|By Kulvir Singh Bhogal, Brad Bouldin||
|March 30, 2004 12:00 AM EST||
The quest for increased application performance is a science in itself. IBM WebSphere Application Server includes a powerful caching technology called the dynamic cache service, which you can employ in your Web applications to dramatically improve performance.
In this article, we'll use the dynamic cache service to increase the performance of a simple Web application. We will then use Apache JMeter, an open source load generator, to load-test our cached application in order to measure the application performance gains achieved by leveraging the dynamic cache service.
As you will see, the potential performance gains realized by using the dynamic cache service can be achieved with minimal effort. No changes to your application code are required, which means there is no impact on application portability.
The dynamic cache service is the name given to a set of services provided by WebSphere Application Server. The types of caching services include servlet and JSP caching, a Java object cache facility, a cache for Web services, and a command cache. In this introductory article our example will focus on the use of the servlet and JSP caching facility.
Enter Stage Left - Our Application to Tweak
Our demonstration application is implemented as a servlet that fetches a large piece of content from a remote HTTP server, then performs some text processing and returns the result to the end user. Our servlet grabs content from the Gutenberg Web site, which hosts downloadable books in ASCII format (www.gutenberg.net). For those unfamiliar with the Gutenberg project, this site hosts downloadable books that have expired copyrights and are therefore freely available.
Our example servlet will perform some text processing on the downloaded book: it will italicize the introductory section in the book's text that describes the Gutenberg project. We will test the performance before and after turning on caching and then compare the results. Once caching is enabled, the book will be downloaded on the first servlet request and presented to the user. Subsequent servlet requests will be served from the cache.
The servlet code (see Listing 1) is simple and straightforward, and uses standard Java packages and classes to read, parse, and transmit the content.
The servlet opens a URL connection to a book on gutenberg.net (see Figure 1) and copies the output to the servlet's output stream. The first section of the book contains the Gutenberg preamble (disclaimers and such), which the servlet puts in italics. Once the servlet reaches the end of the preamble (marked in the text stream with "*END*" at the end of a line), the servlet stops italicizing and switches to a more readable font for books (Times). The servlet also logs how long it took to produce the result, which has the side effect of showing us when the servlet is called (versus served from the cache). This will be handy once we enable caching because the log will show that WebSphere is using the cached result and bypassing the servlet call completely.
You can download an EAR file containing the servlet and test the performance on your own system. The source code for this article can be downloaded from www.sys-con.com/websphere/sourcec.cfm.
To see the effect of using dynamic caching in our application, we'll juxtapose the performance of our application with and without caching enabled. To study our application's performance, we'll leverage Apache JMeter. It is beyond the scope of this article to delve into the details of how to use JMeter, but you can learn more about how to use JMeter at www.devx.com/webdev/Article/17950/0. JMeter allows us to simulate a load of requests against our application server and measure subsequent performance.
We used JMeter v1.9.1 from http://jakarta.apache.org/jmeter. Our test environment consisted of one machine running WebSphere Studio Advanced Edition 5.0.1 with the WebSphere v5.0 Test Environment on a Windows 2000 Pro machine configured with a single AMD 3000+ processor and 1GB of RAM. We ran JMeter on the same machine. Since this example is "I/O-bound," running JMeter on another machine does not significantly affect performance. We used WebSphere Application Server 5.0.1, but other versions will yield similar results.
We configured JMeter with a "Jakarta Users" thread group, using 5 threads and 100 iterations (see Figure 2).
Under the thread group we added an HTTP request to access our servlet. We used port 9080 to access our servlet's Web container directly (see Figure 3). Figure 4 shows the results of our baseline (precache) test.
It's not too surprising that the average servlet response time is almost 15 seconds; it takes time to process and transmit 901K of text. Because each request takes so long (by design), our throughput is a mere 18.7 requests per minute. Our next step is to enable the dynamic cache service and measure the performance improvement.
Enabling the Dynamic Cache Service in WebSphere Application Server
Enable the dynamic cache service in the WebSphere administrative console as follows: open the administrative console, click Servers > Application Servers in the navigation tree, click on your server, and select Dynamic Cache Service under Additional Properties. Select Enable service at server startup in the Startup state field and click OK.
