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  • What Makes a Good Design Critic? CHI 2010 Panel Review

    - by jatin.thaker
    Author: Daniel Schwartz, Senior Interaction Designer, Oracle Applications User Experience Oracle Applications UX Chief Evangelist Patanjali Venkatacharya organized and moderated an innovative and stimulating panel discussion titled "What Makes a Good Design Critic? Food Design vs. Product Design Criticism" at CHI 2010, the annual ACM Conference on Human Factors in Computing Systems. The panelists included Janice Rohn, VP of User Experience at Experian; Tami Hardeman, a food stylist; Ed Seiber, a restaurant architect and designer; John Kessler, a food critic and writer at the Atlanta Journal-Constitution; and Larry Powers, Chef de Cuisine at Shaun's restaurant in Atlanta, Georgia. Building off the momentum of his highly acclaimed panel at CHI 2009 on what interaction design can learn from food design (for which I was on the other side as a panelist), Venkatacharya brought together new people with different roles in the restaurant and software interaction design fields. The session was also quite delicious -- but more on that later. Criticism, as it applies to food and product or interaction design, was the tasty topic for this forum and showed that strong parallels exist between food and interaction design criticism. Figure 1. The panelists in discussion: (left to right) Janice Rohn, Ed Seiber, Tami Hardeman, and John Kessler. The panelists had great insights to share from their respective fields, and they enthusiastically discussed as if they were at a casual collegial dinner. John Kessler stated that he prefers to have one professional critic's opinion in general than a large sampling of customers, however, "Web sites like Yelp get users excited by the collective approach. People are attracted to things desired by so many." Janice Rohn added that this collective desire was especially true for users of consumer products. Ed Seiber remarked that while people looked to the popular view for their target tastes and product choices, "professional critics like John [Kessler] still hold a big weight on public opinion." Chef Powers indicated that chefs take in feedback from all sources, adding, "word of mouth is very powerful. We also look heavily at the sales of the dishes to see what's moving; what's selling and thus successful." Hearing this discussion validates our design work at Oracle in that we listen to our users (our diners) and industry feedback (our critics) to ensure an optimal user experience of our products. Rohn considers that restaurateur Danny Meyer's book, Setting the Table: The Transforming Power of Hospitality in Business, which is about creating successful restaurant experiences, has many applicable parallels to user experience design. Meyer actually argues that the customer is not always right, but that "they must always feel heard." Seiber agreed, but noted "customers are not designers," and while designers need to listen to customer feedback, it is the designer's job to synthesize it. Seiber feels it's the critic's job to point out when something is missing or not well-prioritized. In interaction design, our challenges are quite similar, if not parallel. Software tasks are like puzzles that are in search of a solution on how to be best completed. As a food stylist, Tami Hardeman has the demanding and challenging task of presenting food to be as delectable as can be. To present food in its best light requires a lot of creativity and insight into consumer tastes. It's no doubt then that this former fashion stylist came up with the ultimate catch phrase to capture the emotion that clients want to draw from their users: "craveability." The phrase was a hit with the audience and panelists alike. Sometime later in the discussion, Seiber remarked, "designers strive to apply craveability to products, and I do so for restaurants in my case." Craveabilty is also very applicable to interaction design. Creating straightforward and smooth workflows for users of Oracle Applications is a primary goal for my colleagues. We want our users to really enjoy working with our products where it makes them more efficient and better at their jobs. That's our "craveability." Patanjali Venkatacharya asked the panel, "if a design's "craveability" appeals to some cultures but not to others, then what is the impact to the food or product design process?" Rohn stated that "taste is part nature and part nurture" and that the design must take the full context of a product's usage into consideration. Kessler added, "good design is about understanding the context" that the experience necessitates. Seiber remarked how important seat comfort is for diners and how the quality of seating will add so much to the complete dining experience. Sometimes if these non-food factors are not well executed, they can also take away from an otherwise pleasant dining experience. Kessler recounted a time when he was dining at a restaurant that actually had very good food, but the photographs hanging on all the walls did not fit in with the overall décor and created a negative overall dining experience. While the tastiness of the food is critical to a restaurant's success, it is a captivating complete user experience, as in interaction design, which will keep customers coming back and ultimately making the restaurant a hit. Figure 2. Patanjali Venkatacharya enjoyed the Sardinian flatbread salad. As a surprise Chef Powers brought out a signature dish from Shaun's restaurant for all the panelists to sample and critique. The Sardinian flatbread dish showcased Atlanta's taste for fresh and local produce and cheese at its finest as a salad served on a crispy flavorful flat bread. Hardeman said it could be photographed from any angle, a high compliment coming from a food stylist. Seiber really enjoyed the colors that the dish brought together and thought it would be served very well in a casual restaurant on a summer's day. The panel really appreciated the taste and quality of the different components and how the rosemary brought all the flavors together. Seiber remarked that "a lot of effort goes into the appearance of simplicity." Rohn indicated that the same notion holds true with software user interface design. A tremendous amount of work goes into crafting straightforward interfaces, including user research, prototyping, design iterations, and usability studies. Design criticism for food and software interfaces clearly share many similarities. Both areas value expert opinions and user feedback. Both areas understand the importance of great design needing to work well in its context. Last but not least, both food and interaction design criticism value "craveability" and how having users excited about experiencing and enjoying the designs is an important goal. Now if we can just improve the taste of software user interfaces, people may choose to dine on their enterprise applications over a fresh organic salad.

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  • Modern/Metro Internet Explorer: What were they thinking???

    - by Rick Strahl
    As I installed Windows 8.1 last week I decided that I really should take a closer look at Internet Explorer in the Modern/Metro environment again. Right away I ran into two issues that are real head scratchers to me.Modern Split Windows don't resize Viewport but Zoom OutThis one falls in the "WTF, really?" department: It looks like Modern Internet Explorer's Modern doesn't resize the browser window as every other browser (including IE 11 on the desktop) does, but rather tries to adjust the zoom to the width of the browser. This means that if you use the Modern IE browser and you split the display between IE and another application, IE will be zoomed out, with text becoming much, much smaller, rather than resizing the browser viewport and adjusting the pixel width as you would when a browser window is typically resized.Here's what I'm talking about in a couple of pictures. First here's the full screen Internet Explorer version (this shot is resized down since it's full screen at 1080p, click to see the full image):This brings up the first issue which is: On the desktop who wants to browse a site full screen? Most sites aren't fully optimized for 1080p widescreen experience and frankly most content that wide just looks weird. Even in typical 10" resolutions of 1280 width it's weird to look at things this way. At least this issue can be worked around with @media queries and either constraining the view, or adding additional content to make use of the extra space. Still running a desktop browser full screen is not optimal on a desktop machine - ever.Regardless, this view, while oversized, is what I expect: Everything is rendered in the right ratios, with font-size and the responsive design styling properly respected.But now look what happens when you split the desktop windows and show half desktop and have modern IE (this screen shot is not resized but cropped - this is actual size content as you can see in the cropped Twitter window on the right half of the screen):What's happening here is that IE is zooming out of the content to make it fit into the smaller width, shrinking the content rather than resizing the viewport's pixel width. In effect it looks like the pixel width stays at 1080px and the viewport expands out height-wise in response resulting in some crazy long portrait view.There goes responsive design - out the window literally. If you've built your site using @media queries and fixed viewport sizes, Internet Explorer completely screws you in this split view. On my 1080p monitor, the site shown at a little under half width becomes completely unreadable as the fonts are too small and break up. As you go into split view and you resize the window handle the content of the browser gets smaller and smaller (and effectively longer and longer on the bottom) effectively throwing off any responsive layout to the point of un-readability even on a big display, let alone a small tablet screen.What could POSSIBLY be the benefit of this screwed up behavior? I checked around a bit trying different pages in this shrunk down view. Other than the Microsoft home page, every page I went to was nearly unreadable at a quarter width. The only page I found that worked 'normally' was the Microsoft home page which undoubtedly is optimized just for Internet Explorer specifically.Bottom Address Bar opaquely overlays ContentAnother problematic feature for me is the browser address bar on the bottom. Modern IE shows the status bar opaquely on the bottom, overlaying the content area of the Web Page - until you click on the page. Until you do though, the address bar overlays the bottom content solidly. And not just a little bit but by good sizable chunk.In the application from the screen shot above I have an application toolbar on the bottom and the IE Address bar completely hides that bottom toolbar when the page is first loaded, until the user clicks into the content at which point the address bar shrinks down to a fat border style bar with a … on it. Toolbars on the bottom are pretty common these days, especially for mobile optimized applications, so I'd say this is a common use case. But even if you don't have toolbars on the bottom maybe there's other fixed content on the bottom of the page that is vital to display. While other browsers often also show address bars and then later hide them, these other browsers tend to resize the viewport when the address bar status changes, so the content can respond to the size change. Not so with Modern IE. The address bar overlays content and stays visible until content is clicked. No resize notification or viewport height change is sent to the browser.So basically Internet Explorer is telling me: "Our toolbar is more important than your content!" - AND gives me no chance to re-act to that behavior. The result on this page/application is that the user sees no actionable operations until he or she clicks into the content area, which is terrible from a UI perspective as the user has no idea what options are available on initial load.It's doubly confounding in that IE is running in full screen mode and has an the entire height of the screen at its disposal - there's plenty of real estate available to not require this sort of hiding of content in the first place. Heck, even Windows Phone with its more constrained size doesn't hide content - in fact the address bar on Windows Phone 8 is always visible.What were they thinking?Every time I use anything in the Modern Metro interface in Windows 8/8.1 I get angry.  I can pretty much ignore Metro/Modern for my everyday usage, but unfortunately with Internet Explorer in the modern shell I have to live with, because there will be users using it to access my sites. I think it's inexcusable by Microsoft to build such a crappy shell around the browser that impacts the actual usability of Web content. In both of the cases above I can only scratch my head at what could have possibly motivated anybody designing the UI for the browser to make these screwed up choices, that manipulate the content in a totally unmaintainable way.© Rick Strahl, West Wind Technologies, 2005-2013Posted in Windows  HTML5   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • What Makes a Good Design Critic? CHI 2010 Panel Review

    - by Applications User Experience
    Author: Daniel Schwartz, Senior Interaction Designer, Oracle Applications User Experience Oracle Applications UX Chief Evangelist Patanjali Venkatacharya organized and moderated an innovative and stimulating panel discussion titled "What Makes a Good Design Critic? Food Design vs. Product Design Criticism" at CHI 2010, the annual ACM Conference on Human Factors in Computing Systems. The panelists included Janice Rohn, VP of User Experience at Experian; Tami Hardeman, a food stylist; Ed Seiber, a restaurant architect and designer; Jonathan Kessler, a food critic and writer at the Atlanta Journal-Constitution; and Larry Powers, Chef de Cuisine at Shaun's restaurant in Atlanta, Georgia. Building off the momentum of his highly acclaimed panel at CHI 2009 on what interaction design can learn from food design (for which I was on the other side as a panelist), Venkatacharya brought together new people with different roles in the restaurant and software interaction design fields. The session was also quite delicious -- but more on that later. Criticism, as it applies to food and product or interaction design, was the tasty topic for this forum and showed that strong parallels exist between food and interaction design criticism. Figure 1. The panelists in discussion: (left to right) Janice Rohn, Ed Seiber, Tami Hardeman, and Jonathan Kessler. The panelists had great insights to share from their respective fields, and they enthusiastically discussed as if they were at a casual collegial dinner. Jonathan Kessler stated that he prefers to have one professional critic's opinion in general than a large sampling of customers, however, "Web sites like Yelp get users excited by the collective approach. People are attracted to things desired by so many." Janice Rohn added that this collective desire was especially true for users of consumer products. Ed Seiber remarked that while people looked to the popular view for their target tastes and product choices, "professional critics like John [Kessler] still hold a big weight on public opinion." Chef Powers indicated that chefs take in feedback from all sources, adding, "word of mouth is very powerful. We also look heavily at the sales of the dishes to see what's moving; what's selling and thus successful." Hearing this discussion validates our design work at Oracle in that we listen to our users (our diners) and industry feedback (our critics) to ensure an optimal user experience of our products. Rohn considers that restaurateur Danny Meyer's book, Setting the Table: The Transforming Power of Hospitality in Business, which is about creating successful restaurant experiences, has many applicable parallels to user experience design. Meyer actually argues that the customer is not always right, but that "they must always feel heard." Seiber agreed, but noted "customers are not designers," and while designers need to listen to customer feedback, it is the designer's job to synthesize it. Seiber feels it's the critic's job to point out when something is missing or not well-prioritized. In interaction design, our challenges are quite similar, if not parallel. Software tasks are like puzzles that are in search of a solution on how to be best completed. As a food stylist, Tami Hardeman has the demanding and challenging task of presenting food to be as delectable as can be. To present food in its best light requires a lot of creativity and insight into consumer tastes. It's no doubt then that this former fashion stylist came up with the ultimate catch phrase to capture the emotion that clients want to draw from their users: "craveability." The phrase was a hit with the audience and panelists alike. Sometime later in the discussion, Seiber remarked, "designers strive to apply craveability to products, and I do so for restaurants in my case." Craveabilty is also very applicable to interaction design. Creating straightforward and smooth workflows for users of Oracle Applications is a primary goal for my colleagues. We want our users to really enjoy working with our products where it makes them more efficient and better at their jobs. That's our "craveability." Patanjali Venkatacharya asked the panel, "if a design's "craveability" appeals to some cultures but not to others, then what is the impact to the food or product design process?" Rohn stated that "taste is part nature and part nurture" and that the design must take the full context of a product's usage into consideration. Kessler added, "good design is about understanding the context" that the experience necessitates. Seiber remarked how important seat comfort is for diners and how the quality of seating will add so much to the complete dining experience. Sometimes if these non-food factors are not well executed, they can also take away from an otherwise pleasant dining experience. Kessler recounted a time when he was dining at a restaurant that actually had very good food, but the photographs hanging on all the walls did not fit in with the overall décor and created a negative overall dining experience. While the tastiness of the food is critical to a restaurant's success, it is a captivating complete user experience, as in interaction design, which will keep customers coming back and ultimately making the restaurant a hit. Figure 2. Patnajali Venkatacharya enjoyed the Sardian flatbread salad. As a surprise Chef Powers brought out a signature dish from Shaun's restaurant for all the panelists to sample and critique. The Sardinian flatbread dish showcased Atlanta's taste for fresh and local produce and cheese at its finest as a salad served on a crispy flavorful flat bread. Hardeman said it could be photographed from any angle, a high compliment coming from a food stylist. Seiber really enjoyed the colors that the dish brought together and thought it would be served very well in a casual restaurant on a summer's day. The panel really appreciated the taste and quality of the different components and how the rosemary brought all the flavors together. Seiber remarked that "a lot of effort goes into the appearance of simplicity." Rohn indicated that the same notion holds true with software user interface design. A tremendous amount of work goes into crafting straightforward interfaces, including user research, prototyping, design iterations, and usability studies. Design criticism for food and software interfaces clearly share many similarities. Both areas value expert opinions and user feedback. Both areas understand the importance of great design needing to work well in its context. Last but not least, both food and interaction design criticism value "craveability" and how having users excited about experiencing and enjoying the designs is an important goal. Now if we can just improve the taste of software user interfaces, people may choose to dine on their enterprise applications over a fresh organic salad.

