|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
The world's leading Cloud event, Cloud Expo has launched Microservices Journal on the SYS-CON.com portal, featuring over 19,000 original articles, news stories, features, and blog entries. DevOps Journal is focused on this critical enterprise IT topic in the world of cloud computing. Microservices Journal offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. Follow new article posts on Twitter at @MicroservicesE
Mar. 30, 2015 12:00 PM EDT Reads: 1,483
SYS-CON Events announced today the IoT Bootcamp – Jumpstart Your IoT Strategy, being held June 9–10, 2015, in conjunction with 16th Cloud Expo and Internet of @ThingsExpo at the Javits Center in New York City. This is your chance to jumpstart your IoT strategy. Combined with real-world scenarios and use cases, the IoT Bootcamp is not just based on presentations but includes hands-on demos and walkthroughs. We will introduce you to a variety of Do-It-Yourself IoT platforms including Arduino, Raspberry Pi, BeagleBone, Spark and Intel Edison. You will also get an overview of cloud technologies s...
Mar. 30, 2015 11:00 AM EDT Reads: 2,136
SYS-CON Events announced today that SafeLogic has been named “Bag Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. SafeLogic provides security products for applications in mobile and server/appliance environments. SafeLogic’s flagship product CryptoComply is a FIPS 140-2 validated cryptographic engine designed to secure data on servers, workstations, appliances, mobile devices, and in the Cloud.
Mar. 30, 2015 11:00 AM EDT Reads: 1,485
After making a doctor’s appointment via your mobile device, you receive a calendar invite. The day of your appointment, you get a reminder with the doctor’s location and contact information. As you enter the doctor’s exam room, the medical team is equipped with the latest tablet containing your medical history – he or she makes real time updates to your medical file. At the end of your visit, you receive an electronic prescription to your preferred pharmacy and can schedule your next appointment.
Mar. 30, 2015 10:00 AM EDT Reads: 869
Wearable technology was dominant at this year’s International Consumer Electronics Show (CES) , and MWC was no exception to this trend. New versions of favorites, such as the Samsung Gear (three new products were released: the Gear 2, the Gear 2 Neo and the Gear Fit), shared the limelight with new wearables like Pebble Time Steel (the new premium version of the company’s previously released smartwatch) and the LG Watch Urbane. The most dramatic difference at MWC was an emphasis on presenting wearables as fashion accessories and moving away from the original clunky technology associated with t...
Mar. 30, 2015 10:00 AM EDT Reads: 1,453
Containers and microservices have become topics of intense interest throughout the cloud developer and enterprise IT communities. Accordingly, attendees at the upcoming 16th Cloud Expo at the Javits Center in New York June 9-11 will find fresh new content in a new track called PaaS | Containers & Microservices Containers are not being considered for the first time by the cloud community, but a current era of re-consideration has pushed them to the top of the cloud agenda. With the launch of Docker's initial release in March of 2013, interest was revved up several notches. Then late last...
Mar. 30, 2015 09:15 AM EDT Reads: 2,245
The WebRTC Summit 2014 New York, to be held June 9-11, 2015, at the Javits Center in New York, NY, announces that its Call for Papers is open. Topics include all aspects of improving IT delivery by eliminating waste through automated business models leveraging cloud technologies. WebRTC Summit is co-located with 16th International Cloud Expo, @ThingsExpo, Big Data Expo, and DevOps Summit.
Mar. 30, 2015 09:00 AM EDT Reads: 1,635
SOA Software has changed its name to Akana. With roots in Web Services and SOA Governance, Akana has established itself as a leader in API Management and is expanding into cloud integration as an alternative to the traditional heavyweight enterprise service bus (ESB). The company recently announced that it achieved more than 90% year-over-year growth. As Akana, the company now addresses the evolution and diversification of SOA, unifying security, management, and DevOps across SOA, APIs, microservices, and more.
Mar. 30, 2015 08:30 AM EDT Reads: 2,073
GENBAND has announced that SageNet is leveraging the Nuvia platform to deliver Unified Communications as a Service (UCaaS) to its large base of retail and enterprise customers. Nuvia’s cloud-based solution provides SageNet’s customers with a full suite of business communications and collaboration tools. Two large national SageNet retail customers have recently signed up to deploy the Nuvia platform and the company will continue to sell the service to new and existing customers. Nuvia’s capabilities include HD voice, video, multimedia messaging, mobility, conferencing, Web collaboration, deskt...
