Welcome!

Java IoT Authors: Liz McMillan, Elizabeth White, Yeshim Deniz, Tim Hinds, Douglas Lyon

Related Topics: Java IoT

Java IoT: Article

Optimizing Database Performance in J2EE Applications

Optimizing Database Performance in J2EE Applications

The Java 2 Platform, Enterprise Edition (J2EE), is the platform of choice for implementing scalable and reliable enterprise applications from reusable components. But Java developers building enterprise-class J2EE applications face a quandary.

The object paradigm has proven ideal for modeling a wide variety of real-world scenarios. However, finding a Java-compatible data repository optimized for such applications has become a stumbling block. While object database management systems (ODBMSs) provide the convenience of transparent persistence of Java objects, their client-centric architecture has not scaled well in enterprise environments. Relational database management systems (RDBMSs) do scale well, but map each object to a two-dimensional relational table. The increased overhead can reduce application performance to a crawl.

This article discusses the limits of using these two types of databases with Java and suggests a better alternative for J2EE - a hybrid database that combines the best features of both. Hybrid databases share with ODBMSs the ability to map data stored in back-end databases directly into an implementation-neutral Java representation. As with relational systems, hybrid databases can scale to meet the performance requirements of an enterprise-class J2EE application.

ODBMSs: The Hidden Headache of Transparent Persistence
Over the years, finding a database that's both Java-compatible and scalable enough for enterprise-class J2EE applications has not been easy. Ideally, a Java-compatible database should store Java objects whose classes have been declared "persistent-capable" and can be manipulated seamlessly by the Java language.

That has been the promise of ODBMSs, which made their appearance in the mid-1990s as a solution designed specifically for objects and thus better suited for object development. With ODBMSs, Java developers can define persistent Java classes in the same way transient Java classes are defined in the application.

An apparent advantage of pure object databases is the implementation of transparent persistence that automates the process of mapping persistent data objects into the data repository. With transparent persistence, you don't even have to alter your existing Java classes to describe the persistent data that's permanently stored in the database (see Listing 1). That means you don't have to decide ahead of time, usually during the design phase, which objects to include and exclude from the database.

Adding a new customer order into the database is as simple as creating a new object in Java. Persistent-capable objects are transient until attached to a persistent manager or to other persistent objects.

This convenience quickly becomes a nightmare, however, when developing scalable enterprise-class applications. In a typical application, objects are highly interconnected, and it's very important to know precisely which objects have been stored with the database and which have not. Consider an e-commerce application in which products, customers, and orders are all linked together (see Figure 1). The object model naturally captures the interrelationships of real-world applications. With transparent persistence, you wind up loading an entire closure of objects even though you want to access only a single object (see Figure 2). While the programmer wants to load only one customer, the closure of instances reachable from this object recursively loads a large portion of the database. Loading unneeded data in the Java VM limits concurrency and scalability.

A simple customer query, for example, could also lock pending orders and products purchased, even though this data was not requested and will remain unchanged. Such "overloading" is not a noticeable problem within a standalone environment that manipulates a small amount of data. However, in an enterprise-class, multiuser, transaction-intensive application, large portions of data get locked and instantiated, limiting concurrency and scalability.

During the pilot phase of development, performance is usually acceptable since the system is not running under heavy computational loads. But with wider deployment and more users, transaction rates can slow unacceptably as a massive amount of data - much of it unneeded - fills the pipeline. In the end, transparent persistence leads to a performance black hole, requiring substantial work to improve scalability, increase concurrency, and reduce network traffic. To gain sufficient control over which objects stay persistent and which do not, the ODBMS's transparent persistence mechanism must be bypassed and the ODBMS's proprietary API used instead. Developers must master the ODBMS's proprietary API and then invest the many hours required for the complex, trial-and-error process, which has no guarantee of success.

The hard lesson, often learned at company expense, is that the ODBMS used to validate a pilot application must be replaced by a relational database when the system goes into production. That's the programming equivalent of a heart transplant, setting development schedules back by months. As we will see, relational databases bring their own set of problems in terms of overhead, and can require 25-50% more Java code.

RDBMSs: The Frustration of Object-Relational Mapping
Java developers are hindered by relational databases; however, RDBMSs do have two major advantages: a long, successful track record of deployment in scalable, transaction-processing systems and a standard language, SQL. While the relational model works well enough in banking applications where the row-and-column model reflects the two-dimensional world of ledgers and spreadsheets, it has proven more limited in tracking highly interconnected information. Relationship navigation commonly used in J2EE applications requires extensive use of multitable joins. But joins are computationally intensive, and each join is computed at runtime to link information on-the-fly (see Listing 2). Reconstructing an order object with its line items from row-and-column tables requires two SQL queries and much coding. The same operation in an object database would require only one call. Moreover, relational systems require the rebuilding of relationships between objects each time they're accessed, substantially impacting performance.

