|By Vitaly Mikheev||
|November 11, 2004 12:00 AM EST||
The JFC/Swing API, natively precompiled on Linux for the first time, delivers measurable improvement in Java GUI performance.
The Excelsior Engineering Team has ported Excelsior JET, a Java Virtual Machine (JVM) with an ahead-of-time compiler, to the Linux/x86 platform. As the JET JVM supports the entire J2SE platform API including the Java Foundation Classes (JFC/Swing), Excelsior engineers had an opportunity to evaluate the response time of natively compiled JFC/Swing on Linux. The results of the comparison with conventional, dynamically optimizing JVMs were encouraging: response time has improved by 40% or even doubled on some benchmarks. What's more important is that real-world Swing applications performed perceivably faster.
This article describes Excelsior JET JVM and JFCMark, free benchmark software by Excelsior that measures Swing-based GUI performance. Moreover, the authors share their technical experience in optimizing JFC/Swing and argue why ahead-of-time Java compilation has advantages over dynamic compilation for certain application types.
Two Recipes for JavaThe definition of the term "virtual machine" has been revised in the past few years. Modern Java Virtual Machines are no longer just interpreters of the Java bytecode. High performance, state-of-the-art implementations are made up of optimizing compilers that translate bytecode instructions down to the native code that runs directly on the hardware. However, one technical decision distinguishes contemporary JVMs: what's the best time to run the performance engine, an optimizing native compiler? Two options exist: run it before or after the application starts.
Most JVMs initially interpret the program and then analyze how it runs by looking for hot spots, that is, frequently executed portions of bytecode. Hot spots are then compiled to optimized native code during program execution. This approach is called Just-In-Time (JIT) compilation. Other JVMs feature static native compilers similar to traditional C/C++ compilers, enabling developers to optimize their Java applications before execution. For Java, this old trick has a new name - Ahead-Of-Time (AOT) compilation. However, solely static compilation is not enough for Java compatibility. Remember that many Java applications use custom classloaders to load some components or plug-ins at runtime. To have the "J" in "JVM," such virtual machines must be supplied with an interpreter or JIT compiler to handle classes that could not be precompiled.
Either approach alone is not a silver bullet for Java performance. JIT-oriented JVMs can "see through" program execution, which may help them optimize hot code better than static compilers do. In return, AOT-oriented JVMs do not spend execution time on interpretation, profiling, and compilation, so optimized programs run fast from start-up. Not surprisingly, single-loop benchmarks fail to reveal a clear performance winner between the two approaches. Instead of carrying the "microbenchmark war" into the Linux camp, let's take a look at a vital example: the performance of Java GUI applications based on JFC/Swing.
Penguin-Driven JVMsBoth JIT and AOT-oriented implementations are available for Linux. The well-known Sun HotSpot Client and Server JVMs are powered by JIT compilers. BEA WebLogic JRockit and IBM Java 2 Runtime Environment also play in the JIT team. GCJ, the GNU compiler for Java, now supported by Red Hat, and Excelsior JET feature AOT compilation.
At the core of Excelsior JET is a static optimizing compiler that enables developers to transform their Java applications into native executables or shared libraries (.so) on a Linux flavor. The AOT compiler comes with a JET Control Panel (see Figure 1), a graphical front end that makes the product easy to learn and use. The command-line interface provides the integration of Excelsior JET into automated builds. The redistributable JET runtime system includes a JIT compiler to support Java dynamic classloading. Another graphical tool, JetPackII (see Figure 2), enables the rapid creation of installation packages for optimized applications. Excelsior JET supports all Java 2 platform packages up to version 1.4.2.
Another static Java compiler is GCJ, a member of the GNU Compiler Collection. Following the FSF philosophy, GCJ uses a clean-room, free implementation of the Java 2 Platform API. Although most packages are now supported, there are noticeable exceptions such as the Abstract Window Toolkit (AWT), Swing, and some of the APIs introduced to J2SE 1.4. Contributors to the GNU Classpath project are currently implementing the missing packages. The GNU Interpreter for Java complements GCJ to enable Java dynamic loading. The implementation of a JIT compiler is planned for the future.
Accelerated Swing TempoGUI response time is in the eye of the beholder. As a result, it's tough to obtain GUI performance scores. To address this problem, Excelsior has developed JFCMark, a free benchmark suite to measure the performance of the JFC/Swing API. The included tests are manipulating with frames, trees, and tables; switching look-and-feels; decoding and drawing images; displaying and scrolling HTML texts; and using Swing layout managers. JFCMark requires JVMs that support the Java 2 Platform at the level of J2SE 1.3, 1.4, or 1.5.