Enable servlet caching as follows: in the administrative console, click Servers > Application Servers in the navigation tree, select your server, and click Web Container. Check the Enable servlet caching checkbox under the Configuration tab. Click Apply or OK.
To complete the configuration changes, click Save on the top menu bar, click the Save button, and then restart the application server.
Configuring Our Servlet to Use Dynamic Cache
To specify the cache settings for our servlet, we created a cachespec.xml file (see Listing 2), located in the WEB-INF subdirectory of our WAR file. Let's take some time to discuss some of the cache settings in this file.
We have only scratched the surface of the configuration parameters you can set for a cacheable object. For example, you can opt to persist cache entries to disk in case of overflows or the housing server being stopped. Refer to the WebSphere Information Center (www-306.ibm.com/software/webservers/appserv/infocenter.html) to find out more information about which parameters can be used to achieve the desired caching effect you'd like to associate with a specific cacheable object. These design considerations are of course specific to your enterprise application's business requirements.
The WebSphere Application Server continually monitors the cachspec.xml file for changes, so the changes will take place immediately when you save the file. You therefore don't need to restart your enterprise application or application server when you want to make adjustments to your caching strategy.
The Performance Gain with the Dynamic Caching Service Enabled
Once we saved our cachespec.xml file in the WEB-INF directory, WebSphere Application Server noticed the new file, and wrote the following line to System.out:
[2/2/04 17:09:50:812 CST] 435b6a5a ConfigManager I DYNA0047I: Successfully loaded
cache configuration file k:\wsad\workspace5\Dynamic Cache Example\Web
Then we reran our JMeter test. Figure 5 shows the results.
We started with a throughput of 18.7 transactions per minute, and with cachspec.xml in place we were able to achieve quite a bit more: 568 transactions per minute. The average time to serve a request went from 14.9 seconds down to a speedy 0.416 seconds. The dramatic improvement demonstrates the power of using WebSphere's dynamic caching service.
Our test servlet was deliberately constructed to demonstrate a dramatic effect, but most Web applications that do any processing or back-end calls will benefit substantially from using the dynamic cache service. It's important to point out that we didn't need to make any changes to our servlet code. We simply created a cachespec.xml file in our WEB-INF directory and witnessed an immediate performance improvement.
WebSphere Application Server 5.0 ships with a Cache Monitor application (see Figure 6) that allows you to use a Web browser to view reports on cache statistics, and also allows you do things like view the cache IDs of objects in the cache.
The Cache Monitor is located in the <WAS_ROOT>/installableApps directory (CacheMonitor.ear) and is easy to install and use. After you have installed the Cache Monitor enterprise application, open the URL: http://<your_server>:<your_port>/cachemonitor. You can use the Reset Statistics and Clear Cache buttons to clean out the cache and get ready for another load test after you tweak the caching policy settings in your cachespec.xml file. This saves time, since you won't have to restart the application server between load tests.
Java servlets and JavaServer Pages are typically used to present dynamic content to a Web site visitor. WebSphere Application Server's dynamic cache service can be used to serve requests for content from an in-memory cache. Servlet output is stored in memory, expediting delivery to the end user.
In this article, you used the dynamic cache service offerings on a Web application and witnessed the added performance benefits using Apache JMeter. The process of enabling WebSphere Application Server's dynamic cache service and modifying your Web application to use dynamic caching is rather simple. Leveraging these highly configurable caching options should be a major consideration for organizations trying to squeeze the most performance out of their application servers. You can learn more about the dynamic cache service in the WebSphere Information Center.
The authors would like to thank Lisa Tomita for her review of this article.
|Carlos Melvin 04/14/04 05:24:26 PM EDT|
I have been reading a little on dynamic cache service. I have yet to see any reference to a system other than Windows. Does this work on an AIX platform?
|Pierre Comtois 03/31/04 02:06:01 PM EST|
How would the cache work/react when using the same JSP as a template for dynamic data recovered from a DB. An application we implemented with older version of WAS involved using about 10 template JSPs and populated over 10000 different "pages" on-demand, a "page" being a template with simply different content. Each "page"''s content was retrieved by the servlet and command classes based on keys present on the URL.
