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JPRT: A Build & Test System
- by kto
DRAFT A while back I did a little blogging on a system called JPRT, the hardware used and a summary on my java.net weblog. This is an update on the JPRT system. JPRT ("JDK Putback Reliablity Testing", but ignore what the letters stand for, I change what they mean every day, just to annoy people :\^) is a build and test system for the JDK, or any source base that has been configured for JPRT. As I mentioned in the above blog, JPRT is a major modification to a system called PRT that the HotSpot VM development team has been using for many years, very successfully I might add. Keeping the source base always buildable and reliable is the first step in the 12 steps of dealing with your product quality... or was the 12 steps from Alcoholics Anonymous... oh well, anyway, it's the first of many steps. ;\^) Internally when we make changes to any part of the JDK, there are certain procedures we are required to perform prior to any putback or commit of the changes. The procedures often vary from team to team, depending on many factors, such as whether native code is changed, or if the change could impact other areas of the JDK. But a common requirement is a verification that the source base with the changes (and merged with the very latest source base) will build on many of not all 8 platforms, and a full 'from scratch' build, not an incremental build, which can hide full build problems. The testing needed varies, depending on what has been changed. Anyone that was worked on a project where multiple engineers or groups are submitting changes to a shared source base knows how disruptive a 'bad commit' can be on everyone. How many times have you heard: "So And So made a bunch of changes and now I can't build!". But multiply the number of platforms by 8, and make all the platforms old and antiquated OS versions with bizarre system setup requirements and you have a pretty complicated situation (see http://download.java.net/jdk6/docs/build/README-builds.html). We don't tolerate bad commits, but our enforcement is somewhat lacking, usually it's an 'after the fact' correction. Luckily the Source Code Management system we use (another antique called TeamWare) allows for a tree of repositories and 'bad commits' are usually isolated to a small team. Punishment to date has been pretty drastic, the Queen of Hearts in 'Alice in Wonderland' said 'Off With Their Heads', well trust me, you don't want to be the engineer doing a 'bad commit' to the JDK. With JPRT, hopefully this will become a thing of the past, not that we have had many 'bad commits' to the master source base, in general the teams doing the integrations know how important their jobs are and they rarely make 'bad commits'. So for these JDK integrators, maybe what JPRT does is keep them from chewing their finger nails at night. ;\^) Over the years each of the teams have accumulated sets of machines they use for building, or they use some of the shared machines available to all of us. But the hunt for build machines is just part of the job, or has been. And although the issues with consistency of the build machines hasn't been a horrible problem, often you never know if the Solaris build machine you are using has all the right patches, or if the Linux machine has the right service pack, or if the Windows machine has it's latest updates. Hopefully the JPRT system can solve this problem. When we ship the binary JDK bits, it is SO very important that the build machines are correct, and we know how difficult it is to get them setup. Sure, if you need to debug a JDK problem that only shows up on Windows XP or Solaris 9, you'll still need to hunt down a machine, but not as a regular everyday occurance. I'm a big fan of a regular nightly build and test system, constantly verifying that a source base builds and tests out. There are many examples of automated build/tests, some that trigger on any change to the source base, some that just run every night. Some provide a protection gateway to the 'golden' source base which only gets changes that the nightly process has verified are good. The JPRT (and PRT) system is meant to guard the source base before anything is sent to it, guarding all source bases from the evil developer, well maybe 'evil' isn't the right word, I haven't met many 'evil' developers, more like 'error prone' developers. ;\^) Humm, come to think about it, I may be one from time to time. :\^{ But the point is that by spreading the build up over a set of machines, and getting the turnaround down to under an hour, it becomes realistic to completely build on all platforms and test it, on every putback. We have the technology, we can build and rebuild and rebuild, and it will be better than it was before, ha ha... Anybody remember the Six Million Dollar Man? Man, I gotta get out more often.. Anyway, now the nightly build and test can become a 'fetch the latest JPRT build bits' and start extensive testing (the testing not done by JPRT, or the platforms not tested by JPRT). Is it Open Source? No, not yet. Would you like to be? Let me know. Or is it more important that you have the ability to use such a system for JDK changes? So enough blabbering on about this JPRT system, tell me what you think. And let me know if you want to hear more about it or not. Stay tuned for the next episode, same Bloody Bat time, same Bloody Bat channel. ;\^) -ktoRead the article
