|By Dipak Patel, Michel Betancourt, Lorrie Barber||
|July 29, 2005 05:30 PM EDT||
A Java dump, also known as a Java core, Java thread dump, or a thread dump is a file that contains the following sections:
- All of the threads that run on a Java Virtual Machine (JVM).
- All of the monitors on a JVM.
- Some useful information about the system that the JVM runs under.
Format – Dump Routines
The following picture is a representation of a Java dump broken into subcomponents:
The following list describes the subcomponents found in Figure 1:
- Tags – The tags are located on the left side of the Java dump. They help you visualize the subcomponent represented by the data on the right side of the file. For example, 2LKINFLATEDMON is a tag for the LK subcomponent.
- TITLE – Describes what causes the JVM to produce the Java dump file. The TITLE subcomponent contains the date and time of occurrence and the location in your file system. You can use this information to determine if the Java dump was created by a user or was system-generated.
- XHPI – When available, this dump routine describes the operating environment, memory information, user limits, and other operating system related details.
- CI – Use this section to identify the JVM build, the class path that the JVM uses, the JVM system property variables, and other system information related to the JVM.
- LK – Provides information for all of the monitors in the JVM. You can use this section to analyze how resources are used by various threads.
- XM – This section provides a detailed list of all the threads and their states. It also provides the current stack trace for each thread listed. You can use the stack trace to relate the current activity of thread with the source code.
- CL – Lists all of the classes and class loaders that load at run time. If you know the classes or libraries required by your application, you can cross-reference the information against the list of classes provided in this section.
- JVMMI DC DG ST XE – See the Appendix for more details on these sections.
Operating System Differences
Java dumps vary from one operating system to another. Although the variation doesn’t differ greatly, most of the differences are found in the operating-specific information that the Java dump routines collect. One of these differences is how the environment variables that are set on a specific operating system in a Unix system, for example, are handled differently than Windows environment variables. These variables will display differently when you collect a Java dump on a Unix system and compare it to one collected on a Windows system.
Java Service Release Differences
Between each Java service release, the Java dump routine is enhanced to provide the most information possible when diagnosing problems.
For this reason, you’ll notice that a Java dump from one service release of the JDK to another is formatted differently in terms of tabs or spaces or additional information. For example, if you compare JDK 1.2.x Java dumps to JDK 1.3.x Java dumps, you’ll notice that the structure of the two documents is very different. Some data that’s found on the JDK 1.2.x Java dump is rearranged in the JDK 1.3.x Java dumps, such as the XM dump and LK dump routine locations.
Java Dump – Thread & Monitor Analysis
The following is an example of a thread stack trace in the XM dump routine:
3XMTHREADINFO “Thread-6” (TID:0x181D6A0, sys_thread_
t:0x133AA648, state:R, native ID:0x948) prio=5
4XESTACKTRACE at java.net.PlainSocketImpl.
4XESTACKTRACE at java.net.PlainSocketImpl.
4XESTACKTRACE at java.net.ServerSocket.
4XESTACKTRACE at java.net.ServerSocket.
4XESTACKTRACE at com.ibm.disthub.impl.multi.server.
4XESTACKTRACE at com.ibm.disthub.impl.client.
DebugThread.run(DebugThread.java:66)Example 1 – This is an example of a Java thread’s stack trace in the XM Dump Routine The first line of the previous example indicates that there’s a thread named Thread-6 that’s in a runnable state as indicated by the “state:R” parameter. This means that Thread-6 is either running or ready to run. Like all threads, Thread-6 has two primary identifiers: TID and sys_thread_t. For Thread-6, the values include 0x181D6A0 and 0x133AA648 respectively. You can cross-reference these values with the monitor data in the LK dump routine to detect deadlocks and identify problematic threads.
The remaining lines of text, identified by the “4XESTACKTRACE” tag, indicate the sequence of methods performed by the thread when the Java dump occurred. It is like a standard Java stack trace where the beginning of the code execution is read from the bottom to the top.
Just In Time (JIT) compiling is enabled when line numbers are replaced by the keywords “Compiled Code” in a stack trace as shown in Example 2. Disable JIT compiling to display the line numbers. Refer to the WebSphere Application Server InfoCenter for instructions on disabling JIT compiling in a WebSphere Application Server environment at http://www.ibm.com/software/webservers/appserv/infocenter.html.
Disabling JIT compiling can affect the performance of the JVM significantly especially during periods of high load.
4XESTACKTRACE at com.ibm.ws.util.BoundedBuffer.
take(BoundedBuffer.java(Inlined Compiled Code))
4XESTACKTRACE at com.ibm.ws.util.ThreadPool.
|WebSphere News Desk 07/29/05 05:13:02 PM EDT|
WebSphere Application Server Java Dumps
|WebSphere News Desk 07/29/05 05:08:40 PM EDT|
WebSphere Application Server Java Dumps
SYS-CON Events announced today that Tintri Inc., a leading producer of VM-aware storage (VAS) for virtualization and cloud environments, will exhibit at the 18th International CloudExpo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, New York, and the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
May. 27, 2016 04:15 AM EDT Reads: 2,263
SYS-CON Events announced today that BMC Software has been named "Siver Sponsor" of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2015 at the Javits Center in New York, New York. BMC is a global leader in innovative software solutions that help businesses transform into digital enterprises for the ultimate competitive advantage. BMC Digital Enterprise Management is a set of innovative IT solutions designed to make digital business fast, seamless, and optimized from mainframe to mo...
May. 27, 2016 01:45 AM EDT Reads: 2,084
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, wh...
