Welcome!

Weblogic Authors: Elizabeth White, Michael Meiner, Michael Bushong, Avi Rosenthal

Related Topics: Weblogic

Weblogic: Article

Caching

Caching

Application server performance. Database performance. Hardware performance. These are numbers measured in the popular press, although in most situations they have little to do with your application's real-world performance. The number one way to increase performance, the thing that gives you the biggest boost, is caching. Caching in every tier is becoming more and more prevalent. On the front end, we have caching proxy servers like Squid and AOL. On the back end, we have databases and file systems that are caching our data. This month, I'm going to talk about caching in the Web application layer of the middle tier, where your application meets the Internet.

In WebLogic Server 5.1, the JSP cache tag was introduced for caching in the Web application tier. This tag allows you to cache both input (values of variables) and output (typically, the generated HTML). Ideally, these tags can be used so you have what I call "exact caching." In other words, even though caching was introduced, no change in the functionality of the application was made because the data in the cache is always the same as the real data. This is similar to how caches are used on CPUs, databases, and file systems. Just because something is cached, it doesn't mean that it's out of date. This isn't the only way to architect your caching layer. It's also possible to analyze the system and find places where you'd rather have an out-of-date answer right now, rather than an up-to-date answer after blocking the user for a time.

Here's an example of "exact caching." On my Web site I built a DVD check-out service for the people who live in my loft building. At the time, I was experimenting with XML and wanted to use it to store all the information about the registered users and the DVDs. Since I was just using the file system, parsing the XML all the time was time consuming. However, since I knew when the application was updating the XML files, I could use the cache tag to store the results of the parse and only flush the cache when they changed. This led to an order-of-magnitude increase in speed, with no loss of functionality. Voila, "exact caching."

Similarly, in the first application of the cache tag in production, a customer used the tag to cache the content from their content management system. Since they could cache based on variables in the page, they were able to only query the update time of the document in question on each request, instead of pulling the whole document over to the file system each time. This also garnered them an order-of-magnitude improvement in performance for the affected operations.

Much more difficult to architect properly is timeout-based caching. This is the normal caching that your browser and proxy servers do. When you get a Web page back from a Web site, a time stamp is returned that tells you when the page might be out of date; it's stored in the "Expires" header. If you request the page before that time, your browser will first go to its local cache for the contents (unless you force it to return to the Web site). Obviously, this method assumes that all content on the page expires at the same time and that your primary concern is reducing the bandwidth load on the server. For many application server deployments, the primary concern isn't bandwidth, but reducing the load on the servers themselves. That's where caching in the middle-tier has its sweet spot. Timeout-based caches assume that the application developer has special knowledge about the time sensitivity of the data that is being used to generate the Web page. For instance, you might be offering 20-minute delayed stock quotes and you might decide that the most popular stocks should be cached so that when users request a quote they are given the same one as everyone else who asks within some specified period of time. Determining that period is the important part of the exercise. Let's say you decide that you're only going to update the cache every 5 seconds; the quotes are already 20 minutes old anyway. If you're getting 10 requests per second for a particular ticker, that means you get 50 requests in 5 seconds, so you're doing 50 times less work to get each quote minus the cache overhead! Quite a savings for very little loss in functionality.

As you can see, caching can tremendously improve the performance of your Web applications. Using cache tags and cache filters (new in 7.0), you can build very robust, performant, scalable applications with only a bit more careful investment in design and architecture. We have only touched the surface of what you can do with caches in the Web application layer in this article; you can find out much more about caching using these tools on my Web site at www.sampullara.com/caching.

More Stories By Sam Pullara

Sam Pullara has been a software engineer at WebLogic since 1996 and has contributed to the architecture, design, and implementation of many aspects of the application server.

e-mail: [email protected]

Comments (1) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
wesnur 03/24/10 05:28:00 AM EDT

I agreed that caching is the best way to increase the performance of the app as it reduces expensive data trips to the data base by reducing the performance bottle neck. It’s the arena of distributed caching now as concept of local caching has become a bit old. You can’t achieve desired results if you have local cache especially if your data is distributed over many servers. There many distributed caching solution are available now days but NCache and MS Velocity being the most famous ones.