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Webcast WebCenter Content, April 11th, 2012
- by rituchhibber
Our next WebCenter Content webcast will be on April 10th, 2012. This WebCast will help you to prepare yourself for the WebCenter Content Certified Implementation Specialist EXAM. Webcast Details: Date Topic Speaker Web Call Details Intercall Details April 10th WebCenter Content Refresh Course Markus NeubauerSilburyWebCenter ContentSpecialized Partner Join Webcast Dial-in numbers:CC/SP: 1579222/9221 Time: 12:00 -15:00 CET Break around 13:30 Conference ID/Key: 9819145/1004 For more details, please click here.Read the article
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Sources of NetBeans Gradle Plugin
- by Geertjan
Here is where you can find the sources of the latest and greatest NetBeans Gradle plugin: http://java.net/projects/nb-api-samples/sources/api-samples/show/versions/7.1/misc/GradleSupport To use it, download the sources above, open the sources into the IDE (which must be 7.1.1 or above), then you'll have a NetBeans module. Right-click it to run the module into a new instance of NetBeans IDE. In the Options window's Miscellaneous tab, there's a Gradle subtab for setting the Gradle location. In the New File dialog, in the Other category, you'll find a template named "Empty Gradle file". Make sure to name it "build" and to put it in the root directory of the application (by leaving the Folder field empty, you're specifying it should be created in the root directory). You'll then be able to expand the build.gradle file: Double-click a task to run it. When you open the file, it opens in the Groovy editor, if the Groovy editor is installed. When you make changes in the file, the list of tasks, shown above, is automatically recreated. It's at a really early stage of development and it would be great if developers out there would be interested in adding more features to it.Read the article
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Architects, Leadership, and Influence
- by Bob Rhubart
Technical expertise is a given for architects. In addition to solid development experience, extensive knowledge of technical trends, tools, standards, and methodolgies (not to mention business accumen) provides the foundation for the decisions the architect must make in the effort to get all the pieces to work together. But even superior technical chops can't overcome a lack of leadership. Leadership is about influence: the ability to effectively communicate — to sell your ideas and defend your decisions in a manner that affects the decisions of the people around you. Leadership and influence are especially important in situations in which the architect may not have the authority to simply tell people what to do. And even when the architect has that kind of authority, influential leadership can mean the difference between gaining real buy-in and support from colleagues and stakeholders, and settling for their grudging acceptance (or worse). Guess which outcome is likely to produce the best results. In a previous post I presented some examples of the kind of criticism that is leveled at architects, a great deal of which can be attributed to a lack of leadership and influence on the part of the targets of that criticism. So it was serendipitous that I recently ran across a post on the Harvard Business Review blog written by Chris Musselwhite and Tammie Plouffe. That post, When Your Influence Is Ineffective, includes this: [I]nfluence becomes ineffective when individuals become so focused on the desired outcome that they fail to fully consider the situation. While the influencer may still gain the short-term desired outcome, he or she can do long-term damage to personal effectiveness and the organization, as it creates an atmosphere of distrust where people stop listening, and the potential for innovation or progress is diminished. The need to "see the big picture" is a grossly reductive assesement of the architect's responsibilities — but that doesn't mean it's not true. That big picture perspective must encompass both the technological elements of the architecture and the elements responsible for implementing those technologies in compliance with the prescribed architecture. Technologies may be tempermental, but they don't have personalities or egos, and they are unlikely to carry a grudge — not yet, anyway (Hello, Skynet!). Effective leadership and the ability to influence people can help to ensure that all the pieces fit and that they work together, today and tomorrow.Read the article
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JavaOne Latin America Early Bird Discount: R$300,00 Off
- by Tori Wieldt
Learn how to code in Java more efficiently, pick up Java best practices, and participate in world-class networking at JavaOne Latin America—all for R$300,00 less if you register by 16 November. Have you ever wondered how to construct embedded Java applications for next-generation smart devices? Want to profit from client-side solutions using JavaFX, or simply build modern applications in Java 7? Techniques for these and much more are showcased at JavaOne Latin America—and you’re invited! Choose from more than 50 sessions, multiple demos, plus keynotes and hands-on labs. Topics include: Core Java Platform JavaFX and Rich User Experiences Java EE, Web Services, and the Cloud Java ME, Java Embedded, and Java Card Secure Your Place Now—Register now! Para mais informações ou inscrição ligue para (11) 2875-4163.Read the article
