Search Results

Search found 21396 results on 856 pages for 'oracle jdeveloper and adf events and announcements'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 578/856 | < Previous Page | 574 575 576 577 578 579 580 581 582 583 584 585  | Next Page >

  • Tab Sweep: Arquillian, Power Mac, PowerPC, JSP Performance, JMX Connection, ...

    - by arungupta
    Recent Tips and News on Java, Java EE 6, GlassFish & more : • Extreme Portability: OpenJDK 7 and GlassFish 3.1.1 on Power Mac G5! (Mark Heckler) • Using GlassFish domain templates to easily create several customized domains (Masoud Kalali) • OpenJDK 7 on Apple G5 PowerPC on Mac OS X 10.5.8 (John Yeary) • ENABLING REMOTE ADMINISTRATION FOR GLASSFISH (Adam Bien) • The Java EE 7 Feature List: Cloud Focused Upgrades (devx) • Improve JavaServer Pages Performance with Caching (distributedcaching) • Interactive Glassfish configuration and application deployment (mpashworth) • Allow JMX connection on JVM 1.6.x (Martin Muller) • Arquillian 1.0.0.Final released! Ready for GlassFish and WebLogic! Death to all bugs! (Markus Eisele) • Using GlassFish and APEXListener as backend for Apache so server APEX (Ronald Rod) • Installing and running Eclipse, Glassfish and Ubuntu 12.04 Precise for Web Applications (Connected Web) • Java EE 6 and modular JAX-RS services (Parijat) • ARQUILLIAN CONFIGURATION FOR EMBEDDED GLASSFISH 3.1.2 AND MAVEN 3 (Adam Bien) • Atmosphere .9 released (JeanFrancois Arcand) • Make JSF your friend again (Daniel Pfeifer)

    Read the article

  • Happy 1st Birthday to GlassFish and Java EE

    - by pieter.humphrey
    Java EE and GlassFish are officially one year old!  As with all newborns, time moves fast and it seems like just yesterday it was shiny and new.     Feel free to post any birthday wishes on the blog comments, or even better, tell us a story about your experience with Java EE6 and GlassFish in the last year and we'll work with you to get it posted on the stories blog. http://blogs.sun.com/stories/ As all parents know, it takes a village to raise a child, and we want you as part of the village!  Get involved in the project at http://glassfish.java.net .     Technorati Tags: java,java ee,development,glassfish del.icio.us Tags: java,java ee,development,glassfish

    Read the article

  • Defining Discovery: Core Concepts

    - by Joe Lamantia
    Discovery tools have had a referencable working definition since at least 2001, when Ben Shneiderman published 'Inventing Discovery Tools: Combining Information Visualization with Data Mining'.  Dr. Shneiderman suggested the combination of the two distinct fields of data mining and information visualization could manifest as new category of tools for discovery, an understanding that remains essentially unaltered over ten years later.  An industry analyst report titled Visual Discovery Tools: Market Segmentation and Product Positioning from March of this year, for example, reads, "Visual discovery tools are designed for visual data exploration, analysis and lightweight data mining." Tools should follow from the activities people undertake (a foundational tenet of activity centered design), however, and Dr. Shneiderman does not in fact describe or define discovery activity or capability. As I read it, discovery is assumed to be the implied sum of the separate fields of visualization and data mining as they were then understood.  As a working definition that catalyzes a field of product prototyping, it's adequate in the short term.  In the long term, it makes the boundaries of discovery both derived and temporary, and leaves a substantial gap in the landscape of core concepts around discovery, making consensus on the nature of most aspects of discovery difficult or impossible to reach.  I think this definitional gap is a major reason that discovery is still an ambiguous product landscape. To help close that gap, I'm suggesting a few definitions of four core aspects of discovery.  These come out of our sustained research into discovery needs and practices, and have the goal of clarifying the relationship between discvoery and other analytical categories.  They are suggested, but should be internally coherent and consistent.   Discovery activity is: "Purposeful sense making activity that intends to arrive at new insights and understanding through exploration and analysis (and for these we have specific defintions as well) of all types and sources of data." Discovery capability is: "The ability of people and organizations to purposefully realize valuable insights that address the full spectrum of business questions and problems by engaging effectively with all types and sources of data." Discovery tools: "Enhance individual and organizational ability to realize novel insights by augmenting and accelerating human sense making to allow engagement with all types of data at all useful scales." Discovery environments: "Enable organizations to undertake effective discovery efforts for all business purposes and perspectives, in an empirical and cooperative fashion." Note: applicability to a world of Big data is assumed - thus the refs to all scales / types / sources - rather than stated explicitly.  I like that Big Data doesn't have to be written into this core set of definitions, b/c I think it's a transitional label - the new version of Web 2.0 - and goes away over time. References and Resources: Inventing Discovery Tools Visual Discovery Tools: Market Segmentation and Product Positioning Logic versus usage: the case for activity-centered design A Taxonomy of Enterprise Search and Discovery

