|By Andreas Grabner||
|April 14, 2014 11:00 AM EDT||
Have you seen this error message before "java.sql.Exception: ORA-00060: deadlock detected while waiting for resource"?
This is caused when parallel updates require locks on either rows or tables in your database. I recently ran into this exception on an instance of an IBM eCommerce Server. The first thought was that there are simply too many people hitting the same functionality that updates Sales Tax Summary information - which was showing up in the call stack of the exception:
Exception stack trace showing that createOrderTaxes ran into the deadlock issue on the database
The logical conclusion would be to blame this on too many folks accessing this functionality or outdated table statistics causing update statements to run too long causing others to run into that lock. It turned out to be caused by something that wasn't that obvious and wouldn't have shown up in any Exception stack traces or log files. A misconfigured timeout setting on the load balancer caused a re-execute of the original incoming web request. While the first app server was still updating the table and holding the lock - as it had a longer timeout specified as the load balancer - the second app server tried to do the same thing causing that exception.
In this article I'll show you the steps necessary to analyze the symptoms (timeouts and client errors) and to identify and fix the root cause of the problem.
Step #1: Identifying Who and What Is Impacted
Identifying failing results is easy - start by looking at HTTP Response Codes (Web Server Access Log), Severe Log Messages (App Server Logs) or problematic Exception objects (either in log files or other monitoring tools). In our case I identified the SQL Lock Exception, a corresponding severe log message and the resulting HTTP 500 and also traced it back to the individual users and their actions that caused these issues.
Linking the errors to the User Action reveals that the problem happens when adding items to the shopping cart
This impacts our business.
Now we know that this problem impacts a critical feature in our app: Users can't add items to their cart.
Step #2: Understanding the Transaction Flow
Before drilling deeper I typically get an overview of the flow of the transaction from the browser all the way back to the database. This high-level view lets me understand which application components are involved and how they are interconnected. The transaction flow in this case highlights some interesting issues with the "Add Item to Cart" click. It appears to execute more than 33k SQL Statements for this single user interaction, causing 45% time executed just in Oracle:
Transaction Flow highlights several hotspots such as 33k SQL Executions in Total and Load Balancer (IHS) splitting up a request
This Is an Architectural Problem
Getting the full end-to-end execution path for a single user interaction (Add Item to Cart) and seeing how it "branches" out makes it really obvious how these individual problems (too many SQL, High Execution Time, ...) end up impacting end users. Just spotting the individual hotspots without having this connection would make it harder to understand the real root cause.
For steps 3 & 4, and for a list of key takeaways, click here for the full article
Dyn solutions are at the core of Internet Performance. Through traffic management, message management and performance assurance, Dyn is connecting people through the Internet and ensuring information gets where it needs to go, faster and more reliably than ever before. Founded in 2001 at WPI, Dyn’s global presence services more than four million enterprise, small business and personal customers.
Oct. 31, 2014 01:00 PM EDT Reads: 1,991
SimpleECM is the only platform to offer a powerful combination of enterprise content management (ECM) services, capture solutions, and third-party business services providing simplified integrations and workflow development for solution providers. SimpleECM is opening the market to businesses of all sizes by reinventing the delivery of ECM services. Our APIs make the development of ECM services simple with the use of familiar technologies for a frictionless integration directly into web applicat...
Oct. 31, 2014 11:00 AM EDT Reads: 1,982
The Internet of Things will greatly expand the opportunities for data collection and new business models driven off of that data. In her session at Internet of @ThingsExpo, Esmeralda Swartz, CMO of MetraTech, will discuss how for this to be effective you not only need to have infrastructure and operational models capable of utilizing this new phenomenon, but increasingly service providers will need to convince a skeptical public to participate. Get ready to show them the money! Speaker Bio: ...