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RPi and Java Embedded GPIO: Connecting LEDs
- by hinkmond
Next, we need some low-level peripherals to connect to the Raspberry Pi GPIO header. So, we'll do what's called a "Fry's Run" in Silicon Valley, which means we go shop at the local Fry's Electronics store for parts. In this case, we'll need some breadboard jumper wires (blue wires in photo), some LEDs, and some resistors (for the RPi GPIO, 150 ohms - 300 ohms would work for the 3.3V output of the GPIO ports). And, if you want to do other projects, you might as well by a breadboard, which is a development board with lots of holes in it. Ask a Fry's clerk for help. Or, better yet, ask the customer standing next to you in the electronics components aisle for help. (Might be faster) So, go to your local hobby electronics store, or go to Fry's if you have one close by, and come back here to the next blog post to see how to hook these parts up. HinkmondRead the article
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Java ME Tech Holiday Gift Idea #3: Kindle Touch Wi-Fi
- by hinkmond
Here's a Java ME tech-enabled device holiday gift idea: The venerable Amazon Kindle Touch with built-in Wi-Fi. Niiiice! See: Java ME Tech Gift Idea #3 Here's a quote: + Most-advanced E Ink display, now with multi-touch + New sleek design - 8% lighter, 11% smaller, holds 3,000 books + Only e-reader with text-to-speech, audiobooks and mp3 support + Built in Wi-Fi - Get books in 60 seconds If you want to give someone special a cool device, you want to give something with Java ME technology. Give only the best this holiday season! HinkmondRead the article
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Un-used Indexes on MDP_MATRIX Consuming Resources
- by user702295
Disable un-used Indexes: As much as it is recommended to create relevant indexes, it is advised not to have too many indexes on the mdp_matrix table. Too many indexes will cause long waits on the table as indexes needs to get updated every time the table is updated. There are many seeded indexes on mdp_matrix, every out of the box data model level has an index on the matrix table. If a level is unused in the specific data model of the implementation, it is advisable to disable that index. If the customer is not sure if and how indexes are utilized, the DBA can monitor all indexes. After a few cycles of operation, the DBA should go over that list and see which indexes have not been used. Consider disabling them. There are scripts on the net to monitor indexes or use the monitoring usage clause in the alter index statement.Read the article
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When to use each user research method
- by user12277104
There are a lot of user research methods out there, but sometimes we get stuck in a rut, conducting all formative usability testing before coding, or running surveys to gather satisfaction data. I'll be the first to admit that it happens to me, but to get out of a rut, it just takes a minute to look at where I am in the design & development cycle, what kind(s) of data I need, and what methods are available to me. We need reminders, or refreshers, every once in a while. One tool I've found useful is a graphic organizer that I created many years ago. It's been through several revisions, as I've adapted it to the product cycles of the places I've worked, changed my mind about how to categorize it, and added methods that I've used or created over time. I shared a version of this table at the 2012 International UPA conference, and I was contacted by someone yesterday who wanted to use it in a university course on user-center design. I was flattered at the the thought, but embarrassed, because I was sure it needed updating -- that was a year ago, after all. But I opened it today, and really, there's not much I'd change -- sure, I could add some nuance regarding what types of formative testing, such as modality (remote, unmoderated remote, or in-person) or flavor of testing (RITE, RITE-Krug, comparative, performance), but I think it's pretty much ok as is. Click on the image below, to get the full-size PDF. And whether it's entirely "right" or "wrong" isn't the whole value of looking at these methods across the product lifecycle. The real value lies in the reminder that I have options. And what those options are change as the field changes, so while I don't expect this graphic to have an eternal shelf life, it's still ok a year after I last updated it. That said, if you find something missing or out of place, let me know :)Read the article
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Why are embedded device apps still written in C/C++? Why not Java programming language?
- by hinkmond
At the recent Black Hat 2014 conference in Sin City, the Black Hatters were focusing on Embedded Devices and IoT. You know? Make your networked-toaster burn your bread 10,000 miles away, over the Web for grins and giggles. Well, apparently the Black Hatters say it can be done pretty easily these days, which is scary. See: Securing Embedded Devices & IoT Here's a quote: All these devices are still written in C and C++. The challenges associated with developing securely in these languages have been fought for nearly two decades. "You often hear people say, 'Well, why don't we just get rid of the C and C++ language if it's so problematic. Why don't we just write everything in C# or Java, or something that is a little safer to develop in?'," DeMott says. Gah! Why are all these IoT devices still using C/C++? Of course they should be using Java SE Embedded technology! It's a natural fit to use for better security on embedded devices. Or, I guess, developers really don't mind if their networked-toasters do char their breakfast. If it can be burned, it will be... That's what I say. Unless they use Java. HinkmondRead the article