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  • Fix overscan in Linux with Intel graphics Vizio HDTV

    - by Padenton
    I am connecting my server to my HDTV so that I can conveniently display it there. My VIZIO HDTV cuts off all 4 edges. I already realize it is not optimal to be running a GUI on a server; this server will not have much external traffic so I prefer it for convenience. I have already spent countless hours searching for a fix, but all I could find required an ATI or NVIDIA graphics card, or didn’t work. In Windows, the Intel driver has a setting for underscan, though it seems only to be available by a glitch. Here’s my specs: Ubuntu Linux (Quantal 12.10) (Likely to switch to Arch) This is a home server computer, with KDE for managing(for now, at least) Graphics: Intel HD Graphics 4000 from Ivy Bridge Motherboard: ASRock Z77 Extreme4 CPU: Intel Core i5-3450 My monitors: Dell LCD monitor Vizio VX37L_HDTV10A 37" on HDMI input I have tried all of the following from both HDMI?HDMI and DVI?HDMI cables connected to the ports on my motherboard: Setting properties in xrandr Making sure drivers are all up to date Trying several different modes The TV was “cheap”; max resolution 1080i. I am able to get a 1920x1080 modeline, in both GNU/Linux and Windows, without difficulty. There is no setting in the menu to fix the overscan (I have tried all of them, I realize it’s not always called overscan). I have been in the service menu for the TV, which still does not contain an option to fix it. No aspect ratio settings, etc. The TV has a VGA connector but I am unsure if it would fix it, as I don’t have a VGA cable long enough, and am not sure it would get me the 1920x1080 resolution which I want. Using another resolution does not fix the problem. I tried custom modelines with the dimensions of my screen’s viewable area, but it wouldn’t let me use them. Ubuntu apparently doesn’t automatically generate an xorg.conf file for use. I read somewhere that modifying it may help solve it. I tried X -configure several times(with reboots, etc.) but it consistently gave the following error messages: In log file: … (WW) Falling back to old probe method for vesa Number of created screens does not match number of detected devices. Configuration failed. In output: … (++) Using config file: "/root/xorg.conf.new" (==) Using system config directory "/usr/share/X11/xorg.conf.d" Number of created screens does not match number of detected devices. Configuration failed. Server terminated with error (2). Closing log file. Tried using 'overscan' prop in xrandr: root@xxx:/home/xxx# xrandr --output HDMI1 --set overscan off X Error of failed request: BadName (named color or font does not exist) Major opcode of failed request: 140 (RANDR) Minor opcode of failed request: 11 (RRQueryOutputProperty) Serial number of failed request: 42 Current serial number in output stream: 42 'overscan on', 'underscan off', 'underscan on' were all also tried. Originally tried with Ubuntu 12.04, but failed and so updated to 12.10 when it was released. All software is up to date. I am not opposed to reinstalling my OS, likely will anyways (my preference being Arch).

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  • Waterfall Model (SDLC) vs. Prototyping Model

    The characters in the fable of the Tortoise and the Hare can easily be used to demonstrate the similarities and differences between the Waterfall and Prototyping software development models. This children fable is about a race between a consistently slow moving but steadfast turtle and an extremely fast but unreliable rabbit. After closely comparing each character’s attributes in correlation with both software development models, a trend seems to appear in that the Waterfall closely resembles the Tortoise in that Waterfall Model is typically a slow moving process that is broken up in to multiple sequential steps that must be executed in a standard linear pattern. The Tortoise can be quoted several times in the story saying “Slow and steady wins the race.” This is the perfect mantra for the Waterfall Model in that this model is seen as a cumbersome and slow moving. Waterfall Model Phases Requirement Analysis & Definition This phase focuses on defining requirements for a project that is to be developed and determining if the project is even feasible. Requirements are collected by analyzing existing systems and functionality in correlation with the needs of the business and the desires of the end users. The desired output for this phase is a list of specific requirements from the business that are to be designed and implemented in the subsequent steps. In addition this phase is used to determine if any value will be gained by completing the project. System Design This phase focuses primarily on the actual architectural design of a system, and how it will interact within itself and with other existing applications. Projects at this level should be viewed at a high level so that actual implementation details are decided in the implementation phase. However major environmental decision like hardware and platform decision are typically decided in this phase. Furthermore the basic goal of this phase is to design an application at the system level in those classes, interfaces, and interactions are defined. Additionally decisions about scalability, distribution and reliability should also be considered for all decisions. The desired output for this phase is a functional  design document that states all of the architectural decisions that have been made in regards to the project as well as a diagrams like a sequence and class diagrams. Software Design This phase focuses primarily on the refining of the decisions found in the functional design document. Classes and interfaces are further broken down in to logical modules based on the interfaces and interactions previously indicated. The output of this phase is a formal design document. Implementation / Coding This phase focuses primarily on implementing the previously defined modules in to units of code. These units are developed independently are intergraded as the system is put together as part of a whole system. Software Integration & Verification This phase primarily focuses on testing each of the units of code developed as well as testing the system as a whole. There are basic types of testing at this phase and they include: Unit Test and Integration Test. Unit Test are built to test the functionality of a code unit to ensure that it preforms its desired task. Integration testing test the system as a whole because it focuses on results of combining specific units of code and validating it against expected results. The output of this phase is a test plan that includes test with expected results and actual results. System Verification This phase primarily focuses on testing the system as a whole in regards to the list of project requirements and desired operating environment. Operation & Maintenance his phase primarily focuses on handing off the competed project over to the customer so that they can verify that all of their requirements have been met based on their original requirements. This phase will also validate the correctness of their requirements and if any changed need to be made. In addition, any problems not resolved in the previous phase will be handled in this section. The Waterfall Model’s linear and sequential methodology does offer a project certain advantages and disadvantages. Advantages of the Waterfall Model Simplistic to implement and execute for projects and/or company wide Limited demand on resources Large emphasis on documentation Disadvantages of the Waterfall Model Completed phases cannot be revisited regardless if issues arise within a project Accurate requirement are never gather prior to the completion of the requirement phase due to the lack of clarification in regards to client’s desires. Small changes or errors that arise in applications may cause additional problems The client cannot change any requirements once the requirements phase has been completed leaving them no options for changes as they see their requirements changes as the customers desires change. Excess documentation Phases are cumbersome and slow moving Learn more about the Major Process in the Sofware Development Life Cycle and Waterfall Model. Conversely, the Hare shares similar traits with the prototyping software development model in that ideas are rapidly converted to basic working examples and subsequent changes are made to quickly align the project with customers desires as they are formulated and as software strays from the customers vision. The basic concept of prototyping is to eliminate the use of well-defined project requirements. Projects are allowed to grow as the customer needs and request grow. Projects are initially designed according to basic requirements and are refined as requirement become more refined. This process allows customer to feel their way around the application to ensure that they are developing exactly what they want in the application This model also works well for determining the feasibility of certain approaches in regards to an application. Prototypes allow for quickly developing examples of implementing specific functionality based on certain techniques. Advantages of Prototyping Active participation from users and customers Allows customers to change their mind in specifying requirements Customers get a better understanding of the system as it is developed Earlier bug/error detection Promotes communication with customers Prototype could be used as final production Reduced time needed to develop applications compared to the Waterfall method Disadvantages of Prototyping Promotes constantly redefining project requirements that cause major system rewrites Potential for increased complexity of a system as scope of the system expands Customer could believe the prototype as the working version. Implementation compromises could increase the complexity when applying updates and or application fixes When companies trying to decide between the Waterfall model and Prototype model they need to evaluate the benefits and disadvantages for both models. Typically smaller companies or projects that have major time constraints typically head for more of a Prototype model approach because it can reduce the time needed to complete the project because there is more of a focus on building a project and less on defining requirements and scope prior to the start of a project. On the other hand, Companies with well-defined requirements and time allowed to generate proper documentation should steer towards more of a waterfall model because they are in a position to obtain clarified requirements and have to design and optimal solution prior to the start of coding on a project.

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  • Configuring Oracle HTTP Server 12c for WebLogic Server Domain

    - by Emin Askerov
    Oracle HTTP Server (OHS) 12c 12.1.2 which was released in July 2013 as a part of Oracle Web Tier 12c is the web server component of Oracle Fusion Middleware. In essence this is Apache HTTP Server 2.2.22 (with critical bug fixes from higher versions) which includes modules developed specifically by Oracle. It provides a listener functionality for Oracle WebLogic Server and the framework for hosting static pages, dynamic pages, and applications over the Web. OHS can be easily managed by Weblogic Management Framework, a set of tools which provides administrative capabilities (start, stop, lifecycle operations, etc.) for Oracle Fusion Middleware products. In other words all tools which are familiar to us (Node Manager, WLST, Administration Console, Fusion Middleware Control etc.) presented as a part of Weblogic Management Framework and using for managing Java and System Components both for Weblogic Server and Standalone Domain types. You can familiarize yourself with these terms using related documentation: 1. Introduction to Oracle HTTP Server: http://docs.oracle.com/middleware/1212/webtier/index.html 2. Weblogic Management Framework: http://docs.oracle.com/middleware/1212/core/ASCON/terminology.htm#ASCON11260 In the given post I would like to cover rather simple use case how to configure OHS as web proxy in Weblogic Cluster environment. For example, we have existing Weblogic Domain where some managed servers have been joined to cluster and host business applications. We need to configure web proxy component which will act as entry point, load balancer for our cluster for user requests. Of course, we could install old good Apache HTTP Server and configure mod_wl plugin. However this solution not optimal from manageability perspective: we need to install Apache, install additional plugin then configure it by editing configuration file which is not really convenient for FMW Administrators and often increase time of performing of simple administrative task. Alternatively, we could use OHS as System Component within Weblogic Domain and use full power of Weblogic Management Framework in order to configure, manage and monitor it! I like this idea! What about you? I hope after reading this post you will agree with me. First of all it is necessary to download OHS binaries. You can use this link for downloading: http://www.oracle.com/technetwork/java/webtier/downloads/index2-303202.html As we will use Fusion Middleware Control for managing OHS instances it is necessary to extend your domain with Enterprise Manager and Oracle ADF and JRF templates. This is not topic for focusing in this post, but you could get more information from documentation or one of my previous posts: http://docs.oracle.com/middleware/1212/wls/WLDTR/fmw_templates.htm#sthref64 https://blogs.oracle.com/imc/entry/the_specifics_of_adf_12c Note: you should have properly configured Node Manager utility for managing OHS instances Let’s consider configuration process step by step: 1. Shut down all Weblogic instances of existing domain including Admin Server; 2. Install Oracle HTTP Server. You should use your Fusion Middleware Home Path (e.g. /u01/Oracle/FMW12) for Installation Location and select Colocated HTTP Server option as Installation Type. I will not focus on this topic in this post. All information related to OHS installation you could find here: http://docs.oracle.com/middleware/1212/webtier/WTINS/install_gui.htm#i1082009 3. Next we need to extend our existing domain with OHS component. In order to do this you should do the following: a. Run Fusion Middleware Configuration Wizard (ORACLE_HOME/oracle_common/common/bin/config.sh); b. On the step 1 select Update an existing domain option and point your Fusion Middleware Home Path; c. On the step 2 check Oracle HTTP Server, Oracle Enterprise Manager Plugin for WEBTIER templates; d. Go through other steps without any changes and finish configuration process. 4. Start Admin Server and all managed servers related to your cluster 5. Log in to Enterprise Manager FMW Control using http://<hostname>:<port>/em URL 6. Now we will create OHS instance within our Weblogic Domain Infrastructure. Navigate to Weblogic Domain -> Administration -> Create/Delete OHS menu item; 7. Enter to edit mode, clicking Changes -> Lock&Edit menu item; 8. Create new OHS instance clicking Create button; 9. Define Instance Name (e.g. DevOSH) and Machine parameters; 10. Now we need to define listen port. By default OHS will use 7777 port number for income HTTP requests. We could change it to any free port number we would like to use. In order to do it, right click on our created OHS instance (left hand panel) and navigate to Administration -> Port Configuration; 11. Click on record with port number 7777 and then click Edit button; 12. Change port number value (in our case this will be 8080) and then click OK button; 13. Now we need to edit mod_wl_ohs configuration in order to enable OHS to act as proxy for WebLogic Server Instances/Cluster; 14. In order to do it right click on our created OHS instance (left panel) and navigate to Administration -> mod_wl_ohs Configuration; a. In Weblogic Cluster you should enter cluster address (define <host:port> for all managed servers which participated in cluster), e.g: 192.168.56.2:7004,192.168.56.2:7005 b. Define Weblogic Port parameter at which the Oracle WebLogic Server host is listening for connection requests from the module (or from other servers); c. Check Dynamic Server List option. This will dynamically update cluster list for every request; d. In the Location table define list of endpoint locations which you would like to process. In order to do this click Add Row button and define Location, Weblogic Cluster, Path Trim and Path Prefix parameters (if required); e. Click Apply button in order to save changes. 15. Activate changes clicking Changes ? Activate Changes menu item; 16. Finally we will start configured OHS instance. Right click on OHS instance tree item under Web Tier folder, select Control -> Start Up menu item; 17. Ensure that OHS instance up and running and then test your environment. Run deployed application to your Weblogic Cluster accessing via OHS web proxy; Normal 0 false false false RU 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-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;}

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  • IP Micro-outages, telephone micro-outages, and CATV micro-outages

