Welcome!

Server Monitoring Authors: Carmen Gonzalez, Ken Schwaber, JP Morgenthal, Pat Romanski, Elizabeth White

Related Topics: @DevOpsSummit, Microservices Expo, Linux Containers, Containers Expo Blog, Server Monitoring

@DevOpsSummit: Blog Feed Post

Configuration with #Jenkins | @DevOpsSummit #DevOps #APM #Monitoring

Configuration settings that are enabled during the application development are very useful

When Configuration Settings from Development Wreak Havoc in Production
By Asad Ali

As applications are promoted from the development environment to the CI or the QA environment and then into the production environment, it is very common for the configuration settings to be changed as the code is promoted. For example, the settings for the database connection pools are typically lower in development environment than the QA/Load Testing environment. The primary reason for the existence of the configuration setting differences is to enhance application performance. However, occasionally there are instances where the application code is mistakenly promoted into production without changing these settings. In such cases, such promotion of code can cause performance havoc in the production environment. This blog describes one such scenario.

During their proof of concept, a prospect requested we identify and resolve an issue that they were observing in the production environment. They had just promoted a newer version of their critical application to production and soon after the promotion of the code they stared to see significant increase in the response time when the end users tried to login to their web application. To diagnose the issue the prospect injected our agents into their production JVMs that were exhibiting the issue to the end user. With Dynatrace agents injected, we observed both high response time for login and that most of the time for the login request was spent in class loading.

Additionally, breakdown of the response time showed that most of the time for login web request was spent in synchronization (92%).

The response time breakdown of the login request clearly shows that 92% of the time is spent in synchronization.

The response time breakdown of the login request clearly shows that 92% of the time is spent in synchronization.

With the response time breakdown showing the highest amount of time in synchronization we took a thread dump on the JVM where the login request was being processed to get insight into thread locking issue. The thread dump showed 67 threads that were blocked in the JVM.

67 Threads were blocked on the JVM.

67 Threads were blocked on the JVM.

Locking Hotspots view shows the breakdown of the blocked threads

Locking Hotspots view shows the breakdown of the blocked threads

Further analysis of the content of the thread dump showed that most of the blocked threads were waiting for the resource (CompoundClassLoader) held by one running thread (Thread Id 5570678).

Thread Id 5570678 owned the monitor on which the other threads were blocked.

Thread Id 5570678 owned the monitor on which the other threads were blocked.

CompoundClassLoader is held by Thread 5570678.

CompoundClassLoader is held by Thread 5570678.

All blocked threads are waiting on CompoundClassLoader.

All blocked threads are waiting on CompoundClassLoader.

The thread stack trace for the running thread showed that it is trying to load the class from the file system. Examining the full trace of the thread dump shows that the threads on this JVM are creating a new facelet every time a web request is received.

getFacelet being called every time a request is processed by the thread.

getFacelet being called every time a request is processed by the thread.

While it is very normal for a JVM to spend some time to load classes when the JVM is initially started, it is NOT normal (or good for performance) for the class loading to continue even after the JVM has warmed up and most of the classes are already loaded.

The thread stack showed call to getFacelet(java.util.URL) method in the com.sun.facelets.impl.DefaultFaceletFactory class. Review of the source of this class showed that the method tries to load the class if the method needsToBeRefreshed() returns true.

Code snippet of com.sun.facelets.impl.DefaultFaceletFactory class.

Code snippet of com.sun.facelets.impl.DefaultFaceletFactory class.

And finally the code for needsToBeRefreshed() clearly shows that it returns true  if the refreshPeriod is set to 0.

needsToBeRefreshed() method shows that if the refresh period is set to 0, the class is refreshed every time.

needsToBeRefreshed() method shows that if the refresh period is set to 0, the class is refreshed every time.

The Facelets are capable of precompiling if you set javax.faces.FACELETS_REFRESH_PERIOD to -1. However, once set to -1, the JSF never re-compile/re-parses the Facelets files and holds the entire SAX-compiled/parsed XML tree.

Insert11

In the development process the REFRESH_PERIOD is typically set to 0 because it allows the developers to keep editing the Facelets file without the need to restart the server. What happened at this prospect is that the application code was promoted into production with the REFRESH_PERIOD is to 0 value and hence every time the user tried to login, the Facelets were forced to recompile and that in turn resulted in high response time.

Conclusion
Configuration settings that are enabled during the application development are very useful as they reduce the number of times the application server has to be started to test code changes. However, as this example shows, it is very important to disable development-level settings as the code moves out of the development environment because they can cause performance havoc in the production environment. One of the best practices to eliminate occurrences of such scenario is to make the configuration changes a part of the continuous integration tools like Jenkins.

The post When configuration settings from development wreak havoc in production appeared first on about:performance.