@ThingsExpo Stories
The cloud market growth today is largely in public clouds. While there is a lot of spend in IT departments in virtualization, these aren’t yet translating into a true “cloud” experience within the enterprise. What is stopping the growth of the “private cloud” market? In his general session at 18th Cloud Expo, Nara Rajagopalan, CEO of Accelerite, explored the challenges in deploying, managing, and getting adoption for a private cloud within an enterprise. What are the key differences between wh...
Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 19th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world and ThingsExpo Silicon Valley Call for Papers is now open.
It is one thing to build single industrial IoT applications, but what will it take to build the Smart Cities and truly society changing applications of the future? The technology won’t be the problem, it will be the number of parties that need to work together and be aligned in their motivation to succeed. In his Day 2 Keynote at @ThingsExpo, Henrik Kenani Dahlgren, Portfolio Marketing Manager at Ericsson, discussed how to plan to cooperate, partner, and form lasting all-star teams to change t...
Connected devices and the industrial internet are growing exponentially every year with Cisco expecting 50 billion devices to be in operation by 2020. In this period of growth, location-based insights are becoming invaluable to many businesses as they adopt new connected technologies. Knowing when and where these devices connect from is critical for a number of scenarios in supply chain management, disaster management, emergency response, M2M, location marketing and more. In his session at @Th...
Machine Learning helps make complex systems more efficient. By applying advanced Machine Learning techniques such as Cognitive Fingerprinting, wind project operators can utilize these tools to learn from collected data, detect regular patterns, and optimize their own operations. In his session at 18th Cloud Expo, Stuart Gillen, Director of Business Development at SparkCognition, discussed how research has demonstrated the value of Machine Learning in delivering next generation analytics to imp...
SYS-CON Events announced today that ReadyTalk, a leading provider of online conferencing and webinar services, has been named Vendor Presentation Sponsor at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. ReadyTalk delivers audio and web conferencing services that inspire collaboration and enable the Future of Work for today’s increasingly digital and mobile workforce. By combining intuitive, innovative tec...
Amazon has gradually rolled out parts of its IoT offerings, but these are just the tip of the iceberg. In addition to optimizing their backend AWS offerings, Amazon is laying the ground work to be a major force in IoT - especially in the connected home and office. In his session at @ThingsExpo, Chris Kocher, founder and managing director of Grey Heron, explained how Amazon is extending its reach to become a major force in IoT by building on its dominant cloud IoT platform, its Dash Button strat...
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, provided 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 sett...
19th Cloud Expo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, 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 enterpri...
SYS-CON Events announced today that Bsquare has been named “Silver Sponsor” of SYS-CON's @ThingsExpo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. For more than two decades, Bsquare has helped its customers extract business value from a broad array of physical assets by making them intelligent, connecting them, and using the data they generate to optimize business processes.
There are several IoTs: the Industrial Internet, Consumer Wearables, Wearables and Healthcare, Supply Chains, and the movement toward Smart Grids, Cities, Regions, and Nations. There are competing communications standards every step of the way, a bewildering array of sensors and devices, and an entire world of competing data analytics platforms. To some this appears to be chaos. In this power panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, Bradley Holt, Developer Advocate a...
There is little doubt that Big Data solutions will have an increasing role in the Enterprise IT mainstream over time. Big Data at Cloud Expo - to be held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA - has announced its Call for Papers is open. Cloud computing is being adopted in one form or another by 94% of enterprises today. Tens of billions of new devices are being connected to The Internet of Things. And Big Data is driving this bus. An exponential increase is...
Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 19th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devices - comp...
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...
Cloud computing is being adopted in one form or another by 94% of enterprises today. Tens of billions of new devices are being connected to The Internet of Things. And Big Data is driving this bus. An exponential increase is expected in the amount of information being processed, managed, analyzed, and acted upon by enterprise IT. This amazing is not part of some distant future - it is happening today. One report shows a 650% increase in enterprise data by 2020. Other estimates are even higher....
Cognitive Computing is becoming the foundation for a new generation of solutions that have the potential to transform business. Unlike traditional approaches to building solutions, a cognitive computing approach allows the data to help determine the way applications are designed. This contrasts with conventional software development that begins with defining logic based on the current way a business operates. In her session at 18th Cloud Expo, Judith S. Hurwitz, President and CEO of Hurwitz & ...
In his general session at 18th Cloud Expo, Lee Atchison, Principal Cloud Architect and Advocate at New Relic, discussed cloud as a ‘better data center’ and how it adds new capacity (faster) and improves application availability (redundancy). The cloud is a ‘Dynamic Tool for Dynamic Apps’ and resource allocation is an integral part of your application architecture, so use only the resources you need and allocate /de-allocate resources on the fly.
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, Digital Transformation, 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 opportuni...
industrial company for a multi-year contract initially valued at over $4.0 million. In addition to DataV software, Bsquare will also provide comprehensive systems integration, support and maintenance services. DataV leverages advanced data analytics, predictive reasoning, data-driven diagnostics, and automated orchestration of remediation actions in order to improve asset uptime while reducing service and warranty costs.
Vidyo, Inc., has joined the Alliance for Open Media. The Alliance for Open Media is a non-profit organization working to define and develop media technologies that address the need for an open standard for video compression and delivery over the web. As a member of the Alliance, Vidyo will collaborate with industry leaders in pursuit of an open and royalty-free AOMedia Video codec, AV1. Vidyo’s contributions to the organization will bring to bear its long history of expertise in codec technolo...