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Java EE @ Devoxx UK
- by delabassee
Devoxx UK is taking place next week (12th and 13th June) in London. As with any Devoxx conference, this UK edition will have a nice mix of content, an impressive list of speakers and obviously Java EE will be well will covered too: Apache TomEE, Java EE Web Profile and more on Tomcat (David Blevins) Myths, Tales and Voodoo - About Java EE and Testing (Adam Bien) 50 new features of Java EE 7 (Antonio Goncalves & Arun Gupta) Java EE 7 Hands-on Lab (Arun Gupta) In addition, there will be 2 BoF related to Java EE on Thursday evening, the first BoF will be about the Java EE platform and the second one will be about the Java EE Reference Implementation, i.e. GlassFish. I will participate in the Java EE Community BoF where will discuss Java EE general but with all recent activities, I suspect that a large portion of the BoF will spent on discussing the current plans for Java EE 8. Right after and in the same room, I will join Steve Millidge of C2B2 for the GlassFish is here to stay! BoF. The goal is to discuss on GlassFish, the current status, the plans for the next release, how the community can contributes, etc. It should be mentioned that attending those BoFs is completely free, just make sure to register here. So if you are in London next week, mind the Geek and see you at Devoxx UK!Read the article
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My JavaOne 2012
- by Geertjan
I received a JavaOne speaker invitation for the following sessions and BOFs. Only one involves me on my own: Session ID: CON2987Session Title: Unlocking the Java EE 6 Platform The rest are combo packages, i.e., you get multiple speakers for the price of one. Sessions and BOFs together with others: Session ID: BOF4227 (together with Zoran Sevarac)Session Title: Building Smart Java Applications with Neural Networks, Using the Neuroph Framework Session ID: BOF5806 (together with Manfred Riem)Session Title: Doing JSF Development in NetBeans 7.1 Session ID: CON3160 (together with Allan Gregersen and others)Session Title: Dynamic Class Reloading in the Wild with Javeleon Discussion Panels: Session ID: CON4952 (together with several NetBeans Platform developers)Session Title: NetBeans Platform Panel Discussion Session ID: CON6139 (together with several NetBeans IDE users)Session Title: Lessons Learned in Building Enterprise and Desktop Applications with the NetBeans IDERead the article
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On-demand Webcast: Java in the Smart Grid
- by Jacob Lehrbaum
The Smart Grid is one of the most significant evolutions of our utility infrastructure in recent history. This innovative grid will soon revolutionize how utilities manage and control the energy in our homes--helping utilities reduce energy usage during peak hours, improve overall energy efficiency, and lower your energy bills. If you'd like to learn more about the Smart Grid and the role that Java is poised to play in this important initiative you can check out our on-demand webcast. We'll show you how Java solutions--including Java ME and Java SE for Embedded --can help build devices and infrastructure that take advantage of this new market. As the world's most popular developer language, Java enables you to work with a wide range of developers and provides access to tools and resources to build smarter devices, faster and more affordably.Read the article
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Finding which activities will execute next in a process instance
- by Mark Nelson
We have had a few queries lately about how to find out what activity (or activities) will be the next to execute in a particular process instance. It is possible to do this, however you will need to use a couple of undocumented APIs. That means that they could (and probably will) change in some future release and break your code. If you understand the risks of using undocumented APIs and are prepared to accept that risk, read on… READ MORE >>Read the article
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Library order is important
- by Darryl Gove
