Welcome!

Weblogic Authors: Yeshim Deniz, Elizabeth White, Michael Meiner, Michael Bushong, Avi Rosenthal

Related Topics: Weblogic

Weblogic: Article

Custom Debugging with WebLogic JMX

Trace your JDBC calls without modifying your existing code

Maintaining complicated legacy applications is a challenge, which is often made worse by lack of documentation, nonintuitive design, and coding practices. Unfortunately almost all software developers will find themselves with such an assignment at some point in their careers.

In the case of any application that utilizes a database, it is very useful to trace SQL statements generated by the application. Such a trace would help with profiling performance bottlenecks, debugging errors, and in facilitating the developer's understanding of the business processes associated with the application.

In the case of legacy applications we would want to do such tracing without changing any code or application configuration. I was able to use WebLogic's JMX API to quickly put together a little code to trace the JDBC calls of a very large and complicated legacy application without impacting the code and configuration of the application. In addition, this small project helped facilitate my understanding of JMX and how WebLogic uses JMX behind the scenes. In this article I will go over the details of using WebLogic JMX to trace SQL statements.

What is JMX?
JMX stands for Java Management Extensions. MBeans, or managed beans, are resources that can be managed through the JMX API. Most application servers use JMX to provide administration consoles and to manage resources. In addition, application developers can use JMX to provide administration and auditing capabilities in their custom applications.

What Advantages Does WebLogic's JMX Implementation Provide for Developers and Administrators?
WebLogic Servers use JMX MBeans for configuration and management. A WebLogic Server each has a copy of its own MBeans, which is updated by the administration server. The administration server maintains a master copy of the MBeans for all of the servers that it manages. If the administration server fails to come up, the managed servers can function based on their local copy of the MBeans until the administration server can become available to update the server's local MBeans.

Web Logic provides both an administration console, which does its work using JMX MBeans, as well as an API to allow application developers to configure and explore WebLogic resources. The easiest way to take advantage of WebLogic JMX is to use the WebLogic console to change the configuration of WebLogic resources and to view the metrics available in the console. While the monitoring and configuration capabilities of the WebLogic console are very powerful and will meet the needs of most applications running on WebLogic, the WebLogic JMX API provides an even more powerful instrument for managing applications running on the WebLogic platform. Using the WebLogic JMX API it is possible to configure and extend WebLogic resources and to also receive notifications from WebLogic's subsystems. For example, an application that is configured with n as the value for minimum and maximum number of JDBC connections might want to have a listener that listens to notifications from the WebLogic JMX MBeans and sends e-mail to an administrator in case the usage of the application crosses n-x concurrent JDBC connections, so that the administrator can decide on an increased value for n and reconfigure the JDBC connection pool(s) (where x is an arbitrary number that depends on the comfort level of the administrator). Examples of advanced uses of JMX by application developers include tracing events in the WebLogic subsystems, including EJB events and server start/stop events.

What Options Are Available for Profiling JDBC Statements in WebLogic Applications?
There are several techniques that can be used to create a dynamic trace of JDBC statements in a WebLogic application. Subclassing the Statement,PreparedStatement and CallableStatement classes from the java.sql package to print a trace using a logging system like Log4J or WebLogic logging and then using the subclasses in the application is a viable option, but it is not practical in the case of legacy code. Such traces may be available from tools such as TOAD, but such tools may not be easily available to application developers and may not provide all of the information that is required. AOP techniques are another valid choice for printing JDBC statements. However, at the time of writing AOP is not officially supported in WebLogic by BEA even though articles about WebLogic AOP have appeared on the dev2dev site. At the time of writing, getting AOP to work in WebLogic is not a trivial project. Using WebLogic JMX with WebLogic 6.1 and 8.1 does not require the use of any additional libraries or configuration, since all the required classes are available in weblogic.jar and the code is very simple to implement. In addition WebLogic JMX is a very mature technology and can be implemented without any changes to the core application code or bytecode.

Using the WebLogic JMX API
The WebLogic javadocs are available online at http://e-docs.bea.com/wls/docs81/javadocs/. The API contains several packages with management in their names. These packages are WebLogic's JMX implementation (see Table 1).