In today's economy where business intelligence is key, the Java object model provides a more powerful mechanism for capturing real-world relationships and concept commonalities. In the relational model the relationships disappear and are replaced by primary keys; foreign keys, columns, and indexes; and often by intermediate tables (see Figure 3).

In response to the demands from object developers, relational vendors have extended the relational model to support objects, much the way C++ was an object extension of C. But just as C programmers did not fully embrace C++, Java programmers have remained skeptical of object extensions to what is clearly not an object-oriented environment.

The underlying model of object-relational databases remains the same: rows and columns. As a result, the simplicity of the object model vanishes because classes, inheritance, and relationships must be mapped into tables - a structure ill-suited to the task. Even a simple many-to-many relationship between two classes must be expressed using intermediate tables, with two associated indexes. Therefore, a cleanly designed Java application translated through the normalization process results in a thicket of tables that must be recombined whenever an object is called by the application. The process adds significant load, especially when executing extensive table joins.

To solve the problem of mapping objects into relational databases, a number of OR mapping tools have been created. While these tools do make it easier to develop Java applications that use relational databases, they don't eliminate the underlying RDBMS problems of code complexity and poor performance.

Both database technologies have limitations for Java programming. A pure object database makes sense in a standalone environment in which concurrency and network traffic are not issues. Relational databases, while accommodating transaction-processing loads, merely simulate a true object environment.

Hybrid Databases: The Best of Both Worlds
Hybrid databases represent the best of both worlds: the ability to map objects from Java directly to the database with the support of a standard query language (SQL-99) and the scalable, enterprise capabilities implemented in relational database products. Designed from the ground up as a database server for objects, hybrid databases directly map the object model of Java as well as other object programming languages. Because the database object model matches perfectly with Java, you can freely and easily define the database classes that describe real-world scenarios.

Unlike an RDBMS, a hybrid database preserves the original Java data model. For example, a single class and two subclasses represent customers, consumers, and business customers, respectively. No tables are mapped back into Java objects; no translation of any kind is needed. Unlike an ODBMS, a hybrid database enforces a layered design of the persistent classes. The operations to manipulate objects are explicit, enabling you to keep tight control over the data that's locked and instantiated in the JVM, seamlessly improving the application's scalability.

Hybrid databases eliminate the mismatch between the Java and database environments, while still maintaining the scalability of server-side processing, such as relational systems. Within the J2EE environment, you manipulate Java objects representing a proxy to the object in the database by means of object-to-object mapping. The proxy objects are pure Java classes that map to those of the database schema (see Listing 3). With a hybrid database, the code stays compact and object-based (as in Listing 1), providing the same benefit as a first-generation ODBMS. Hybrid databases don't require any of the special compilation tricks or postprocessing byte code manipulations of ODBMSs - both of which make it hard to identify the root cause of performance degradation.

In a typical application, classes are highly interconnected, and the graph of instances can include large portions of the database. Therefore, controlling object-locking effectively, always a challenge in enterprise-class J2EE applications, is crucial to controlling the instantiation of Java objects in the JVM. To build scalable applications, data-intensive processing needs to take place where the data sits on the server, not on the client, further reducing locking contention as well as network traffic and taking advantage of the faster processing speeds of many server architectures.

Like RDBMSs, hybrid databases support the SQL-99 syntax. While SQL queries are relational in their syntax, they take advantage of the object paradigm by supporting inheritance, polymorphism, and true navigation. Furthermore, the query processing takes place on the server to enforce security and achieve performance. Consider a broad query of two classes of customers: business and consumer. The query is issued from the client, executed on the server, with selected objects from each class retrieved to the client.

This approach gives developers full access to Java objects through JDBC without having to learn a proprietary API (see Listing 4). In this listing, two customer subclasses, Consumer and Business, share properties from the parent Customer class while maintaining properties of their own. A query to locate "good customers" can combine criteria - bonus miles for home consumers, a high credit line for businesses - pulling the information simultaneously from both subclasses. Unlike an RDBMS, a hybrid database returns Java objects through JDBC and natively supports inheritance.

While developers still benefit from the power of expression and performance of SQL queries, these queries eliminate the object-relational mapping layer to reduce source code by 25-50% and improve application performance.