    - by Michael Graff
    This is a long and complicated question, mostly because it has been going on for 2.5 years without a solution in sight. It also is only one-third computer related, the other two-thirds are cable TV and cable-phone related. Background I have COX Communications for a cable provider, and we get Internet, digital cable TV, and digital phone service through them. The Internet is a SB5101 right now, and has been a DPC2100 and SB5120 in the past. Same results. The phone service is provided through a telephone interface mounted on the outside of the house (not classic VoIP) and the CATV is through a Scientific Atlanta receiver without DVR. I do have a TiVo connected to the CATV box. Symptoms The CATV shows "blocking" -- sometimes very very short duration where a few blocks appear on the screen. Sometimes it lasts long enough that the video "pauses" for 2-5 seconds, and rarely but not unseen the audio also fails. The CATV decoder box shows no correctable (FEC) or uncorrectable errors. That is, all BER counters are zero for the video stream. The Internet shows "micro-outages" where it appears that sent packets are not making it out, but I continue to receive packets from local modems. That is, pings stop coming back, but I continue to see modems broadcast for DHCP, and sometimes they ask more than once. The cable modem shows no errors during this time, but cable modems lie like you would not believe. It is actually possible to unplug the coax from the modem for 20 seconds and it reports NO ERRORS to the provider's tools. The phone service cuts out for 1-3 seconds, infrequently. When this happens, I hear NOTHING (not even comfort noise) and the remote side hears a "click" as if I were getting a call waiting message. However, there is no call incoming, other than the one I'm currently on of course. Things SEEM to happen more frequently when the temperature outside swings from cold to warm, so fall/spring seems worse than summer/winter. All micro-outages occur between once or twice a day (which I could ignore) to 10 times per hour. All SNR, signal levels, noise levels, etc. show very close to optimal when measured. COX's diagnosis This is a continual pain for me. Over the last 2.5 years, they have opened, "fixed" something, and closed the tickets. They close it without confirming that it is indeed better, and when I reopen they cannot do that, but instead they open a new ticket and send yet another low-level tech out to do the same signal tests and report that all is OK. I've finally gotten a line tech who has a clue and is motivated enough to pursue this with me. We have tried things like switching the local nodes over to UPS and generator power, but this does not trigger the noise. We have tried replacing all cabling, the tap outside my house, the modem, the CATV decoder -- all without resolution. Recently they have decided it is both my computer or switch, my TiVo, and my phone that are all broken and causing this issue. My debugging steps I spent the worse day of my TV-watching life yesterday and part of today. I watched live TV without the TiVo. I witnessed blocking, but it did "feel different." and was actually more severe. Some days it is better, some days it is worse, so perhaps this was just a very bad day. Today, I connected the TiVo to my DVD player, and ran two very long movies through it. I saw no blocking at all during nearly 6 hours of video. Suggestions? Does anyone have any suggestions on what to do next? I understand perhaps only the IP side can be addressed here, but it is one of the more limiting debugging options.

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  • External File Upload Optimizations for Windows Azure

    - by rgillen
    [Cross posted from here: http://rob.gillenfamily.net/post/External-File-Upload-Optimizations-for-Windows-Azure.aspx] I’m wrapping up a bit of the work we’ve been doing on data movement optimizations for cloud computing and the latest set of data yielded some interesting points I thought I’d share. The work done here is not really rocket science but may, in some ways, be slightly counter-intuitive and therefore seemed worthy of posting. Summary: for those who don’t like to read detailed posts or don’t have time, the synopsis is that if you are uploading data to Azure, block your data (even down to 1MB) and upload in parallel. Set your block size based on your source file size, but if you must choose a fixed value, use 1MB. Following the above will result in significant performance gains… upwards of 10x-24x and a reduction in overall file transfer time of upwards of 90% (eg, uploading a 1GB file averaged 46.37 minutes prior to optimizations and averaged 1.86 minutes afterwards). Detail: For those of you who want more detail, or think that the claims at the end of the preceding paragraph are over-reaching, what follows is information and code supporting these claims. As the title would indicate, these tests were run from our research facility pointing to the Azure cloud (specifically US North Central as it is physically closest to us) and do not represent intra-cloud results… we have performed intra-cloud tests and the overall results are similar in notion but the data rates are significantly different as well as the tipping points for the various block sizes… this will be detailed separately). We started by building a very simple console application that would loop through a directory and upload each file to Azure storage. This application used the shipping storage client library from the 1.1 version of the azure tools. The only real variation from the client library is that we added code to collect and record the duration (in ms) and size (in bytes) for each file transferred. The code is available here. We then created a directory that had a collection of files for the following sizes: 2KB, 32KB, 64KB, 128KB, 512KB, 1MB, 5MB, 10MB, 25MB, 50MB, 100MB, 250MB, 500MB, 750MB, and 1GB (50 files for each size listed). These files contained randomly-generated binary data and do not benefit from compression (a separate discussion topic). Our file generation tool is available here. The baseline was established by running the application described above against the directory containing all of the data files. This application uploads the files in a random order so as to avoid transferring all of the files of a given size sequentially and thereby spreading the affects of periodic Internet delays across the collection of results.  We then ran some scripts to split the resulting data and generate some reports. The raw data collected for our non-optimized tests is available via the links in the Related Resources section at the bottom of this post. For each file size, we calculated the average upload time (and standard deviation) and the average transfer rate (and standard deviation). As you likely are aware, transferring data across the Internet is susceptible to many transient delays which can cause anomalies in the resulting data. It is for this reason that we randomized the order of source file processing as well as executed the tests 50x for each file size. We expect that these steps will yield a sufficiently balanced set of results. Once the baseline was collected and analyzed, we updated the test harness application with some methods to split the source file into user-defined block sizes and then to upload those blocks in parallel (using the PutBlock() method of Azure storage). The parallelization was handled by simply relying on the Parallel Extensions to .NET to provide a Parallel.For loop (see linked source for specific implementation details in Program.cs, line 173 and following… less than 100 lines total). Once all of the blocks were uploaded, we called PutBlockList() to assemble/commit the file in Azure storage. For each block transferred, the MD5 was calculated and sent ensuring that the bits that arrived matched was was intended. The timer for the blocked/parallelized transfer method wraps the entire process (source file splitting, block transfer, MD5 validation, file committal). A diagram of the process is as follows: We then tested the affects of blocking & parallelizing the transfers by running the updated application against the same source set and did a parameter sweep on the block size including 256KB, 512KB, 1MB, 2MB, and 4MB (our assumption was that anything lower than 256KB wasn’t worth the trouble and 4MB is the maximum size of a block supported by Azure). The raw data for the parallel tests is available via the links in the Related Resources section at the bottom of this post. This data was processed and then compared against the single-threaded / non-optimized transfer numbers and the results were encouraging. The Excel version of the results is available here. Two semi-obvious points need to be made prior to reviewing the data. The first is that if the block size is larger than the source file size you will end up with a “negative optimization” due to the overhead of attempting to block and parallelize. The second is that as the files get smaller, the clock-time cost of blocking and parallelizing (overhead) is more apparent and can tend towards negative optimizations. For this reason (and is supported in the raw data provided in the linked worksheet) the charts and dialog below ignore source file sizes less than 1MB. (click chart for full size image) The chart above illustrates some interesting points about the results: When the block size is smaller than the source file, performance increases but as the block size approaches and then passes the source file size, you see decreasing benefit to the point of negative gains (see the values for the 1MB file size) For some of the moderately-sized source files, small blocks (256KB) are best As the size of the source file gets larger (see values for 50MB and up), the smallest block size is not the most efficient (presumably due, at least in part, to the increased number of blocks, increased number of individual transfer requests, and reassembly/committal costs). Once you pass the 250MB source file size, the difference in rate for 1MB to 4MB blocks is more-or-less constant The 1MB block size gives the best average improvement (~16x) but the optimal approach would be to vary the block size based on the size of the source file.    (click chart for full size image) The above is another view of the same data as the prior chart just with the axis changed (x-axis represents file size and plotted data shows improvement by block size). It again highlights the fact that the 1MB block size is probably the best overall size but highlights the benefits of some of the other block sizes at different source file sizes. This last chart shows the change in total duration of the file uploads based on different block sizes for the source file sizes. Nothing really new here other than this view of the data highlights the negative affects of poorly choosing a block size for smaller files.   Summary What we have found so far is that blocking your file uploads and uploading them in parallel results in significant performance improvements. Further, utilizing extension methods and the Task Parallel Library (.NET 4.0) make short work of altering the shipping client library to provide this functionality while minimizing the amount of change to existing applications that might be using the client library for other interactions.   Related Resources Source code for upload test application Source code for random file generator ODatas feed of raw data from non-optimized transfer tests Experiment Metadata Experiment Datasets 2KB Uploads 32KB Uploads 64KB Uploads 128KB Uploads 256KB Uploads 512KB Uploads 1MB Uploads 5MB Uploads 10MB Uploads 25MB Uploads 50MB Uploads 100MB Uploads 250MB Uploads 500MB Uploads 750MB Uploads 1GB Uploads Raw Data OData feeds of raw data from blocked/parallelized transfer tests Experiment Metadata Experiment Datasets Raw Data 256KB Blocks 512KB Blocks 1MB Blocks 2MB Blocks 4MB Blocks Excel worksheet showing summarizations and comparisons

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  • 5 Best Practices - Laying the Foundation for WebCenter Projects

    - by Kellsey Ruppel
    Today’s guest post comes from Oracle WebCenter expert John Brunswick. John specializes in enterprise portal and content management solutions and actively contributes to the enterprise software business community and has authored a series of articles about optimal business involvement in portal, business process management and SOA development, examining ways of helping organizations move away from monolithic application development. We’re happy to have John join us today! Maximizing success with Oracle WebCenter portal requires a strategic understanding of Oracle WebCenter capabilities.  The following best practices enable the creation of portal solutions with minimal resource overhead, while offering the greatest flexibility for progressive elaboration. They are inherently project agnostic, enabling a strong foundation for future growth and an expedient return on your investment in the platform.  If you are able to embrace even only a few of these practices, you will materially improve your deployment capability with WebCenter. 1. Segment Duties Around 3Cs - Content, Collaboration and Contextual Data "Agility" is one of the most common business benefits touted by modern web platforms.  It sounds good - who doesn't want to be Agile, right?  How exactly IT organizations go about supplying agility to their business counterparts often lacks definition - hamstrung by ambiguity. Ultimately, businesses want to benefit from reduced development time to deliver a solution to a particular constituent, which is augmented by as much self-service as possible to develop and manage the solution directly. All done in the absence of direct IT involvement. With Oracle WebCenter's depth in the areas of content management, pallet of native collaborative services, enterprise mashup capability and delegated administration, it is very possible to execute on this business vision at a technical level. To realize the benefits of the platform depth we can think of Oracle WebCenter's segmentation of duties along the lines of the 3 Cs - Content, Collaboration and Contextual Data.  All three of which can have their foundations developed by IT, then provisioned to the business on a per role basis. Content – Oracle WebCenter benefits from an extremely mature content repository.  Work flow, audit, notification, office integration and conversion capabilities for documents (HTML & PDF) make this a haven for business users to take control of content within external and internal portals, custom applications and web sites.  When deploying WebCenter portal take time to think of areas in which IT can provide the "harness" for content to reside, then allow the business to manage any content items within the site, using the content foundation to ensure compliance with business rules and process.  This frees IT to work on more mission critical challenges and allows the business to respond in short order to emerging market needs. Collaboration – Native collaborative services and WebCenter spaces are a perfect match for business users who are looking to enable document sharing, discussions and social networking.  The ability to deploy the services is granular and on the basis of roles scoped to given areas of the system - much like the first C “content”.  This enables business analysts to design the roles required and IT to provision with peace of mind that users leveraging the collaborative services are only able to do so in explicitly designated areas of a site. Bottom line - business will not need to wait for IT, but cannot go outside of the scope that has been defined based on their roles. Contextual Data – Collaborative capabilities are most powerful when included within the context of business data.  The ability to supply business users with decision shaping data that they can include in various parts of a portal or portals, just as they would with content items, is one of the most powerful aspects of Oracle WebCenter.  Imagine a discussion about new store selection for a retail chain that re-purposes existing information from business intelligence services about various potential locations and or custom backend systems - presenting it directly in the context of the discussion.  If there are some data sources that are preexisting in your enterprise take a look at how they can be made into discrete offerings within the portal, then scoped to given business user roles for inclusion within collaborative activities. 2. Think Generically, Execute Specifically Constructs.  Anyone who has spent much time around me knows that I am obsessed with this word.  Why? Because Constructs offer immense power - more than APIs, Web Services or other technical capability. Constructs offer organizations the ability to leverage a platform's native characteristics to offer substantial business functionality - without writing code.  This concept becomes more powerful with the additional understanding of the concepts from the platform that an organization learns over time.  Let's take a look at an example of where an Oracle WebCenter construct can substantially reduce the time to get a subscription-based site out the door and into the hands of the end consumer. Imagine a site that allows members to subscribe to specific disciplines to access information and application data around that various discipline.  A space is a collection of secured pages within Oracle WebCenter.  Spaces are not only secured, but also default content stored within it to be scoped automatically to that space. Taking this a step further, Oracle WebCenter’s Activity Stream surfaces events, discussions and other activities that are scoped to the given user on the basis of their space affiliations.  In order to have a portal that would allow users to "subscribe" to information around various disciplines - spaces could be used out of the box to achieve this capability and without using any APIs or low level technical work to achieve this. 3. Make Governance Work for You Imagine driving down the street without the painted lines on the road.  The rules of the road are so ingrained in our minds, we often do not think about the process, but seemingly mundane lane markers are critical enablers. Lane markers allow us to travel at speeds that would be impossible if not for the agreed upon direction of flow. Additionally and more importantly, it allows people to act autonomously - going where they please at any given time. The return on the investment for mobility is high enough for people to buy into globally agreed up governance processes. In Oracle WebCenter we can use similar enablers to lane markers.  Our goal should be to enable the flow of information and provide end users with the ability to arrive at business solutions as needed, not on the basis of cumbersome processes that cannot meet the business needs in a timely fashion. How do we do this? Just as with "Segmentation of Duties" Oracle WebCenter technologies offer the opportunity to compartmentalize various business initiatives from each other within the system due to constructs and security that are available to use within the platform. For instance, when a WebCenter space is created, any content added within that space by default will be secured to that particular space and inherits meta data that is associated with a folder created for the space. Oracle WebCenter content uses meta data to support a broad range of rich ECM functionality and can automatically impart retention, workflow and other policies automatically on the basis of what has been defaulted for that space. Depending on your business needs, this paradigm will also extend to sub sections of a space, offering some interesting possibilities to enable automated management around content. An example may be press releases within a particular area of an extranet that require a five year retention period and need to the reviewed by marketing and legal before release.  The underlying content system will transparently take care of this process on the basis of the above rules, enabling peace of mind over unstructured data - which could otherwise become overwhelming. 4. Make Your First Project Your Second Imagine if Michael Phelps was competing in a swimming championship, but told right before his race that he had to use a brand new stroke.  There is no doubt that Michael is an outstanding swimmer, but chances are that he would like to have some time to get acquainted with the new stroke. New technologies should not be treated any differently.  Before jumping into the deep end it helps to take time to get to know the new approach - even though you may have been swimming thousands of times before. To quickly get a handle on Oracle WebCenter capabilities it can be helpful to deploy a sandbox for the team to use to share project documents, discussions and announcements in an effort to help the actual deployment get under way, while increasing everyone’s knowledge of the platform and its functionality that may be helpful down the road. Oracle Technology Network has made a pre-configured virtual machine available for download that can be a great starting point for this exercise. 5. Get to Know the Community If you are reading this blog post you have most certainly faced a software decision or challenge that was solved on the basis of a small piece of missing critical information - which took substantial research to discover.  Chances were also good that somewhere, someone had already come across this information and would have been excited to share it. There is no denying the power of passionate, connected users, sharing key tips around technology.  The Oracle WebCenter brand has a rich heritage that includes industry-leading technology and practitioners.  With the new Oracle WebCenter brand, opportunities to connect with these experts has become easier. Oracle WebCenter Blog Oracle Social Enterprise LinkedIn WebCenter Group Oracle WebCenter Twitter Oracle WebCenter Facebook Oracle User Groups Additionally, there are various Oracle WebCenter related blogs by an excellent grouping of services partners.