Using JMX to Trace JDBC Calls
A simple way to organize the tracing code and provide a UI to view the SQL is to write a JSP, a servlet, and a Java Bean or object. We'll go through the details of the bean/POJO here and leave most of the details of the UI/controller aspect out since most WebLogic developers already understand these very well. Note that you need not modify any deployment descriptors, database connection pools, or data sources in order to get the tracing to work. All changes to the needed application will happen at run time.

Step 1
First we'll create a class called MyTracerBean.java and import the WebLogic JMX packages and classes that we'll need.

import javax.naming.Context;
import weblogic.jndi.Environment;
import weblogic.management.MBeanHome;
import weblogic.management.configuration.JDBCConnectionPoolMBean;
import weblogic.management.runtime.JDBCStatementProfile;
import weblogic.management.runtime.JDBCConnectionPoolRuntimeMBean;
import javax.management.InstanceNotFoundException;
import javax.management.InvalidAttributeValueException;
import javax.naming.NamingException;

See Figure 1

These classes are in the weblogic.jar so you won't need to add any JARs or classes to the WebLogic classpath.

Step 2
Next we'll write a method to get the MBeanHome.


private MBeanHome getMBeanHome() {
//URL to the serve whose JDBC activity we are tracing
String url = "t3://localhost:7001";
    String username = "mywlconsoleuname";
    String password = "mywlconsolepsswd";
//The MBeanHome will allow us to
//retrieve the MBeans related to JDBC statement tracing
MBeanHome home = null;

try { //We'll need the environment so that we can //retrieve the initial context
    Environment env = new Environment();
    env.setProviderUrl(url);
    env.setSecurityPrincipal(username);
    env.setSecurityCredentials(password Context ctx = env.getInitialContext();
//Retrieving the MBeanHome interface for the server with //the url t3://localhost:7001
    home =(MBeanHome)ctx.lookup(MBeanHome.LOCAL_JNDI_NAME);
    } catch (NamingException ne) {
     System.out.println("Error getting MBeanHome " + ne);
    }
    return home;
}

More Stories By Salma Saad

Salma started her career back in 1993, working on Steve Jobs NeXT platform and moved on to Java when it was at the ‘bleeding edge’. She has worked as a consultant for more than ten years, working primarily on website development projects for a large variety of clients. In addition to her fascination with everything technical she also has a strong interest in developing her leadership and management expertise. She enjoys living in Chicago and being the mother of two rugrats, ...um boys and is currently working for Arc Worldwide/Leo Burnett helping fortune 500 clients build awe-inspiring websites.

Comments (1) 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
Oscar Madrigal 11/23/05 08:17:44 PM EST

Great tip but only log the succesfull statements, how can trace fails statements?