    Read the article

  • The Social Business Thought Leaders - John Hagel

    - by kellsey.ruppel
    While many European economies are on the brink of a recession between increasing taxation and mounting loss of jobs and bankruptcy filing rates, there's an understandable risk of losing sight of the deeper forces at play. Yet instead of surrendering to uncertainty and trying to survive in the short term, many organizations are feeling the urge to be better prepared to thrive in these complex times by developing a more articulated long term understanding of both the opportunities / challenges ahead. For example: What long-term economic, technological and societal changes are rolling out? Which foundational dynamics will affect our companies' performance, productivity, competition, and innovative potential in the upcoming decades? How will digital infrastructure change our business landscape? What kind of capabilities will be key to compete in a market shaped by growing turbulence, unpredictability and volatility? Breaking out from a strictly cyclical thinking, studies such as the Shift Index by John Hagel, Co-Chairman of the Center for the Edge at Deloitte & Touche (See Measuring the forces of long-term change - The 2009 Shift Index), depict a worrying performance challenge that affected every industry in the entire US economy over the last 45 years. Amidst a more than doubled competitive intensity of the market, and even with an improved labor productivity, the actual performance of US firms has consistently fallen to 25% of what it was in 1965. Most of this reported value is shifting from institutions and organizations to individuals, whether they are customers or young creative talent. To thrive in the digital economy and reverse declining performance trends, companies will have to fundamentally rethink their management approach by moving from knowledge stocks to knowledge flows, from scalable efficiency to scalable learning, from push organizations to pull organizations. Based on the outcomes of the Shift Index and on the book The Power of Pull, the first episode of the Social Business Thought-Leaders features John Hagel to provide strategic insights on how companies will succeed in the 21st century.

    Read the article

  • Data Governance 2010 Conference in San Diego

    - by Tony Ouk
    The Data Governance Annual Conference is one of the world's most authoritative and vendor neutral event on Data Governance and Data Quality.  The conference will focus on the "how-tos" from starting a data governance and stewardship program to attaining data governance maturity with specific topics on MDM.  This year's event will be hosted June 7 through June 10 in San Diego, California. For more information, including registration details, visit the Data Governance 2010 Conference website.

    Read the article

  • Back home :-)

    - by Mike Dietrich
    Wrote this entry last night in the ICE from Stuttgart to Munich but the conncetion broke: 28.5 hour journey - and close by now. Actually I would have been even closer if our TGV wouldn't have had break problems as soon as we had entered German territory. And you don't want a train which goes up to a speed of 200 mph having issues with its breaks, right? So we missed the connection in Stuttgart but I've catched the last train this night towards Munich. Distance approx 1900 km all together. Usually it takes 2.5 hours with a direct flight with Air Lingus from Munich or a bit more when you'll go through Zurich or Frankfurt. But at least you meet more people and see a bit more from the landscapes passing by :-) Except for the break problem everything worked out well so far (I'm no there finally!). I had 4 hours to change in Paris from Gare de Nord to Gare de l'Est and one thing I really have to point out: the people working for SNCF, the French National Railways, were so organized and helpful, purely amazing. I asked the man at the counter where I had to pick up my prepaid tickets for directions to Gare de l'Est - and after we had a chat about Marlene Dietrich he just grabbed his iPhone, started Google Earth and showed me the way to walk. I pretty sure it's a stupid stereotype that people in Paris or France are so unfriendly to foreigners if they don't speak French. In my past 3 stays or travels to Paris in the past 2 years I had only great experiences. And another thing I really enjoy when being in France: the food!!! The sandwich I had at the train station was packed with yummy goat cheese. And there's always Paul. You might ask yourself: Who the heck is Paul? That's Paul - or actually their website. And at Paul's they serve usually excellent fruit tartes - and this time a nice Gateau Au Chocolate. And very good Cafe Cremé as well :-) That's actually the positive part traveling this way: the food you'll get is much better than the airline food - if your airline still serves something called food ...