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  • Oracle OpenWorld 2013 – Wrap up by Sven Bernhardt

    - by JuergenKress
    OOW 2013 is over and we’re heading home, so it is time to lean back and reflecting about the impressions we have from the conference. First of all: OOW was great! It was a pleasure to be a part of it. As already mentioned in our last blog article: It was the biggest OOW ever. Parallel to the conference the America’s Cup took place in San Francisco and the Oracle Team America won. Amazing job by the team and again congratulations from our side Back to the conference. The main topics for us are: Oracle SOA / BPM Suite 12c Adaptive Case management (ACM) Big Data Fast Data Cloud Mobile Below we will go a little more into detail, what are the key takeaways regarding the mentioned points: Oracle SOA / BPM Suite 12c During the five days at OOW, first details of the upcoming major release of Oracle SOA Suite 12c and Oracle BPM Suite 12c have been introduced. Some new key features are: Managed File Transfer (MFT) for transferring big files from a source to a target location Enhanced REST support by introducing a new REST binding Introduction of a generic cloud adapter, which can be used to connect to different cloud providers, like Salesforce Enhanced analytics with BAM, which has been totally reengineered (BAM Console now also runs in Firefox!) Introduction of templates (OSB pipelines, component templates, BPEL activities templates) EM as a single monitoring console OSB design-time integration into JDeveloper (Really great!) Enterprise modeling capabilities in BPM Composer These are only a few points from what is coming with 12c. We are really looking forward for the new realese to come out, because this seems to be really great stuff. The suite becomes more and more integrated. From 10g to 11g it was an evolution in terms of developing SOA-based applications. With 12c, Oracle continues it’s way – very impressive. Adaptive Case Management Another fantastic topic was Adaptive Case Management (ACM). The Oracle PMs did a great job especially at the demo grounds in showing the upcoming Case Management UI (will be available in 11g with the next BPM Suite MLR Patch), the roadmap and the differences between traditional business process modeling. They have been very busy during the conference because a lot of partners and customers have been interested Big Data Big Data is one of the current hype themes. Because of huge data amounts from different internal or external sources, the handling of these data becomes more and more challenging. Companies have a need for analyzing the data to optimize their business. The challenge is here: the amount of data is growing daily! To store and analyze the data efficiently, it is necessary to have a scalable and flexible infrastructure. Here it is important that hardware and software are engineered to work together. Therefore several new features of the Oracle Database 12c, like the new in-memory option, have been presented by Larry Ellison himself. From a hardware side new server machines like Fujitsu M10 or new processors, such as Oracle’s new M6-32 have been announced. The performance improvements, when using one of these hardware components in connection with the improved software solutions were really impressive. For more details about this, please take look at our previous blog post. Regarding Big Data, Oracle also introduced their Big Data architecture, which consists of: Oracle Big Data Appliance that is preconfigured with Hadoop Oracle Exdata which stores a huge amount of data efficently, to achieve optimal query performance Oracle Exalytics as a fast and scalable Business analytics system Analysis of the stored data can be performed using SQL, by streaming the data directly from Hadoop to an Oracle Database 12c. Alternatively the analysis can be directly implemented in Hadoop using “R”. In addition Oracle BI Tools can be used to analyze the data. Fast Data Fast Data is a complementary approach to Big Data. A huge amount of mostly unstructured data comes in via different channels with a high frequency. The analysis of these data streams is also important for companies, because the incoming data has to be analyzed regarding business-relevant patterns in real-time. Therefore these patterns must be identified efficiently and performant. To do so, in-memory grid solutions in combination with Oracle Coherence and Oracle Event Processing demonstrated very impressive how efficient real-time data processing can be. One example for Fast Data solutions that was shown during the OOW was the analysis of twitter streams regarding customer satisfaction. The feeds with negative words like “bad” or “worse” have been filtered and after a defined treshold has been reached in a certain timeframe, a business event was triggered. Cloud Another key trend in the IT market is of course Cloud Computing and what it means for companies and their businesses. Oracle announced their Cloud strategy and vision – companies can focus on their real business while all of the applications are available via Cloud. This also includes Oracle Database or Oracle Weblogic, so that companies can also build, deploy and run their own applications within the cloud. Three different approaches have been introduced: Infrastructure as a Service (IaaS) Platform as a Service (PaaS) Software as a Service (SaaS) Using the IaaS approach only the infrastructure components will be managed in the Cloud. Customers will be very flexible regarding memory, storage or number of CPUs because those parameters can be adjusted elastically. The PaaS approach means that besides the infrastructure also the platforms (such as databases or application servers) necessary for running applications will be provided within the Cloud. Here customers can also decide, if installation and management of these infrastructure components should be done by Oracle. The SaaS approach describes the most complete one, hence all applications a company uses are managed in the Cloud. Oracle is planning to provide all of their applications, like ERP systems or HR applications, as Cloud services. In conclusion this seems to be a very forward-thinking strategy, which opens up new possibilities for customers to manage their infrastructure and applications in a flexible, scalable and future-oriented manner. As you can see, our OOW days have been very very interresting. We collected many helpful informations for our projects. The new innovations presented at the confernce are great and being part of this was even greater! We are looking forward to next years’ conference! Links: http://www.oracle.com/openworld/index.html http://thecattlecrew.wordpress.com/2013/09/23/first-impressions-from-oracle-open-world-2013 SOA & BPM Partner Community For regular information on Oracle SOA Suite become a member in the SOA & BPM Partner Community for registration please visit www.oracle.com/goto/emea/soa (OPN account required) If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Facebook Wiki Mix Forum Technorati Tags: cattleCrew,Sven Bernhard,OOW2013,SOA Community,Oracle SOA,Oracle BPM,Community,OPN,Jürgen Kress

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  • Refactoring Part 1 : Intuitive Investments

    - by Wes McClure
    Fear, it’s what turns maintaining applications into a nightmare.  Technology moves on, teams move on, someone is left to operate the application, what was green is now perceived brown.  Eventually the business will evolve and changes will need to be made.  The approach to those changes often dictates the long term viability of the application.  Fear of change, lack of passion and a lack of interest in understanding the domain often leads to a paranoia to do anything that doesn’t involve duct tape and bailing twine.  Don’t get me wrong, those have a place in the short term viability of a project but they don’t have a place in the long term.  Add to it “us versus them” in regards to the original team and those that maintain it, internal politics and other factors and you have a recipe for disaster.  This results in code that quickly becomes unmanageable.  Even the most clever of designs will eventually become sub optimal and debt will amount that exponentially makes changes difficult.  This is where refactoring comes in, and it’s something I’m very passionate about.  Refactoring is about improving the process whereby we make change, it’s an exponential investment in the process of change. Without it we will incur exponential complexity that halts productivity. Investments, especially in the long term, require intuition and reflection.  How can we tackle new development effectively via evolving the original design and paying off debt that has been incurred? The longer we wait to ask and answer this question, the more it will cost us.  Small requests don’t warrant big changes, but realizing when changes now will pay off in the long term, and especially in the short term, is valuable. I have done my fair share of maintaining applications and continuously refactoring as needed, but recently I’ve begun work on a project that hasn’t had much debt, if any, paid down in years.  This is the first in a series of blog posts to try to capture the process which is largely driven by intuition of smaller refactorings from other projects. Signs that refactoring could help: Testability How can decreasing test time not pay dividends? One of the first things I found was that a very important piece often takes 30+ minutes to test.  I can only imagine how much time this has cost historically, but more importantly the time it might cost in the coming weeks: I estimate at least 10-20 hours per person!  This is simply unacceptable for almost any situation.  As it turns out, about 6 hours of working with this part of the application and I was able to cut the time down to under 30 seconds!  In less than the lost time of one week, I was able to fix the problem for all future weeks! If we can’t test fast then we can’t change fast, nor with confidence. Code is used by end users and it’s also used by developers, consider your own needs in terms of the code base.  Adding logic to enable/disable features during testing can help decouple parts of an application and lead to massive improvements.  What exactly is so wrong about test code in real code?  Often, these become features for operators and sometimes end users.  If you cannot run an integration test within a test runner in your IDE, it’s time to refactor. Readability Are variables named meaningfully via a ubiquitous language? Is the code segmented functionally or behaviorally so as to minimize the complexity of any one area? Are aspects properly segmented to avoid confusion (security, logging, transactions, translations, dependency management etc) Is the code declarative (what) or imperative (how)?  What matters, not how.  LINQ is a great abstraction of the what, not how, of collection manipulation.  The Reactive framework is a great example of the what, not how, of managing streams of data. Are constants abstracted and named, or are they just inline? Do people constantly bitch about the code/design? If the code is hard to understand, it will be hard to change with confidence.  It’s a large undertaking if the original designers didn’t pay much attention to readability and as such will never be done to “completion.”  Make sure not to go over board, instead use this as you change an application, not in lieu of changes (like with testability). Complexity Simplicity will never be achieved, it’s highly subjective.  That said, a lot of code can be significantly simplified, tidy it up as you go.  Refactoring will often converge upon a simplification step after enough time, keep an eye out for this. Understandability In the process of changing code, one often gains a better understanding of it.  Refactoring code is a good way to learn how it works.  However, it’s usually best in combination with other reasons, in effect killing two birds with one stone.  Often this is done when readability is poor, in which case understandability is usually poor as well.  In the large undertaking we are making with this legacy application, we will be replacing it.  Therefore, understanding all of its features is important and this refactoring technique will come in very handy. Unused code How can deleting things not help? This is a freebie in refactoring, it’s very easy to detect with modern tools, especially in statically typed languages.  We have VCS for a reason, if in doubt, delete it out (ok that was cheesy)! If you don’t know where to start when refactoring, this is an excellent starting point! Duplication Do not pray and sacrifice to the anti-duplication gods, there are excellent examples where consolidated code is a horrible idea, usually with divergent domains.  That said, mediocre developers live by copy/paste.  Other times features converge and aren’t combined.  Tools for finding similar code are great in the example of copy/paste problems.  Knowledge of the domain helps identify convergent concepts that often lead to convergent solutions and will give intuition for where to look for conceptual repetition. 80/20 and the Boy Scouts It’s often said that 80% of the time 20% of the application is used most.  These tend to be the parts that are changed.  There are also parts of the code where 80% of the time is spent changing 20% (probably for all the refactoring smells above).  I focus on these areas any time I make a change and follow the philosophy of the Boy Scout in cleaning up more than I messed up.  If I spend 2 hours changing an application, in the 20%, I’ll always spend at least 15 minutes cleaning it or nearby areas. This gives a huge productivity edge on developers that don’t. Ironically after a short period of time the 20% shrinks enough that we don’t have to spend 80% of our time there and can move on to other areas.   Refactoring is highly subjective, never attempt to refactor to completion!  Learn to be comfortable with leaving one part of the application in a better state than others.  It’s an evolution, not a revolution.  These are some simple areas to look into when making changes and can help get one started in the process.  I’ve often found that refactoring is a convergent process towards simplicity that sometimes spans a few hours but often can lead to massive simplifications over the timespan of weeks and months of regular development.