I've written quite extensively about link ordering issues, but I've not discussed the interaction between archive libraries and shared libraries. So let's take a simple program that calls a maths library function: #include <math.h int main() { for (int i=0; i<10000000; i++) { sin(i); } } We compile and run it to get the following performance: bash-3.2$ cc -g -O fp.c -lm bash-3.2$ timex ./a.out real 6.06 user 6.04 sys 0.01 Now most people will have heard of the optimised maths library which is added by the flag -xlibmopt. This contains optimised versions of key mathematical functions, in this instance, using the library doubles performance: bash-3.2$ cc -g -O -xlibmopt fp.c -lm bash-3.2$ timex ./a.out real 2.70 user 2.69 sys 0.00 The optimised maths library is provided as an archive library (libmopt.a), and the driver adds it to the link line just before the maths library - this causes the linker to pick the definitions provided by the static library in preference to those provided by libm. We can see the processing by asking the compiler to print out the link line: bash-3.2$ cc -### -g -O -xlibmopt fp.c -lm /usr/ccs/bin/ld ... fp.o -lmopt -lm -o a.out... The flag to the linker is -lmopt, and this is placed before the -lm flag. So what happens when the -lm flag is in the wrong place on the command line: bash-3.2$ cc -g -O -xlibmopt -lm fp.c bash-3.2$ timex ./a.out real 6.02 user 6.01 sys 0.01 If the -lm flag is before the source file (or object file for that matter), we get the slower performance from the system maths library. Why's that? If we look at the link line we can see the following ordering: /usr/ccs/bin/ld ... -lmopt -lm fp.o -o a.out So the optimised maths library is still placed before the system maths library, but the object file is placed afterwards. This would be ok if the optimised maths library were a shared library, but it is not - instead it's an archive library, and archive library processing is different - as described in the linker and library guide: "The link-editor searches an archive only to resolve undefined or tentative external references that have previously been encountered." An archive library can only be used resolve symbols that are outstanding at that point in the link processing. When fp.o is placed before the libmopt.a archive library, then the linker has an unresolved symbol defined in fp.o, and it will search the archive library to resolve that symbol. If the archive library is placed before fp.o then there are no unresolved symbols at that point, and so the linker doesn't need to use the archive library. This is why libmopt needs to be placed after the object files on the link line. On the other hand if the linker has observed any shared libraries, then at any point these are checked for any unresolved symbols. The consequence of this is that once the linker "sees" libm it will resolve any symbols it can to that library, and it will not check the archive library to resolve them. This is why libmopt needs to be placed before libm on the link line. This leads to the following order for placing files on the link line: Object files Archive libraries Shared libraries If you use this order, then things will consistently get resolved to the archive libraries rather than to the shared libaries.Read the article
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Inline template efficiency
- by Darryl Gove
I like inline templates, and use them quite extensively. Whenever I write code with them I'm always careful to check the disassembly to see that the resulting output is efficient. Here's a potential cause of inefficiency. Suppose we want to use the mis-named Leading Zero Detect (LZD) instruction on T4 (this instruction does a count of the number of leading zero bits in an integer register - so it should really be called leading zero count). So we put together an inline template called lzd.il looking like: .inline lzd lzd %o0,%o0 .end And we throw together some code that uses it: int lzd(int); int a; int c=0; int main() { for(a=0; a<1000; a++) { c=lzd(c); } return 0; } We compile the code with some amount of optimisation, and look at the resulting code: $ cc -O -xtarget=T4 -S lzd.c lzd.il $ more lzd.s .L77000018: /* 0x001c 11 */ lzd %o0,%o0 /* 0x0020 9 */ ld [%i1],%i3 /* 0x0024 11 */ st %o0,[%i2] /* 0x0028 9 */ add %i3,1,%i0 /* 0x002c */ cmp %i0,999 /* 0x0030 */ ble,pt %icc,.L77000018 /* 0x0034 */ st %i0,[%i1] What is surprising is that we're seeing a number of loads and stores in the code. Everything could be held in registers, so why is this happening? The problem is that the code is only inlined at the code generation stage - when the actual instructions are generated. Earlier compiler phases see a function call. The called functions can do all kinds of nastiness to global variables (like 'a' in this code) so we need to load them from memory after the function call, and store them to memory before the function call. Fortunately we can use a #pragma directive to tell the compiler that the routine lzd() has no side effects - meaning that it does not read or write to memory. The directive to do that is #pragma no_side_effect(<routine name), and it needs to be placed after the declaration of the function. The new code looks like: int lzd(int); #pragma no_side_effect(lzd) int a; int c=0; int main() { for(a=0; a<1000; a++) { c=lzd(c); } return 0; } Now the loop looks much neater: /* 0x0014 10 */ add %i1,1,%i1 ! 11 ! { ! 12 ! c=lzd(c); /* 0x0018 12 */ lzd %o0,%o0 /* 0x001c 10 */ cmp %i1,999 /* 0x0020 */ ble,pt %icc,.L77000018 /* 0x0024 */ nopRead the article
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Schema Based Code Completion for NetBeans Platform Applications
- by Geertjan
Toni's recent blog entry provides, among several other interesting things, instructions for something I've been wanting to cover for a long time, which is schema based code completion: The above is a sample I created via Toni's tutorial, using the schema described here: http://www.w3schools.com/schema/schema_example.asp The support for the Navigator ain't bad either, especially considering I didn't do any coding at all to get all this: And here's where you can find the whole sample: http://java.net/projects/nb-api-samples/sources/api-samples/show/versions/7.2/misc/ShipOrderRead the article