    Read the article

  • eBay Leads Mobile Commerce

    - by David Dorf
    For the first time, more smartphones where shipped than PCs. This important milestone helps reinforce that retailers need a strong mobile commerce strategy. IDC reported that for the 4th quarter of 2010, manufacturers shipped 100.9 million devices versus 92.1 million PCs shipped. One early adopter for the retail industry is eBay, the popular online auction and shopping site. In July 2008 they released their first mobile app and have increased investments ever since. In 2002 they bought PayPal for use with its online channel, but its becoming a force in the mobile world as well. In June 2010 they acquired RedLaser, the popular barcode scanning mobile app. Both pieces of technology enhance the mobile experience, and are available to other retailers as well. More recently, in December 2010 they acquired Critical Path Software, the developer of their eBay, StubHub, and Shopping.com mobile applications. Taking their mobile development in-house was a clear signal that mobile commerce is important to their strategy. Pop on over the eBay Inc's mobile commerce stats page to see just how well they are doing. You can use the animated map to see where people are using the app on any given day, and you can compare sales of the different categories. eBay's hottest category is Cars & Trucks, garnering 16.5% of the total $2B (yes, billion) in mobile sales in 2010. To understand why that category is so large, let's look at the top 10 most expensive cars sold on eBay mobile in 2010: $240,001 Mercedes-Benz: SLR McLaren $209,888 Lamborghini: Gallardo $208,500 Ferrari: 430 $199,900 Lamborghini: Gallardo $189,000 Lamborghini: Murcielago $185,000 Ferrari: 430 $175,000 Porsche: 911 $170,000 Ferrari: 550 $160,000 Bentley: Continental, GT $159,900 Lamborghini: Gallardo eBay claims they sell 3-4 Ferraris on their mobile app each month. Yes, mobile commerce is not limited to small items. While I would wait to get home and fire up the PC, the current generation that has grown up with mobile phones has no issue satisfying their impulses. Dave Sikora of Digby told me he's seen people buy furniture sets, mattresses, and diamonds via their mobile phones. I guess mobile commerce is rapidly becoming the norm.

    Read the article

  • Device being used by VxVM

    - by Onur Bingul
    If you are using vxvm, you may have issues when you try to unconfigure a disk root@techsupport2 # cfgadm -c unconfigure c1::dsk/c1t3d0cfgadm: Component system is busy, try again: failed to offline:     Resource             Information       ----------------       -------------------------/dev/dsk/c1t3d0   Device being used by VxVM“cfgadm unconfigure” command fails here.The way to resolve this is to disable the disks path from DMP control. Since there is only one path to this disk, the “-f” (for force) option needs to be used:root@techsupport2 # vxdmpadm -f disable path=c1t3d0s2root@techsupport2 # vxdmpadm getsubpaths NAME         STATE[A]   PATH-TYPE[M] DMPNODENAME  ENCLR-NAME   CTLR   ATTRS================================================================================c1t6d0       ENABLED(A)   -          disk_0       disk         c1       -c1t3d0       DISABLED(M)   -          disk_1       disk         c1       -c1t0d0s2     ENABLED(A)   -          disk_2       disk         c1       -c1t1d0       ENABLED(A)   -          disk_3       disk         c1       -c3t47d0      ENABLED(A)   -          sun35100_0   sun35100     c3       -c3t47d1      ENABLED(A)   -          sun35100_1   sun35100     c3       -c3t47d2s2    ENABLED(A)   -          sun35100_2   sun35100     c3       -c3t47d3s2    ENABLED(A)   -          sun35100_3   sun35100     c3       -You can see the path now disabled from DMP.root@techsupport2 # cfgadm -c unconfigure c1::dsk/c1t3d0Now you can unconfigure the disk

