Search Results

Search found 5695 results on 228 pages for 's60 3rd edition'.

Page 91/228 | < Previous Page | 87 88 89 90 91 92 93 94 95 96 97 98  | Next Page >

  • Oracle WebLogic Server 12c Launch Event - Dec 1, 2011, 10am PT

    - by arungupta
    Calling all IT managers, architects, and developers, to find out how the new release of Oracle WebLogic Server 12c is: Designed to help you seamlessly move into the public or private cloud with an open, standards-based platform Built to drive higher value for your current infrastructure and significantly reduce development time and cost Optimized to run your solutions for Java Platform, Enterprise Edition (Java EE); Oracle Fusion Middleware; and Oracle Fusion Enhanced with transformational platforms and technologies such as Java EE 6, Oracle’s Active GridLink for RAC, Oracle Traffic Director, and Oracle Virtual Assembly Builder When ? Dec 1, 2011, 10am - 12pm PT Where ? Register online! Here are some other links for you to follow: blogs.oracle.com/weblogicserver @OracleWebLogic youtube.com/OracleWebLogic facebook.com/OracleWebLogic Steve Button's Blog Jeff West's Blog WebLogic Forums WebLogic @ OTN Almost ready to unwrap the ribbons, pop open the cork, at the start line ... or whatever fits your analogy :-) And in case you are wondering ... here is a snapshot of WebLogic 12c administration console snapshot:

    Read the article

  • Lightweight PHP/HTML/CSS editor with code browser

    - by Nisto
    I'm looking for a freeware editor which has; syntax highlighting and a code browser (or code suggestions/hints). Preferably freeware license! I've tried out quite a few editors, but a lot of them are unfortunately very resource heavy and provides a lot more functions than I ever needed. So far, there's two editors that I really like, and is lightweight: jEdit and Notepad++. Although, unfortunately... Notepad++ doesn't have code browser support for both control structures and functions for PHP. Also, there's no code browser for HTML... I really liked jEdit as well, but there doesn't seem to be a code browser for it. Except for maybe Completion, but it's a bothersome plugin, and doesn't show the code browser unless you type something in and press CTRL+B. Other editors I've tried, but wasn't satisfied with: Adobe Dreamweaver CodeLobster PHP Edition Aptana Studio Komodo Edit EditPlus BlueFish PHP Designer 2007 - Personal PhpStorm Scriptly Eclipse UltraEdit Notepad2 EditPad Pro Rapid PHP EDIT I'm using Windows XP

    Read the article

  • Microsoft announces Tech.Ed India in Bengaluru on April 12-14 2010

    Hi, if you too are a Developer, IT professional, Decision-maker, Designer, Solution Architect, Technology Manager or a Student, this will definitely excite you. Microsoft is back this year with the Indian edition of Tech.Ed, it's global education & networking conference for technology professionals. Expect to run into S. Somasegar (Sr. VP, Microsoft Developer Division), Kevin J. Smith (Senior Director, Intel), Stephen Forte (Chief Strategy Officer, Telerik) and other technology stalwarts....Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