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  • Best Practices - which domain types should be used to run applications

    - by jsavit
    This post is one of a series of "best practices" notes for Oracle VM Server for SPARC (formerly named Logical Domains) One question that frequently comes up is "which types of domain should I use to run applications?" There used to be a simple answer in most cases: "only run applications in guest domains", but enhancements to T-series servers, Oracle VM Server for SPARC and the advent of SPARC SuperCluster have made this question more interesting and worth qualifying differently. This article reviews the relevant concepts and provides suggestions on where to deploy applications in a logical domains environment. Review: division of labor and types of domain Oracle VM Server for SPARC offloads many functions from the hypervisor to domains (also called virtual machines). This is a modern alternative to using a "thick" hypervisor that provides all virtualization functions, as in traditional VM designs, This permits a simpler hypervisor design, which enhances reliability, and security. It also reduces single points of failure by assigning responsibilities to multiple system components, which further improves reliability and security. In this architecture, management and I/O functionality are provided within domains. Oracle VM Server for SPARC does this by defining the following types of domain, each with their own roles: Control domain - management control point for the server, used to configure domains and manage resources. It is the first domain to boot on a power-up, is an I/O domain, and is usually a service domain as well. I/O domain - has been assigned physical I/O devices: a PCIe root complex, a PCI device, or a SR-IOV (single-root I/O Virtualization) function. It has native performance and functionality for the devices it owns, unmediated by any virtualization layer. Service domain - provides virtual network and disk devices to guest domains. Guest domain - a domain whose devices are all virtual rather than physical: virtual network and disk devices provided by one or more service domains. In common practice, this is where applications are run. Typical deployment A service domain is generally also an I/O domain: otherwise it wouldn't have access to physical device "backends" to offer to its clients. Similarly, an I/O domain is also typically a service domain in order to leverage the available PCI busses. Control domains must be I/O domains, because they boot up first on the server and require physical I/O. It's typical for the control domain to also be a service domain too so it doesn't "waste" the I/O resources it uses. A simple configuration consists of a control domain, which is also the one I/O and service domain, and some number of guest domains using virtual I/O. In production, customers typically use multiple domains with I/O and service roles to eliminate single points of failure: guest domains have virtual disk and virtual devices provisioned from more than one service domain, so failure of a service domain or I/O path or device doesn't result in an application outage. This is also used for "rolling upgrades" in which service domains are upgraded one at a time while their guests continue to operate without disruption. (It should be noted that resiliency to I/O device failures can also be provided by the single control domain, using multi-path I/O) In this type of deployment, control, I/O, and service domains are used for virtualization infrastructure, while applications run in guest domains. Changing application deployment patterns The above model has been widely and successfully used, but more configuration options are available now. Servers got bigger than the original T2000 class machines with 2 I/O busses, so there is more I/O capacity that can be used for applications. Increased T-series server capacity made it attractive to run more vertical applications, such as databases, with higher resource requirements than the "light" applications originally seen. This made it attractive to run applications in I/O domains so they could get bare-metal native I/O performance. This is leveraged by the SPARC SuperCluster engineered system, announced a year ago at Oracle OpenWorld. In SPARC SuperCluster, I/O domains are used for high performance applications, with native I/O performance for disk and network and optimized access to the Infiniband fabric. Another technical enhancement is the introduction of Direct I/O (DIO) and Single Root I/O Virtualization (SR-IOV), which make it possible to give domains direct connections and native I/O performance for selected I/O devices. A domain with either a DIO or SR-IOV device is an I/O domain. In summary: not all I/O domains own PCI complexes, and there are increasingly more I/O domains that are not service domains. They use their I/O connectivity for performance for their own applications. However, there are some limitations and considerations: at this time, a domain using physical I/O cannot be live-migrated to another server. There is also a need to plan for security and introducing unneeded dependencies: if an I/O domain is also a service domain providing virtual I/O go guests, it has the ability to affect the correct operation of its client guest domains. This is even more relevant for the control domain. where the ldm has to be protected from unauthorized (or even mistaken) use that would affect other domains. As a general rule, running applications in the service domain or the control domain should be avoided. To recap: Guest domains with virtual I/O still provide the greatest operational flexibility, including features like live migration. I/O domains can be used for applications with high performance requirements. This is used to great effect in SPARC SuperCluster and in general T4 deployments. Direct I/O (DIO) and Single Root I/O Virtualization (SR-IOV) make this more attractive by giving direct I/O access to more domains. Service domains should in general not be used for applications, because compromised security in the domain, or an outage, can affect other domains that depend on it. This concern can be mitigated by providing guests' their virtual I/O from more than one service domain, so an interruption of service in the service domain does not cause an application outage. The control domain should in general not be used to run applications, for the same reason. SPARC SuperCluster use the control domain for applications, but it is an exception: it's not a general purpose environment; it's an engineered system with specifically configured applications and optimization for optimal performance. These are recommended "best practices" based on conversations with a number of Oracle architects. Keep in mind that "one size does not fit all", so you should evaluate these practices in the context of your own requirements. Summary Higher capacity T-series servers have made it more attractive to use them for applications with high resource requirements. New deployment models permit native I/O performance for demanding applications by running them in I/O domains with direct access to their devices. This is leveraged in SPARC SuperCluster, and can be leveraged in T-series servers to provision high-performance applications running in domains. Carefully planned, this can be used to provide higher performance for critical applications.

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  • To SYNC or not to SYNC – Part 3

    - by AshishRay
    I can't believe it has been almost a year since my last blog post. I know, that's an absolute no-no in the blogosphere. And I know that "I have been busy" is not a good excuse. So - without trying to come up with an excuse - let me state this - my apologies for taking such a long time to write the next Part. Without further ado, here goes. This is Part 3 of a multi-part blog article where we are discussing various aspects of setting up Data Guard synchronous redo transport (SYNC). In Part 1 of this article, I debunked the myth that Data Guard SYNC is similar to a two-phase commit operation. In Part 2, I discussed the various ways that network latency may or may not impact a Data Guard SYNC configuration. In this article, I will talk in details regarding why Data Guard SYNC is a good thing. I will also talk about distance implications for setting up such a configuration. So, Why Good? Why is Data Guard SYNC a good thing? Because, at the end of the day, this gives you the assurance of zero data loss - it doesn’t matter what outage may befall your primary system. Befall! Boy, that sounds theatrical. But seriously - think about this - it minimizes your data risks. That’s a big deal. Whether you have an outage due to bad disks, faulty hardware components, hardware / software bugs, physical data corruptions, power failures, lightning that takes out significant part of your data center, fire that melts your assets, water leakage from the cooling system, human errors such as accidental deletion of online redo log files - it doesn’t matter - you can have that “Om - peace” look on your face and then you can failover to the standby system, without losing a single bit of data in your Oracle database. You will be a hero, as shown in this not so imaginary conversation: IT Manager: Well, what’s the status? You: John is doing the trace analysis on the storage array. IT Manager: So? How long is that gonna take? You: Well, he is stuck, waiting for a response from <insert your not-so-favorite storage vendor here>. IT Manager: So, no root cause yet? You: I told you, he is stuck. We have escalated with their Support, but you know how long these things take. IT Manager: Darn it - the site is down! You: Not really … IT Manager: What do you mean? You: John is stuck, but Sreeni has already done a failover to the Data Guard standby. IT Manager: Whoa, whoa - wait! Failover means we lost some data, why did you do this without letting the Business group know? You: We didn’t lose any data. Remember, we had set up Data Guard with SYNC? So now, any problems on the production – we just failover. No data loss, and we are up and running in minutes. The Business guys don’t need to know. IT Manager: Wow! Are we great or what!! You: I guess … Ok, so you get it - SYNC is good. But as my dear friend Larry Carpenter says, “TANSTAAFL”, or "There ain't no such thing as a free lunch". Yes, of course - investing in Data Guard SYNC means that you have to invest in a low-latency network, you have to monitor your applications and database especially in peak load conditions, and you cannot under-provision your standby systems. But all these are good and necessary things, if you are supporting mission-critical apps that are supposed to be running 24x7. The peace of mind that this investment will give you is priceless, especially if you are serious about HA. How Far Can We Go? Someone may say at this point - well, I can’t use Data Guard SYNC over my coast-to-coast deployment. Most likely - true. So how far can you go? Well, we have customers who have deployed Data Guard SYNC over 300+ miles! Does this mean that you can also deploy over similar distances? Duh - no! I am going to say something here that most IT managers don’t like to hear - “It depends!” It depends on your application design, application response time / throughput requirements, network topology, etc. However, because of the optimal way we do SYNC, customers have been able to stretch Data Guard SYNC deployments over longer distances compared to traditional, storage-centric ways of doing this. The MAA Database 10.2 best practices paper Data Guard Redo Transport & Network Configuration, and Oracle Database 11.2 High Availability Best Practices Manual talk about some of these SYNC-related metrics. For example, a test deployment of Data Guard SYNC over 330 miles with 10ms latency showed an impact less than 5% for a busy OLTP application. Even if you can’t deploy Data Guard SYNC over your WAN distance, or if you already have an ASYNC standby located 1000-s of miles away, here’s another nifty way to boost your HA. Have a local standby, configured SYNC. How local is “local”? Again - it depends. One customer runs a local SYNC standby across the campus. Another customer runs it across 15 miles in another data center. Both of these customers are running Data Guard SYNC as their HA standard. If a localized outage affects their primary system, no problem! They have all the data available on the standby, to which they can failover. Very fast. In seconds. Wait - did I say “seconds”? Yes, Virginia, there is a Santa Claus. But you have to wait till the next blog article to find out more. I assure you tho’ that this time you won’t have to wait for another year for this.

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  • Adding multiple data importers support to web applications

    - by DigiMortal
    I’m building web application for customer and there is requirement that users must be able to import data in different formats. Today we will support XLSX and ODF as import formats and some other formats are waiting. I wanted to be able to add new importers on the fly so I don’t have to deploy web application again when I add new importer or change some existing one. In this posting I will show you how to build generic importers support to your web application. Importer interface All importers we use must have something in common so we can easily detect them. To keep things simple I will use interface here. public interface IMyImporter {     string[] SupportedFileExtensions { get; }     ImportResult Import(Stream fileStream, string fileExtension); } Our interface has the following members: SupportedFileExtensions – string array of file extensions that importer supports. This property helps us find out what import formats are available and which importer to use with given format. Import – method that does the actual importing work. Besides file we give in as stream we also give file extension so importer can decide how to handle the file. It is enough to get started. When building real importers I am sure you will switch over to abstract base class. Importer class Here is sample importer that imports data from Excel and Word documents. Importer class with no implementation details looks like this: public class MyOpenXmlImporter : IMyImporter {     public string[] SupportedFileExtensions     {         get { return new[] { "xlsx", "docx" }; }     }     public ImportResult Import(Stream fileStream, string extension)     {         // ...     } } Finding supported import formats in web application Now we have importers created and it’s time to add them to web application. Usually we have one page or ASP.NET MVC controller where we need importers. To this page or controller we add the following method that uses reflection to find all classes that implement our IMyImporter interface. private static string[] GetImporterFileExtensions() {     var types = from a in AppDomain.CurrentDomain.GetAssemblies()                 from t in a.GetTypes()                 where t.GetInterfaces().Contains(typeof(IMyImporter))                 select t;       var extensions = new Collection<string>();     foreach (var type in types)     {         var instance = (IMyImporter)type.InvokeMember(null,                        BindingFlags.CreateInstance, null, null, null);           foreach (var extension in instance.SupportedFileExtensions)         {             if (extensions.Contains(extension))                 continue;               extensions.Add(extension);         }     }       return extensions.ToArray(); } This code doesn’t look nice and is far from optimal but it works for us now. It is possible to improve performance of web application if we cache extensions and their corresponding types to some static dictionary. We have to fill it only once because our application is restarted when something changes in bin folder. Finding importer by extension When user uploads file we need to detect the extension of file and find the importer that supports given extension. We add another method to our page or controller that uses reflection to return us importer instance or null if extension is not supported. private static IMyImporter GetImporterForExtension(string extensionToFind) {     var types = from a in AppDomain.CurrentDomain.GetAssemblies()                 from t in a.GetTypes()                 where t.GetInterfaces().Contains(typeof(IMyImporter))                 select t;     foreach (var type in types)     {         var instance = (IMyImporter)type.InvokeMember(null,                        BindingFlags.CreateInstance, null, null, null);           if (instance.SupportedFileExtensions.Contains(extensionToFind))         {             return instance;         }     }       return null; } Here is example ASP.NET MVC controller action that accepts uploaded file, finds importer that can handle file and imports data. Again, this is sample code I kept minimal to better illustrate how things work. public ActionResult Import(MyImporterModel model) {     var file = Request.Files[0];     var extension = Path.GetExtension(file.FileName).ToLower();     var importer = GetImporterForExtension(extension.Substring(1));     var result = importer.Import(file.InputStream, extension);     if (result.Errors.Count > 0)     {         foreach (var error in result.Errors)             ModelState.AddModelError("file", error);           return Import();     }     return RedirectToAction("Index"); } Conclusion That’s it. Using couple of ugly methods and one simple interface we were able to add importers support to our web application. Example code here is not perfect but it works. It is possible to cache mappings between file extensions and importer types to some static variable because changing of these mappings means that something is changed in bin folder of web application and web application is restarted in this case anyway.

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  • Apache Tomcat Server failure

    - by Kenneth Ordona
    I'm trying to set up Apache Tomcat 6 with SSL and once I edited the server.xml file to include the following definitions the server started to fail as soon as I hit startup.bat: <-- Define a SSL Coyote HTTP/1.1 Connector on port 8443 -- < Connector protocol="org.apache.coyote.http11.Http11Protocol" port="8445" maxThreads="200" scheme="https" secure="true" SSLEnabled="true" keystoreFile="${user.home}/.tomcat" keystorePass="pnnlpw" clientAuth="false" sslProtocol="TLS"/ The logs that I have are as follows: Jul 05, 2012 1:52:15 PM org.apache.catalina.core.AprLifecycleListener init INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files\Java\jdk1.7.0_05\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;. Jul 05, 2012 1:52:15 PM org.apache.tomcat.util.digester.Digester fatalError SEVERE: Parse Fatal Error at line 91 column 2: The content of elements must consist of well-formed character data or markup. org.xml.sax.SAXParseException; systemId: file://C/tomcat6/conf/server.xml; lineNumber: 91; columnNumber: 2; The content of elements must consist of well-formed character data or markup. at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:198) at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:177) at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:441) at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:368) at com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1388) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.startOfMarkup(XMLDocumentFragmentScannerImpl.java:2565) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2663) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:607) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:488) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:835) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:764) at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:123) at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1210) at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:568) at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1642) at org.apache.catalina.startup.Catalina.load(Catalina.java:524) at org.apache.catalina.startup.Catalina.load(Catalina.java:562) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.apache.catalina.startup.Bootstrap.load(Bootstrap.java:261) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413) Jul 05, 2012 1:52:15 PM org.apache.catalina.startup.Catalina load WARNING: Catalina.start using conf/server.xml: org.xml.sax.SAXParseException; systemId: file://C/tomcat6/conf/server.xml; lineNumber: 91; columnNumber: 2; The content of elements must consist of well-formed character data or markup. at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1236) at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:568) at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1642) at org.apache.catalina.startup.Catalina.load(Catalina.java:524) at org.apache.catalina.startup.Catalina.load(Catalina.java:562) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.apache.catalina.startup.Bootstrap.load(Bootstrap.java:261) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413) Jul 05, 2012 1:52:15 PM org.apache.tomcat.util.digester.Digester fatalError SEVERE: Parse Fatal Error at line 91 column 2: The content of elements must consist of well-formed character data or markup. org.xml.sax.SAXParseException; systemId: file://C/tomcat6/conf/server.xml; lineNumber: 91; columnNumber: 2; The content of elements must consist of well-formed character data or markup. at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:198) at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:177) at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:441) at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:368) at com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1388) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.startOfMarkup(XMLDocumentFragmentScannerImpl.java:2565) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2663) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:607) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:488) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:835) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:764) at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:123) at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1210) at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:568) at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1642) at org.apache.catalina.startup.Catalina.load(Catalina.java:524) at org.apache.catalina.startup.Catalina.start(Catalina.java:582) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414) Jul 05, 2012 1:52:15 PM org.apache.catalina.startup.Catalina load WARNING: Catalina.start using conf/server.xml: org.xml.sax.SAXParseException; systemId: file://C/tomcat6/conf/server.xml; lineNumber: 91; columnNumber: 2; The content of elements must consist of well-formed character data or markup. at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1236) at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:568) at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1642) at org.apache.catalina.startup.Catalina.load(Catalina.java:524) at org.apache.catalina.startup.Catalina.start(Catalina.java:582) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414) Jul 05, 2012 1:52:15 PM org.apache.catalina.startup.Catalina start SEVERE: Cannot start server. Server instance is not configured. Does anyone have an idea why this is happening? I believe it has to do with the configuration of my connector. I'm pretty new to this so any help would be much appreciated.