    Read the article

  • Networking in VirtualBox

    - by Fat Bloke
    Networking in VirtualBox is extremely powerful, but can also be a bit daunting, so here's a quick overview of the different ways you can setup networking in VirtualBox, with a few pointers as to which configurations should be used and when. VirtualBox allows you to configure up to 8 virtual NICs (Network Interface Controllers) for each guest vm (although only 4 are exposed in the GUI) and for each of these NICs you can configure: Which virtualized NIC-type is exposed to the Guest. Examples include: Intel PRO/1000 MT Server (82545EM),  AMD PCNet FAST III (Am79C973, the default) or  a Paravirtualized network adapter (virtio-net). How the NIC operates with respect to your Host's physical networking. The main modes are: Network Address Translation (NAT) Bridged networking Internal networking Host-only networking NAT with Port-forwarding The choice of NIC-type comes down to whether the guest has drivers for that NIC.  VirtualBox, suggests a NIC based on the guest OS-type that you specify during creation of the vm, and you rarely need to modify this. But the choice of networking mode depends on how you want to use your vm (client or server) and whether you want other machines on your network to see it. So let's look at each mode in a bit more detail... Network Address Translation (NAT) This is the default mode for new vm's and works great in most situations when the Guest is a "client" type of vm. (i.e. most network connections are outbound). Here's how it works: When the guest OS boots,  it typically uses DHCP to get an IP address. VirtualBox will field this DHCP request and tell the guest OS its assigned IP address and the gateway address for routing outbound connections. In this mode, every vm is assigned the same IP address (10.0.2.15) because each vm thinks they are on their own isolated network. And when they send their traffic via the gateway (10.0.2.2) VirtualBox rewrites the packets to make them appear as though they originated from the Host, rather than the Guest (running inside the Host). This means that the Guest will work even as the Host moves from network to network (e.g. laptop moving between locations), and from wireless to wired connections too. However, how does another computer initiate a connection into a Guest?  e.g. connecting to a web server running in the Guest. This is not (normally) possible using NAT mode as there is no route into the Guest OS. So for vm's running servers we need a different networking mode.... Bridged Networking Bridged Networking is used when you want your vm to be a full network citizen, i.e. to be an equal to your host machine on the network. In this mode, a virtual NIC is "bridged" to a physical NIC on your host, like this: The effect of this is that each VM has access to the physical network in the same way as your host. It can access any service on the network such as external DHCP services, name lookup services, and routing information just as the host does. Logically, the network looks like this: The downside of this mode is that if you run many vm's you can quickly run out of IP addresses or your network administrator gets fed up with you asking for statically assigned IP addresses. Secondly, if your host has multiple physical NICs (e.g. Wireless and Wired) you must reconfigure the bridge when your host jumps networks.  Hmm, so what if you want to run servers in vm's but don't want to involve your network administrator? Maybe one of the next 2 modes is for you... Internal Networking When you configure one or more vm's to sit on an Internal network, VirtualBox ensures that all traffic on that network stays within the host and is only visible to vm's on that virtual network. Configuration looks like this: The internal network ( in this example "intnet" ) is a totally isolated network and so is very "quiet". This is good for testing when you need a separate, clean network, and you can create sophisticated internal networks with vm's that provide their own services to the internal network. (e.g. Active Directory, DHCP, etc). Note that not even the Host is a member of the internal network, but this mode allows vm's to function even when the Host is not connected to a network (e.g. on a plane). Note that in this mode, VirtualBox provides no "convenience" services such as DHCP, so your machines must be statically configured or one of the vm's needs to provide a DHCP/Name service. Multiple internal networks are possible and you can configure vm's to have multiple NICs to sit across internal and other network modes and thereby provide routes if needed. But all this sounds tricky. What if you want an Internal Network that the host participates on with VirtualBox providing IP addresses to the Guests? Ah, then for this, you might want to consider Host-only Networking... Host-only Networking Host-only Networking is like Internal Networking in that you indicate which network the Guest sits on, in this case, "vboxnet0": All vm's sitting on this "vboxnet0" network will see each other, and additionally, the host can see these vm's too. However, other external machines cannot see Guests on this network, hence the name "Host-only". Logically, the network looks like this: This looks very similar to Internal Networking but the host is now on "vboxnet0" and can provide DHCP services. To configure how a Host-only network behaves, look in the VirtualBox Manager...Preferences...Network dialog: Port-Forwarding with NAT Networking Now you may think that we've provided enough modes here to handle every eventuality but here's just one more... What if you cart around a mobile-demo or dev environment on, say, a laptop and you have one or more vm's that you need other machines to connect into? And you are continually hopping onto different (customer?) networks. In this scenario: NAT - won't work because external machines need to connect in. Bridged - possibly an option, but does your customer want you eating IP addresses and can your software cope with changing networks? Internal - we need the vm(s) to be visible on the network, so this is no good. Host-only - same problem as above, we want external machines to connect in to the vm's. Enter Port-forwarding to save the day! Configure your vm's to use NAT networking; Add Port Forwarding rules; External machines connect to "host":"port number" and connections are forwarded by VirtualBox to the guest:port number specified. For example, if your vm runs a web server on port 80, you could set up rules like this:  ...which reads: "any connections on port 8080 on the Host will be forwarded onto this vm's port 80".  This provides a mobile demo system which won't need re-configuring every time you open your laptop lid. Summary VirtualBox has a very powerful set of options allowing you to set up almost any configuration your heart desires. For more information, check out the VirtualBox User Manual on Virtual Networking. -FB 

    Read the article

  • Pyglet vs. PyQt

    - by L. De Leo
    I need to implement a really simple card game. As the game logic is written in Python I chose to stick with some Python framework even if my goal is to develop a Windows only version. I also don't like to work with .NET so I ruled out Iron Python + WPF. I tried to write a simple prototype with Pyglet but soon discovered that I will have to do a lot of stuff by hand: things like detecting mouseover events and finding which card was clicked on and moving it, etc... very low level and unnecessary for my use-case. So I thought it might be easier to do things in PyQt. Do you reckon it would be feasible to use PyQt for implementing a simple card game? Will I have higher level events I can work with?