SYS-CON Events announced today that the "Second Containers & Microservices Expo" will take place November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Containers and microservices have become topics of intense interest throughout the cloud developer and enterprise IT communities.
Sep. 2, 2015 06:45 PM EDT Reads: 631
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 business opportunity. Submit your speaking proposal today!
Sep. 2, 2015 06:30 PM EDT Reads: 1,655
SYS-CON Events announced today that IceWarp will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. IceWarp, the leader of cloud and on-premise messaging, delivers secured email, chat, documents, conferencing and collaboration to today's mobile workforce, all in one unified interface
Sep. 2, 2015 06:00 PM EDT Reads: 463
SYS-CON Events announced today that Micron Technology, Inc., a global leader in advanced semiconductor systems, will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Micron’s broad portfolio of high-performance memory technologies – including DRAM, NAND and NOR Flash – is the basis for solid state drives, modules, multichip packages and other system solutions. Backed by more than 35 years of technology leadership, Micron's memory solutions enable the world's most innovative computing, consumer,...
Sep. 2, 2015 05:30 PM EDT Reads: 266
SYS-CON Events announced today the Containers & Microservices Bootcamp, being held November 3-4, 2015, in conjunction with 17th Cloud Expo, @ThingsExpo, and @DevOpsSummit at the Santa Clara Convention Center in Santa Clara, CA. This is your chance to get started with the latest technology in the industry. Combined with real-world scenarios and use cases, the Containers and Microservices Bootcamp, led by Janakiram MSV, a Microsoft Regional Director, will include presentations as well as hands-on demos and comprehensive walkthroughs.
Sep. 2, 2015 04:45 PM EDT Reads: 390
SYS-CON Events announced today that Pythian, a global IT services company specializing in helping companies leverage disruptive technologies to optimize revenue-generating systems, has been named “Bronze Sponsor” of SYS-CON's 17th Cloud Expo, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Founded in 1997, Pythian is a global IT services company that helps companies compete by adopting disruptive technologies such as cloud, Big Data, advanced analytics, and DevOps to advance innovation and increase agility. Specializing in designing, imple...
Sep. 2, 2015 04:15 PM EDT Reads: 350
In his session at @ThingsExpo, Lee Williams, a producer of the first smartphones and tablets, will talk about how he is now applying his experience in mobile technology to the design and development of the next generation of Environmental and Sustainability Services at ETwater. He will explain how M2M controllers work through wirelessly connected remote controls; and specifically delve into a retrofit option that reverse-engineers control codes of existing conventional controller systems so they don't have to be replaced and are instantly converted to become smart, connected devices.
Sep. 2, 2015 04:15 PM EDT Reads: 211
Akana has announced the availability of the new Akana Healthcare Solution. The API-driven solution helps healthcare organizations accelerate their transition to being secure, digitally interoperable businesses. It leverages the Health Level Seven International Fast Healthcare Interoperability Resources (HL7 FHIR) standard to enable broader business use of medical data. Akana developed the Healthcare Solution in response to healthcare businesses that want to increase electronic, multi-device access to health records while reducing operating costs and complying with government regulations.
Sep. 2, 2015 04:00 PM EDT Reads: 279
17th Cloud Expo, taking place Nov 3-5, 2015, 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 enterprises are using some form of XaaS – software, platform, and infrastructure as a service.
Sep. 2, 2015 04:00 PM EDT Reads: 1,581
With the Apple Watch making its way onto wrists all over the world, it’s only a matter of time before it becomes a staple in the workplace. In fact, Forrester reported that 68 percent of technology and business decision-makers characterize wearables as a top priority for 2015. Recognizing their business value early on, FinancialForce.com was the first to bring ERP to wearables, helping streamline communication across front and back office functions. In his session at @ThingsExpo, Kevin Roberts, GM of Platform at FinancialForce.com, will discuss the value of business applications on wearable ...