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  • Unable to access intel fake RAID 1 array in Fedora 14 after reboot

    - by Sim
    Hello everyone, 1st I am relatively new to linux (but not to *nix). I have 4 disks assembled in the following intel ahci bios fake raid arrays: 2x320GB RAID1 - used for operating systems md126 2x1TB RAID1 - used for data md125 I have used the raid of size 320GB to install my operating system and the second raid I didn't even select during the installation of Fedora 14. After successful partitioning and installation of Fedora, I tried to make the second array available, it was possible to make it visible in linux with mdadm --assembe --scan , after that I created one maximum size partition and 1 maximum size ext4 filesystem in it. Mounted, and used it. After restart - a few I/O errors during boot regarding md125 + inability to mount the filesystem on it and dropped into repair shell. I commented the filesystem in fstab and it booted. To my surprise, the array was marked as "auto read only": [root@localhost ~]# cat /proc/mdstat Personalities : [raid1] md125 : active (auto-read-only) raid1 sdc[1] sdd[0] 976759808 blocks super external:/md127/0 [2/2] [UU] md127 : inactive sdc[1](S) sdd[0](S) 4514 blocks super external:imsm md126 : active raid1 sda[1] sdb[0] 312566784 blocks super external:/md1/0 [2/2] [UU] md1 : inactive sdb[1](S) sda[0](S) 4514 blocks super external:imsm unused devices: <none> [root@localhost ~]# and the partition in it was not available as device special file in /dev: [root@localhost ~]# ls -l /dev/md125* brw-rw---- 1 root disk 9, 125 Jan 6 15:50 /dev/md125 [root@localhost ~]# But the partition is there according to fdisk: [root@localhost ~]# fdisk -l /dev/md125 Disk /dev/md125: 1000.2 GB, 1000202043392 bytes 19 heads, 10 sectors/track, 10281682 cylinders, total 1953519616 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x1b238ea9 Device Boot Start End Blocks Id System /dev/md125p1 2048 1953519615 976758784 83 Linux [root@localhost ~]# I tried to "activate" the array in different ways (I'm not experienced with mdadm and the man page is gigantic so I was only browsing it looking for my answer) but it was impossible - the array would still stay in "auto read only" and the device special file for the partition it will not be in /dev. It was only after I recreated the partition via fdisk that it reappeared in /dev... until next reboot. So, my question is - How do I make the array automatically available after reboot? Here is some additional information: 1st I am able to see the UUID of the array in blkid: [root@localhost ~]# blkid /dev/sdc: UUID="b9a1149f-ae11-4fc8-a600-0d77354dc42a" SEC_TYPE="ext2" TYPE="ext3" /dev/sdd: UUID="b9a1149f-ae11-4fc8-a600-0d77354dc42a" SEC_TYPE="ext2" TYPE="ext3" /dev/md126p1: UUID="60C8D9A7C8D97C2A" TYPE="ntfs" /dev/md126p2: UUID="3d1b38a3-b469-4b7c-b016-8abfb26a5d7d" TYPE="ext4" /dev/md126p3: UUID="1Msqqr-AAF8-k0wi-VYnq-uWJU-y0OD-uIFBHL" TYPE="LVM2_member" /dev/mapper/vg00-rootlv: LABEL="_Fedora-14-x86_6" UUID="34cc1cf5-6845-4489-8303-7a90c7663f0a" TYPE="ext4" /dev/mapper/vg00-swaplv: UUID="4644d857-e13b-456c-ac03-6f26299c1046" TYPE="swap" /dev/mapper/vg00-homelv: UUID="82bd58b2-edab-4b4b-aec4-b79595ecd0e3" TYPE="ext4" /dev/mapper/vg00-varlv: UUID="1b001444-5fdd-41b6-a59a-9712ec6def33" TYPE="ext4" /dev/mapper/vg00-tmplv: UUID="bf7d2459-2b35-4a1c-9b81-d4c4f24a9842" TYPE="ext4" /dev/md125: UUID="b9a1149f-ae11-4fc8-a600-0d77354dc42a" SEC_TYPE="ext2" TYPE="ext3" /dev/sda: TYPE="isw_raid_member" /dev/md125p1: UUID="420adfdd-6c4e-4552-93f0-2608938a4059" TYPE="ext4" [root@localhost ~]# Here is how /etc/mdadm.conf looks like: [root@localhost ~]# cat /etc/mdadm.conf # mdadm.conf written out by anaconda MAILADDR root AUTO +imsm +1.x -all ARRAY /dev/md1 UUID=89f60dee:e46a251f:7475814b:d4cc19a9 ARRAY /dev/md126 UUID=a8775c90:cee66376:5310fc13:63bcba5b ARRAY /dev/md125 UUID=b9a1149f:ae114fc8:a6000d77:354dc42a [root@localhost ~]# here is how /proc/mdstat looks like after I recreate the partition in the array so that it becomes available: [root@localhost ~]# cat /proc/mdstat Personalities : [raid1] md125 : active raid1 sdc[1] sdd[0] 976759808 blocks super external:/md127/0 [2/2] [UU] md127 : inactive sdc[1](S) sdd[0](S) 4514 blocks super external:imsm md126 : active raid1 sda[1] sdb[0] 312566784 blocks super external:/md1/0 [2/2] [UU] md1 : inactive sdb[1](S) sda[0](S) 4514 blocks super external:imsm unused devices: <none> [root@localhost ~]# Detailed output regarding the array in subject: [root@localhost ~]# mdadm --detail /dev/md125 /dev/md125: Container : /dev/md127, member 0 Raid Level : raid1 Array Size : 976759808 (931.51 GiB 1000.20 GB) Used Dev Size : 976759940 (931.51 GiB 1000.20 GB) Raid Devices : 2 Total Devices : 2 Update Time : Fri Jan 7 00:38:00 2011 State : clean Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 UUID : 30ebc3c2:b6a64751:4758d05c:fa8ff782 Number Major Minor RaidDevice State 1 8 32 0 active sync /dev/sdc 0 8 48 1 active sync /dev/sdd [root@localhost ~]# and /etc/fstab, with /data commented (the filesystem that is on this array): # # /etc/fstab # Created by anaconda on Thu Jan 6 03:32:40 2011 # # Accessible filesystems, by reference, are maintained under '/dev/disk' # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info # /dev/mapper/vg00-rootlv / ext4 defaults 1 1 UUID=3d1b38a3-b469-4b7c-b016-8abfb26a5d7d /boot ext4 defaults 1 2 #UUID=420adfdd-6c4e-4552-93f0-2608938a4059 /data ext4 defaults 0 1 /dev/mapper/vg00-homelv /home ext4 defaults 1 2 /dev/mapper/vg00-tmplv /tmp ext4 defaults 1 2 /dev/mapper/vg00-varlv /var ext4 defaults 1 2 /dev/mapper/vg00-swaplv swap swap defaults 0 0 tmpfs /dev/shm tmpfs defaults 0 0 devpts /dev/pts devpts gid=5,mode=620 0 0 sysfs /sys sysfs defaults 0 0 proc /proc proc defaults 0 0 [root@localhost ~]# Thanks in advance to everyone that even read this whole issue :-)

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  • Tomcat 7 on Ubuntu 12.04 with JRE 7 not starting

    - by Andreas Krueger
    I am running a virtual server in the web on Ubuntu 12.04 LTS / 32 Bit. After a clean install of JRE 7 and Tomcat 7, following the instructions on http://www.sysadminslife.com, I don't get Tomcat 7 up and running. > java -version java version "1.7.0_09" Java(TM) SE Runtime Environment (build 1.7.0_09-b05) Java HotSpot(TM) Client VM (build 23.5-b02, mixed mode) > /etc/init.d/tomcat start Starting Tomcat Using CATALINA_BASE: /usr/local/tomcat Using CATALINA_HOME: /usr/local/tomcat Using CATALINA_TMPDIR: /usr/local/tomcat/temp Using JRE_HOME: /usr/lib/jvm/java-7-oracle Using CLASSPATH: /usr/local/tomcat/bin/bootstrap.jar:/usr/local/tomcat/bin/tomcat-juli.jar > telnet localhost 8080 Trying ::1... Trying 127.0.0.1... telnet: Unable to connect to remote host: Connection refused netstat sometimes shows a Java process, most of the times not. If it does, nothing works either. Does anyone have a solution or encountered similar situations? Here are the contents of catalina.out: 16.11.2012 18:36:39 org.apache.catalina.core.AprLifecycleListener init INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: /usr/lib/jvm/java-6-oracle/lib/i386/client:/usr/lib/jvm/java-6-oracle/lib/i386:/usr/lib/jvm/java-6-oracle/../lib/i386:/usr/java/packages/lib/i386:/lib:/usr/lib 16.11.2012 18:36:40 org.apache.coyote.AbstractProtocol init INFO: Initializing ProtocolHandler ["http-bio-8080"] 16.11.2012 18:36:40 org.apache.coyote.AbstractProtocol init INFO: Initializing ProtocolHandler ["ajp-bio-8009"] 16.11.2012 18:36:40 org.apache.catalina.startup.Catalina load INFO: Initialization processed in 1509 ms 16.11.2012 18:36:40 org.apache.catalina.core.StandardService startInternal INFO: Starting service Catalina 16.11.2012 18:36:40 org.apache.catalina.core.StandardEngine startInternal INFO: Starting Servlet Engine: Apache Tomcat/7.0.29 16.11.2012 18:36:40 org.apache.catalina.startup.HostConfig deployDirectory INFO: Deploying web application directory /usr/local/tomcat/webapps/manager Here come the results of ps -ef, iptables --list and netstat -plut: > ps -ef UID PID PPID C STIME TTY TIME CMD root 1 0 0 Nov16 ? 00:00:00 init root 2 1 0 Nov16 ? 00:00:00 [kthreadd/206616] root 3 2 0 Nov16 ? 00:00:00 [khelper/2066167] root 4 2 0 Nov16 ? 00:00:00 [rpciod/2066167/] root 5 2 0 Nov16 ? 00:00:00 [rpciod/2066167/] root 6 2 0 Nov16 ? 00:00:00 [rpciod/2066167/] root 7 2 0 Nov16 ? 00:00:00 [rpciod/2066167/] root 8 2 0 Nov16 ? 00:00:00 [nfsiod/2066167] root 119 1 0 Nov16 ? 00:00:00 upstart-udev-bridge --daemon root 125 1 0 Nov16 ? 00:00:00 /sbin/udevd --daemon root 157 125 0 Nov16 ? 00:00:00 /sbin/udevd --daemon root 158 125 0 Nov16 ? 00:00:00 /sbin/udevd --daemon root 205 1 0 Nov16 ? 00:00:00 upstart-socket-bridge --daemon root 276 1 0 Nov16 ? 00:00:00 /usr/sbin/sshd -D root 335 1 0 Nov16 ? 00:00:00 /usr/sbin/xinetd -dontfork -pidfile /var/run/xinetd.pid -stayalive -inetd root 348 1 0 Nov16 ? 00:00:00 cron syslog 368 1 0 Nov16 ? 00:00:00 /sbin/syslogd -u syslog root 472 1 0 Nov16 ? 00:00:00 /usr/lib/postfix/master postfix 482 472 0 Nov16 ? 00:00:00 qmgr -l -t fifo -u root 520 1 0 Nov16 ? 00:00:04 /usr/sbin/apache2 -k start www-data 523 520 0 Nov16 ? 00:00:00 /usr/sbin/apache2 -k start www-data 525 520 0 Nov16 ? 00:00:00 /usr/sbin/apache2 -k start www-data 526 520 0 Nov16 ? 00:00:00 /usr/sbin/apache2 -k start tomcat 1074 1 0 Nov16 ? 00:01:08 /usr/lib/jvm/java-6-oracle/bin/java -Djava.util.logging.config.file=/usr/ postfix 1351 472 0 Nov16 ? 00:00:00 tlsmgr -l -t unix -u -c postfix 3413 472 0 17:00 ? 00:00:00 pickup -l -t fifo -u -c root 3457 276 0 17:31 ? 00:00:00 sshd: root@pts/0 root 3459 3457 0 17:31 pts/0 00:00:00 -bash root 3470 3459 0 17:31 pts/0 00:00:00 ps -ef > iptables --list Chain INPUT (policy ACCEPT) target prot opt source destination ACCEPT tcp -- anywhere anywhere tcp dpt:http-alt ACCEPT tcp -- anywhere anywhere tcp dpt:8005 ACCEPT tcp -- anywhere anywhere tcp dpt:http-alt Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination > netstat -plut Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 *:smtp *:* LISTEN 472/master tcp 0 0 *:3213 *:* LISTEN 276/sshd tcp6 0 0 [::]:smtp [::]:* LISTEN 472/master tcp6 0 0 [::]:8009 [::]:* LISTEN 1074/java tcp6 0 0 [::]:3213 [::]:* LISTEN 276/sshd tcp6 0 0 [::]:http-alt [::]:* LISTEN 1074/java tcp6 0 0 [::]:http [::]:* LISTEN 520/apache2

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  • Accessing a broken mdadm raid