Each test performs its scenario in the main loop through a given number of iterations. This allows you to obtain performance scores in short- and long-running modes. Upon completion, these tests report performance measured in units specific to their specific scenarios, for instance, frames opened per second. When designing JFCMark, we paid close attention to benchmarking accuracy. For a particular configuration, every benchmark always performs the same number of operations independently of the JVM under test. This requirement is achieved through synchronous processing of Swing events, that is, a next event is sent only after the previous one is processed. Therefore, a possible difference in reported speed depends solely on the time of the benchmark execution.
Let's consider the performance of the Swing windowing system that provides operations with frames. We have used a part of JFCMark to test typical manipulations with frames such as opening/closing, dragging, and selecting. The testbed configuration was as follows.]
- CPU: AMD Athlon running at 1,8 GHz
- RAM: 512MB DDR SDRAM
- Video: NVidia GeForce2 MX-200 at 1024x768x65536c
- OS: Red Hat Linux release 8.0 (Psyche)
- Linux Kernel: 2.4.18-14
- Excelsior JET 3.6 Professional Edition with JRE 1.4.2_04
- Sun Java HotSpot Client VM 1.4.2_04
- IBM J2RE 1.4.2 Classic with JIT enabled
- Sun Java HotSpot Server VM 1.4.2_04
- BEA WebLogic JRockit 8.1 with JRE 1.4.2_04
Figure 3 shows Swing performance scores for the long-playing version of JFCMark. For example, 600 frames are opened and closed by one of the tests. In this scenario, JIT-based JVMs have a chance to "warm up," that is, to optimize hot code for maximum speed. Note, however, that this level of performance may be reached only after doing a "good amount of mouse-clicking" in real-world Java GUI applications. Nevertheless, Excelsior JET still outperforms by 40% the first runner-up (HotSpot Client VM).
To see how Swing works on dynamic JVMs that have not been "warmed up" yet, look at Figure 4. It shows out-of-the-box performance scores for the short-running configuration. This case would correspond to the way Java GUI applications perform right after start-up. As can be seen, the JET-compiled Swing runs fast and it runs fast from the start. Other test participants work at least twice as slow for this scenario. Note that short-running benchmarks are mostly important for the client-side application's performance. For instance, if you start a GUI application and drag something with the mouse, you don't want to see it stumbling just because the JVM has not yet done its job. People talking about "snail Java" often ignore the fact that many JVMs take time to warm up. It's not an issue for server-side applications, which typically run for hours and days. However, the performance of client-side applications is most heavily impacted by the JVM warm-up cycle.
JEdit, a Practical ExampleIf you don't trust vendor benchmarks, check the results yourself. One of the samples that comes with Excelsior JET is a project for compiling jEdit, an open source, cross-platform text editor written in Java. jEdit has many advanced features that make text editing easier, such as syntax highlighting, auto indent, abbreviation expansion, registers, macros, regular expressions, and multiple file search/replace. It's a good example of a full-featured Swing-based application to evaluate GUI response time.
Behind the Performance FiguresAn interesting question is why don't the JIT-powered JVMs hit the performance bar raised by Excelsior JET? Of course, aggressive static optimizations and the removal of bytecode interpretation make Swing work smoothly. However, it seems that the long-running mode of JFCMark should be comfortable for the JIT compilers. Where does the 40% performance win come from? We found the answer unexpectedly when we aimed at further improving Swing performance: the absence of hot methods.
Under the covers, JFC/Swing is quite a complex event-driven system implemented on top of AWT. The implementation consists of several hundred classes which, in turn, use a variety of other core classes. Many thousands of Java methods are executed when, for example, you open a Swing frame. When we obtained the Swing execution profile, it proved to be almost flat. Lots of methods were executed but each of them took hundredths of one percent in total execution time. Only a few methods took more than 1-2%. At this point, we encountered an interesting problem: what should we improve in the absence of clear performance bottlenecks? As you may have guessed, the same problem exists for profile-guided JIT compilers. Instead of a few hot spots to be aggressively optimized, there are plenty of "warm spots" that are left intact. The flat execution profile is an application-specific property that some JVMs cannot effectively manage to achieve top performance.
ConclusionThis article is not about fast and slow JVMs. Rather, it demonstrates that for some Java applications, a JVM with AOT compilation can work faster than JIT-based JVMs. The main lesson we have learned from this study is that one size does not fit all and JFC/Swing is not the only example. One way or another, the Java platform wins and we were happy to make Excelsior JET JVM available to Java/Linux developers.
|Blind Earl 11/08/04 09:04:35 AM EST|
Once I actually found the article it was an interesting read. However, this website looks *terrible*. When a column is only 11 characters wide due to advertising squishing it down, it is time to find some other magazine to read.
|the author 11/08/04 07:14:08 AM EST|
>>A VM based on a JIT compiler loads always only byte code
The thing you are talking about is called Caching JIT compilation (at least HotSpot and BEA engineers called it so when I talked with them at JavaOne 2004)
Besides, Caching JIT compilation does not occur on the first invocation - it would take long long time and miss profile information useful for optimizations.