Sep. 2, 2015 04:00 PM EDT
The 3rd International WebRTC Summit, to be held Nov. 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA, announces that its Call for Papers is now 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 15th International Cloud Expo, 6th International Big Data Expo, 3rd International DevOps Summit and 2nd Internet of @ThingsExpo. WebRTC (Web-based Real-Time Communication) is an open source project supported by Google, Mozilla and Opera that aims to enable bro...
Sep. 2, 2015 03:45 PM EDT Reads: 1,563
WebRTC services have already permeated corporate communications in the form of videoconferencing solutions. However, WebRTC has the potential of going beyond and catalyzing a new class of services providing more than calls with capabilities such as mass-scale real-time media broadcasting, enriched and augmented video, person-to-machine and machine-to-machine communications. In his session at @ThingsExpo, Luis Lopez, CEO of Kurento, will introduce the technologies required for implementing these ideas and some early experiments performed in the Kurento open source software community in areas ...
Sep. 2, 2015 02:15 PM EDT
Consumer IoT applications provide data about the user that just doesn’t exist in traditional PC or mobile web applications. This rich data, or “context,” enables the highly personalized consumer experiences that characterize many consumer IoT apps. This same data is also providing brands with unprecedented insight into how their connected products are being used, while, at the same time, powering highly targeted engagement and marketing opportunities. In his session at @ThingsExpo, Nathan Treloar, President and COO of Bebaio, will explore examples of brands transforming their businesses by t...
Sep. 2, 2015 02:00 PM EDT Reads: 266
SYS-CON Events announced today that HPM Networks will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. For 20 years, HPM Networks has been integrating technology solutions that solve complex business challenges. HPM Networks has designed solutions for both SMB and enterprise customers throughout the San Francisco Bay Area.
Sep. 2, 2015 01:30 PM EDT Reads: 942
While many app developers are comfortable building apps for the smartphone, there is a whole new world out there. In his session at @ThingsExpo, Narayan Sainaney, Co-founder and CTO of Mojio, will discuss how the business case for connected car apps is growing and, with open platform companies having already done the heavy lifting, there really is no barrier to entry.
Sep. 2, 2015 12:45 PM EDT Reads: 196
Too often with compelling new technologies market participants become overly enamored with that attractiveness of the technology and neglect underlying business drivers. This tendency, what some call the “newest shiny object syndrome,” is understandable given that virtually all of us are heavily engaged in technology. But it is also mistaken. Without concrete business cases driving its deployment, IoT, like many other technologies before it, will fade into obscurity.
Sep. 2, 2015 12:15 PM EDT Reads: 418
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo in Silicon Valley. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th 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 an...
Sep. 2, 2015 11:30 AM EDT Reads: 1,999
With the proliferation of connected devices underpinning new Internet of Things systems, Brandon Schulz, Director of Luxoft IoT – Retail, will be looking at the transformation of the retail customer experience in brick and mortar stores in his session at @ThingsExpo. Questions he will address include: Will beacons drop to the wayside like QR codes, or be a proximity-based profit driver? How will the customer experience change in stores of all types when everything can be instrumented and analyzed? As an area of investment, how might a retail company move towards an innovation methodolo...
Sep. 2, 2015 11:15 AM EDT Reads: 497
As more intelligent IoT applications shift into gear, they’re merging into the ever-increasing traffic flow of the Internet. It won’t be long before we experience bottlenecks, as IoT traffic peaks during rush hours. Organizations that are unprepared will find themselves by the side of the road unable to cross back into the fast lane. As billions of new devices begin to communicate and exchange data – will your infrastructure be scalable enough to handle this new interconnected world?
Sep. 2, 2015 11:15 AM EDT Reads: 188
The Internet of Things is in the early stages of mainstream deployment but it promises to unlock value and rapidly transform how organizations manage, operationalize, and monetize their assets. IoT is a complex structure of hardware, sensors, applications, analytics and devices that need to be able to communicate geographically and across all functions. Once the data is collected from numerous endpoints, the challenge then becomes converting it into actionable insight.
Sep. 2, 2015 09:00 AM EDT