    Read the article

  • Verizon Wireless Supports its Mission-Critical Employee Portal with MySQL

    - by Bertrand Matthelié
    Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Cambria","serif"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin;} Verizon Wireless, the #1 mobile carrier in the United States, operates the nation’s largest 3G and 4G LTE network, with the most subscribers (109 millions) and the highest revenue ($70.2 Billion in 2011). Verizon Wireless built the first wide-area wireless broadband network and delivered the first wireless consumer 3G multimedia service in the US, and offers global voice and data services in more than 200 destinations around the world. To support 4.2 million daily wireless transactions and 493,000 calls and emails transactions produced by 94.2 million retail customers, Verizon Wireless employs over 78,000 employees with area headquarters across the United States. The Business Challenge Seeing the stupendous rise in social media, video streaming, live broadcasting…etc which redefined the scope of technology, Verizon Wireless, as a technology savvy company, wanted to provide a platform to its employees where they could network socially, view and host microsites, stream live videos, blog and provide the latest news. The IT team at Verizon Wireless had abundant experience with various technology platforms to support the huge number of applications in the company. However, open-source products weren’t yet widely used in the organization and the team had the ambition to adopt such technologies and see if the architecture could meet Verizon Wireless’ rigid requirements. After evaluating a few solutions, the IT team decided to use the LAMP stack for Vzweb, its mission-critical, 24x7 employee portal, with Drupal as the front end and MySQL on Linux as the backend, and for a few other internal websites also on MySQL. The MySQL Solution Verizon Wireless started to support its employee portal, Vzweb, its online streaming website, Vztube, and internal wiki pages, Vzwiki, with MySQL 5.1 in 2010. Vzweb is the main internal communication channel for Verizon Wireless, while Vztube hosts important company-wide webcasts regularly for executive-level announcements, so both channels have to be live and accessible all the time for its 78,000 employees across the United States. However during the initial deployment of the MySQL based Intranet, the application experienced performance issues. High connection spikes occurred causing slow user response time, and the IT team applied workarounds to continue the service. A number of key performance indexes (KPI) for the infrastructure were identified and the operational framework redesigned to support a more robust website and conform to the 99.985% uptime SLA (Service-Level Agreement). The MySQL DBA team made a series of upgrades in MySQL: Step 1: Moved from MyISAM to InnoDB storage engine in 2010 Step 2: Upgraded to the latest MySQL 5.1.54 release in 2010 Step 3: Upgraded from MySQL 5.1 to the latest GA release MySQL 5.5 in 2011, and leveraging MySQL Thread Pool as part of MySQL Enterprise Edition to scale better After making those changes, the team saw a much better response time during high concurrency use cases, and achieved an amazing performance improvement of 1400%! In January 2011, Verizon CEO, Ivan Seidenberg, announced the iPhone launch during the opening keynote at Consumer Electronic Show (CES) in Las Vegas, and that presentation was streamed live to its 78,000 employees. The event was broadcasted flawlessly with MySQL as the database. Later in 2011, Hurricane Irene attacked the East Coast of United States and caused major life and financial damages. During the hurricane, the team directed more traffic to its west coast data center to avoid potential infrastructure damage in the East Coast. Such transition was executed smoothly and even though the geographical distance became longer for the East Coast users, there was no impact in the performance of Vzweb and Vztube, and the SLA goal was achieved. “MySQL is the key component of Verizon Wireless’ mission-critical employee portal application,” said Shivinder Singh, senior DBA at Verizon Wireless. “We achieved 1400% performance improvement by moving from the MyISAM storage engine to InnoDB, upgrading to the latest GA release MySQL 5.5, and using the MySQL Thread Pool to support high concurrent user connections. MySQL has become part of our IT infrastructure, on which potentially more future applications will be built.” To learn more about MySQL Enterprise Edition, Get our Product Guide.

    Read the article

  • Week in Geek: Official 64-Bit ‘Nightly Builds’ of Mozilla Firefox have been Discontinued

    - by Asian Angel
    Our last edition of WIG for November is filled with news link coverage on topics such as how Microsoft gave Windows 8 Pro to pirates by mistake, Nintendo warns against interrupting the Wii U update, a new trojan is using Google Docs to communicate with its control server, and more. Original wallpaper by hackSkillz, available at deviantART. Why Does 64-Bit Windows Need a Separate “Program Files (x86)” Folder? Why Your Android Phone Isn’t Getting Operating System Updates and What You Can Do About It How To Delete, Move, or Rename Locked Files in Windows

    Read the article

  • Jetzt geht’s los - speaking in Germany!

    - by Hugo Kornelis
    It feels just like yesterday that I went to Munich for the very first German edition of SQL Saturday – and it was a great event. An agenda that was packed with three tracks of great sessions, and lots of fun with the organization, attendees, and other speakers. That was such a great time that I didn’t have to hesitate long before deciding that I wanted to repeat this event this year. Especially when I heard that it will be held in Rheinland, on July 13 – that is a distance I can travel by car! The...(read more)