Unlike first-generation ODBMSs, hybrid databases can be accessed through JDBC and ODBC drivers, both of which support the SQL-99 language, thereby taking advantage of in-house SQL expertise. Support for ODBC and JDBC drivers also allows IT staff to use off-the-shelf database tools without having to master SQL.

First Major Optimization: Keep It Simple
Building enterprise-class J2EE applications with a hybrid database is straightforward. Here are some considerations to make the process even smoother:

  • Carefully define the object model of your persistent classes, reflecting the business model as closely as possible. That's common sense in an object environment, but is even more crucial in database applications because the way you define the model greatly impacts system performance.

    Defining the right level of granularity for your objects has a big payoff in terms of transaction rate because only the specific queried data gets locked.

  • Avoid cross-referencing persistent and transient objects as transient information can access persistent information, but not the other way around. Doing so makes the application much more complex to manage since the persistent objects loaded from the database may need to be linked to transient information that's not yet available. While a callback can also be used, it unnecessarily complicates program flow and can usually be avoided with more ordered layering of the application.
  • Keep transactions as short as possible. Long transactions will unnecessarily lock data for long periods of time, making it unavailable to other business transactions.
  • In some cases, data is cached by the middleware, reducing contention, but it requires "dirty reads" (reading data without locking) from the database. A way around this is to use a versioning facility, which allows a consistent view of the database any time, even while users are modifying the current version.

    Conclusion
    Hybrid databases give developers a new and important option when selecting a database for their J2EE application. Until now, Java developers have really had just one viable option: an RDBMS. Despite the drawbacks of the relational model, only RDBMSs solved the performance requirements intrinsic to enterprise applications. As for ODBMSs, they haven't even begun to meet these requirements. Without that, an adaptable object model is irrelevant to large-scale J2EE development.

    With hybrid databases, J2EE developers can demand both: a database that meets the intrinsic requirements of scalability, high transaction volumes, high-volume data transfer, and the need for fast throughput, together with an object data model that more accurately represents business processes, now and in the future.

    As the number of J2EE applications grows, the limitations of RDBMSs and ODBMSs will become more and more apparent. Hybrid databases represent the missing ingredient for broader J2EE implementation, providing scalability without compromising Java's object environment.

  • More Stories By Didier Cabannes

    Didier Cabannes, chief technology officer at Fresher Information, is the chief architect of the Matisse database, a hybrid database for object developers. For the past 15 years, he has been focused on object and database technology, and developing and deploying mission-critical object-based applications in a variety of environments. He holds a master degree in engineering and has conducted post-graduate research in computer science.

    Comments (16) View Comments

    Share your thoughts on this story.

    Add your comment
    You must be signed in to add a comment. Sign-in | Register

    In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


    Most Recent Comments
    kasiazaki 07/25/08 06:06:47 AM EDT

    dfdf

    prakash 09/05/03 02:40:50 AM EDT

    Dear Sir/Madam

    This is Prakash.I am finished my M.C.A this year(Fresher).I am looking an opportunity in any esteemed organization.I know the software are as follows Java,J2EE,JSP,EJB,HTML,DHTML,JVSCRIPT,VBSCRIPT,ASP,VB,ORACLE.

    But my familiar in my line is JavaTechnologies.So could you help me send any concern opportunities e-address and help me to get.

    Kind Regards.

    prakash 09/05/03 02:40:10 AM EDT

    Dear Sir/Madam

    This is Prakash.I am finished my M.C.A this year(Fresher).I am looking an opportunity in any esteemed organization.I know the software are as follows Java,J2EE,JSP,EJB,HTML,DHTML,JVSCRIPT,VBSCRIPT,ASP,VB,ORACLE.

    But my familiar in my line is JavaTechnologies.So could you help me send any concern opportunities e-address and help me to get.

    Kind Regards.

    john santhosh 07/06/03 08:25:00 AM EDT

    dear sir/madam,
    Iam john santhosh and i have completed MCA by the year 2002 and iam in search of job and i know JAVA,C,C++,COBOL,ASP,XML,MS-SQL SERVER..ETC..
    SO please find me aplace.

