|By Wolfgang Gottesheim||
|October 27, 2012 05:00 PM EDT||
Does the following situation sound familiar? From one minute to the other, your production servers grind to a halt, terse emails are complemented by equally hectic phone calls, and the first order of business is to get back up and running. After the dust settles, you're usually left with a pile of log files and the assignment of figuring out what happened, why it happened, and what to do to keep it from happening again.
A common first step is trying to reproduce what has gone wrong. More often than not, this consumes a considerable amount of time that would be better spent on actually fixing the problem. In this first blog post of a series, I will present a Step-by-Step Guide to Diagnose Stuck Transactions within minutes and show how a modern APM Solution helps to pinpoint common production problems, without spending hours on reproducing it at first.
The Problem: Response Time Increases
One of our customers deployed a new version of their prime web application and, for the first couple of days, everything seemed fine. One evening, their operations team was alerted about significantly increasing response time, and upon further investigation they recognized that a Stuck Transaction was blocking their application. While restarting the server solved the problem from an operations perspective it is not a long term solution as currently processing transactions get canceled and users are thrown off the system.
Their APM solution automatically captures thread dumps in case of too long running or stuck transactions. These dumps assist developers with diagnosing the issue. Let's take this example and walk through one of the problems often seen in a production environment: Diagnosing Stuck Transactions and Identifying the Root Cause.
Step 1: Identify problematic JVM/CLR
To identify the correct thread dump to analyze, it's important to know which server was affected by the stuck transaction and at what time that happened.
The transaction flow indicates a problem on one of the application servers
When drilling to the actual transactions that flow through that application server and focusing on the timeframe just before the server got restarted, I noticed a timed-out PurePath that spent 100% in sync time. This means that all it did was wait for one or more monitors, which makes it a likely culprit for our stuck transaction.
The PurePath reveals the information about which Application Server (=Agent) was involved in that stuck transaction
Step 2: Identify blocked threads
Having identified the affected application server, we can browse the list of available thread dumps and open the corresponding one.
Thread dump overview on runnable, blocked, waiting and timed waiting threads
When looking at the thread dump, threads can be grouped by their state to get a quick overview on how many threads the application executed when the dump was performed and how many of them were actually blocked. In this case, we are looking at four threads as Figure 4 shows.
Out of the 600+ Threads in the application, 4 are blocked and subject for further investigation
Step 3: Identify root cause
Already the first one of these threads is the thread from our timed-out PurePath we looked at in Step 1 - identifiable by its ID. We also get the most important piece of information we need to identify the root cause: Which object is this thread waiting on, and who owns it?
We now know which method is blocking and that it is blocked because it waits for an object owned by another thread -> a potential deadlock?
Usually, the thread owning the object we are waiting for is highlighted in red. Given the number of threads in this dump, it's unlikely to spot it this way, but search for the ID of the owning thread giving us the following information:
The HistoryLayout thread owns a monitor object with two waiting threads, which causes the web request handler to block and run into a timeout for the end user - the deadlock is identified!
In this case, the method com.vaadin.ui.Table.unregisterPropertiesAndComponents is working on the same instance of ConfigurableReportsApplication that AbstractApplicationPortlet.handleRequest is waiting for. Having identified the thread, we have the full stack trace at hand in the lower pane, and can track down how this situation occurred.
Trying to reproduce such concurrency-related problems on a developer machine with typically requires a major effort. If your APM tool fully supports collaboration between teams, all analysis steps described above can be performed in your local environment, without direct access to production servers. Using an APM Solution like dynaTrace, it only took a couple of minutes to answer the crucial questions named above: we know exactly what happened and how it happened, and are thus also able to modify our application in a way to avoid this situation in the future.
SYS-CON Events announced today that On the Avenue Marketing Group, a sales and marketing firm that utilizes events to market and sell products to consumers, 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. On the Avenue Marketing Group (OTA) is a sales and marketing firm that utilizes events to market and sell products to consumers. On behalf of our clients, we attend thousands of fairs, festivals, exp...