    Read the article

  • A Database and LDAP Ice Breaker Video

    - by mark.wilcox
    I made another GoAnimate video - this time it's about using LDAP for database passwords. Since it's on the free site - I didn't want to violate any terms of agreement - so it doesn't mention Oracle explicitly. But if you wanted to actually do what the animation talks about with Oracle database - you need to configure the Oracle database to use Oracle Enterprise User Security. EUS requires OVD or OID and works with most popular LDAP servers including Active Directory and of course our newest Oracle Directory member - Directory Server Enterprise Edition (aka the former Sun directory). So - if you are looking for a simple way to explain why you might want to use LDAP passwords with your databases or maybe just a slight chuckle on a Friday afternoon have a look at the video: -- Posted via email from Virtual Identity Dialogue

    Read the article

  • O&rsquo;Reilly offer to 05:00 PT 12/Aug/2014 - Ivor Horton's Beginning Visual C++ 2013

    - by TATWORTH
    Originally posted on: http://geekswithblogs.net/TATWORTH/archive/2014/08/05/orsquoreilly-offer-to-0500-pt-12aug2014---ivor-hortons-beginning.aspxUntil 05:00 PT 12/Aug/2014, O’Reilly at http://shop.oreilly.com/product/9781118845714.do?code=WKCPPS are offering 50% off Ivor Horton's Beginning Visual C++ 2013. “This latest edition of the bestselling book on the C++ language follows the proven approach that has made all of Ivor Horton’s C++ books so popular. Horton provides a comprehensive introduction to both the Standard C++ language, and to Visual C++. The book—thoroughly updated for the 2013 release—shows readers how to build real-world applications using Visual C++. No previous programming experience is required. The author uses numerous step-by-step programming examples to guide readers through the ins and outs of C++ development.”

    Read the article

  • What are reasons for Unity3D's owners to force rich guys buying Pro version?

    - by mhambra
    Well, I have to say that Unity is a really nice thing that can save one a dozen of hours on coding (letting instantly work on gameplay). But what's the idea of forcing (EULA) any party, which made over 100k last fiscal year, to purchase Pro instead of using normal edition!? It feels that this kind of licensing provides hidden benefits to rich guys over me, poor sloven, who can afford buying $3.5k license but obviously will not receive any additional cookies from it. And, by the way, anyone estimated how much Unity's source + Playstation + Xbox license will cost?

    Read the article

  • Podcast interview with Michael Kane

    - by mhornick
    In this podcast interview with Michael Kane, Data Scientist and Associate Researcher at Yale University, Michael discusses the R statistical programming language, computational challenges associated with big data, and two projects involving data analysis he conducted on the stock market "flash crash" of May 6, 2010, and the tracking of transportation routes bird flu H5N1. Michael also worked with Oracle on Oracle R Enterprise, a component of the Advanced Analytics option to Oracle Database Enterprise Edition. In the closing segment of the interview, Michael comments on the relationship between the data analyst and the database administrator and how Oracle R Enterprise provides secure data management, transparent access to data, and improved performance to facilitate this relationship. Listen now...

    Read the article

  • La première bêta de Mandriva 2011 est disponible, la distribution Linux va de l'avant

    La première bêta de Mandriva 2011 est disponible, la distribution Linux va de l'avant Mandriva vient de sortir la première bêta de l'édition 2011 de sa distribution Linux. Cette dernière se base sur KDE 4.6.1 et s'articule autour du noyau 2.6.37. Mais l'éditeur a déjà prévenu que la version 38 du kernel serait intégrée au système d'exploitation dès que possible. Cette mouture apporte de nombreuses améliorations, du côté des pilotes graphiques mais aussi du lecteur multimédia Clémentine. Parmi les composants systèmes, on notera : rpm-5.3.9-0.20110303.2, systemd-20, networkmanager-0.8.3.997 et bash 4.2 Enfin, la très récente RC de Firefox 4 est déjà inclue dans le pack logiciels.