    - by CarstenCarsten
    Hi! I used a western digital mybookworld (SOHO NAS storage using Linux) as backup for my Linux box. Suddenly, the mybookworld does not boot up any more. So I opened the box, removed the hard disk and put the hard disk into an external USB HDD case, and connected it to my Linux box. [ 530.640301] usb 2-1: new high speed USB device using ehci_hcd and address 3 [ 530.797630] scsi7 : usb-storage 2-1:1.0 [ 531.794844] scsi 7:0:0:0: Direct-Access WDC WD75 00AAKS-00RBA0 PQ: 0 ANSI: 2 [ 531.796490] sd 7:0:0:0: Attached scsi generic sg3 type 0 [ 531.797966] sd 7:0:0:0: [sdc] 1465149168 512-byte logical blocks: (750 GB/698 GiB) [ 531.800317] sd 7:0:0:0: [sdc] Write Protect is off [ 531.800327] sd 7:0:0:0: [sdc] Mode Sense: 38 00 00 00 [ 531.800333] sd 7:0:0:0: [sdc] Assuming drive cache: write through [ 531.803821] sd 7:0:0:0: [sdc] Assuming drive cache: write through [ 531.803836] sdc: sdc1 sdc2 sdc3 sdc4 [ 531.815831] sd 7:0:0:0: [sdc] Assuming drive cache: write through [ 531.815842] sd 7:0:0:0: [sdc] Attached SCSI disk The dmesg output looks normal, but I was wondering why the hardisk was not mounted at all. And why there are 4 different partitions on it. fdisk showed the following: root@ubuntu:/home/ubuntu# fdisk /dev/sdc WARNING: DOS-compatible mode is deprecated. It's strongly recommended to switch off the mode (command 'c') and change display units to sectors (command 'u'). Command (m for help): p Disk /dev/sdc: 750.2 GB, 750156374016 bytes 255 heads, 63 sectors/track, 91201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00007c00 Device Boot Start End Blocks Id System /dev/sdc1 4 369 2939895 fd Linux raid autodetect /dev/sdc2 370 382 104422+ fd Linux raid autodetect /dev/sdc3 383 505 987997+ fd Linux raid autodetect /dev/sdc4 506 91201 728515620 fd Linux raid autodetect Oh no! Everything seems to be created as a mdadm software raid. Calling mdadm --examine with the different partitions seems to affirm that. I think the only partition I am interested in, is /dev/sdc4 (because it is the largest). But nevertheless I called mdadm --examine with every partition. root@ubuntu:/home/ubuntu# mdadm --examine /dev/sdc1 /dev/sdc1: Magic : a92b4efc Version : 00.90.00 UUID : 5626a2d8:070ad992:ef1c8d24:cd8e13e4 Creation Time : Wed Feb 20 00:57:49 2002 Raid Level : raid1 Used Dev Size : 2939776 (2.80 GiB 3.01 GB) Array Size : 2939776 (2.80 GiB 3.01 GB) Raid Devices : 2 Total Devices : 1 Preferred Minor : 1 Update Time : Sun Nov 21 11:05:27 2010 State : clean Active Devices : 1 Working Devices : 1 Failed Devices : 1 Spare Devices : 0 Checksum : 4c90bc55 - correct Events : 16682 Number Major Minor RaidDevice State this 0 8 1 0 active sync /dev/sda1 0 0 8 1 0 active sync /dev/sda1 1 1 0 0 1 faulty removed root@ubuntu:/home/ubuntu# mdadm --examine /dev/sdc2 /dev/sdc2: Magic : a92b4efc Version : 00.90.00 UUID : 9734b3ee:2d5af206:05fe3413:585f7f26 Creation Time : Wed Feb 20 00:57:54 2002 Raid Level : raid1 Used Dev Size : 104320 (101.89 MiB 106.82 MB) Array Size : 104320 (101.89 MiB 106.82 MB) Raid Devices : 2 Total Devices : 1 Preferred Minor : 2 Update Time : Wed Oct 27 20:19:08 2010 State : clean Active Devices : 1 Working Devices : 1 Failed Devices : 1 Spare Devices : 0 Checksum : 55560b40 - correct Events : 9884 Number Major Minor RaidDevice State this 0 8 2 0 active sync /dev/sda2 0 0 8 2 0 active sync /dev/sda2 1 1 0 0 1 faulty removed root@ubuntu:/home/ubuntu# mdadm --examine /dev/sdc3 /dev/sdc3: Magic : a92b4efc Version : 00.90.00 UUID : 08f30b4f:91cca15d:2332bfef:48e67824 Creation Time : Wed Feb 20 00:57:54 2002 Raid Level : raid1 Used Dev Size : 987904 (964.91 MiB 1011.61 MB) Array Size : 987904 (964.91 MiB 1011.61 MB) Raid Devices : 2 Total Devices : 1 Preferred Minor : 3 Update Time : Sun Nov 21 11:05:27 2010 State : clean Active Devices : 1 Working Devices : 1 Failed Devices : 1 Spare Devices : 0 Checksum : 39717874 - correct Events : 73678 Number Major Minor RaidDevice State this 0 8 3 0 active sync 0 0 8 3 0 active sync 1 1 0 0 1 faulty removed root@ubuntu:/home/ubuntu# mdadm --examine /dev/sdc4 /dev/sdc4: Magic : a92b4efc Version : 00.90.00 UUID : febb75ca:e9d1ce18:f14cc006:f759419a Creation Time : Wed Feb 20 00:57:55 2002 Raid Level : raid1 Used Dev Size : 728515520 (694.77 GiB 746.00 GB) Array Size : 728515520 (694.77 GiB 746.00 GB) Raid Devices : 2 Total Devices : 1 Preferred Minor : 4 Update Time : Sun Nov 21 11:05:27 2010 State : clean Active Devices : 1 Working Devices : 1 Failed Devices : 1 Spare Devices : 0 Checksum : 2f36a392 - correct Events : 519320 Number Major Minor RaidDevice State this 0 8 4 0 active sync 0 0 8 4 0 active sync 1 1 0 0 1 faulty removed If I read the output correctly everything was removed, because it was faulty. Is there ANY way to see the contents of the largest partition? Or seeing somehow which files are broken? I see that everything is raid1 which is only mirroring, so this should be a normal partition. I am anxious to do anything with mdadm, in fear that I destroy the data on the hard disk. I would be very thankful for any help.

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  • Parallelism in .NET – Part 9, Configuration in PLINQ and TPL

    - by Reed
    Parallel LINQ and the Task Parallel Library contain many options for configuration.  Although the default configuration options are often ideal, there are times when customizing the behavior is desirable.  Both frameworks provide full configuration support. When working with Data Parallelism, there is one primary configuration option we often need to control – the number of threads we want the system to use when parallelizing our routine.  By default, PLINQ and the TPL both use the ThreadPool to schedule tasks.  Given the major improvements in the ThreadPool in CLR 4, this default behavior is often ideal.  However, there are times that the default behavior is not appropriate.  For example, if you are working on multiple threads simultaneously, and want to schedule parallel operations from within both threads, you might want to consider restricting each parallel operation to using a subset of the processing cores of the system.  Not doing this might over-parallelize your routine, which leads to inefficiencies from having too many context switches. In the Task Parallel Library, configuration is handled via the ParallelOptions class.  All of the methods of the Parallel class have an overload which accepts a ParallelOptions argument. We configure the Parallel class by setting the ParallelOptions.MaxDegreeOfParallelism property.  For example, let’s revisit one of the simple data parallel examples from Part 2: Parallel.For(0, pixelData.GetUpperBound(0), row => { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } }); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, we’re looping through an image, and calling a method on each pixel in the image.  If this was being done on a separate thread, and we knew another thread within our system was going to be doing a similar operation, we likely would want to restrict this to using half of the cores on the system.  This could be accomplished easily by doing: var options = new ParallelOptions(); options.MaxDegreeOfParallelism = Math.Max(Environment.ProcessorCount / 2, 1); Parallel.For(0, pixelData.GetUpperBound(0), options, row => { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } }); Now, we’re restricting this routine to using no more than half the cores in our system.  Note that I included a check to prevent a single core system from supplying zero; without this check, we’d potentially cause an exception.  I also did not hard code a specific value for the MaxDegreeOfParallelism property.  One of our goals when parallelizing a routine is allowing it to scale on better hardware.  Specifying a hard-coded value would contradict that goal. Parallel LINQ also supports configuration, and in fact, has quite a few more options for configuring the system.  The main configuration option we most often need is the same as our TPL option: we need to supply the maximum number of processing threads.  In PLINQ, this is done via a new extension method on ParallelQuery<T>: ParallelEnumerable.WithDegreeOfParallelism. Let’s revisit our declarative data parallelism sample from Part 6: double min = collection.AsParallel().Min(item => item.PerformComputation()); Here, we’re performing a computation on each element in the collection, and saving the minimum value of this operation.  If we wanted to restrict this to a limited number of threads, we would add our new extension method: int maxThreads = Math.Max(Environment.ProcessorCount / 2, 1); double min = collection .AsParallel() .WithDegreeOfParallelism(maxThreads) .Min(item => item.PerformComputation()); This automatically restricts the PLINQ query to half of the threads on the system. PLINQ provides some additional configuration options.  By default, PLINQ will occasionally revert to processing a query in parallel.  This occurs because many queries, if parallelized, typically actually cause an overall slowdown compared to a serial processing equivalent.  By analyzing the “shape” of the query, PLINQ often decides to run a query serially instead of in parallel.  This can occur for (taken from MSDN): Queries that contain a Select, indexed Where, indexed SelectMany, or ElementAt clause after an ordering or filtering operator that has removed or rearranged original indices. Queries that contain a Take, TakeWhile, Skip, SkipWhile operator and where indices in the source sequence are not in the original order. Queries that contain Zip or SequenceEquals, unless one of the data sources has an originally ordered index and the other data source is indexable (i.e. an array or IList(T)). Queries that contain Concat, unless it is applied to indexable data sources. Queries that contain Reverse, unless applied to an indexable data source. If the specific query follows these rules, PLINQ will run the query on a single thread.  However, none of these rules look at the specific work being done in the delegates, only at the “shape” of the query.  There are cases where running in parallel may still be beneficial, even if the shape is one where it typically parallelizes poorly.  In these cases, you can override the default behavior by using the WithExecutionMode extension method.  This would be done like so: var reversed = collection .AsParallel() .WithExecutionMode(ParallelExecutionMode.ForceParallelism) .Select(i => i.PerformComputation()) .Reverse(); Here, the default behavior would be to not parallelize the query unless collection implemented IList<T>.  We can force this to run in parallel by adding the WithExecutionMode extension method in the method chain. Finally, PLINQ has the ability to configure how results are returned.  When a query is filtering or selecting an input collection, the results will need to be streamed back into a single IEnumerable<T> result.  For example, the method above returns a new, reversed collection.  In this case, the processing of the collection will be done in parallel, but the results need to be streamed back to the caller serially, so they can be enumerated on a single thread. This streaming introduces overhead.  IEnumerable<T> isn’t designed with thread safety in mind, so the system needs to handle merging the parallel processes back into a single stream, which introduces synchronization issues.  There are two extremes of how this could be accomplished, but both extremes have disadvantages. The system could watch each thread, and whenever a thread produces a result, take that result and send it back to the caller.  This would mean that the calling thread would have access to the data as soon as data is available, which is the benefit of this approach.  However, it also means that every item is introducing synchronization overhead, since each item needs to be merged individually. On the other extreme, the system could wait until all of the results from all of the threads were ready, then push all of the results back to the calling thread in one shot.  The advantage here is that the least amount of synchronization is added to the system, which means the query will, on a whole, run the fastest.  However, the calling thread will have to wait for all elements to be processed, so this could introduce a long delay between when a parallel query begins and when results are returned. The default behavior in PLINQ is actually between these two extremes.  By default, PLINQ maintains an internal buffer, and chooses an optimal buffer size to maintain.  Query results are accumulated into the buffer, then returned in the IEnumerable<T> result in chunks.  This provides reasonably fast access to the results, as well as good overall throughput, in most scenarios. However, if we know the nature of our algorithm, we may decide we would prefer one of the other extremes.  This can be done by using the WithMergeOptions extension method.  For example, if we know that our PerformComputation() routine is very slow, but also variable in runtime, we may want to retrieve results as they are available, with no bufferring.  This can be done by changing our above routine to: var reversed = collection .AsParallel() .WithExecutionMode(ParallelExecutionMode.ForceParallelism) .WithMergeOptions(ParallelMergeOptions.NotBuffered) .Select(i => i.PerformComputation()) .Reverse(); On the other hand, if are already on a background thread, and we want to allow the system to maximize its speed, we might want to allow the system to fully buffer the results: var reversed = collection .AsParallel() .WithExecutionMode(ParallelExecutionMode.ForceParallelism) .WithMergeOptions(ParallelMergeOptions.FullyBuffered) .Select(i => i.PerformComputation()) .Reverse(); Notice, also, that you can specify multiple configuration options in a parallel query.  By chaining these extension methods together, we generate a query that will always run in parallel, and will always complete before making the results available in our IEnumerable<T>.

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  • Fixing predicated NSFetchedResultsController/NSFetchRequest performance with SQLite backend?