>>The Excelsior JET is no AOT compiler but just a static
visit http://gcc.gnu.org/java/ (GNU compiler for Java). It's described as an AOT compiler...
>>The next flaw is this: they measure a GUI application
In this test, HotSpot shows 28,9 frames/sec for short-running configuration and 44,6 frames/sec for long-running one. It does not look like "not even attempt to compile much of the covered code". Increasing the number of iteration to open more frames does not improve the HotSpot results. BTW, did you ever open 600+ frames in a Java application?
>>In the "benchmark" of the article,
Check the source code of the benchmark. It includes the loop
for(int j=0;j>IMHO: the Excelsior people tricked the HotSpot/JIT VMs
The standard Swing library and the public JET version were used for benchmarking. As for "synchronized" keywords - some of them are *safely* removed by the JET compiler during the course of escape analysis. There is excellent literature about this optimization technique (for example, see ACM OOPSLA'99 - about 5 papers were devoted to it).
P.S. JITs work well on servers and reusing the same machinery on the desktop is not always appropriate.
|angel'o'sphere 11/08/04 05:28:31 AM EST|
I don't like the article.
|Seun Osewa 11/07/04 02:32:53 PM EST|
combining the two approaches will lead to overhead similar to a JIT approach (hence, there's nothing to be gained for a long-running program)
|RAMMS+EIN 11/06/04 05:40:50 AM EST|
Why compare JIT against AOT? Why not have both?
AOT compilation makes for fast start up time and fast run time. JIT advocates claim that it can lead to better performance, as more optimizations can be performed with run-time information. So why not combine the two? Compile it before the first run, and further optimize it at run-time where appropriate. That way, you get the best of both worlds.
Basho Technologies has announced the latest release of Basho Riak TS, version 1.3. Riak TS is an enterprise-grade NoSQL database optimized for Internet of Things (IoT). The open source version enables developers to download the software for free and use it in production as well as make contributions to the code and develop applications around Riak TS. Enhancements to Riak TS make it quick, easy and cost-effective to spin up an instance to test new ideas and build IoT applications. In addition to...
Jul. 1, 2016 08:30 PM EDT Reads: 785
IoT is rapidly changing the way enterprises are using data to improve business decision-making. In order to derive business value, organizations must unlock insights from the data gathered and then act on these. In their session at @ThingsExpo, Eric Hoffman, Vice President at EastBanc Technologies, and Peter Shashkin, Head of Development Department at EastBanc Technologies, discussed how one organization leveraged IoT, cloud technology and data analysis to improve customer experiences and effi...
Jul. 1, 2016 06:30 PM EDT Reads: 735
Internet of @ThingsExpo has announced today that Chris Matthieu has been named tech chair of Internet of @ThingsExpo 2016 Silicon Valley. The 6thInternet of @ThingsExpo will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
Jul. 1, 2016 06:00 PM EDT Reads: 527
Presidio has received the 2015 EMC Partner Services Quality Award from EMC Corporation for achieving outstanding service excellence and customer satisfaction as measured by the EMC Partner Services Quality (PSQ) program. Presidio was also honored as the 2015 EMC Americas Marketing Excellence Partner of the Year and 2015 Mid-Market East Partner of the Year. The EMC PSQ program is a project-specific survey program designed for partners with Service Partner designations to solicit customer feedbac...
Jul. 1, 2016 05:30 PM EDT Reads: 774
The cloud promises new levels of agility and cost-savings for Big Data, data warehousing and analytics. But it’s challenging to understand all the options – from IaaS and PaaS to newer services like HaaS (Hadoop as a Service) and BDaaS (Big Data as a Service). In her session at @BigDataExpo at @ThingsExpo, Hannah Smalltree, a director at Cazena, provided an educational overview of emerging “as-a-service” options for Big Data in the cloud. This is critical background for IT and data profession...
Jul. 1, 2016 05:15 PM EDT Reads: 631
"There's a growing demand from users for things to be faster. When you think about all the transactions or interactions users will have with your product and everything that is between those transactions and interactions - what drives us at Catchpoint Systems is the idea to measure that and to analyze it," explained Leo Vasiliou, Director of Web Performance Engineering at Catchpoint Systems, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York Ci...
Jul. 1, 2016 04:15 PM EDT Reads: 233
Ask someone to architect an Internet of Things (IoT) solution and you are guaranteed to see a reference to the cloud. This would lead you to believe that IoT requires the cloud to exist. However, there are many IoT use cases where the cloud is not feasible or desirable. In his session at @ThingsExpo, Dave McCarthy, Director of Products at Bsquare Corporation, will discuss the strategies that exist to extend intelligence directly to IoT devices and sensors, freeing them from the constraints of ...
