implementing multi-tenant database have been identified. These methods have been shown to be increasingly better at pooling resources and also processing administrative operations in bulk. This paper reports the requirement of multi-tenant databases, challenges of implementing MTD, database migration for elasticity in MTD and factors influencing the choice of models in MTD. An insightful discussion is presented in this paper by grouping these factors into four categories. This shows that the degree of tenancy is an influence to the approach to be adopted and the capital and operational expenditure are greatly reduced in comparison with an on-premises solutio