@ThingsExpo Stories
I think DevOps is now a rambunctious teenager - it's starting to get a mind of its own, wanting to get its own things but it still needs some adult supervision," explained Thomas Hooker, VP of marketing at CollabNet, in this SYS-CON.tv interview at DevOps Summit at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
"MobiDev is a software development company and we do complex, custom software development for everybody from entrepreneurs to large enterprises," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Major trends and emerging technologies – from virtual reality and IoT, to Big Data and algorithms – are helping organizations innovate in the digital era. However, to create real business value, IT must think beyond the ‘what’ of digital transformation to the ‘how’ to harness emerging trends, innovation and disruption. Architecture is the key that underpins and ties all these efforts together. In the digital age, it’s important to invest in architecture, extend the enterprise footprint to the cl...
Data is the fuel that drives the machine learning algorithmic engines and ultimately provides the business value. In his session at Cloud Expo, Ed Featherston, a director and senior enterprise architect at Collaborative Consulting, discussed the key considerations around quality, volume, timeliness, and pedigree that must be dealt with in order to properly fuel that engine.
Two weeks ago (November 3-5), I attended the Cloud Expo Silicon Valley as a speaker, where I presented on the security and privacy due diligence requirements for cloud solutions. Cloud security is a topical issue for every CIO, CISO, and technology buyer. Decision-makers are always looking for insights on how to mitigate the security risks of implementing and using cloud solutions. Based on the presentation topics covered at the conference, as well as the general discussions heard between sessio...
IoT is rapidly becoming mainstream as more and more investments are made into the platforms and technology. As this movement continues to expand and gain momentum it creates a massive wall of noise that can be difficult to sift through. Unfortunately, this inevitably makes IoT less approachable for people to get started with and can hamper efforts to integrate this key technology into your own portfolio. There are so many connected products already in place today with many hundreds more on the h...
No hype cycles or predictions of zillions of things here. IoT is big. 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, Associate Partner at M&S Consulting, presented a step-by-step plan to develop your technology implementation strategy. He discussed the evaluation of communication standards and IoT messaging protocols, data analytics considerations, edge-to-cloud tec...
Announcing Poland #DigitalTransformation Pavilion
Digital Transformation is much more than a buzzword. The radical shift to digital mechanisms for almost every process is evident across all industries and verticals. This is often especially true in financial services, where the legacy environment is many times unable to keep up with the rapidly shifting demands of the consumer. The constant pressure to provide complete, omnichannel delivery of customer-facing solutions to meet both regulatory and customer demands is putting enormous pressure on...
DXWorldEXPO LLC announced today that All in Mobile, a mobile app development company from Poland, will exhibit at the 22nd International CloudEXPO | DXWorldEXPO. All In Mobile is a mobile app development company from Poland. Since 2014, they maintain passion for developing mobile applications for enterprises and startups worldwide.
CloudEXPO | DXWorldEXPO are the world's most influential, independent events where Cloud Computing was coined and where technology buyers and vendors meet to experience and discuss the big picture of Digital Transformation and all of the strategies, tactics, and tools they need to realize their goals. Sponsors of DXWorldEXPO | CloudEXPO benefit from unmatched branding, profile building and lead generation opportunities.
The best way to leverage your CloudEXPO | DXWorldEXPO presence as a sponsor and exhibitor is to plan your news announcements around our events. The press covering CloudEXPO | DXWorldEXPO will have access to these releases and will amplify your news announcements. More than two dozen Cloud companies either set deals at our shows or have announced their mergers and acquisitions at CloudEXPO. Product announcements during our show provide your company with the most reach through our targeted audienc...
Everything run by electricity will eventually be connected to the Internet. Get ahead of the Internet of Things revolution. In his session at @ThingsExpo, Akvelon expert and IoT industry leader Sergey Grebnov provided an educational dive into the world of managing your home, workplace and all the devices they contain with the power of machine-based AI and intelligent Bot services for a completely streamlined experience.
@DevOpsSummit at Cloud Expo, taking place November 12-13 in New York City, NY, is co-located with 22nd international CloudEXPO | first international DXWorldEXPO and will feature technical sessions from a rock star conference faculty and the leading industry players in the world.
DXWorldEXPO | CloudEXPO are the world's most influential, independent events where Cloud Computing was coined and where technology buyers and vendors meet to experience and discuss the big picture of Digital Transformation and all of the strategies, tactics, and tools they need to realize their goals. Sponsors of DXWorldEXPO | CloudEXPO benefit from unmatched branding, profile building and lead generation opportunities.
22nd International Cloud Expo, taking place June 5-7, 2018, at the Javits Center in New York City, NY, and co-located with the 1st DXWorld Expo will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud ...
In his keynote at 19th Cloud Expo, Sheng Liang, co-founder and CEO of Rancher Labs, discussed the technological advances and new business opportunities created by the rapid adoption of containers. With the success of Amazon Web Services (AWS) and various open source technologies used to build private clouds, cloud computing has become an essential component of IT strategy. However, users continue to face challenges in implementing clouds, as older technologies evolve and newer ones like Docker c...
JETRO showcased Japan Digital Transformation Pavilion at SYS-CON's 21st International Cloud Expo® at the Santa Clara Convention Center in Santa Clara, CA. The Japan External Trade Organization (JETRO) is a non-profit organization that provides business support services to companies expanding to Japan. With the support of JETRO's dedicated staff, clients can incorporate their business; receive visa, immigration, and HR support; find dedicated office space; identify local government subsidies; get...
Dion Hinchcliffe is an internationally recognized digital expert, bestselling book author, frequent keynote speaker, analyst, futurist, and transformation expert based in Washington, DC. He is currently Chief Strategy Officer at the industry-leading digital strategy and online community solutions firm, 7Summits.
Bill Schmarzo, author of "Big Data: Understanding How Data Powers Big Business" and "Big Data MBA: Driving Business Strategies with Data Science," is responsible for setting the strategy and defining the Big Data service offerings and capabilities for EMC Global Services Big Data Practice. As the CTO for the Big Data Practice, he is responsible for working with organizations to help them identify where and how to start their big data journeys. He's written several white papers, is an avid blogge...