This week's giveaway is in the EJB and other Java EE Technologies forum.
We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line!
See this thread for details.
The moose likes Features new in Java 7 and the fly likes Questions for Martin & Benjamin Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login


Win a copy of EJB 3 in Action this week in the EJB and other Java EE Technologies forum!
JavaRanch » Java Forums » Java » Features new in Java 7
Bookmark "Questions for Martin & Benjamin" Watch "Questions for Martin & Benjamin" New topic
Author

Questions for Martin & Benjamin

Jitendra Chittoda
Greenhorn

Joined: Jul 21, 2012
Posts: 21

Hi Martin & Benjamin,

I was going through the contents of the book and had a couple of questions related to the performance tuning.
Does this book put some light on-
  • G1 GC that has been introduced in java 7, and how much performance benefit we can get using G1 GC.
  • How to tune GC, how much should be the Heap, PermGenSpace, OldGen ratio for max performance.
  • Does java has tools like JProfiler, to identify the bottleneck?


  • Few other questions
  • As java has been taken over by the Oracle, will they continue to support java as opensource? What you guys think on the future of Java?
  • Can we expect the same kind of innovations with Oracle as Sun did? It seems Oracle is looking at Java in business terms.


  • Regards,
    Jitendra Chittoda
    Martijn Verburg
    author
    Bartender

    Joined: Jun 24, 2003
    Posts: 3274
        
        5

    Jitendra Chittoda wrote:Hi Martin & Benjamin,

    I was going through the contents of the book and had a couple of questions related to the performance tuning.
    Does this book put some light on-
  • G1 GC that has been introduced in java 7, and how much performance benefit we can get using G1 GC.
  • How to tune GC, how much should be the Heap, PermGenSpace, OldGen ratio for max performance.
  • Does java has tools like JProfiler, to identify the bottleneck?



  • * It does discuss G1 in some detail and the sorts of performance characteristics you'll get out of it. But as Ben and I always say "Measure, don't guess!". You always need to look at GC collectors in the context of your application and how that application is driven by its users.
    * It talks a little bit about tuning GC yes. However, this is a very large topic which takes up at least 1-2 days of our 4-day performance tuning course :-). Again, it always depends on what type of performance you're wanting, lots of small pauses? Or larger more infrequent pauses?
    * Java has VisualVM which you can use for some performance analysis, including GC. However it is fairly basic and will only give you so many insights. Our start-up is actually working on more sophisticated tooling (that still gives simple answers).

    Jitendra Chittoda wrote:
    Few other questions
  • As java has been taken over by the Oracle, will they continue to support java as opensource? What you guys think on the future of Java?
  • Can we expect the same kind of innovations with Oracle as Sun did? It seems Oracle is looking at Java in business terms.



  • * Absolutely - we're very confident that Oracle will continue to support Java as a fully open source project. We actually work closely with them on this and various other community initiatives such as Adopt OpenJDK and Adopt a JSR.
    * Sun actually stopped innovating with Java (the language) towards the end as Java had become the defacto language for what we call the stable layer. This means that millions of developers rely on Java (the language) to not break or change too rapidly. Therefore we're not going to see Java getting the latest language features quickly. However, you have lots of choice with many other languages on the JVM that do have the latest features, who all interoperate with Java nicely.

    Cheers, Martijn - Blog,
    Twitter, PCGen, Ikasan, My The Well-Grounded Java Developer book!,
    My start-up.
    Jitendra Chittoda
    Greenhorn

    Joined: Jul 21, 2012
    Posts: 21

    Thanks for the reply Martin.

    As you specified Adopt OpenJDK and Adopt a JSR are the initiatives that you guys started. I have gone through the websites, as per my understanding Adopt OpenJDK is open for all. But I believe Adopt a JSR is only for London Java Community(LJC), correct me if I am wrong.

    Also I would like to contribute a new concurrency related utility in Java, what you think would OpenJDK would be the good place to start with for this, OR I can create a new JSR for the same on JCP?

    Thanks,
    Jitendra Chittoda
    Palak Mathur
    Ranch Hand

    Joined: Jan 29, 2007
    Posts: 313

    Jitendra Chittoda wrote:Thanks for the reply Martin.

    As you specified Adopt OpenJDK and Adopt a JSR are the initiatives that you guys started. I have gone through the websites, as per my understanding Adopt OpenJDK is open for all. But I believe Adopt a JSR is only for London Java Community(LJC), correct me if I am wrong.



    I will just answer this question. Adopt a JSR is not only for LJC members, it is open for all JUG members. Following link may help: https://blogs.oracle.com/java/entry/adopt_a_jsr


    Palak Mathur | My Blog | TechJaunt | What is JavaRanch? | List of All FAQs
    Ben Evans
    author
    Greenhorn

    Joined: Jan 17, 2011
    Posts: 20
        
        5
    Jitendra Chittoda wrote:Also I would like to contribute a new concurrency related utility in Java, what you think would OpenJDK would be the good place to start with for this, OR I can create a new JSR for the same on JCP?


    I would start by joining Doug Lea's concurrency-interest mailing list and watching the posts there for a few weeks.

    Then, if you think that your idea would fit in well (& hasn't already been proposed), you can propose it there.

    One moderate word of caution - that list has some of the best concurrency people in the world on it. The JVM's concurrency model is also quite subtle. Starting off making small contributions and making sure that you've fully tested your assumptions is probably the best way to get your ideas heard. You should also make sure you have a good understanding of the JMM as defined in the spec, and how java.util.concurrent is implemented (and ideally some knowledge of hardware as well).
    Jitendra Chittoda
    Greenhorn

    Joined: Jul 21, 2012
    Posts: 21

    Thanks for the information Ben,

    I have joined Doug Lea's concurrency-interest mailing list, and I will keep an eye on what is going on. I will also go through the JMM and classes implemented in java.util.concurrent in depth to ensure that my idea is not implemented yet.
     
    I agree. Here's the link: http://aspose.com/file-tools
     
    subject: Questions for Martin & Benjamin
     
    Similar Threads
    URLyBird 1.1.3: Functionality Doubts...
    Hearty Welcome to all of you
    Bitter Java and Patterns
    Next Generation Java Testing: what's new?
    Garbage Collection and Virtual Memory