    Read the article

  • What's the value of a Facebook fan?

    - by David Dorf
    In his blog posting titled "Why Each Facebook Fan Is Worth $2,000 to J. Crew," Joe Skorupa lays out a simplistic calculation for assigning a value to social media efforts within Facebook. While I don't believe the metric, at least its a metric that can be applied consistently. Trying to explain the ROI to management to start a program, then benchmarking to show progress isn't straightforward at all. Social media isn't really mature enough to have hard-and-fast rules around valuation (yet). When I'm asked by retailers how to measure social media efforts, I usually fess-up and say I can't show an ROI but the investment is so low you might was well take a risk. Intuitively, it just seems like a good way to interact with consumers, and since your competition is doing it, you better do it as well. Vitrue, a social media management company, has calculated a fan as being worth $3.60 per year based on impressions generated in Facebook's news feed. That means a fan base of 1 million translates into at least $3.6 million in equivalent media over a year. Don't believe that number either? Fine, Vitrue now has a tool that let's you adjust the earned media value of a fan. Jump over to http://evaluator.vitrue.com/ and enter your brand's Facebook URL to get an assessment of the current value and potential value. For fun, I compared Abercrombie & Fitch (1,077,480 fans), Gap (567,772 fans), and Wet Seal (294,479 fans). The image below shows the results assuming the default $5 earned media value for a fan. The calculation is more complicated than just counting fans. It also accounts for postings and comments. Its possible for a brand with fewer fans to have a higher value based on frequency and relevancy of posts. The tool gathers data via the Social Graph API for the past 30 days of activity. I'm not sure this tool assigns the correct value either, but hey, its a great start.

    Read the article

  • Paying by Cash

    - by David Dorf
    I'll grant you paying by cash in the context of stores isn't particularly interesting, but in my quest to try new payment methods I decided to pay by cash at an online store. Using a credit card means I have to hoist myself off the couch, find the card, and enter all those digits. Google Checkout certainly makes that task easier by storing my credit card information, but what happens to all those people that don't have a credit card? What about the ones that are afraid to use credit cards over the internet. There are three main options for cash payment, not all of which are accepted by every merchant. The most popular is PayPal. The issue I have with them is that returns and disputes have to be handled with PayPal, not the merchant. I once used PayPal at a shady online store and lost my money. Yeah, my bad but they wouldn't help me at all. PayPal was purchased by eBay in 2002. BillMeLater is best for larger purchases, because at checkout they actually run a credit check to make sure you're credit worthy. Assuming you are, they pay the merchant on your behalf and mail you a bill, which you better pay quickly or interest will start to accrue. That's nice for the merchant because they get paid right away, and I presume there's no charge-backs. BillMeLater was purchased by eBay in 2008. Last night I tried eBillMe for the first time. After checkout, they send you a bill via email and expect you to pay either via online banking (they provide the instructions to set everything up) or walk-in locations across the US (typically banks). The process was quick and easy. The merchant doesn't ship the product until the bill is paid, so there's a day or two delay. For the merchant there are no charge-backs, and the fees are less than credit cards. For the shopper, they provide buyer protection similar to that offered by credit cards, and 1% cashback on purchases. Once the online bill-pay is setup, its easy to reuse in the future. Seems like a win-win for merchants and shoppers.

    Read the article

  • QotD: Matt Stephens on OpenJDK in 2012 at the Register

    - by $utils.escapeXML($entry.author)
    While Java SE churns and gets pushed back, the new initiatives do at least show OpenJDK is reinvigorating the Java space. The project has picked up speed just a little too late for the fifth anniversary of the open-sourcing of Java, but if these promised developments really do come together then that means next year should see a series of “one last things” missing from 2011.Matt Stephens in an article in the Register.

    Read the article

  • Doing Time Limited Flight Recordings Using Start Up Parameters

    - by Marcus Hirt
    Just like with the old JRockit Runtime Analyzer, it is possible to start up recordings using command line parameters to JRockit. The parameter is called -XX:StartFlightRecording in R28. Below is an example that starts a flight recording half a minute after the JVM has been started. The recording will last for a minute. The name when viewing the ongoing recordings will be MyRecording, and the resulting file will be written to C:\tmp\myrecording.jfr. The recording will use the settings in jre\lib\jfr\profile.jfs. -XX:StartFlightRecording=delay=30s,duration=60s,name=MyRecording,filename=C:\tmp\myrecording.jfr,settings=profile For more information, see the JRockit R28 command line parameter documentation.

