Skip to main content
View by: Most Recent | Topic | Community | Webloggers   
Monthly Archives:    

Blogs by topic: Performance

• Accessibility • Ajax • Blogging • Business • Community 
• Databases • Deployment • Distributed • Eclipse • Education 
• EJB • Extreme Programming • Games • GlassFish • Grid 
• GUI • IDE • Instant Messaging • J2EE • J2ME 
• J2SE • Jakarta • JavaFX • JavaOne • Jini 
• JSP • JSR • JXTA • LDAP • Linux 
• Mobility • NetBeans • Open Source • OpenSolaris • OSGi 
• P2P • Patterns • Performance • Porting • Programming 
• Research • RMI • RSS Feeds • Search • Security 
• Servlets • Struts • Swing • Testing • Tools 
• Virtual Machine • Web Applications • Web Design • Web Development Tools • Web Services and XML 


Programming

One of my favorite sessions at Jfokus 2013 was presented by Typesafe co-founder and Java Champion Jonas Bonér. I always enjoy discussions about how technology evolves over the decades, how we break away from concepts, then sometimes weave our way back via the latest and greatest thing, which can sometimes appear strikingly similar to something that was very much in vogue a decade or so earlier....
on Mar 18, 2013
Sometimes, life drops a house on your code. Sometimes, it's flying monkeys. Most of the time though, the damn stuff just stops working and it's nothing so obvious as being crushed by a Kansas farmhouse or being carried away by winged primates. For this last common case, there are a good number of great tools to help you out. JMeter may help you to reproduce the conditions under load, while...
on Feb 1, 2013
The results of the latest completed Java.net poll indicate that, in general, developers consider the addition of Lambda Expressions (closures) to Java (which will happen in Java 8) to be a good idea. However, opinion is not universally in this direction. A total of 401 votes were cast in the poll. The exact question and results were: Is adding Lambda Expressions (closures) to Java a good idea...
on Jun 12, 2012
Brian Goetz recently provided new details on the status of JSR 335 in his OpenJDK document State of the Lambda: Libraries Edition. Project Lambda is a fundamentally important enhancement to Java 8. And, based on the response of developers in our recent poll asking how Lambda Expressions in Java 8 will affect their programming, the Java community is excited by the prospect of being able to...
on May 2, 2012
A few nights ago, I was browsing the chapters about concurrent programming in Herbert Schildt's excellent Java: The Complete Reference, 8th Edition, and I was struck by the evolution of concurrency in Java over the years, from threads, through the richness of Java 5's Concurrency Utilities, and on to Java 7's Fork/Join Framework. The Java language truly has grown, adapted to the changing world,...
on Apr 22, 2012
With the advent of multicore processors on everything from desktop computers to tablets, pads, and even mobile phones, parallel processing is gaining increasing attention. This is at least in part what's behind the release of the Fork/Join Framework in Java 7, and the inclusion of Lambda Expressions (aka "closures," JSR 335) in the upcoming Java 8. While the "do-it-yourself" approach to...
on Apr 9, 2012
In my previous blog post, I did some experimentation with simultaneous execution of multiple threads. Since the threads were all doing relatively large chunks of work, the overhead from thread creation and management was almost irrelevant. In this post, I take a look at the overhead that launching a series of threads can have on an application. The starting point is a modified version of the...
on Feb 29, 2012
We all know the standard Fibonacci recursive algorithm:   public BigInteger f(int n) {    if (n == 0) return BigInteger.ZERO;    if (n == 1) return BigInteger.ONE;    return f(n - 1).add(f(n - 2));  } Your challenge is to find the first 10 bytes and the last 10 bytes of f(1_000_000_000). That's right, fibonacci of one billion. Please post...
on Feb 24, 2012
Welcome to the 198th issue of The Java(tm) Specialists' Newsletter sent to you from Chania in Greece. My readers in colder climates frequently get annoyed when I tell them that "life's a beach". They imagine us having constant sun here. It's not true. We do sometimes have torrential rains and cold weather. It even snows here occasionally. In fact, the delivery...
on Feb 14, 2012
I mentioned the idea to use Wordle as an execution profiler while presenting the profiling section of my performance tuning course in Paris last December. The idea was seeded by presentation that Neal Ford did a few years ago in which he used Wordle to expose the vocabulary of a Java application. Neal took a pile of source code and fed it into Wordle. The result was a word cloud that visualized...
on Jan 9, 2012