    MY QUALIFICATION AND PERCENTAGE

    Bsc comuter science-60%
    MCA-65%

    THANKING YOU

    YOURS FAITHFULLY
    JOHN SANTHOSH

    Jyotish Talukdar 05/29/03 04:21:00 AM EDT

    Hi my name is Jyotish Talukdar and i am doing my final year MCA project in J2EE including JSP,JDBC,JAVA BEAN. I have done Java Script also. I have done Oracle including PL/SQl. So I am waiting eagerly for any kindly call for interviewing.
    My MCA % until last sem: 73%.
    Thanks.

    lalit 05/02/03 05:11:00 AM EDT

    I am a mca student continuing
    my training in java for sixth
    semestar.so any one can help
    me ragarding the above matter
    then plz mail me in above Email
    Adds. If u can then ,u also test
    my skill in java

    MCA: - 80%
    B.Sc. 62%

    piyush vijay vergia 04/20/03 01:32:00 PM EDT

    I am a mca student continuing
    my training in java for sixth
    semestar.so any one can help
    me ragarding the above matter
    then plz mail me in above Email
    Adds. If u can then ,u also test
    my skill in java

    MCA: - 74%
    B.Sc. 64%

    Basudeva Kar 04/05/03 09:10:00 AM EST

    Hi,
    I am a mca student continuing
    my training in java for sixth
    semestar.so any one can help
    me ragarding the above matter
    then plz mail me in above Email
    Adds. If u can then ,u also test
    my skill in java

    rini 02/03/03 04:41:00 AM EST

    Tolong dikirim artikel ke alamat di atas

    vaibhav kulkarni 01/23/03 06:00:00 AM EST

    hi i am vaibhav from pune.
    right now i am studing in Pune Institute of Computer Tech. (PICT).
    i need help regarding OODBMS design in JAVA.
    so if anybody is intrested plz mail me
    on [email protected]

    vaibhav kulkarni 01/23/03 04:44:00 AM EST

    hi i am vaibhav from pune.
    right now i am studing in Pune Institute of Computer Tech. (PICT).
    i need help regarding OODBMS design in JAVA.
    so if anybody is intrested plz mail me
    on [email protected]

    Avishek Sachan 11/10/02 12:21:00 PM EST

    Response As Soon As
    Record
    MCA up to 4th sem 72.3%
    B.Sc. ......... 68.0%
    Intermediate..... 71.4%
    High School 70.1%

    10/21/02 06:49:00 PM EDT
    onkar gramopadhye 06/02/02 02:18:00 PM EDT

    I have done master of computer management course from pune university. I am looking for job for almost 1 year now but not getting any positive response from anywhere I am desperately in need of job so if it is possible please tell me any suggestion or give help, any thing from your end is appreciated

    dezo 05/13/02 04:31:00 AM EDT

    thank you

    Iftach Ragoler 05/13/02 01:19:00 AM EDT

    Do you know of vendors that implements Hybrid Databases? or this is just theoretical issue?