    Read the article

  • Tuning GlassFish for Production

    - by arungupta
    The GlassFish distribution is optimized for developers and need simple deployment and server configuration changes to provide the performance typically required for production usage. The formal Performance Tuning Guide provides an explanation of capacity planning and tuning tips for application, GlassFish, JVM, and the operating system. The GlassFish Server Control (only with the commercial edition) also comes with Performance Tuner that optimizes the runtime for optimal throughput and scalability. And then there are multiple blogs that provide more insights as well: • Optimizing GlassFish for Production (Diego Silva, Mar 2012) • GlassFish Production Tuning (Vegard Skjefstad, Nov 2011) • GlassFish in Production (Sunny Saxena, Jul 2011) • Putting GlassFish v3 in Production: Essential Surviving Guide (JeanFrancois, Nov 2009) • A GlassFish Tuning Primer (Scott Oaks, Dec 2007) What is your favorite source for GlassFish Performance Tuning ?

    Read the article

  • How to retrieve the Identity (@@IDENTITY) of a record you just inserted into a table.

    - by Edward Boyle
    SELECT @@IDENTITY will retrive that last generated @@IDENTITY from the current connection. int thisid = (int)cmd.ExecuteScalar("SELECT @@IDENTITY",conn); If there is another write in another connection you do not have to worry. Again, @@IDENTITY will retrieve last generated @@IDENTITY from the current connection. Null if no @@IDENTITY was generated on this connection. Another method is to append ;SELECT @@IDENTITY to your SQL Insert and use ExecuteScalar() What was: INSERT INTO STUFF(Field) VALUES(1) ... cmd.ExecuteNonQuery(); Becomes: string cstring= "INSERT INTO STUFF(Field) VALUES(1);SELECT @@IDENTITY"; int thisid = (int)cmd.ExecuteScalar(cstring, conn); In SQL Server Compact Edition you must send your commands in one at a time, you can not append ;SELECT @@IDENTITY to an insert.

    Read the article

  • Oracle presentations at the CIPS ICE Conference, November 5 - 7, Edmonton, Alberta, Canada

    - by Darin Pendergraft
    Oracle will be presenting at the CIPS ICE conference the last week of October in Calgary and the first week of November in Edmonton. Here is a list of the presentations for Edmonton: SHAW Conference Centre • Session Title: Identity and Access Management Integrated; Analyzing the Platform vs Point Solution Approach • Speaker: Darin Pendergraft • Monday, November 5th @ 10:45 AM - 12:00 PM • Session Title: Is Your IT Security Strategy Putting Your Institution at Risk? • Speaker: Spiros Angelopoulos • Monday, November 5th @ 1:45 PM - 3:00 PM Three sessions under the TRAIN: Practical Knowledge Track • Monday, November 5th @ 10:45 AM, 1:45 PM, 3:30 PM • Title: What's new in the Java Platform   Presenter: Donald Smith • Title: Java Enterprise Edition 6   Presenter: Shaun Smith • Title: The Road Ahead for Java SE, JavaFX and Java EE    Presenters: Donald Smith and Shaun Smith To learn more about the conference, and to see the other sessions go to the conference website.

    Read the article

  • India's Largest Polyglot Conference and Workshops for IT Software Professionals - Great Indian Devel

    Great Indian Developer Summit is the gold standard for India's software developer ecosystem for gaining exposure to and evaluating new projects, tools, services, platforms, languages, software and standards. Packed with premium knowledge, action plans and advise from been-there-done-it veterans, creators, and visionaries, the 2010 edition of Great Indian Developer Summit features focused sessions, case studies, workshops and power panels that will transform you into a force to reckon with. Featuring...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

    Read the article

  • March Oracle Technology Network Offers

    - by Cassandra Clark
    Happy March!  We are pleased to bring you more new discounts this month.  To get discount codes for the books below please visit the Oracle Technology Network Member Discount Page.  New DiscountsOracle Press - 40% off the following Oracle Press title  - Achieving Extreme Performance with Oracle Exadata Packt Publishing - 20% off print and 40% off ebook formats for the following titles - Oracle GoldenGate 11g Implementerís Guide, John P JeffriesOracle Business Intelligence, Yuli Vasiliev, Oracle Fusion Middleware Patterns, Harish Gaur, Marcus Zirn, et al.Oracle JRockit: The Definitive Guide, Marcus Hirt, Marcus LagergrenExtended offers - see offer page for detailsManning is offering a number of titles for 40% to 42% off with OTN promo codeCRS Press is offering 20% off Secure Java: For Web application Development with OTN promo codePearson is offering 35% and free shipping within the U.S. with OTN promo code on two titles.Apress - 25% pff eBooks purchased on apress.com with OTN promo code.Oracle Store has extended its offer of 15% off Oracle Office Enterprise Edition with OTN promo code.