More Stories By APM Blog

APM: It’s all about application performance, scalability, and architecture: best practices, lifecycle and DevOps, mobile and web, enterprise, user experience

@ThingsExpo Stories
The 21st International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Digital Transformation, Machine Learning 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 busin...
Existing Big Data solutions are mainly focused on the discovery and analysis of data. The solutions are scalable and highly available but tedious when swapping in and swapping out occurs in disarray and thrashing takes place. The resolution for thrashing through machine learning algorithms and support nomenclature is through simple techniques. Organizations that have been collecting large customer data are increasingly seeing the need to use the data for swapping in and out and thrashing occurs ...
SYS-CON Events announced today that DivvyCloud will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. DivvyCloud software enables organizations to achieve their cloud computing goals by simplifying and automating security, compliance and cost optimization of public and private cloud infrastructure. Using DivvyCloud, customers can leverage programmatic Bots to identify and remediate common cloud problems in rea...
In his opening keynote at 20th Cloud Expo, Michael Maximilien, Research Scientist, Architect, and Engineer at IBM, will motivate why realizing the full potential of the cloud and social data requires artificial intelligence. By mixing Cloud Foundry and the rich set of Watson services, IBM's Bluemix is the best cloud operating system for enterprises today, providing rapid development and deployment of applications that can take advantage of the rich catalog of Watson services to help drive insigh...
SYS-CON Events announced today that Tintri, Inc, a leading provider of enterprise cloud infrastructure, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Tintri offers an enterprise cloud platform built with public cloud-like web services and RESTful APIs. Organizations use Tintri all-flash storage with scale-out and automation as a foundation for their own clouds – to build agile development environments...
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, whic...
Every successful software product evolves from an idea to an enterprise system. Notably, the same way is passed by the product owner's company. In his session at 20th Cloud Expo, Oleg Lola, CEO of MobiDev, will provide a generalized overview of the evolution of a software product, the product owner, the needs that arise at various stages of this process, and the value brought by a software development partner to the product owner as a response to these needs.
SYS-CON Events announced today that Cloudistics, an on-premises cloud computing company, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Cloudistics delivers a complete public cloud experience with composable on-premises infrastructures to medium and large enterprises. Its software-defined technology natively converges network, storage, compute, virtualization, and management into a ...
SYS-CON Events announced today that delaPlex will exhibit at SYS-CON's @ThingsExpo, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. delaPlex pioneered Software Development as a Service (SDaaS), which provides scalable resources to build, test, and deploy software. It’s a fast and more reliable way to develop a new product or expand your in-house team.
SYS-CON Events announced today that Technologic Systems Inc., an embedded systems solutions company, will exhibit at SYS-CON's @ThingsExpo, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Technologic Systems is an embedded systems company with headquarters in Fountain Hills, Arizona. They have been in business for 32 years, helping more than 8,000 OEM customers and building over a hundred COTS products that have never been discontinued. Technologic Systems’ pr...
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend @CloudExpo | @ThingsExpo, June 6-8, 2017, at the Javits Center in New York City, NY and October 31 - November 2, 2017, Santa Clara Convention Center, CA. Learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.
SYS-CON Events announced today that Tappest will exhibit MooseFS at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. MooseFS is a breakthrough concept in the storage industry. It allows you to secure stored data with either duplication or erasure coding using any server. The newest – 4.0 version of the software enables users to maintain the redundancy level with even 50% less hard drive space required. The software func...
SYS-CON Events announced today that Outscale will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Outscale's technology makes an automated and adaptable Cloud available to businesses, supporting them in the most complex IT projects while controlling their operational aspects. You boost your IT infrastructure's reactivity, with request responses that only take a few seconds.
New competitors, disruptive technologies, and growing expectations are pushing every business to both adopt and deliver new digital services. This ‘Digital Transformation’ demands rapid delivery and continuous iteration of new competitive services via multiple channels, which in turn demands new service delivery techniques – including DevOps. In this power panel at @DevOpsSummit 20th Cloud Expo, moderated by DevOps Conference Co-Chair Andi Mann, panelists will examine how DevOps helps to meet th...
SYS-CON Events announced today that EARP will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. "We are a software house, so we perfectly understand challenges that other software houses face in their projects. We can augment a team, that will work with the same standards and processes as our partners' internal teams. Our teams will deliver the same quality within the required time and budget just as our partn...
Most technology leaders, contemporary and from the hardware era, are reshaping their businesses to do software in the hope of capturing value in IoT. Although IoT is relatively new in the market, it has already gone through many promotional terms such as IoE, IoX, SDX, Edge/Fog, Mist Compute, etc. Ultimately, irrespective of the name, it is about deriving value from independent software assets participating in an ecosystem as one comprehensive solution.
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
SYS-CON Events announced today that A&I Solutions has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Founded in 1999, A&I Solutions is a leading information technology (IT) software and services provider focusing on best-in-class enterprise solutions. By partnering with industry leaders in technology, A&I assures customers high performance levels across all IT environments including: mai...
Five years ago development was seen as a dead-end career, now it’s anything but – with an explosion in mobile and IoT initiatives increasing the demand for skilled engineers. But apart from having a ready supply of great coders, what constitutes true ‘DevOps Royalty’? It’ll be the ability to craft resilient architectures, supportability, security everywhere across the software lifecycle. In his keynote at @DevOpsSummit at 20th Cloud Expo, Jeffrey Scheaffer, GM and SVP, Continuous Delivery Busine...
SYS-CON Events announced today that Progress, a global leader in application development, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Enterprises today are rapidly adopting the cloud, while continuing to retain business-critical/sensitive data inside the firewall. This is creating two separate data silos – one inside the firewall and the other outside the firewall. Cloud ISVs ofte...