    Regards

    @ThingsExpo Stories
    BnkToTheFuture.com is the largest online investment platform for investing in FinTech, Bitcoin and Blockchain companies. We believe the future of finance looks very different from the past and we aim to invest and provide trading opportunities for qualifying investors that want to build a portfolio in the sector in compliance with international financial regulations.
    A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, whic...
    Imagine if you will, a retail floor so densely packed with sensors that they can pick up the movements of insects scurrying across a store aisle. Or a component of a piece of factory equipment so well-instrumented that its digital twin provides resolution down to the micrometer.
    In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, provided an overview of the evolution of the Internet and the Database and the future of their combination – the Blockchain. Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settle...
    Product connectivity goes hand and hand these days with increased use of personal data. New IoT devices are becoming more personalized than ever before. In his session at 22nd Cloud Expo | DXWorld Expo, Nicolas Fierro, CEO of MIMIR Blockchain Solutions, will discuss how in order to protect your data and privacy, IoT applications need to embrace Blockchain technology for a new level of product security never before seen - or needed.
    Leading companies, from the Global Fortune 500 to the smallest companies, are adopting hybrid cloud as the path to business advantage. Hybrid cloud depends on cloud services and on-premises infrastructure working in unison. Successful implementations require new levels of data mobility, enabled by an automated and seamless flow across on-premises and cloud resources. In his general session at 21st Cloud Expo, Greg Tevis, an IBM Storage Software Technical Strategist and Customer Solution Architec...
    Nordstrom is transforming the way that they do business and the cloud is the key to enabling speed and hyper personalized customer experiences. In his session at 21st Cloud Expo, Ken Schow, VP of Engineering at Nordstrom, discussed some of the key learnings and common pitfalls of large enterprises moving to the cloud. This includes strategies around choosing a cloud provider(s), architecture, and lessons learned. In addition, he covered some of the best practices for structured team migration an...
    No hype cycles or predictions of a gazillion things here. IoT is here. You get it. You know your business and have great ideas for a business transformation strategy. What comes next? Time to make it happen. In his session at @ThingsExpo, Jay Mason, an Associate Partner of Analytics, IoT & Cybersecurity at M&S Consulting, presented a step-by-step plan to develop your technology implementation strategy. He also discussed the evaluation of communication standards and IoT messaging protocols, data...
    Coca-Cola’s Google powered digital signage system lays the groundwork for a more valuable connection between Coke and its customers. Digital signs pair software with high-resolution displays so that a message can be changed instantly based on what the operator wants to communicate or sell. In their Day 3 Keynote at 21st Cloud Expo, Greg Chambers, Global Group Director, Digital Innovation, Coca-Cola, and Vidya Nagarajan, a Senior Product Manager at Google, discussed how from store operations and ...
    In his session at 21st Cloud Expo, Raju Shreewastava, founder of Big Data Trunk, provided a fun and simple way to introduce Machine Leaning to anyone and everyone. He solved a machine learning problem and demonstrated an easy way to be able to do machine learning without even coding. Raju Shreewastava is the founder of Big Data Trunk (www.BigDataTrunk.com), a Big Data Training and consulting firm with offices in the United States. He previously led the data warehouse/business intelligence and B...
    "IBM is really all in on blockchain. We take a look at sort of the history of blockchain ledger technologies. It started out with bitcoin, Ethereum, and IBM evaluated these particular blockchain technologies and found they were anonymous and permissionless and that many companies were looking for permissioned blockchain," stated René Bostic, Technical VP of the IBM Cloud Unit in North America, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventi...
    When shopping for a new data processing platform for IoT solutions, many development teams want to be able to test-drive options before making a choice. Yet when evaluating an IoT solution, it’s simply not feasible to do so at scale with physical devices. Building a sensor simulator is the next best choice; however, generating a realistic simulation at very high TPS with ease of configurability is a formidable challenge. When dealing with multiple application or transport protocols, you would be...
    Smart cities have the potential to change our lives at so many levels for citizens: less pollution, reduced parking obstacles, better health, education and more energy savings. Real-time data streaming and the Internet of Things (IoT) possess the power to turn this vision into a reality. However, most organizations today are building their data infrastructure to focus solely on addressing immediate business needs vs. a platform capable of quickly adapting emerging technologies to address future ...
    We are given a desktop platform with Java 8 or Java 9 installed and seek to find a way to deploy high-performance Java applications that use Java 3D and/or Jogl without having to run an installer. We are subject to the constraint that the applications be signed and deployed so that they can be run in a trusted environment (i.e., outside of the sandbox). Further, we seek to do this in a way that does not depend on bundling a JRE with our applications, as this makes downloads and installations rat...
    Widespread fragmentation is stalling the growth of the IIoT and making it difficult for partners to work together. The number of software platforms, apps, hardware and connectivity standards is creating paralysis among businesses that are afraid of being locked into a solution. EdgeX Foundry is unifying the community around a common IoT edge framework and an ecosystem of interoperable components.
    DX World EXPO, LLC, a Lighthouse Point, Florida-based startup trade show producer and the creator of "DXWorldEXPO® - Digital Transformation Conference & Expo" has announced its executive management team. The team is headed by Levent Selamoglu, who has been named CEO. "Now is the time for a truly global DX event, to bring together the leading minds from the technology world in a conversation about Digital Transformation," he said in making the announcement.
    In this strange new world where more and more power is drawn from business technology, companies are effectively straddling two paths on the road to innovation and transformation into digital enterprises. The first path is the heritage trail – with “legacy” technology forming the background. Here, extant technologies are transformed by core IT teams to provide more API-driven approaches. Legacy systems can restrict companies that are transitioning into digital enterprises. To truly become a lead...
    Digital Transformation (DX) is not a "one-size-fits all" strategy. Each organization needs to develop its own unique, long-term DX plan. It must do so by realizing that we now live in a data-driven age, and that technologies such as Cloud Computing, Big Data, the IoT, Cognitive Computing, and Blockchain are only tools. In her general session at 21st Cloud Expo, Rebecca Wanta explained how the strategy must focus on DX and include a commitment from top management to create great IT jobs, monitor ...
    "Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
    The IoT Will Grow: In what might be the most obvious prediction of the decade, the IoT will continue to expand next year, with more and more devices coming online every single day. What isn’t so obvious about this prediction: where that growth will occur. The retail, healthcare, and industrial/supply chain industries will likely see the greatest growth. Forrester Research has predicted the IoT will become “the backbone” of customer value as it continues to grow. It is no surprise that retail is ...