    Read the article

  • Updated Technical Best Practices whitepaper

    - by ACShorten
    The Technical Best Practices whitepaper has been updated with the latest advice. This edition of the whitepaper covers advice from our internal management team from the product group that manages our environments. Our product teams manage over 1500+ copies of the product, covering every version, every platform and every phase of our development, testing and production product development cycle. The technical team managing that group of environments has compiled some additional advice that has been incorporated into the Technical Best Practices and other whitepapers (inclusding Performance Troubleshooting and the Software Configuration Management Series). New advice includes new installation advice, advanced settings, new security settings and advice for both Oracle WebLogic and IBM WebSphere installations. The Technical Best Practices whitepaper is available from My Oracle Support at Doc Id: 560367.1. To assist readers of past editions of the whitepaper, new or updated advice is marked with an appropriate graphic.

    Read the article

  • can't install with usb pen drive, SYSLINUX problem

    - by nkint
    i'm on ubuntustudio and i want to format my hd and try kubuntu (install in my acer notebook, no partion, no double operating system problem, only istall it) i've downloaded iso file ( kubuntu-10.10-desktop-i386.iso ), insert usb pen drive, then: system administration startup disk creator erased usb pen content, and "make startup disk" finally, reboot computer with pen inside usb port normal boot didn't start (as expected) but only black screen with this signal: SYSLINUX 4.03 2010-10-22 EDD Copyright (c) 1994-2010, H. Peter Anvin et al unknown keyword in configuration file boot: i've tried different usb pen stick and different iso files (ubuntu, kubuntu, netbook edition).. always same problem (sometimes only the first line without "unknow keyword in conf file" error) some advice?? sorry for my bad english

    Read the article

  • MySQL Connect and OurSQL Interview

    - by Keith Larson
    In the latest episode of our "Meet The MySQL Experts" podcast, I had the pleasure of being able to interview the hosts of the OurSQL podcast, Sheeri Cabral of Mozilla and Gerry Narvaja of Tokutek, about the upcoming MySQL Connect Conference.  Enjoy the podcast ! MySQL Connect Blog posts: MySQL Connect: New Keynote Announced MySQL Connect: Sessions From Users and Customers MySQL Connect: Some Fun Stuff! MySQL Connect: Replication Sessions MySQL Connect: Optimizer Sessions MySQL Connect: Focus on InnoDB Sessions Interview with Ronald Bradford about MySQL Connect Interview with Sarah Novotny about MySQL Connect Interview with Giuseppe Maxia "the datacharmer" about MySQL Connect Interview with Lenz Grimmer about MySQL Connect Plan Your MySQL Connect Conference With Schedule Builder You can check out the full program here as well as in the September edition of the MySQL newsletter. Not registered yet? You can still save US$ 300 over the on-site fee – Register Now!

    Read the article

  • IntelliTrace Causing Slow WPF Debugging in Visual Studio 2010

    - by WeigeltRo
    Just a quick note to myself (and others that may stumble across this blog entry via a web search): If a WPF application is running slow inside the debugger of Visual Studio 2010, but perfectly fine without a debugger (e.g. by hitting Ctrl-F5), then the reason may be Intellitrace. In my case switching off Intellitrace (only available in the Ultimate Edition of Visual Studio 2010) helped gitting rid of the sluggish behavior of a DataGrid. In the “Tools” menu select “Options”, on the Options dialog click “Intellitrace” and then uncheck “Enable Intellitrace”. Note that I do not have access to Visual Studio 2012 at the time of this writing, thus I cannot make a statement about its debugging behavior.

    Read the article

  • The JRockit Book is Now in Print!

