Memory Monitoring in a Multi-tenant OSGi Execution Environment

International audienceSmart Home market players aim to deploy component-based and service-oriented applications from untrusted third party providers on a single OSGi execution environment. This creates the risk of resource abuse by buggy and malicious applications, which raises the need for resource monitoring mechanisms. Existing resource monitoring solutions either are too intrusive or fail to identify the relevant resource consumer in numerous multi-tenant situations. This paper proposes a system to monitor the memory consumed by each tenant, while allowing them to continue communicating di-rectly to render services. We propose a solution based on a list of configurable resource accounting rules between tenants, which is far less intrusive than existing OSGi monitoring sys-tems. We modified an experimental Java Virtual Machine in order to provide the memory monitoring features for the multi-tenant OSGi environment. Our evaluation of the mem-ory monitoring mechanism on the DaCapo benchmarks shows an overhead below 46%

Challenges for the comprehensive management of cloud services in a PaaS framework

The 4CaaSt project aims at developing a PaaS framework that enables flexible definition, marketing, deployment and management of Cloud-based services and applications. The major innovations proposed by 4CaaSt are the blueprint and its lifecycle management, a one stop shop for Cloud services and a PaaS level resource management featuring elasticity. 4CaaSt also provides a portfolio of ready to use Cloud native services and Cloud-aware immigrant technologies

SLA-Driven Simulation of Multi-Tenant Scalable Cloud-Distributed Enterprise Information Systems

Cloud Computing is an enabler for delivering large-scale, distributed enterprise applications with strict requirements in terms of performance. It is often the case that such applications have complex scaling and Service Level Agreement (SLA) management requirements. In this paper we present a simulation approach for validating and comparing SLA-aware scaling policies using the CloudSim simulator, using data from an actual Distributed Enterprise Information System (dEIS). We extend CloudSim with concurrent and multi-tenant task simulation capabilities. We then show how different scaling policies can be used for simulating multiple dEIS applications. We present multiple experiments depicting the impact of VM scaling on both datacenter energy consumption and dEIS performance indicators

Extending an open source enterprise service bus for cloud data access support

In the last years Cloud computing has become popular among IT organizations aiming to reduce its operational costs. Applications can be designed to be run on the Cloud, and utilize its technologies, or can be partially or totally migrated to the Cloud. The application's architecture contains three layers: presentation, business logic, and data layer. The presentation layer provides a user friendly interface, and acts as intermediary between the user and the application logic. The business logic separates the business logic from the underlaying layers of the application. The Data Layer (DL) abstracts the underlaying database storage system from the business layer. It is responsible for storing the application's data. The DL is divided into two sublayers: Data Access Layer (DAL), and Database Layer (DBL). The former provides the abstraction to the business layer of the database operations, while the latter is responsible for the data persistency, and manipulation. When migrating an application to the Cloud, it can be fully or partially migrated. Each application layer can be hosted using different Cloud deployment models. Possible Cloud deployment models are: Private Cloud, Public Cloud, Community Cloud, and Hybrid Cloud. In this diploma thesis we focus on the database layer, which is one of the most expensive layers to build and maintain in an IT infrastructure. Application data is typically moved to the Cloud because of , e. g. Cloud bursting, data analysis, or backup and archiving. Currently, there is little support and guidance how to enable appropriate data access to the Cloud. In this diploma thesis the we extend an Open Source Enterprise Service Bus to provide support for enabling transparent data access in the Cloud. After a research in the different protocols used by the Cloud providers to manage and store data, we design and implement the needed components in the Enterprise Service Bus to provide the user transparent access to his data previously migrated to the Cloud

Integration of different aspects of multi-tenancy in an open source enterprise service bus

The EU project 4CaaSt aims to create an advance PaaS Cloud platform which supports the optimized and elastic hosting of composite Internet-scale multi-tier applications. Cloud computing is essentially changing the way services are built, provided and consumed. Nowadays applications are composed out of multiple reusable services consisting of newly developed services as well as legacy applications made available as services. These services do not necessarily use the same protocols for communication. So a component for the mediation between various protocols, dynamic service selection and routing based on non-functional requirements is needed. Nowadays an Enterprise Service Bus (ESB) is used in Service-Oriented Architectures (SOAs) to serve precisely these objectives. One important aspect of bringing an ESB as building block into the Cloud is to enable multi-tenancy. This includes multi-tenant aware management and administration of the ESB as well as multi-tenant aware messaging. In this student thesis we design and implement the extensions of the ESB and the components needed for the integration and evaluation of two approaches to extend an open source ESB for multi-tenancy support: the first covers the multi-tenant aware administration and management and the second covers the multi-tenant aware messaging. Both approaches require the extension of the ESB, which implements the Java Business Integration (JBI). As a result, we provide an integrated prototype based on a scenario emerged from the EU project 4CaaSt and a performance's evaluation of the extended JBI Components in the ESB

Extending an open source enterprise service bus for PostgreSQL statement transformation to enable cloud data access