Apr. 26, 2015 07:30 PM EDT Reads: 3,507
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 ...
Apr. 26, 2015 07:00 PM EDT Reads: 2,892
While DevOps most critically and famously fosters collaboration, communication, and integration through cultural change, culture is more of an output than an input. In order to actively drive cultural evolution, organizations must make substantial organizational and process changes, and adopt new technologies, to encourage a DevOps culture. Moderated by Andi Mann, panelists will discuss how to balance these three pillars of DevOps, where to focus attention (and resources), where organizations m...
Apr. 26, 2015 05:15 PM EDT Reads: 2,051
“In the past year we've seen a lot of stabilization of WebRTC. You can now use it in production with a far greater degree of certainty. A lot of the real developments in the past year have been in things like the data channel, which will enable a whole new type of application," explained Peter Dunkley, Technical Director at Acision, in this SYS-CON.tv interview at @ThingsExpo, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
Apr. 26, 2015 05:00 PM EDT Reads: 4,492
of cloud, colocation, managed services and disaster recovery solutions, 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. TierPoint, LLC, is a leading national provider of information technology and data center services, including cloud, colocation, disaster recovery and managed IT services, with corporate headquarters in St. Louis, MO. TierPoint was formed through the strategic combination of some of t...
Apr. 26, 2015 04:30 PM EDT Reads: 1,667
SYS-CON Events announced today that Column Technologies, a global technology solutions company, will exhibit at SYS-CON's DevOps Summit 2015 New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Established in 1998, Column Technologies is a leader in application performance and infrastructure management for commercial and federal markets. The company is headquartered in the United States, with a diverse and talented team of more than 350 employees around th...
Apr. 26, 2015 04:00 PM EDT Reads: 1,807
Health care systems across the globe are under enormous strain, as facilities reach capacity and costs continue to rise. M2M and the Internet of Things have the potential to transform the industry through connected health solutions that can make care more efficient while reducing costs. In fact, Vodafone's annual M2M Barometer Report forecasts M2M applications rising to 57 percent in health care and life sciences by 2016. Lively is one of Vodafone's health care partners, whose solutions enable o...
Apr. 26, 2015 03:00 PM EDT Reads: 1,535
SYS-CON Events announced today that Ciqada 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. Ciqada™ makes it easy to connect your products to the Internet. By integrating key components - hardware, servers, dashboards, and mobile apps - into an easy-to-use, configurable system, your products can quickly and securely join the internet of things. With remote monitoring, control, and alert messaging capability, you will mee...
Apr. 26, 2015 03:00 PM EDT Reads: 1,934
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
Apr. 26, 2015 03:00 PM EDT Reads: 2,515
SYS-CON Events announced today that GENBAND, a leading developer of real time communications software solutions, has been named “Silver Sponsor” of SYS-CON's WebRTC Summit, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. The GENBAND team will be on hand to demonstrate their newest product, Kandy. Kandy is a communications Platform-as-a-Service (PaaS) that enables companies to seamlessly integrate more human communications into their Web and mobile applicatio...
Apr. 26, 2015 02:00 PM EDT Reads: 2,752
Public Cloud IaaS started it's life in the developer and startup communities and has grown rapidly to a $20B+ industry, but it still pales in comparison to how much is spent worldwide on IT: $3.6 trillion. In fact, there are 8.6 million data centers worldwide, the reality is many small and medium sized business have server closets and colocation footprints filled with servers and storage gear. While on-premise environment virtualization may have peaked at 75%, the Public Cloud has lagged in ado...
Apr. 26, 2015 02:00 PM EDT Reads: 1,322
Dave will share his insights on how Internet of Things for Enterprises are transforming and making more productive and efficient operations and maintenance (O&M) procedures in the cleantech industry and beyond. Speaker Bio: Dave Landa is chief operating officer of Cybozu Corp (kintone US). Based in the San Francisco Bay Area, Dave has been on the forefront of the Cloud revolution driving strategic business development on the executive teams of multiple leading Software as a Services (SaaS) ap...