    - by Marcus Hirt
    Yes. I know. It’s been in print for some days already, but I haven’t found time to write about it until now. The book is a good guide for JVM’s in general, and for JRockit in particular. If you’ve ever wondered how the innards of the Java Virtual Machine works, or how to use the JRockit Mission Control to hunt down problems in your Java applications, this book is for you. The book is written for intermediate to advanced Java Developers. These are the chapters: Getting Started Adaptive Code Generation Adaptive Memory Management Threads and Synchronization Benchmarking and Tuning JRockit Mission Control The Management Console The Runtime Analyzer The Flight Recorder The Memory Leak Detector JRCMD Using the JRockit Management APIs JRockit Virtual Edition Appendix A: Bibliography Appendix B: Glossary Index The book is 588 pages long. For more information about the book, see the book page at Packt.

    Read the article

  • Need Drivers for D-link DWA 525 PCI Wireless adapter

    - by Hari
    I'm using Ubuntu 12.10 32-Bit Edition. I have racently purchased D-link DWA 525 PCI Wireless Adapter. But i can't find the drivers for the adapter. I have been searching in internet for a while. Tried many options, including ndiswrapper. When i run lspci command, it detects and shows as below. 04:00.0 Network controller: Ralink corp. RT5360 Wireless 802.11n 1T/1R My kernel version is 3.5.0-18-generic. Please help me out.

    Read the article

  • The videocard driver killed Unity

    - by iUngi
    Hy, I just installed the ubuntu 11.04. After I restarted the PC I got a little notification that some drivers are missing, I click to activate the driver. So after the activation I can't use the unity. When in the preference page I click to the Ati catalyst control center I get the following error: There was a problem initializing Catalyst Control Center Linux edition. It could be caused by the following. No ATI graphics driver is installed, or the ATI driver is not functioning properly. Please install the ATI driver appropriate for you ATI hardware, or configure using aticonfig. My video card is ATI so I don't know what is the problem!?!

    Read the article

  • Windows 7 Virtualized on Ubuntu Server

    - by garbagecollector
    I have an issue, we are moving to a production build server now. I need a virtual machine up and running on my Ubuntu 10.10 server edition. I have to setup and install various tool and plugins, on this windows 7 virtual machine as well The problem I am facing is how do I install windows 7 on this machine ( ubuntu 10.10 server) also, how am i supposed to gain access to it in order to install tools that are required on it. I would prefer virtual box as my tool of choice. Please and thank you.