May. 27, 2016 01:30 AM EDT Reads: 1,951
SYS-CON Events announced today that EastBanc Technologies will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. EastBanc Technologies has been working at the frontier of technology since 1999. Today, the firm provides full-lifecycle software development delivering flexible technology solutions that seamlessly integrate with existing systems – whether on premise or cloud. EastBanc Technologies partners with p...
May. 27, 2016 01:30 AM EDT Reads: 2,137
Companies can harness IoT and predictive analytics to sustain business continuity; predict and manage site performance during emergencies; minimize expensive reactive maintenance; and forecast equipment and maintenance budgets and expenditures. Providing cost-effective, uninterrupted service is challenging, particularly for organizations with geographically dispersed operations.
May. 27, 2016 01:00 AM EDT Reads: 1,879
SYS-CON Events announced today that Alert Logic, Inc., the leading provider of Security-as-a-Service solutions for the cloud, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. Alert Logic, Inc., provides Security-as-a-Service for on-premises, cloud, and hybrid infrastructures, delivering deep security insight and continuous protection for customers at a lower cost than traditional security solutions. Ful...
May. 27, 2016 12:45 AM EDT Reads: 2,705
The IoT is changing the way enterprises conduct business. In his session at @ThingsExpo, Eric Hoffman, Vice President at EastBanc Technologies, discuss how businesses can gain an edge over competitors by empowering consumers to take control through IoT. We'll cite examples such as a Washington, D.C.-based sports club that leveraged IoT and the cloud to develop a comprehensive booking system. He'll also highlight how IoT can revitalize and restore outdated business models, making them profitable...
May. 27, 2016 12:45 AM EDT Reads: 2,773
The essence of data analysis involves setting up data pipelines that consist of several operations that are chained together – starting from data collection, data quality checks, data integration, data analysis and data visualization (including the setting up of interaction paths in that visualization). In our opinion, the challenges stem from the technology diversity at each stage of the data pipeline as well as the lack of process around the analysis.
May. 27, 2016 12:15 AM EDT Reads: 1,358
SYS-CON Events announced today that Commvault, a global leader in enterprise data protection and information management, has been named “Bronze Sponsor” of SYS-CON's 18th International Cloud Expo, which will take place on June 7–9, 2016, at the Javits Center in New York City, NY, and the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Commvault is a leading provider of data protection and information management...
May. 27, 2016 12:00 AM EDT Reads: 3,045
Designing IoT applications is complex, but deploying them in a scalable fashion is even more complex. A scalable, API first IaaS cloud is a good start, but in order to understand the various components specific to deploying IoT applications, one needs to understand the architecture of these applications and figure out how to scale these components independently. In his session at @ThingsExpo, Nara Rajagopalan is CEO of Accelerite, will discuss the fundamental architecture of IoT applications, ...
May. 27, 2016 12:00 AM EDT Reads: 1,143
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York and Silicon Valley. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty ...
May. 26, 2016 11:30 PM EDT Reads: 2,561
As cloud and storage projections continue to rise, the number of organizations moving to the cloud is escalating and it is clear cloud storage is here to stay. However, is it secure? Data is the lifeblood for government entities, countries, cloud service providers and enterprises alike and losing or exposing that data can have disastrous results. There are new concepts for data storage on the horizon that will deliver secure solutions for storing and moving sensitive data around the world. ...
May. 26, 2016 11:00 PM EDT Reads: 1,249
SYS-CON Events announced today that MangoApps will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. MangoApps provides modern company intranets and team collaboration software, allowing workers to stay connected and productive from anywhere in the world and from any device. For more information, please visit https://www.mangoapps.com/.
May. 26, 2016 10:45 PM EDT Reads: 685
18th Cloud Expo, taking place June 7-9, 2016, at the Javits Center in New York City, NY, 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 strategy. Meanwhile, 94% of enterprises are using some...
May. 26, 2016 10:45 PM EDT Reads: 3,104
SoftLayer operates a global cloud infrastructure platform built for Internet scale. With a global footprint of data centers and network points of presence, SoftLayer provides infrastructure as a service to leading-edge customers ranging from Web startups to global enterprises. SoftLayer's modular architecture, full-featured API, and sophisticated automation provide unparalleled performance and control. Its flexible unified platform seamlessly spans physical and virtual devices linked via a world...
May. 26, 2016 10:15 PM EDT Reads: 2,075
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, will provide 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 ...
May. 26, 2016 10:00 PM EDT Reads: 1,894
In his session at 18th Cloud Expo, Bruce Swann, Senior Product Marketing Manager at Adobe, will discuss how the Adobe Marketing Cloud can help marketers embrace opportunities for personalized, relevant and real-time customer engagement across offline (direct mail, point of sale, call center) and digital (email, website, SMS, mobile apps, social networks, connected objects). Bruce Swann has more than 15 years of experience working with digital marketing disciplines like web analytics, social med...
May. 26, 2016 09:00 PM EDT Reads: 1,266
Join us at Cloud Expo | @ThingsExpo 2016 – June 7-9 at the Javits Center in New York City and November 1-3 at the Santa Clara Convention Center in Santa Clara, CA – and deliver your unique message in a way that is striking and unforgettable by taking advantage of SYS-CON's unmatched high-impact, result-driven event / media packages.
May. 26, 2016 08:00 PM EDT Reads: 2,333
SYS-CON Events announced today that ContentMX, the marketing technology and services company with a singular mission to increase engagement and drive more conversations for enterprise, channel and SMB technology marketers, has been named “Sponsor & Exhibitor Lounge Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2016, at the Javits Center in New York City, New York. “CloudExpo is a great opportunity to start a conversation with new prospects, but what happens after the...
May. 26, 2016 07:15 PM EDT Reads: 1,011
The 19th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit y...
May. 26, 2016 07:00 PM EDT Reads: 1,952