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Getting Started with Amazon Web Services in NetBeans IDE
- by Geertjan
When you need to connect to Amazon Web Services, NetBeans IDE gives you a nice start. You can drag and drop the "itemSearch" service into a Java source file and then various Amazon files are generated for you. From there, you need to do a little bit of work because the request to Amazon needs to be signed before it can be used. Here are some references and places that got me started: http://associates-amazon.s3.amazonaws.com/signed-requests/helper/index.html http://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSGettingStartedGuide/AWSCredentials.html https://affiliate-program.amazon.com/gp/flex/advertising/api/sign-in.html You definitely need to sign up to the Amazon Associates program and also register/create an Access Key ID, which will also get you a Secret Key, as well. Here's a simple Main class that I created that hooks into the generated RestConnection/RestResponse code created by NetBeans IDE: public static void main(String[] args) { try { String searchIndex = "Books"; String keywords = "Romeo and Juliet"; RestResponse result = AmazonAssociatesService.itemSearch(searchIndex, keywords); String dataAsString = result.getDataAsString(); int start = dataAsString.indexOf("<Author>")+8; int end = dataAsString.indexOf("</Author>"); System.out.println(dataAsString.substring(start,end)); } catch (Exception ex) { ex.printStackTrace(); }} Then I deleted the generated properties file and the authenticator and changed the generated AmazonAssociatesService.java file to the following: public class AmazonAssociatesService { private static void sleep(long millis) { try { Thread.sleep(millis); } catch (Throwable th) { } } public static RestResponse itemSearch(String searchIndex, String keywords) throws IOException { SignedRequestsHelper helper; RestConnection conn = null; Map queryMap = new HashMap(); queryMap.put("Service", "AWSECommerceService"); queryMap.put("AssociateTag", "myAssociateTag"); queryMap.put("AWSAccessKeyId", "myAccessKeyId"); queryMap.put("Operation", "ItemSearch"); queryMap.put("SearchIndex", searchIndex); queryMap.put("Keywords", keywords); try { helper = SignedRequestsHelper.getInstance( "ecs.amazonaws.com", "myAccessKeyId", "mySecretKey"); String sign = helper.sign(queryMap); conn = new RestConnection(sign); } catch (IllegalArgumentException | UnsupportedEncodingException | NoSuchAlgorithmException | InvalidKeyException ex) { } sleep(1000); return conn.get(null); }} Finally, I copied this class into my application, which you can see is referred to above: http://code.google.com/p/amazon-product-advertising-api-sample/source/browse/src/com/amazon/advertising/api/sample/SignedRequestsHelper.java Here's the completed app, mostly generated via the drag/drop shown at the start, but slightly edited as shown above: That's all, now everything works as you'd expect.Read the article
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ZFS for Database Log Files
- by user12620111
I've been troubled by drop outs in CPU usage in my application server, characterized by the CPUs suddenly going from close to 90% CPU busy to almost completely CPU idle for a few seconds. Here is an example of a drop out as shown by a snippet of vmstat data taken while the application server is under a heavy workload. # vmstat 1 kthr memory page disk faults cpu r b w swap free re mf pi po fr de sr s3 s4 s5 s6 in sy cs us sy id 1 0 0 130160176 116381952 0 16 0 0 0 0 0 0 0 0 0 207377 117715 203884 70 21 9 12 0 0 130160160 116381936 0 25 0 0 0 0 0 0 0 0 0 200413 117162 197250 70 20 9 11 0 0 130160176 116381920 0 16 0 0 0 0 0 0 1 0 0 203150 119365 200249 72 21 7 8 0 0 130160176 116377808 0 19 0 0 0 0 0 0 0 0 0 169826 96144 165194 56 17 27 0 0 0 130160176 116377800 0 16 0 0 0 0 0 0 0 0 1 10245 9376 9164 2 1 97 0 0 0 130160176 116377792 0 16 0 0 0 0 0 0 0 0 2 15742 12401 14784 4 1 95 0 0 0 130160176 116377776 2 16 0 0 0 0 0 0 1 0 0 19972 17703 19612 6 2 92 14 0 0 130160176 116377696 0 16 0 0 0 0 0 0 0 0 0 202794 116793 199807 71 21 8 9 0 0 130160160 116373584 0 30 0 0 0 0 0 0 18 0 0 203123 117857 198825 69 20 11 This behavior occurred consistently while the application server was processing synthetic transactions: HTTP requests from JMeter running on an external machine. I explored many theories trying to explain the drop outs, including: Unexpected JMeter behavior Network contention Java Garbage Collection Application Server thread pool problems Connection pool problems Database transaction processing Database I/O contention Graphing the CPU %idle led to a breakthrough: Several of the drop outs were 30 seconds apart. With that insight, I went digging through the data again and looking for other outliers that were 30 seconds apart. In the database server statistics, I found spikes in the iostat "asvc_t" (average response time of disk transactions, in milliseconds) for the disk drive that was being used for the database log files. Here is an example: extended device statistics r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device 0.0 2053.6 0.0 8234.3 0.0 0.2 0.0 0.1 0 24 c3t60080E5...F4F6d0s0 0.0 2162.2 0.0 8652.8 0.0 0.3 0.0 0.1 0 28 c3t60080E5...F4F6d0s0 0.0 1102.5 0.0 10012.8 0.0 4.5 0.0 4.1 0 69 c3t60080E5...F4F6d0s0 0.0 74.0 0.0 7920.6 0.0 10.0 0.0 135.1 0 100 c3t60080E5...F4F6d0s0 0.0 568.7 0.0 6674.0 0.0 6.4 0.0 11.2 0 90 c3t60080E5...F4F6d0s0 