Implementing Infopipes: The SIP/XIP Experiment

We describe an implementation of the Infopipe abstraction for information flow applications. We have implemented software tools that translate the SIP/XIP variant of Infopipe specification into executable code. These tools are evaluated through the rewriting of two realistic applications using Infopipes: a multimedia streaming program and a web source combination application. Measurements show that Infopipe-generated code has the same execution overhead as the manually written original version. Source code of Infopipe version is reduced by 36% to 85% compared to the original

Clearwater: Extensible, Flexible, Modular Code Generation

International audienceDistributed applications typically interact with a number of heterogeneous and autonomous components that evolve independently. Methodical development of such applications can benefit from approaches based on domain-specific languages (DSLs). However, the evolution and customization of heterogeneous components introduces significant challenges to accommodating the syntax and semantics of a DSL in addition to the heterogeneous platforms on which they must run. In this paper, we address the challenge of implementing code generators for two such DSLs that are flexible (resilient to changes in generators or input formats), extensible (able to support multiple output targets and multiple input variants), and modular (generated code can be rewritten). Our approach, Clearwater, leverages XML and XSLT standards: XML supports extensibility and mutability for inprogress specification formats, and XSLT provides flexibility and extensibility for multiple target languages. Modularity arises from using XML meta-tags in the code generator itself, which supports controlled addition, subtraction, or replacement to the generated code via XML-weaving. We discuss the use of our approach and show its advantages in two non-trivial code generators: the Infopipe Stub Generator (ISG) to support distributed flow applications, and the Automated Composable Code Translator to support automated distributed application deployment. As an example, the ISG accepts as input an XML description and generates output for C, C++, or Java using a number of communications platforms such as sockets and publish-subscribe

Clearwater: An Extensible, Pliable, and Customizable Approach to Code Generation

Since the advent of RPC Stub Generator, software tools that translate a high level specification into executable programs have been instrumental in facilitating the development of distributed software systems. Developers write programs at a high level abstraction with high readability and reduced initial development cost. However, existing approaches to building code generation tools for such systems have difficulties evolving these tools to meet challenges of new standards, new platforms and languages, or changing product scopes, resulting in generator tools with limited lifespan. The difficulties in evolving generator tools can be characterized as a combination of three challenges that appear inherently difficult to solve simultaneously: the abstraction mapping challenge translating a high-level abstraction into a low-level implementation), the interoperable heterogeneity challenge stemming from multiple input and output formats, and the flexible customization challenge to extend base functionality for evolution or new applications. The Clearwater approach to code generation uses XML-based technologies and software tools to resolve these three challenges with three important code generation features: specification extensibility, whereby an existing specification format can accommodate extensions or variations at low cost; generator pliability, which allows the generator to operator on an extensible specification and/or support multiple and new platforms; and flexible customization, which allows an application developer to make controlled changes to the output of a code generator to support application-specific goals. The presentation will outline the Clearwater approach and apply it to meet the above three challenges in two domain areas. The first area is information flow applications (e.g., multimedia streaming and event processing), a horizontal domain in which the ISG code generator creates QoS-customized communication code using the Infopipe abstraction and specification language. The second area is enterprise application staging (e.g., complex N-tier distributed applications), a vertical domain in which the Mulini code generator creates multiple types of source code supporting automatic staging of distributed heterogeneous applications in a data center environment. The success of applying Clearwater to these domains shows the effectiveness of our approach.Ph.D.Committee Chair: Calton Pu; Committee Member: Donald F. Ferguson; Committee Member: Karsten Schwan; Committee Member: Ling Liu; Committee Member: Olin Shiver

Code generation for WSLAs using AXpect

WSLAs can be viewed as describing the service aspect of web services. By their nature, web services are distributed. Therefore, integrating support code into a web service application is potentially costly and error prone. Viewed from this AOP perspective, then, we present a method for integrating WSLAs into code generation using the AXpect weaver, the AOP technology for Infopipes. This helps to localize the code physically and therefore increase the eventual maintainability and enhance the reuse of the WSLA code. We then illustrate the weavers capability by using a WSLA document to codify constraints and metrics for a streaming image application that requires CPU resource monitoring

Automated staging for built-to-order application systems

automation, utility computing, staging, TPC-W, benchmark, e-commerce The increasing complexity of enterprise and distributed systems accompanying a move to grid and utility computing demands automated design, testing, deployment and monitoring of applications. In this paper, we present the Elba project and Mulini generator. The goal of Elba is creating automated staging and testing of complex enterprise systems before deployment to production. Automating the staging process lowers the cost of testing applications. Feedback from staging, especially when coupled with appropriate resource costs, can be used to ensure correct functionality and provisioning for the application. The Elba project extracts test parameters from production specifications, such as SLAs, and deployment specifications, and via the Mulini generator, creates staging plans for the application. We then demonstrate Mulini on an example application, TPC-W, and show how information from automated staging and monitoring allows us to refine application deployments easily based on performance and cost

Detecting bottleneck in n-Tier IT applications through analysis

Abstract. As the complexity of large-scale enterprise applications increases, providing performance verification through staging becomes an important part of reducing business risks associated with violating sophisticated service-level agreement (SLA). Currently, performance verification during the staging process is accomplished through either an expensive, cumbersome manual approach or ad hoc automation. This paper describes an automation approach as part of the Elba project supporting monitoring and performance analysis of distributed multi-tiered applications that helps in bottleneck detection. We use machinelearning to determine service-level objectives (SLOs) satisfaction and locate bottlenecks in candidate deployment scenarios. We evaluate our tools with TPC-W, an on-line bookstore, and RUBiS, an on-line auction site