Jul. 1, 2016 03:15 PM EDT Reads: 305
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...
Jul. 1, 2016 02:00 PM EDT Reads: 1,420
Extracting business value from Internet of Things (IoT) data doesn’t happen overnight. There are several requirements that must be satisfied, including IoT device enablement, data analysis, real-time detection of complex events and automated orchestration of actions. Unfortunately, too many companies fall short in achieving their business goals by implementing incomplete solutions or not focusing on tangible use cases. In his general session at @ThingsExpo, Dave McCarthy, Director of Products...
Jul. 1, 2016 01:15 PM EDT Reads: 326
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...
Jul. 1, 2016 01:00 PM EDT Reads: 1,047
The Internet of Things will challenge the status quo of how IT and development organizations operate. Or will it? Certainly the fog layer of IoT requires special insights about data ontology, security and transactional integrity. But the developmental challenges are the same: People, Process and Platform and how we integrate our thinking to solve complicated problems. In his session at 19th Cloud Expo, Craig Sproule, CEO of Metavine, will demonstrate how to move beyond today's coding paradigm ...
Jul. 1, 2016 01:00 PM EDT Reads: 699
Apixio Inc. has raised $19.3 million in Series D venture capital funding led by SSM Partners with participation from First Analysis, Bain Capital Ventures and Apixio’s largest angel investor. Apixio will dedicate the proceeds toward advancing and scaling products powered by its cognitive computing platform, further enabling insights for optimal patient care. The Series D funding comes as Apixio experiences strong momentum and increasing demand for its HCC Profiler solution, which mines unstruc...
Jul. 1, 2016 12:30 PM EDT Reads: 685
SYS-CON Events has announced today that Roger Strukhoff has been named conference chair of Cloud Expo and @ThingsExpo 2016 Silicon Valley. The 19th Cloud Expo and 6th @ThingsExpo will take place on November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. "The Internet of Things brings trillions of dollars of opportunity to developers and enterprise IT, no matter how you measure it," stated Roger Strukhoff. "More importantly, it leverages the power of devices and the Interne...
Jul. 1, 2016 12:00 PM EDT Reads: 655
In addition to all the benefits, IoT is also bringing new kind of customer experience challenges - cars that unlock themselves, thermostats turning houses into saunas and baby video monitors broadcasting over the internet. This list can only increase because while IoT services should be intuitive and simple to use, the delivery ecosystem is a myriad of potential problems as IoT explodes complexity. So finding a performance issue is like finding the proverbial needle in the haystack.
Jul. 1, 2016 10:45 AM EDT Reads: 572
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...
Jul. 1, 2016 10:30 AM EDT Reads: 1,097
Whether your IoT service is connecting cars, homes, appliances, wearable, cameras or other devices, one question hangs in the balance – how do you actually make money from this service? The ability to turn your IoT service into profit requires the ability to create a monetization strategy that is flexible, scalable and working for you in real-time. It must be a transparent, smoothly implemented strategy that all stakeholders – from customers to the board – will be able to understand and comprehe...
Jul. 1, 2016 10:00 AM EDT Reads: 528
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...
Jul. 1, 2016 09:30 AM EDT Reads: 1,198
The IoT is changing the way enterprises conduct business. In his session at @ThingsExpo, Eric Hoffman, Vice President at EastBanc Technologies, discussed how businesses can gain an edge over competitors by empowering consumers to take control through IoT. He cited examples such as a Washington, D.C.-based sports club that leveraged IoT and the cloud to develop a comprehensive booking system. He also highlighted how IoT can revitalize and restore outdated business models, making them profitable ...
Jul. 1, 2016 09:00 AM EDT Reads: 693
IoT offers a value of almost $4 trillion to the manufacturing industry through platforms that can improve margins, optimize operations & drive high performance work teams. By using IoT technologies as a foundation, manufacturing customers are integrating worker safety with manufacturing systems, driving deep collaboration and utilizing analytics to exponentially increased per-unit margins. However, as Benoit Lheureux, the VP for Research at Gartner points out, “IoT project implementers often ...
Jul. 1, 2016 08:45 AM EDT Reads: 810
When people aren’t talking about VMs and containers, they’re talking about serverless architecture. Serverless is about no maintenance. It means you are not worried about low-level infrastructural and operational details. An event-driven serverless platform is a great use case for IoT. In his session at @ThingsExpo, Animesh Singh, an STSM and Lead for IBM Cloud Platform and Infrastructure, will detail how to build a distributed serverless, polyglot, microservices framework using open source tec...
Jul. 1, 2016 08:30 AM EDT Reads: 816