Oct. 31, 2014 09:00 AM EDT Reads: 2,327
Samsung VP Jacopo Lenzi, who headed the company's recent SmartThings acquisition under the auspices of Samsung's Open Innovaction Center (OIC), answered a few questions we had about the deal. This interview was in conjunction with our interview with SmartThings CEO Alex Hawkinson. IoT Journal: SmartThings was developed in an open, standards-agnostic platform, and will now be part of Samsung's Open Innovation Center. Can you elaborate on your commitment to keep the platform open? Jacopo Lenzi: S...
Oct. 31, 2014 09:00 AM EDT Reads: 3,373
Things are being built upon cloud foundations to transform organizations. This CEO Power Panel at 15th Cloud Expo, moderated by Roger Strukhoff, Cloud Expo and @ThingsExpo conference chair, will address the big issues involving these technologies and, more important, the results they will achieve. How important are public, private, and hybrid cloud to the enterprise? How does one define Big Data? And how is the IoT tying all this together?
Oct. 31, 2014 08:45 AM EDT Reads: 1,983
The only place to be June 9-11 is Cloud Expo & @ThingsExpo 2015 East at the Javits Center in New York City. Join us there as delegates from all over the world come to listen to and engage with speakers & sponsors from the leading Cloud Computing, IoT & Big Data companies. Cloud Expo & @ThingsExpo are the leading events covering the booming market of Cloud Computing, IoT & Big Data for the enterprise. Speakers from all over the world will be hand-picked for their ability to explore the economic...
Oct. 30, 2014 05:30 PM EDT Reads: 1,421
SYS-CON Events announced today that Cloudian, Inc., the leading provider of hybrid cloud storage solutions, has been named “Bronze Sponsor” of SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Cloudian is a Foster City, Calif.-based software company specializing in cloud storage. Cloudian HyperStore® is an S3-compatible cloud object storage platform that enables service providers and enterprises to bui...
Oct. 30, 2014 04:45 PM EDT Reads: 1,918
SAP is delivering break-through innovation combined with fantastic user experience powered by the market-leading in-memory technology, SAP HANA. In his General Session at 15th Cloud Expo, Thorsten Leiduck, VP ISVs & Digital Commerce, SAP, will discuss how SAP and partners provide cloud and hybrid cloud solutions as well as real-time Big Data offerings that help companies of all sizes and industries run better. SAP launched an application challenge to award the most innovative SAP HANA and SAP ...
Oct. 30, 2014 09:00 AM EDT Reads: 2,095
SYS-CON Events announced today that O'Reilly Media has been named “Media Sponsor” of SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. O'Reilly Media spreads the knowledge of innovators through its books, online services, magazines, and conferences. Since 1978, O'Reilly Media has been a chronicler and catalyst of cutting-edge development, homing in on the technology trends that really matter and spurri...
Oct. 29, 2014 01:00 PM EDT Reads: 1,640
Samsung promises to be one of the 800-pound gorillas of the IoT, if its success in recent years with Android devices and other consumer electronics is any guide. Showing its willingness to be a big IoT player, the company recently acquired SmartThings, a recent startup that's developed an open smarthome appliation that currently supports 1,000 devices and 8,000 apps. SmartThings will now work under the auspices of Samsung's Open Innovation Center (OIC). SmartThings Founder and CEO Alex Hawkinson...
Oct. 29, 2014 09:00 AM EDT Reads: 3,846
The Internet of Things (IoT) is going to require a new way of thinking and of developing software for speed, security and innovation. This requires IT leaders to balance business as usual while anticipating for the next market and technology trends. Cloud provides the right IT asset portfolio to help today’s IT leaders manage the old and prepare for the new. Today the cloud conversation is evolving from private and public to hybrid. This session will provide use cases and insights to reinforce t...
Oct. 29, 2014 09:00 AM EDT Reads: 2,097
What process has your provider undertaken to ensure that the cloud tenant will receive predictable performance and service? What was involved in the planning? Who owns and operates the data center? What technology is being used? How is it being supported? In his session at 14th Cloud Expo, Dave Weisbrot, Cloud Business Manager for QTS, will provide the attendees a look into what it takes to stand up and stand behind a highly available certified cloud IaaS.