Mar. 30, 2015 01:00 AM EDT Reads: 1,489
SYS-CON Media announced today that @WebRTCSummit Blog, the largest WebRTC resource in the world, has been launched. @WebRTCSummit Blog offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. @WebRTCSummit Blog can be bookmarked ▸ Here @WebRTCSummit conference site can be bookmarked ▸ Here
Mar. 29, 2015 10:00 PM EDT Reads: 1,835
SYS-CON Events announced today that Cisco, the worldwide leader in IT that transforms how people connect, communicate and collaborate, has been named “Gold Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Cisco makes amazing things happen by connecting the unconnected. Cisco has shaped the future of the Internet by becoming the worldwide leader in transforming how people connect, communicate and collaborate. Cisco and our partners are building the platform for the Internet of Everything by connecting the...
Mar. 29, 2015 07:00 PM EDT Reads: 5,259
Temasys has announced senior management additions to its team. Joining are David Holloway as Vice President of Commercial and Nadine Yap as Vice President of Product. Over the past 12 months Temasys has doubled in size as it adds new customers and expands the development of its Skylink platform. Skylink leads the charge to move WebRTC, traditionally seen as a desktop, browser based technology, to become a ubiquitous web communications technology on web and mobile, as well as Internet of Things compatible devices.
Mar. 29, 2015 06:00 PM EDT Reads: 1,871
SYS-CON Events announced today that robomq.io will exhibit at SYS-CON's @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. robomq.io is an interoperable and composable platform that connects any device to any application. It helps systems integrators and the solution providers build new and innovative products and service for industries requiring monitoring or intelligence from devices and sensors.
Mar. 29, 2015 06:00 PM EDT Reads: 1,500
Docker is an excellent platform for organizations interested in running microservices. It offers portability and consistency between development and production environments, quick provisioning times, and a simple way to isolate services. In his session at DevOps Summit at 16th Cloud Expo, Shannon Williams, co-founder of Rancher Labs, will walk through these and other benefits of using Docker to run microservices, and provide an overview of RancherOS, a minimalist distribution of Linux designed expressly to run Docker. He will also discuss Rancher, an orchestration and service discovery platf...
Mar. 29, 2015 04:15 PM EDT Reads: 2,449
SYS-CON Events announced today that Vitria Technology, Inc. will exhibit at SYS-CON’s @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Vitria will showcase the company’s new IoT Analytics Platform through live demonstrations at booth #330. Vitria’s IoT Analytics Platform, fully integrated and powered by an operational intelligence engine, enables customers to rapidly build and operationalize advanced analytics to deliver timely business outcomes for use cases across the industrial, enterprise, and consumer segments.
Mar. 29, 2015 03:30 PM EDT Reads: 2,197
SYS-CON Events announced today that Solgenia will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY, and the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Solgenia is the global market leader in Cloud Collaboration and Cloud Infrastructure software solutions. Designed to “Bridge the Gap” between Personal and Professional Social, Mobile and Cloud user experiences, our solutions help large and medium-sized organizations dr...
Mar. 29, 2015 03:00 PM EDT Reads: 2,877
SYS-CON Events announced today that Liaison Technologies, a leading provider of data management and integration cloud services and solutions, has been named "Silver Sponsor" of SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York, NY. Liaison Technologies is a recognized market leader in providing cloud-enabled data integration and data management solutions to break down complex information barriers, enabling enterprises to make smarter decisions, faster.
Mar. 29, 2015 03:00 PM EDT Reads: 3,490
@ThingsExpo has been named the Top 5 Most Influential M2M Brand by Onalytica in the ‘Machine to Machine: Top 100 Influencers and Brands.' Onalytica analyzed the online debate on M2M by looking at over 85,000 tweets to provide the most influential individuals and brands that drive the discussion. According to Onalytica the "analysis showed a very engaged community with a lot of interactive tweets. The M2M discussion seems to be more fragmented and driven by some of the major brands present in the M2M space. This really allows some room for influential individuals to create more high value inter...
Mar. 29, 2015 01:45 PM EDT Reads: 4,684
The list of ‘new paradigm’ technologies that now surrounds us appears to be at an all time high. From cloud computing and Big Data analytics to Bring Your Own Device (BYOD) and the Internet of Things (IoT), today we have to deal with what the industry likes to call ‘paradigm shifts’ at every level of IT. This is disruption; of course, we understand that – change is almost always disruptive.
Mar. 29, 2015 11:45 AM EDT Reads: 1,143
SYS-CON Events announced today that Akana, formerly SOA Software, has been named “Bronze Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Akana’s comprehensive suite of API Management, API Security, Integrated SOA Governance, and Cloud Integration solutions helps businesses accelerate digital transformation by securely extending their reach across multiple channels – mobile, cloud and Internet of Things. Akana enables enterprises to share data as APIs, connect and integrate applications, drive part...
Mar. 28, 2015 04:15 PM EDT Reads: 1,571