    Read the article

  • OrbitFX: JavaFX 8 3D & NetBeans Platform in Space!

    - by Geertjan
    Here is a collection of screenshots from a proof of concept tool being developed by Nickolas Sabey and Sean Phillips from a.i. solutions. Before going further, read a great new article here written on java.net by Kevin Farnham, in light of the Duke's Choice Award (DCA) recently received at JavaOne 2013 by the a.i. solutions team. Here's Sean receiving the award on behalf of the a.i. solutions team, surrounded by the DCA selection committee and other officials: They won the DCA for helping facilitate and deploy the 2014 launch of NASA's Magnetospheric Multiscale mission, using JDK 7, the NetBeans Platform, and JavaFX to create the GEONS Ground Support System, helping reduce software development time by approximately 35%. The prototype tool that Nicklas and Sean are now working on uses JavaFX 3D with the NetBeans Platform and is nicknamed OrbitFX. Much of the early development is being done to experiment with different patterns, so that accuracy is currently not the goal. For example, you'll notice in the screenshots that the Earth is really close to the Sun, which is obviously not correct. The screenshots are generated using Java 8 build 111, together with NetBeans Platform 7.4. Inspired by various JavaOne demos using JavaFX 3D, Nick began development integrating them into their existing NetBeans Platform infrastructure. The 3D scene showing the Sun and Earth objects is all JavaFX 8 3D, demonstrating the use of Phong Material support, along with multiple light and camera objects. Each JavaFX component extends a JFXPanel type, so that each can easily be added to NetBeans Platform TopComponents. Right-clicking an item in the explorer view offers a context menu that animates and centers the 3D scene on the selected celestial body.  With each JavaFX scene component wrapped in a JFXPanel, they can easily be integrated into a NetBeans Platform Visual Library scene.  In this case, Nick and Sean are using an instance of their custom Slipstream PinGraphScene, which is an extension of the NetBeans Platform VMDGraphScene. Now, via the NetBeans Platform Visual Library, the OrbitFX celestial body viewer can be used in the same space as a WorldWind viewer, which is provided by a previously developed plugin. "This is a clear demonstration of the power of the NetBeans Platform as an application development framework," says Sean Phillips. "How else could you have so much rich application support placed literally side by side so easily?"

    Read the article

  • Class Loading Deadlocks

    - by tomas.nilsson
    Mattis follows up on his previous post with one more expose on Class Loading Deadlocks As I wrote in a previous post, the class loading mechanism in Java is very powerful. There are many advanced techniques you can use, and when used wrongly you can get into all sorts of trouble. But one of the sneakiest deadlocks you can run into when it comes to class loading doesn't require any home made class loaders or anything. All you need is classes depending on each other, and some bad luck. First of all, here are some basic facts about class loading: 1) If a thread needs to use a class that is not yet loaded, it will try to load that class 2) If another thread is already loading the class, the first thread will wait for the other thread to finish the loading 3) During the loading of a class, one thing that happens is that the <clinit method of a class is being run 4) The <clinit method initializes all static fields, and runs any static blocks in the class. Take the following class for example: class Foo { static Bar bar = new Bar(); static { System.out.println("Loading Foo"); } } The first time a thread needs to use the Foo class, the class will be initialized. The <clinit method will run, creating a new Bar object and printing "Loading Foo" But what happens if the Bar object has never been used before either? Well, then we will need to load that class as well, calling the Bar <clinit method as we go. Can you start to see the potential problem here? A hint is in fact #2 above. What if another thread is currently loading class Bar? The thread loading class Foo will have to wait for that thread to finish loading. But what happens if the <clinit method of class Bar tries to initialize a Foo object? That thread will have to wait for the first thread, and there we have the deadlock. Thread one is waiting for thread two to initialize class Bar, thread two is waiting for thread one to initialize class Foo. All that is needed for a class loading deadlock is static cross dependencies between two classes (and a multi threaded environment): class Foo { static Bar b = new Bar(); } class Bar { static Foo f = new Foo(); } If two threads cause these classes to be loaded at exactly the same time, we will have a deadlock. So, how do you avoid this? Well, one way is of course to not have these circular (static) dependencies. On the other hand, it can be very hard to detect these, and sometimes your design may depend on it. What you can do in that case is to make sure that the classes are first loaded single threadedly, for example during an initialization phase of your application. The following program shows this kind of deadlock. To help bad luck on the way, I added a one second sleep in the static block of the classes to trigger the unlucky timing. Notice that if you uncomment the "//Foo f = new Foo();" line in the main method, the class will be loaded single threadedly, and the program will terminate as it should. public class ClassLoadingDeadlock { // Start two threads. The first will instansiate a Foo object, // the second one will instansiate a Bar object. public static void main(String[] arg) { // Uncomment next line to stop the deadlock // Foo f = new Foo(); new Thread(new FooUser()).start(); new Thread(new BarUser()).start(); } } class FooUser implements Runnable { public void run() { System.out.println("FooUser causing class Foo to be loaded"); Foo f = new Foo(); System.out.println("FooUser done"); } } class BarUser implements Runnable { public void run() { System.out.println("BarUser causing class Bar to be loaded"); Bar b = new Bar(); System.out.println("BarUser done"); } } class Foo { static { // We are deadlock prone even without this sleep... // The sleep just makes us more deterministic try { Thread.sleep(1000); } catch(InterruptedException e) {} } static Bar b = new Bar(); } class Bar { static { try { Thread.sleep(1000); } catch(InterruptedException e) {} } static Foo f = new Foo(); }