0.0 1358.0 0.0 5456.0 0.0 0.6 0.0 0.4 0 55 c3t60080E5...F4F6d0s0 0.0 1314.3 0.0 5285.2 0.0 0.7 0.0 0.5 0 70 c3t60080E5...F4F6d0s0 Here is a little more information about my database configuration: The database and application server were running on two different SPARC servers. Storage for the database was on a storage array connected via 8 gigabit Fibre Channel Data storage and log file were on different physical disk drives Reliable low latency I/O is provided by battery backed NVRAM Highly available: Two Fibre Channel links accessed via MPxIO Two Mirrored cache controllers The log file physical disks were mirrored in the storage device Database log files on a ZFS Filesystem with cutting-edge technologies, such as copy-on-write and end-to-end checksumming Why would I be getting service time spikes in my high-end storage? First, I wanted to verify that the database log disk service time spikes aligned with the application server CPU drop outs, and they did: At first, I guessed that the disk service time spikes might be related to flushing the write through cache on the storage device, but I was unable to validate that theory. After searching the WWW for a while, I decided to try using a separate log device: # zpool add ZFS-db-41 log c3t60080E500017D55C000015C150A9F8A7d0 The ZFS log device is configured in a similar manner as described above: two physical disks mirrored in the storage array. This change to the database storage configuration eliminated the application server CPU drop outs: Here is the zpool configuration: # zpool status ZFS-db-41 pool: ZFS-db-41 state: ONLINE scan: none requested config: NAME STATE ZFS-db-41 ONLINE c3t60080E5...F4F6d0 ONLINE logs c3t60080E5...F8A7d0 ONLINE Now, the I/O spikes look like this: extended device statistics r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device 0.0 1053.5 0.0 4234.1 0.0 0.8 0.0 0.7 0 75 c3t60080E5...F8A7d0s0 extended device statistics r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device 0.0 1131.8 0.0 4555.3 0.0 0.8 0.0 0.7 0 76 c3t60080E5...F8A7d0s0 extended device statistics r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device 0.0 1167.6 0.0 4682.2 0.0 0.7 0.0 0.6 0 74 c3t60080E5...F8A7d0s0 0.0 162.2 0.0 19153.9 0.0 0.7 0.0 4.2 0 12 c3t60080E5...F4F6d0s0 extended device statistics r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device 0.0 1247.2 0.0 4992.6 0.0 0.7 0.0 0.6 0 71 c3t60080E5...F8A7d0s0 0.0 41.0 0.0 70.0 0.0 0.1 0.0 1.6 0 2 c3t60080E5...F4F6d0s0 extended device statistics r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device 0.0 1241.3 0.0 4989.3 0.0 0.8 0.0 0.6 0 75 c3t60080E5...F8A7d0s0 extended device statistics r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device 0.0 1193.2 0.0 4772.9 0.0 0.7 0.0 0.6 0 71 c3t60080E5...F8A7d0s0 We can see the steady flow of 4k writes to the ZIL device from O_SYNC database log file writes. The spikes are from flushing the transaction group. Like almost all problems that I run into, once I thoroughly understand the problem, I find that other people have documented similar experiences. Thanks to all of you who have documented alternative approaches. Saved for another day: now that the problem is obvious, I should try "zfs:zfs_immediate_write_sz" as recommended in the ZFS Evil Tuning Guide. References: The ZFS Intent Log Solaris ZFS, Synchronous Writes and the ZIL Explained ZFS Evil Tuning Guide: Cache Flushes ZFS Evil Tuning Guide: Tuning ZFS for Database PerformanceRead the article
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Eclipse Java Code Formatter in NetBeans Plugin Manager
- by Geertjan
Great news for Eclipse refugees everywhere. Benno Markiewicz forked the Eclipse formatter plugin that I blogged about sometime ago (here and here)... and he fixed many bugs, while also adding new features. It's a handy plugin when you're (a) switching from Eclipse to NetBeans and want to continue using your old formatting rules and (b) working in a polyglot IDE team, i.e., now the formatting rules defined in Eclipse can be imported into NetBeans IDE and everyone will happily be able to conform to the same set of formatting standards. And now you can get it directly from Tools | Plugins in NetBeans IDE 7.4: News from Benno on the plugin, received from him today: The plugin is verified by the NetBeans community and available in the Plugin Manager in NetBeans IDE 7.4 (as shown above) and also at the NetBeans Plugin Portal here, where you can also read quite some info about the plugin: http://plugins.netbeans.org/plugin/50877/eclipse-code-formatter-for-java The issue with empty undo buffer was solved with the help of junichi11: https://github.com/markiewb/eclipsecodeformatter_for_netbeans/issues/18 The issue with the lost breakpoints remains unsolved and there was no further feedback. That is the main reason why the save action isn't activated by default. See also the open known issues at https://github.com/markiewb/eclipsecodeformatter_for_netbeans/issues?state=open Features are as follows: Global configuration and project specific configuration. On save action, which is disabled by default. Show the used formatter as a notification, which is enabled by default. Finally, Benno testifies to the usefulness, stability, and reliability of the plugin: I use the Eclipse formatter provided by this plugin every day at work. Before I commit, I format the sources. It works and that's it. I am pleased with it. Here's where the Eclipse formatter is defined globally in Tools | Options: And here is per-project configuration, i.e., use the Project Properties dialog of any project to override the global settings: Interested to hear from anyone who tries the plugin and has any feedback of any kind!Read the article