Eclipse

More than a few days ago a friend pinged me complaining that recent Eclipse release was quite sluggish. Since she had taken my performance tuning seminar she knew exactly how to get and read a GC log but as we all do, she was looking for a second opinion. After looking at the log for a minute it because quite apparent that the default configuration left the IDE starved for memory. After a bit...
on Oct 21, 2012

Community

    Nowadays there are too many NOSQL database, with different architecture and data structure. However with much variety they share one thing in common: Only search information from the keys. A good option is uses other service to help the NOSQL databases. In this post will how the Lucene does work together a NOSQL database, join two world in one application.     The...
on Oct 13, 2012

Databases

by Florian Müller, Jay Brown, and Jeff Potts, authors of CMIS and Apache Chemistry in Action Save 40% on CMIS and Apache Chemistry in Action. Use promo code 12netja when you check out at manning.com Enterprise Content Management (ECM) repositories often have a lot of types defined, sometimes hundreds in extreme cases. This means that there needs to be a way to organize and retrieve them in a...
on Sep 19, 2012
Release the newest version of the framework to persist objects in Apache Cassandra in easy way. Among improvement is the JPA annotations, also JPQL.   JCassandra jCassandra=persistence.createJCassandra("select * from Person"); List<Person> persons=jCassandra.getResultList(); table 1: sample using JPQL in Easy-Cassandra Easy-Cassandra 1.0.8 Easy-Cassandra 1.0...
on Apr 21, 2012
Sometimes we use caches for speeding up by alleviating database load. And the Memcached is the bestknown in-memory key-value store(cache). For using Memcached, you need clients and many clients already exist. You can also find Memcached clients based on Java. Though there are already good Memcached clients which have optimized Memcached operations a long time, I would like to introduce...
on Mar 2, 2012

J2EE

While I don't normally blog about the exiting world of JVM command line options, this new 7.0 option, which allows you to rotate to a new GC log file, was just so exciting... err... not so widely published that I decided to share. Of course these options only apply when you've used the -Xloggc: option. The settings are; UseGCLogFileRotation, default value: false NumberOfGCLogsFiles, default value...
on Aug 20, 2012

Performance

In this post I introduce Samplr: an open source, intelligent sampling profiler that can be embedded in any Java application for automatic identification of performance bottlenecks Tools of the Trade If you read the Developer Power story in the July/August issue of Oracle Java Magazine, you already know that I love VisualVM. It is the best tool I know for inspecting the inner workings of a...
on Aug 6, 2012
In some earlier posts, I've talked about Java threads, Java Thread Overhead, and Amdahl's Law and Parallel Processing Speed-Up. My next investigation in this series is Java 7's new Fork/Join Framework. I plan to spend quite a lot of time in this particular investigation. For one, Java Threads have been around for a long time, and undoubtedly there are many resources available that discuss them;...
on Apr 16, 2012

Accessibility

                 Easy-Cassandra is a framework ORM API and a high client for Apache Cassandra in java, with this is possible persist information from the Java Object in easy way. For this is only necessary add some annotations in some fields and your class. It works like an abstraction's tier in the Thrift, doing call for Cassandra. The Easy-Cassandra...
on Feb 21, 2012

Testing

Today I decided it was past time to reorganize the slides in the performance testing section of the course. I added a number of new diagrams and charts to help organize the materials and then I went back and started to review some of the definitions that I was using. First up was the question; what is performance testing and how is it related to load testing.  I must confess that I derived a...
on Jan 12, 2012