Oct. 29, 2014 08:30 AM EDT Reads: 1,549
I'll be hosting an SAP HANA Cloud webinar at 11am eastern time, Wednesday, October 29. You can sign up now. Featured speakers will be Allan Adler, Managing Partner, Channel Cloud Consulting, and Thorsten Leiduck, VP ISVs & Digital Commerce, SAP. Attendees will learn about • Cloud economics, hybrid cloud strategy, market size and opportunity • Introduction to SAP HANA Cloud Platform and how to: - Build new next-generation applications - Extend on-premise solutions non-disruptively throu...
Oct. 28, 2014 11:45 PM EDT Reads: 1,474
SYS-CON Events announced today that Gigaom Research has been named "Media Sponsor" of SYS-CON's 15th International Cloud Expo®, which will take place on November 4-6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Ashar Baig, Research Director, Cloud, at Gigaom Research, will also lead a Power Panel on the topic "Choosing the Right Cloud Option." Gigaom Research provides timely, in-depth analysis of emerging technologies for individual and corporate subscribers. Gigaom Research'...
Oct. 28, 2014 11:45 PM EDT Reads: 1,704
Join both SAP and Channel Cloud Consulting for our webcast and uncover how you can extend your reach to capture a piece of the US$17 billion cloud application services market with SAP. Learn about SAPs market-leading SAP HANA Cloud Platform and an exciting opportunity to join SAPs growing ecosystem of Application Development partners. When: October 29, 11:00am EST Speakers: Allan Adler, Managing Partner, Channel Cloud Consulting Thorsten Leiduck, Vice President ISVs & Digital Commerce, SAP
Oct. 28, 2014 09:00 PM EDT Reads: 1,358
Application Performance Management (APM) has been bred with all the right elements to give us the insights we need to see the health of our applications. Similar to your most trusted watch dog, it alerts us to anomalies when events occur, providing awareness to the environment that only they can observe. As enterprises embrace the DevOps philosophy, and the coalescence of the Development and Operations continues, I foresee the conditions ripening to foster innovative methods of making applicati...
Oct. 28, 2014 08:15 PM EDT Reads: 5,217
SYS-CON Events announced today that IBM is holding a Bluemix Developer Playground on November 5, 10:30 am to 5:30 pm at 15th Cloud Expo. 15th Cloud Expo, co-located with @ThingsExpo, Big Data Expo, and DevOps Summit is taking place Nov. 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. The labs, for developers of all levels, will highlight the ease of use of Bluemix, its services and functionality and provide short-term introductory projects that developers can complete betw...
Oct. 28, 2014 08:00 PM EDT Reads: 1,613
The Industrial Internet revolution is now underway, enabled by connected machines and billions of devices that communicate and collaborate. The massive amounts of Big Data requiring real-time analysis is flooding legacy IT systems and giving way to cloud environments that can handle the unpredictable workloads. Yet many barriers remain until we can fully realize the opportunities and benefits from the convergence of machines and devices with Big Data and the cloud, including interoperability, da...
Oct. 28, 2014 12:00 PM EDT Reads: 1,959
Software AG helps organizations transform into Digital Enterprises, so they can differentiate from competitors and better engage customers, partners and employees. Using the Software AG Suite, companies can close the gap between business and IT to create digital systems of differentiation that drive front-line agility. We offer four on-ramps to the Digital Enterprise: alignment through collaborative process analysis; transformation through portfolio management; agility through process automation...
Oct. 28, 2014 10:00 AM EDT Reads: 2,062
How do you know when a technology has become mainstream? A good clue may be when politicians start talking about it on the campaign trail and with mainstream media. David Cameron, the UK prime minister, was the latest, indicating that the world was now on “fast-forward” with the Internet of Things (IoT) ushering in the new industrial revolution. No mention of IoT targeted at the masses would be complete without the clichéd example of the communicating fridge. While it is easy to get caught up in...
Oct. 28, 2014 08:00 AM EDT Reads: 6,300