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Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 4)
- by hinkmond
And now here's the Java code that you'll need to read your ghost sensor on your Raspberry Pi The general idea is that you are using Java code to access the GPIO pin on your Raspberry Pi where the ghost sensor (JFET trasistor) detects minute changes in the electromagnetic field near the Raspberry Pi and will change the GPIO pin to high (+3 volts) when something is detected, otherwise there is no value (ground). Here's that Java code: try { /*** Init GPIO port(s) for input ***/ // Open file handles to GPIO port unexport and export controls FileWriter unexportFile = new FileWriter("/sys/class/gpio/unexport"); FileWriter exportFile = new FileWriter("/sys/class/gpio/export"); for (String gpioChannel : GpioChannels) { System.out.println(gpioChannel); // Reset the port File exportFileCheck = new File("/sys/class/gpio/gpio"+gpioChannel); if (exportFileCheck.exists()) { unexportFile.write(gpioChannel); unexportFile.flush(); } // Set the port for use exportFile.write(gpioChannel); exportFile.flush(); // Open file handle to input/output direction control of port FileWriter directionFile = new FileWriter("/sys/class/gpio/gpio" + gpioChannel + "/direction"); // Set port for input directionFile.write(GPIO_IN); } /*** Read data from each GPIO port ***/ RandomAccessFile[] raf = new RandomAccessFile[GpioChannels.length]; int sleepPeriod = 10; final int MAXBUF = 256; byte[] inBytes = new byte[MAXBUF]; String inLine; int zeroCounter = 0; // Get current timestamp with Calendar() Calendar cal; DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss.SSS"); String dateStr; // Open RandomAccessFile handle to each GPIO port for (int channum=0; channum And, then we just load up our Java SE Embedded app, place each Raspberry Pi with a ghost sensor attached in strategic locations around our Santa Clara office (which apparently is very haunted by ghosts from the Agnews Insane Asylum 1906 earthquake), and watch our analytics for any ghosts. Easy peazy. See the previous posts for the full series on the steps to this cool demo: Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 1) Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 2) Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 3) Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 4) HinkmondRead the article
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Several New Hints
- by Ondrej Brejla
Hi all! Today we would like to introduce you some of our new experimental hints for NetBeans 7.2. They are called: Unused Use Statement and Immutable Variables. Unused Use Statement This hint is quite simple. It highlights (underlines) your use statements, which are not used. Typical use case is after some refactoring, when you forgot to remove some obsolete use statements. This hint warns you on them and allows you to remove them easily. Just click on the hint bulb in the gutter and select Remove Unused Use Statement. And of course, it works in multiple use statements combined too. Immutable Variables The next one is the hint which checks too many assignments into a variable. And why? That's simple. Mostly you should use just one assignment into one variable. But sometimes you are lazy and you do something like: But it's quite wrong, because what you really do is: And that's exactly the case, when our new hint warns you, that Too many assignments (2) into variable $foo occured. Nothing more. Yes, we know that there are some cases, where could be more assignments and no warning should occur, e.g.: Because maybe one likes longer increment syntax more than the short one. So we tried to handle these cases to don't bother you if it's not a need. Note: We are almost sure that this hint doesn't cover all your use cases, because there are a lot of them. So if you find something strange, write it into our bugzilla so we can handle it better for you. Thanks for your patience! And the last thing is, that you can set the number of allowed assignments in Tools -> Options -> Editor -> Hints -> PHP: Immutable Variables. Note: This hint works just for a common variables, not for fields. We have an enhancement request for that and it should be implemented in next version of NetBeans (probably 7.3). And that's all for today and as usual, please test it and if you find something strange, don't hesitate to file a new issue (product php, component Editor). Thanks.Read the article
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Maxco Quickly Implements JD Edwards World A9.1
David Bryant, Vice President and CFO of Maxco, explains to Cliff why Maxco chose to be one of the first to implement JD Edwards World A9.1, how the implementation is going to be a huge competitive advantage for Maxco and its customers, and the value Bryant sees in being part of the Quest User Group community.Read the article
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Video Whiteboard on Exadata Smart Flash Cache
- by jean-pierre.dijcks
Personally, I like this stuff. It places the unique features of Exadata in perspective with the overall business value. Enjoy the presentation!Read the article