    Read the article

  • How to Achieve OC4J RMI Load Balancing

    - by fip
    This is an old, Oracle SOA and OC4J 10G topic. In fact this is not even a SOA topic per se. Questions of RMI load balancing arise when you developed custom web applications accessing human tasks running off a remote SOA 10G cluster. Having returned from a customer who faced challenges with OC4J RMI load balancing, I felt there is still some confusions in the field how OC4J RMI load balancing work. Hence I decide to dust off an old tech note that I wrote a few years back and share it with the general public. Here is the tech note: Overview A typical use case in Oracle SOA is that you are building web based, custom human tasks UI that will interact with the task services housed in a remote BPEL 10G cluster. Or, in a more generic way, you are just building a web based application in Java that needs to interact with the EJBs in a remote OC4J cluster. In either case, you are talking to an OC4J cluster as RMI client. Then immediately you must ask yourself the following questions: 1. How do I make sure that the web application, as an RMI client, even distribute its load against all the nodes in the remote OC4J cluster? 2. How do I make sure that the web application, as an RMI client, is resilient to the node failures in the remote OC4J cluster, so that in the unlikely case when one of the remote OC4J nodes fail, my web application will continue to function? That is the topic of how to achieve load balancing with OC4J RMI client. Solutions You need to configure and code RMI load balancing in two places: 1. Provider URL can be specified with a comma separated list of URLs, so that the initial lookup will land to one of the available URLs. 2. Choose a proper value for the oracle.j2ee.rmi.loadBalance property, which, along side with the PROVIDER_URL property, is one of the JNDI properties passed to the JNDI lookup.(http://docs.oracle.com/cd/B31017_01/web.1013/b28958/rmi.htm#BABDGFBI) More details below: About the PROVIDER_URL The JNDI property java.name.provider.url's job is, when the client looks up for a new context at the very first time in the client session, to provide a list of RMI context The value of the JNDI property java.name.provider.url goes by the format of a single URL, or a comma separate list of URLs. A single URL. For example: opmn:ormi://host1:6003:oc4j_instance1/appName1 A comma separated list of multiple URLs. For examples:  opmn:ormi://host1:6003:oc4j_instanc1/appName, opmn:ormi://host2:6003:oc4j_instance1/appName, opmn:ormi://host3:6003:oc4j_instance1/appName When the client looks up for a new Context the very first time in the client session, it sends a query against the OPMN referenced by the provider URL. The OPMN host and port specifies the destination of such query, and the OC4J instance name and appName are actually the “where clause” of the query. When the PROVIDER URL reference a single OPMN server Let's consider the case when the provider url only reference a single OPMN server of the destination cluster. In this case, that single OPMN server receives the query and returns a list of the qualified Contexts from all OC4Js within the cluster, even though there is a single OPMN server in the provider URL. A context represent a particular starting point at a particular server for subsequent object lookup. For example, if the URL is opmn:ormi://host1:6003:oc4j_instance1/appName, then, OPMN will return the following contexts: appName on oc4j_instance1 on host1 appName on oc4j_instance1 on host2, appName on oc4j_instance1 on host3,  (provided that host1, host2, host3 are all in the same cluster) Please note that One OPMN will be sufficient to find the list of all contexts from the entire cluster that satisfy the JNDI lookup query. You can do an experiment by shutting down appName on host1, and observe that OPMN on host1 will still be able to return you appname on host2 and appName on host3. When the PROVIDER URL reference a comma separated list of multiple OPMN servers When the JNDI propery java.naming.provider.url references a comma separated list of multiple URLs, the lookup will return the exact same things as with the single OPMN server: a list of qualified Contexts from the cluster. The purpose of having multiple OPMN servers is to provide high availability in the initial context creation, such that if OPMN at host1 is unavailable, client will try the lookup via OPMN on host2, and so on. After the initial lookup returns and cache a list of contexts, the JNDI URL(s) are no longer used in the same client session. That explains why removing the 3rd URL from the list of JNDI URLs will not stop the client from getting the EJB on the 3rd server. About the oracle.j2ee.rmi.loadBalance Property After the client acquires the list of contexts, it will cache it at the client side as “list of available RMI contexts”.  This list includes all the servers in the destination cluster. This list will stay in the cache until the client session (JVM) ends. The RMI load balancing against the destination cluster is happening at the client side, as the client is switching between the members of the list. Whether and how often the client will fresh the Context from the list of Context is based on the value of the  oracle.j2ee.rmi.loadBalance. The documentation at http://docs.oracle.com/cd/B31017_01/web.1013/b28958/rmi.htm#BABDGFBI list all the available values for the oracle.j2ee.rmi.loadBalance. Value Description client If specified, the client interacts with the OC4J process that was initially chosen at the first lookup for the entire conversation. context Used for a Web client (servlet or JSP) that will access EJBs in a clustered OC4J environment. If specified, a new Context object for a randomly-selected OC4J instance will be returned each time InitialContext() is invoked. lookup Used for a standalone client that will access EJBs in a clustered OC4J environment. If specified, a new Context object for a randomly-selected OC4J instance will be created each time the client calls Context.lookup(). Please note the regardless of the setting of oracle.j2ee.rmi.loadBalance property, the “refresh” only occurs at the client. The client can only choose from the "list of available context" that was returned and cached from the very first lookup. That is, the client will merely get a new Context object from the “list of available RMI contexts” from the cache at the client side. The client will NOT go to the OPMN server again to get the list. That also implies that if you are adding a node to the server cluster AFTER the client’s initial lookup, the client would not know it because neither the server nor the client will initiate a refresh of the “list of available servers” to reflect the new node. About High Availability (i.e. Resilience Against Node Failure of Remote OC4J Cluster) What we have discussed above is about load balancing. Let's also discuss high availability. This is how the High Availability works in RMI: when the client use the context but get an exception such as socket is closed, it knows that the server referenced by that Context is problematic and will try to get another unused Context from the “list of available contexts”. Again, this list is the list that was returned and cached at the very first lookup in the entire client session.

    Read the article

< Previous Page | 87 88 89 90 91 92 93 94 95 96 97 98  | Next Page >