    Read the article

  • Is Master Data Management CRM's Secret Sauce?

    - by divya.malik
    This was the title of a recent blog entry by our colleagues in EMEA. Having a good master data management system enables organizations to get a unified, accurate and complete understanding of their customers. Gartner Group's John Radcliffe explains why MDM is destined to be at the heart of future CRM and social CRM projects. Experts are predicting big things for master data management (MDM) in the immediate future. While far from being a new kid on the block, its potential benefits at a time when organisations are drowning in data mean that it is in the right place at the right time. "MDM is not 'nice to have'," explains John Radcliffe, research vice president at Gartner. "If tackled in the right way it can provide near term business value that plays into an organisation's new focus on cost efficiencies, risk management and regulatory compliance, while supporting growth and future transformative strategies." The complete article can be found here.

    Read the article

  • When Less is More

    - by aditya.agarkar
    How do you reconcile the fact that while the overall warehouse volume is down you still need more workers in the warehouse to ship all the orders? A WMS customer recently pointed out this seemingly perplexing fact in a customer conference. So what is going on? Didn't we tell you before that for a warehouse the customer is really the "king"? In this case customers are merely responding to a low overall low demand and uncertainty. They do not want to hold down inventory and one of the ways to do that is by decreasing the order size and ordering more frequently. Overall impact to the warehouse? Two words: "More work!!" This is not all. Smaller order sizes also mean challenges from a transportation perspective including a rise in costlier parcel or LTL shipments instead of cheaper TL shipments. Here is a hypothetical scenario where a customer reduces the order size by 10% and increases the order frequency by 10%. As you can see in the following table, the overall volume declines by 1% but the warehouse has to ship roughly 10% more lines. Order Frequency (Line Count)Order Size (Units)Total VolumeChange (%)10010010,000 -110909,900-1% If you want to see how "Less is More" in graphical terms, this is how it appears: Even though the volume is down, there is going to be more work in the warehouse in terms of number of lines shipped. The operators need to pick more discrete orders, pack them into more shipping containers and ship more deliveries. What do you do differently if you are facing this situation?In this case here are some obvious steps to take:Uno: Change your pick methods. If you are used to doing order picks, it needs to go out the door. You need to evaluate batch picking and grouping techniques. Go for cluster picking, go for zone picking, pick and pass...anything that improves your picker productivity. More than anything, cluster picking works like a charm and above all, its simple and very effective. Dos: Are you minimize "touch" points in your pick process? Consider doing one step pick, pack and confirm i.e. pick and pack stuff directly into shipping cartons. Done correctly the container will not require any more "touch" points all the way to the trailer loading. Use cartonization!Tres: Are the being picked from an optimized pick face? Are the items slotted correctly? This needs to be looked into. Consider automated "pull" or "push" replenishment into your pick face and also make sure that high demand items are occupying the golden zones.  Cuatro: Are you tracking labor productivity? If not there needs to be a concerted push for having labor standards in place. Hope you found these ideas useful.