Apr. 26, 2015 02:00 PM EDT Reads: 1,579
The best mobile applications are augmented by dedicated servers, the Internet and Cloud services. Mobile developers should focus on one thing: writing the next socially disruptive viral app. Thanks to the cloud, they can focus on the overall solution, not the underlying plumbing. From iOS to Android and Windows, developers can leverage cloud services to create a common cross-platform backend to persist user settings, app data, broadcast notifications, run jobs, etc. This session provide...
Apr. 26, 2015 02:00 PM EDT Reads: 1,429
SYS-CON Events announced today that BroadSoft, the leading global provider of Unified Communications and Collaboration (UCC) services to operators worldwide, has been named “Gold Sponsor” of SYS-CON's WebRTC Summit, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. BroadSoft is the leading provider of software and services that enable mobile, fixed-line and cable service providers to offer Unified Communications over their Internet Protocol networks. The Compa...
Apr. 26, 2015 01:30 PM EDT Reads: 2,562
The 5th International DevOps Summit, co-located with 17th International Cloud Expo – being held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA – announces that its Call for Papers is open. Born out of proven success in agile development, cloud computing, and process automation, DevOps is a macro trend you cannot afford to miss. From showcase success stories from early adopters and web-scale businesses, DevOps is expanding to organizations of all sizes, including the...
Apr. 26, 2015 01:00 PM EDT Reads: 2,240
DevOps tasked with driving success in the cloud need a solution to efficiently leverage multiple clouds while avoiding cloud lock-in. Flexiant today announces the commercial availability of Flexiant Concerto. With Flexiant Concerto, DevOps have cloud freedom to automate the build, deployment and operations of applications consistently across multiple clouds. Concerto is available through four disruptive pricing models aimed to deliver multi-cloud at a price point everyone can afford.
Apr. 26, 2015 12:30 PM EDT Reads: 1,716
ProfitBricks has launched its new DevOps Central and REST API, along with support for three multi-cloud libraries and a Python SDK. This, combined with its already existing SOAP API and its new RESTful API, moves ProfitBricks into a position to better serve the DevOps community and provide the ability to automate cloud infrastructure in a multi-cloud world. Following this momentum, ProfitBricks has also introduced several libraries that enable developers to use their favorite language to code ...
Apr. 26, 2015 12:00 PM EDT Reads: 1,708
What exactly is a cognitive application? In her session at 16th Cloud Expo, Ashley Hathaway, Product Manager at IBM Watson, will look at the services being offered by the IBM Watson Developer Cloud and what that means for developers and Big Data. She'll explore how IBM Watson and its partnerships will continue to grow and help define what it means to be a cognitive service, as well as take a look at the offerings on Bluemix. She will also check out how Watson and the Alchemy API team up to off...
Apr. 26, 2015 12:00 PM EDT Reads: 1,869
The IoT Bootcamp is coming to Cloud Expo | @ThingsExpo on June 9-10 at the Javits Center in New York. Instructor. Registration is now available at http://iotbootcamp.sys-con.com/ Instructor Janakiram MSV previously taught the famously successful Multi-Cloud Bootcamp at Cloud Expo | @ThingsExpo in November in Santa Clara. Now he is expanding the focus to Janakiram is the founder and CTO of Get Cloud Ready Consulting, a niche Cloud Migration and Cloud Operations firm that recently got acquir...
Apr. 26, 2015 12:00 PM EDT Reads: 1,678
The 17th International Cloud Expo has announced that its Call for Papers is open. 17th International Cloud Expo, to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, APM, APIs, Microservices, Security, Big Data, Internet of Things, DevOps 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 bu...
Apr. 26, 2015 12:00 PM EDT Reads: 2,329