Cloud computing has enabled a new era in the IT industry and many organizations are interested in moving their business operations to the Cloud. This can be realized by designing new applications that follow the prerequisites of the Cloud provider or just by migrating the existing applications to the Cloud. Each application follows a multi-layered architecture defined by its design approach. Application data is of utmost importance and it is managed by the data layer, which is further divided into two sublayers, the Data Access Layer (DAL) and the Database Layer (DBL). The former abstracts the data access functionality and the latter ensures data persistence and data manipulation. Application migration to the Cloud can be achieved by migrating all layers it consists of or only part of them. In many situations it is chosen to move only the DBL to the Cloud and keep the other layers on-premise. Most preferably, the migration of the DBL should be transparent to the upper layers of the application, so that the effort and the cost of the migration, especially concerning application refactoring, becomes minimal. In this thesis, an open source Enterprise Service Bus (ESB), able to provide multi-tenant and transparent data access to the Cloud, is extended with PostgreSQL transformation functionality. Previously the ESB could only support MySQL source databases. After the integration of two new components, a PostgreSQL proxy and a PostgreSQL transformer, we provide support for PostgreSQL source databases and dialects. Furthermore, we validate and evaluate our approach based on the TPC-H benchmark, in order to ensure results based on realistic SQL statements and appropriate example data. We show linear time complexity, O(n) of the developed PostgreSQL transformer

Enabling horizontal scalability in an open source enterprise services bus

Cloud computing is a recent paradigm which describes a new way of consuming and delivering IT Services. In the Platform as a Service (PaaS) model, an underlying infrastructure such as network, operative system or server is provided to the Cloud consumers for either deploying their own applications, or applications supplied by the Cloud provider. In effect, Cloud computing modifies how applications should be built, provided, and consumed, as they may provide or be totally exposed as services, or consume existing third party applications services. The main advantages in Cloud computing are related to dynamic scaling of resources which are able to adapt to changes based on demand of resources and the use of multi-tenancy techniques in order based on sharing of resources between different users towards achieving the economy of scale. The Enterprise Service Bus (ESB) is essential as an integration middleware between application and services within and between multiple Cloud infrastructures. Different communication protocols might be used by application services and it is therefore necessary to have a mediator between them. Several challenges might arise when using an ESB as communication mediator between applications in cloud when to scale in and scale out to optimize resource consumption. The number of ESB instances should vary depending on the load in the Cloud infrastructure. This can be achieved by dynamically scaling in and out multiple ESB instances which constitute the horizontal ESB cluster. In this Master Thesis we focus on enabling horizontal scalability support for an open source multi-tenant aware Enterprise Service Bus (ESB). The investigation is based on two possible scenarios for enabling horizontal scalability: interconnected vs. non interconnected ESB instances. Therefore, in this work we investigate their advantages, disadvantages, and possible challenges and solutions. Based on previous investigations, a realization approach for enabling multi-instance management of a multi-tenant aware ESB is provided

An Autonomic Cross-Platform Operating Environment for On-Demand Internet Computing

The Internet has evolved into a global and ubiquitous communication medium interconnecting powerful application servers, diverse desktop computers and mobile notebooks. Along with recent developments in computer technology, such as the convergence of computing and communication devices, the way how people use computers and the Internet has changed people´s working habits and has led to new application scenarios. On the one hand, pervasive computing, ubiquitous computing and nomadic computing become more and more important since different computing devices like PDAs and notebooks may be used concurrently and alternately, e.g. while the user is on the move. On the other hand, the ubiquitous availability and pervasive interconnection of computing systems have fostered various trends towards the dynamic utilization and spontaneous collaboration of available remote computing resources, which are addressed by approaches like utility computing, grid computing, cloud computing and public computing. From a general point of view, the common objective of this development is the use of Internet applications on demand, i.e. applications that are not installed in advance by a platform administrator but are dynamically deployed and run as they are requested by the application user. The heterogeneous and unmanaged nature of the Internet represents a major challenge for the on demand use of custom Internet applications across heterogeneous hardware platforms, operating systems and network environments. Promising remedies are autonomic computing systems that are supposed to maintain themselves without particular user or application intervention. In this thesis, an Autonomic Cross-Platform Operating Environment (ACOE) is presented that supports On Demand Internet Computing (ODIC), such as dynamic application composition and ad hoc execution migration. The approach is based on an integration middleware called crossware that does not replace existing middleware but operates as a self-managing mediator between diverse application requirements and heterogeneous platform configurations. A Java implementation of the Crossware Development Kit (XDK) is presented, followed by the description of the On Demand Internet Computing System (ODIX). The feasibility of the approach is shown by the implementation of an Internet Application Workbench, an Internet Application Factory and an Internet Peer Federation. They illustrate the use of ODIX to support local, remote and distributed ODIC, respectively. Finally, the suitability of the approach is discussed with respect to the support of ODIC

Using Infrastructure as Code for Web Application Disaster Recovery

Legacy, industry established disaster recovery approaches are known for impeding a relatively high additional expenditure, thus limiting the usage of such mechanisms only to the most business-critical IT systems and applications. However, with the emergence of Infrastructure-as-Code practices, this paradigm can now be challenged. The objective of this thesis is to design and implement a novel disaster recovery tool, that can be used for the recovery of a web application. By following the design science methodology, this thesis proposes a primary-fallback oriented disaster recovery model, where the fallback site of the infrastructure is an empty cloud service account, into which a near duplicate copy of the primary site is recreated in the event of a disaster. The proposed recovery process consists of two phases, where the 2nd phase stateful application data recovery procedure is kept as an add-on functionality to the 1st phase stateless infrastructure management practices. For switching from primary to fallback site, the design proposes a DNS failover mechanism, whereby modifying the DNS A-record associations of the Public IP address during the start of the recovery process, traffic can be directed to the recovered site with a minimal delay. Based on the insights and data gathered during and after the evaluation phase of the proposed design, the tool created with Ansible and Terraform was found to be functional, performant and cost efficient within the known limits and expectations set by legacy disaster recovery practices