    Read the article

  • Solaris 11 pkg fix is my new friend

    - by user12611829
    While putting together some examples of the Solaris 11 Automated Installer (AI), I managed to really mess up my system, to the point where AI was completely unusable. This was my fault as a combination of unfortunate incidents left some remnants that were causing problems, so I tried to clean things up. Unsuccessfully. Perhaps that was a bad idea (OK, it was a terrible idea), but this is Solaris 11 and there are a few more tricks in the sysadmin toolbox. Here's what I did. # rm -rf /install/* # rm -rf /var/ai # installadm create-service -n solaris11-x86 --imagepath /install/solaris11-x86 \ -s [email protected] Warning: Service svc:/network/dns/multicast:default is not online. Installation services will not be advertised via multicast DNS. Creating service from: [email protected] DOWNLOAD PKGS FILES XFER (MB) SPEED Completed 1/1 130/130 264.4/264.4 0B/s PHASE ITEMS Installing new actions 284/284 Updating package state database Done Updating image state Done Creating fast lookup database Done Reading search index Done Updating search index 1/1 Creating i386 service: solaris11-x86 Image path: /install/solaris11-x86 So far so good. Then comes an oops..... setup-service[168]: cd: /var/ai//service/.conf-templ: [No such file or directory] ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This is where you generally say a few things to yourself, and then promise to quit deleting configuration files and directories when you don't know what you are doing. Then you recall that the new Solaris 11 packaging system has some ability to correct common mistakes (like the one I just made). Let's give it a try. # pkg fix installadm Verifying: pkg://solaris/install/installadm ERROR dir: var/ai Group: 'root (0)' should be 'sys (3)' dir: var/ai/ai-webserver Missing: directory does not exist dir: var/ai/ai-webserver/compatibility-configuration Missing: directory does not exist dir: var/ai/ai-webserver/conf.d Missing: directory does not exist dir: var/ai/image-server Group: 'root (0)' should be 'sys (3)' dir: var/ai/image-server/cgi-bin Missing: directory does not exist dir: var/ai/image-server/images Group: 'root (0)' should be 'sys (3)' dir: var/ai/image-server/logs Missing: directory does not exist dir: var/ai/profile Missing: directory does not exist dir: var/ai/service Group: 'root (0)' should be 'sys (3)' dir: var/ai/service/.conf-templ Missing: directory does not exist dir: var/ai/service/.conf-templ/AI_data Missing: directory does not exist dir: var/ai/service/.conf-templ/AI_files Missing: directory does not exist file: var/ai/ai-webserver/ai-httpd-templ.conf Missing: regular file does not exist file: var/ai/service/.conf-templ/AI.db Missing: regular file does not exist file: var/ai/image-server/cgi-bin/cgi_get_manifest.py Missing: regular file does not exist Created ZFS snapshot: 2012-12-11-21:09:53 Repairing: pkg://solaris/install/installadm Creating Plan (Evaluating mediators): | DOWNLOAD PKGS FILES XFER (MB) SPEED Completed 1/1 3/3 0.0/0.0 0B/s PHASE ITEMS Updating modified actions 16/16 Updating image state Done Creating fast lookup database Done In just a few moments, IPS found the missing files and incorrect ownerships/permissions. Instead of reinstalling the system, or falling back to an earlier Live Upgrade boot environment, I was able to create my AI services and now all is well. # installadm create-service -n solaris11-x86 --imagepath /install/solaris11-x86 \ -s [email protected] Warning: Service svc:/network/dns/multicast:default is not online. Installation services will not be advertised via multicast DNS. Creating service from: [email protected] DOWNLOAD PKGS FILES XFER (MB) SPEED Completed 1/1 130/130 264.4/264.4 0B/s PHASE ITEMS Installing new actions 284/284 Updating package state database Done Updating image state Done Creating fast lookup database Done Reading search index Done Updating search index 1/1 Creating i386 service: solaris11-x86 Image path: /install/solaris11-x86 Refreshing install services Warning: mDNS registry of service solaris11-x86 could not be verified. Creating default-i386 alias Setting the default PXE bootfile(s) in the local DHCP configuration to: bios clients (arch 00:00): default-i386/boot/grub/pxegrub Refreshing install services Warning: mDNS registry of service default-i386 could not be verified. # installadm create-service -n solaris11u1-x86 --imagepath /install/solaris11u1-x86 \ -s [email protected] Warning: Service svc:/network/dns/multicast:default is not online. Installation services will not be advertised via multicast DNS. Creating service from: [email protected] DOWNLOAD PKGS FILES XFER (MB) SPEED Completed 1/1 514/514 292.3/292.3 0B/s PHASE ITEMS Installing new actions 661/661 Updating package state database Done Updating image state Done Creating fast lookup database Done Reading search index Done Updating search index 1/1 Creating i386 service: solaris11u1-x86 Image path: /install/solaris11u1-x86 Refreshing install services Warning: mDNS registry of service solaris11u1-x86 could not be verified. # installadm list Service Name Alias Of Status Arch Image Path ------------ -------- ------ ---- ---------- default-i386 solaris11-x86 on i386 /install/solaris11-x86 solaris11-x86 - on i386 /install/solaris11-x86 solaris11u1-x86 - on i386 /install/solaris11u1-x86 This is way way better than pkgchk -f in Solaris 10. I'm really beginning to like this new IPS packaging system.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 574 575 576 577 578 579 580 581 582 583 584 585  | Next Page >