Performance and Scalability of EJB Applications

Emmanuel Cecchet, Willy Zwaenepoel
2002
Article de conférence

Résumé

We investigate the combined effect of application implementation method, container design, and efficiency of communication layers on the performance scalability of J2EE application servers by detailed measurement and profiling of an auction site server. We have implemented five versions of the auction site. The first version uses stateless session beans, making only minimal use of the services provided by the Enterprise JavaBeans (EJB) container. Two versions use entity beans, one with containermanaged persistence and the other with bean-managed persistence. The fourth version applies the session façade pattern, using session beans as a façade to access entity beans. The last version uses EJB 2.0 local interfaces with the session façade pattern. We evaluate these different implementations on two popular open-source EJB containers with orthogonal designs. JBoss uses dynamic proxies to generate the container classes at run time, making an extensive use of reflection. JOnAS precompiles classes during deployment, minimizing the use of reflection at run time. We also evaluate the communication optimizations provided by each of these EJB containers. The most important factor in determining performance is the application implementation method. EJB applications with session beans perform as well as a Java servlets-only implementation and an order-of-magnitude better than most of the implementations based on entity beans. The fine-granularity access exposed by the entity beans limits scalability. Use of session façade beans improves performance for entity beans, but only if local communication is very efficient or EJB 2.0 local interfaces are used. Otherwise, session façade beans degrade performance. For the implementation using session beans, communication cost forms the major component of the execution time on the EJB server. The design of the container has little effect on performance. With entity beans, the design of the container becomes important. In particular, the cost of reflection affects performance. For implementations using session façade beans, local communication cost is critically important. EJB 2.0 local interfaces improve the performance by avoiding the communication layers for local communications.

Official source

https://infoscience.epfl.ch/record/55718?ln=fr

À propos de ce résultat

Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.

Concepts associés

Chargement

Publications associées

Chargement

Emmanuel Cecchet, Willy Zwaenepoel
2002
Article de conférence

Résumé

Official source

https://infoscience.epfl.ch/record/55718?ln=fr

À propos de ce résultat

Concepts associés (10)

Concepts associés

Chargement

Publications associées (5)

Publications associées

Chargement

Specification and Implementation of Dynamic Web Site Benchmarks

Emmanuel Cecchet, Sameh Mohamed Elnikety, Willy Zwaenepoel

The absence of benchmarks for Web sites with dynamic content has been a major impediment to research in this area. We describe three benchmarks for evaluating the performance of Web sites with dynamic content. The benchmarks model three common types of dynamic content Web sites with widely varying application characteristics: an online bookstore, an auction site, and a bulletin board. For the online bookstore, we use the TPCW specification. For the auction site and the bulletin board, we provide our own specification, modeled after ebay.com and slahdot.org, respectively. For each benchmark we describe the design of the database and the interactions provided by the Web server. We have implemented these three benchmarks with a variety of methods for building dynamic-content applications, including PHP, Java servlets and EJB (Enterprise Java Beans). In all cases, we use commonly used open-source software. We also provide a client emulator that allows a dynamic content Web server to be driven with various workloads. Our implementations are available freely from our Web site for other researchers to use. These benchmarks can be used for research in dynamic Web and application server design. In this paper, we provide one example of such possible use, namely discovering the bottlenecks for applications in a particular server configuration. Other possible uses include studies of clustering and caching for dynamic content, comparison of different application implementation methods, and studying the effect of different workload characteristics on the performance of servers. With these benchmarks we hope to provide a common reference point for studies in these areas.

2002

Chargement

Performance Comparison of Middleware Architectures for Generating Dynamic Web Content

Emmanuel Cecchet, Sameh Mohamed Elnikety, Willy Zwaenepoel

On-line services are making increasing use of dynamically generated Web content. Serving dynamic content is more complex than serving static content. Besides a Web server, it typically involves a server-side application and a database to generate and store the dynamic content. A number of standard mechanisms have evolved to generate dynamic content. We evaluate three specific mechanisms in common use: PHP, Java servlets, and Enterprise Java Beans (EJB). These mechanisms represent three different architectures for generating dynamic content. PHP scripts are tied to the Web server and require writing explicit database queries. Java servlets execute in a different process from the Web server, allowing them to be located on a separate machine for better load balancing. The database queries are written explicitly, as in PHP, but in certain circumstances the Java synchronization primitives can be used to perform locking, reducing database lock contention and the amount of communication between servlets and the database. Enterprise Java Beans (EJB) provide several services and facilities. In particular, many of the database queries can be generated automatically. We measure the performance of these three architectures using two application benchmarks: an online bookstore and an auction site. These benchmarks represent common applications for dynamic content and stress different parts of a dynamic content Web server. The auction site stresses the server front-end, while the online bookstore stresses the server back-end. For all measurements, we use widely available open-source software (the Apache Web server, Tomcat servlet engine, JOnAS EJB server, and MySQL relational database). While Java servlets are less efficient than PHP, their ability to execute on a different machine from the Web server and their ability to perform synchronization leads to better performance when the front-end is the bottleneck or when there is database lock contention. EJB facilities and services come at the cost of lower performance than both PHP and Java servlets.

2003

Chargement

, ,

Linearizability is a key design methodology for reasoning about implementations of concurrent abstract data types in both shared memory and message passing systems. It provides the illusion that operations execute sequentially and fault-free, despite the asynchrony and faults inherent to a concurrent system, especially a distributed one. A key property of linearizability is inter-object composability: implementations of linearizable objects can be composed into more complex linearizable objects. However, devising complete linearizable objects is very difficult requiring complex algorithms to work correctly under general circumstances, and often resulting in bad average-case behavior. Concurrent algorithm designers therefore resort to speculation, namely optimizing algorithms to handle common scenarios more efficiently. Unfortunately, the outcome are even more complex protocols, for which it is no longer tractable to prove their correctness. To simplify the design of efficient yet robust linearizable protocols, we propose a new notion: speculative linarizability. This property is as general as linearizability, yet it allows intra-object composability, namely proving multiple protocol phases separately. In particular, it allows the designer to focus solely on the proof of an optimization and derive the correctness of the overall protocol from the correctness of the existing, non-optimized one. Our notion of protocol phases allows processes to independently switch from one phase to another, without requiring them to reach agreement to determine the change of a phase. To illustrate the applicability of our methodology, we show how examples of speculative algorithms for shared memory and asynchronous message passing naturally fit into our framework. We rigorously define speculative linearizability and prove our intra-object composition theorem in its trace-based as well as its mechanically checked automaton-based versions in an Isabelle I/O automata framework. This framework enables for the first time scalable specifications and mechanical proofs of speculative implementations of linearizable objects.

2011

Chargement

Performance Comparison of Middleware Architectures for Generating Dynamic Web Content

Emmanuel Cecchet, Sameh Mohamed Elnikety, Willy Zwaenepoel

2003

, ,

2011