    - by Jaanus
    I have a series of NSFetchedResultsControllers powering some table views, and their performance on device was abysmal, on the order of seconds. Since it all runs on main thread, it's blocking my app at startup, which is not great. I investigated and turns out the predicate is the problem: NSPredicate *somePredicate = [NSPredicate predicateWithFormat:@"ANY somethings == %@", something]; [fetchRequest setPredicate:somePredicate]; I.e the fetch entity, call it "things", has a many-to-many relation with entity "something". This predicate is a filter that limits the results to only things that have a relation with a particular "something". When I removed the predicate for testing, fetch time (the initial performFetch: call) dropped (for some extreme cases) from 4 seconds to around 100ms or less, which is acceptable. I am troubled by this, though, as it negates a lot of the benefit I was hoping to gain with Core Data and NSFRC, which otherwise seems like a powerful tool. So, my question is, how can I optimize this performance? Am I using the predicate wrong? Should I modify the model/schema somehow? And what other ways there are to fix this? Is this kind of degraded performance to be expected? (There are on the order of hundreds of <1KB objects.) EDIT WITH DETAILS: Here's the code: [fetchRequest setFetchLimit:200]; NSLog(@"before fetch"); BOOL success = [frc performFetch:&error]; if (!success) { NSLog(@"Fetch request error: %@", error); } NSLog(@"after fetch"); Updated logs (previously, I had some application inefficiencies degrading the performance here. These are the updated logs that should be as close to optimal as you can get under my current environment): 2010-02-05 12:45:22.138 Special Ppl[429:207] before fetch 2010-02-05 12:45:22.144 Special Ppl[429:207] CoreData: sql: SELECT DISTINCT 0, t0.Z_PK, t0.Z_OPT, <model fields> FROM ZTHING t0 LEFT OUTER JOIN Z_1THINGS t1 ON t0.Z_PK = t1.Z_2THINGS WHERE t1.Z_1SOMETHINGS = ? ORDER BY t0.ZID DESC LIMIT 200 2010-02-05 12:45:22.663 Special Ppl[429:207] CoreData: annotation: sql connection fetch time: 0.5094s 2010-02-05 12:45:22.668 Special Ppl[429:207] CoreData: annotation: total fetch execution time: 0.5240s for 198 rows. 2010-02-05 12:45:22.706 Special Ppl[429:207] after fetch If I do the same fetch without predicate (by commenting out the two lines in the beginning of the question): 2010-02-05 12:44:10.398 Special Ppl[414:207] before fetch 2010-02-05 12:44:10.405 Special Ppl[414:207] CoreData: sql: SELECT 0, t0.Z_PK, t0.Z_OPT, <model fields> FROM ZTHING t0 ORDER BY t0.ZID DESC LIMIT 200 2010-02-05 12:44:10.426 Special Ppl[414:207] CoreData: annotation: sql connection fetch time: 0.0125s 2010-02-05 12:44:10.431 Special Ppl[414:207] CoreData: annotation: total fetch execution time: 0.0262s for 200 rows. 2010-02-05 12:44:10.457 Special Ppl[414:207] after fetch 20-fold difference in times. 500ms is not that great, and there does not seem to be a way to do it in background thread or otherwise optimize that I can think of. (Apart from going to a binary store where this becomes a non-issue, so I might do that. Binary store performance is consistently ~100ms for the above 200-object predicated query.) (I nested another question here previously, which I now moved away).

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  • SQL SERVER – Repair a SQL Server Database Using a Transaction Log Explorer

    - by Pinal Dave
    In this blog, I’ll show how to use ApexSQL Log, a SQL Server transaction log viewer. You can download it for free, install, and play along. But first, let’s describe some disaster recovery scenarios where it’s useful. About SQL Server disaster recovery Along with database development and administration, you must work on a good recovery plan. Disasters do happen and no one’s immune. What you can do is take all actions needed to be ready for a disaster and go through it with minimal data loss and downtime. Besides creating a recovery plan, it’s necessary to have a list of steps that will be executed when a disaster occurs and to test them before a disaster. This way, you’ll know that the plan is good and viable. Testing can also be used as training for all team members, so they can all understand and execute it when the time comes. It will show how much time is needed to have your servers fully functional again and how much data you can lose in a real-life situation. If these don’t meet recovery-time and recovery-point objectives, the plan needs to be improved. Keep in mind that all major changes in environment configuration, business strategy, and recovery objectives require a new recovery plan testing, as these changes most probably induce a recovery plan changing and tweaking. What is a good SQL Server disaster recovery plan? A good SQL Server disaster recovery strategy starts with planning SQL Server database backups. An efficient strategy is to create a full database backup periodically. Between two successive full database backups, you can create differential database backups. It is essential is to create transaction log backups regularly between full database backups. Keep in mind that transaction log backups can be created only on databases in the full recovery model. In other words, a simple, but efficient backup strategy would be a full database backup every night, a transaction log backup every hour, or every 15 minutes. The frequency depends on how much data you can afford to lose and how busy the database is. Another option, instead of creating a full database backup every night, is to create a full database backup once a week (e.g. on Friday at midnight) and differential database backup every night until next Friday when you will create a full database backup again. Once you create your SQL Server database backup strategy, schedule the backups. You can do that easily using SQL Server maintenance plans. Why are transaction logs important? Transaction log backups contain transactions executed on a SQL Server database. They provide enough information to undo and redo the transactions and roll back or forward the database to a point in time. In SQL Server disaster recovery situations, transaction logs enable to repair a SQL Server database and bring it to the state before the disaster. Be aware that even with regular backups, there will be some data missing. These are the transactions made between the last transaction log backup and the time of the disaster. In some situations, to repair your SQL Server database it’s not necessary to re-create the database from its last backup. The database might still be online and all you need to do is roll back several transactions, such as wrong update, insert, or delete. The restore to a point in time feature is available in SQL Server, but for large databases, it is very time-consuming, as SQL Server first restores a full database backup, and then restores transaction log backups, one after another, up to the recovery point. During that time, the database is unavailable. This is where a SQL Server transaction log viewer can help. For optimal recovery, besides having a database in the full recovery model, it’s important that you haven’t manually truncated the online transaction log. This ensures that all transactions made after the last transaction log backup are still in the online transaction log. All you have to do is read and replay them. How to read a SQL Server transaction log? SQL Server doesn’t provide an option to read transaction logs. There are several SQL Server commands and functions that read the content of a transaction log file (fn_dblog, fn_dump_dblog, and DBCC PAGE), but they are undocumented. They require T-SQL knowledge, return a large number of not easy to read and understand columns, sometimes in binary or hexadecimal format. Another challenge is reading UPDATE statements, as it’s necessary to match it to a value in the MDF file. When you finally read the transactions executed, you have to create a script for it. How to easily repair a SQL database? The easiest solution is to use a transaction log reader that will not only read the transactions in the transaction log files, but also automatically create scripts for the read transactions. In the following example, I will show how to use ApexSQL Log to repair a SQL database after a crash. If a database has crashed and both MDF and LDF files are lost, you have to rely on the full database backup and all subsequent transaction log backups. In another scenario, the MDF file is lost, but the LDF file is available. First, restore the last full database backup on SQL Server using SQL Server Management Studio. I’ll name it Restored_AW2014. Then, start ApexSQL Log It will automatically detect all local servers. If not, click the icon right to the Server drop-down list, or just type in the SQL Server instance name. Select the Windows or SQL Server authentication type and select the Restored_AW2014 database from the database drop-down list. When all options are set, click Next. ApexSQL Log will show the online transaction log file. Now, click Add and add all transaction log backups created after the full database backup I used to restore the database. In case you don’t have transaction log backups, but the LDF file hasn’t been lost during the SQL Server disaster, add it using Add.   To repair a SQL database to a point in time, ApexSQL Log needs to read and replay all the transactions in the transaction log backups (or the LDF file saved after the disaster). That’s why I selected the Whole transaction log option in the Filter setup. ApexSQL Log offers a range of various filters, which are useful when you need to read just specific transactions. You can filter transactions by the time of the transactions, operation type (e.g. to read only data inserts), table name, SQL Server login that made the transaction, etc. In this scenario, to repair a SQL database, I’ll check all filters and make sure that all transactions are included. In the Operations tab, select all schema operations (DDL). If you omit these, only the data changes will be read so if there were any schema changes, such as a new function created, or an existing table modified, they will be ignored and database will not be properly repaired. The data repair for modified tables will fail. In the Tables tab, I’ll make sure all tables are selected. I will uncheck the Show operations on dropped tables option, to reduce the number of transactions. Click Next. ApexSQL Log offers three options. Select Open results in grid, to get a user-friendly presentation of the transactions. As you can see, details are shown for every transaction, including the old and new values for updated columns, which are clearly highlighted. Now, select them all and then create a redo script by clicking the Create redo script icon in the menu.   For a large number of transactions and in a critical situation, when acting fast is a must, I recommend using the Export results to file option. It will save some time, as the transactions will be directly scripted into a redo file, without showing them in the grid first. Select Generate reconstruction (REDO) script , change the output path if you want, and click Finish. After the redo T-SQL script is created, ApexSQL Log shows the redo script summary: The third option will create a command line statement for a batch file that you can use to schedule execution, which is not really applicable when you repair a SQL database, but quite useful in daily auditing scenarios. To repair your SQL database, all you have to do is execute the generated redo script using an integrated developer environment tool such as SQL Server Management Studio or any other, against the restored database. You can find more information about how to read SQL Server transaction logs and repair a SQL database on ApexSQL Solution center. There are solutions for various situations when data needs to be recovered, restored, or transactions rolled back. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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  • Best Practices - updated: which domain types should be used to run applications

    - by jsavit
    This post is one of a series of "best practices" notes for Oracle VM Server for SPARC (formerly named Logical Domains). This is an updated and enlarged version of the post on this topic originally posted October 2012. One frequent question "what type of domain should I use to run applications?" There used to be a simple answer: "run applications in guest domains in almost all cases", but now there are more things to consider. Enhancements to Oracle VM Server for SPARC and introduction of systems like the current SPARC servers including the T4 and T5 systems, the Oracle SuperCluster T5-8 and Oracle SuperCluster M6-32 provide scale and performance much higher than the original servers that ran domains. Single-CPU performance, I/O capacity, memory sizes, are much larger now, and far more demanding applications are now being hosted in logical domains. The general advice continues to be "use guest domains in almost all cases", meaning, "use virtual I/O rather than physical I/O", unless there is a specific reason to use the other domain types. The sections below will discuss the criteria for choosing between domain types. Review: division of labor and types of domain Oracle VM Server for SPARC offloads management and I/O functionality from the hypervisor to domains (also called virtual machines), providing a modern alternative to older VM architectures that use a "thick", monolithic hypervisor. This permits a simpler hypervisor design, which enhances reliability, and security. It also reduces single points of failure by assigning responsibilities to multiple system components, further improving reliability and security. Oracle VM Server for SPARC defines the following types of domain, each with their own roles: Control domain - management control point for the server, runs the logical domain daemon and constraints engine, and is used to configure domains and manage resources. The control domain is the first domain to boot on a power-up, is always an I/O domain, and is usually a service domain as well. It doesn't have to be, but there's no reason to not leverage it for virtual I/O services. There is one control domain per T-series system, and one per Physical Domain (PDom) on an M5-32 or M6-32 system. M5 and M6 systems can be physically domained, with logical domains within the physical ones. I/O domain - a domain that has been assigned physical I/O devices. The devices may be one more more PCIe root complexes (in which case the domain is also called a root complex domain). The domain has native access to all the devices on the assigned PCIe buses. The devices can be any device type supported by Solaris on the hardware platform. a SR-IOV (Single-Root I/O Virtualization) function. SR-IOV lets a physical device (also called a physical function) or PF) be subdivided into multiple virtual functions (VFs) which can be individually assigned directly to domains. SR-IOV devices currently can be Ethernet or InfiniBand devices. direct I/O ownership of one or more PCI devices residing in a PCIe bus slot. The domain has direct access to the individual devices An I/O domain has native performance and functionality for the devices it owns, unmediated by any virtualization layer. It may also have virtual devices. Service domain - a domain that provides virtual network and disk devices to guest domains. The services are defined by commands that are run in the control domain. It usually is an I/O domain as well, in order for it to have devices to virtualize and serve out. Guest domain - a domain whose devices are all virtual rather than physical: virtual network and disk devices provided by one or more service domains. In common practice, this is where applications are run. Device considerations Consider the following when choosing between virtual devices and physical devices: Virtual devices provide the best flexibility - they can be dynamically added to and removed from a running domain, and you can have a large number of them up to a per-domain device limit. Virtual devices are compatible with live migration - domains that exclusively have virtual devices can be live migrated between servers supporting domains. On the other hand: Physical devices provide the best performance - in fact, native "bare metal" performance. Virtual devices approach physical device throughput and latency, especially with virtual network devices that can now saturate 10GbE links, but physical devices are still faster. Physical I/O devices do not add load to service domains - all the I/O goes directly from the I/O domain to the device, while virtual I/O goes through service domains, which must be provided sufficient CPU and memory capacity. Physical I/O devices can be other than network and disk - we virtualize network, disk, and serial console, but physical devices can be the wide range of attachable certified devices, including things like tape and CDROM/DVD devices. In some cases the lines are now blurred: virtual devices have better performance than previously: starting with Oracle VM Server for SPARC 3.1 there is near-native virtual network performance. There is more flexibility with physical devices than before: SR-IOV devices can now be dynamically reconfigured on domains. Tradeoffs one used to have to make are now relaxed: you can often have the flexibility of virtual I/O with performance that previously required physical I/O. You can have the performance and isolation of SR-IOV with the ability to dynamically reconfigure it, just like with virtual devices. Typical deployment A service domain is generally also an I/O domain: otherwise it wouldn't have access to physical device "backends" to offer to its clients. Similarly, an I/O domain is also typically a service domain in order to leverage the available PCI buses. Control domains must be I/O domains, because they boot up first on the server and require physical I/O. It's typical for the control domain to also be a service domain too so it doesn't "waste" the I/O resources it uses. A simple configuration consists of a control domain that is also the one I/O and service domain, and some number of guest domains using virtual I/O. In production, customers typically use multiple domains with I/O and service roles to eliminate single points of failure, as described in Availability Best Practices - Avoiding Single Points of Failure . Guest domains have virtual disk and virtual devices provisioned from more than one service domain, so failure of a service domain or I/O path or device does not result in an application outage. This also permits "rolling upgrades" in which service domains are upgraded one at a time while their guests continue to operate without disruption. (It should be noted that resiliency to I/O device failures can also be provided by the single control domain, using multi-path I/O) In this type of deployment, control, I/O, and service domains are used for virtualization infrastructure, while applications run in guest domains. Changing application deployment patterns The above model has been widely and successfully used, but more configuration options are available now. Servers got bigger than the original T2000 class machines with 2 I/O buses, so there is more I/O capacity that can be used for applications. Increased server capacity made it attractive to run more vertically-scaled applications, such as databases, with higher resource requirements than the "light" applications originally seen. This made it attractive to run applications in I/O domains so they could get bare-metal native I/O performance. This is leveraged by the Oracle SuperCluster engineered systems mentioned previously. In those engineered systems, I/O domains are used for high performance applications with native I/O performance for disk and network and optimized access to the Infiniband fabric. Another technical enhancement is Single Root I/O Virtualization (SR-IOV), which make it possible to give domains direct connections and native I/O performance for selected I/O devices. Not all I/O domains own PCI complexes, and there are increasingly more I/O domains that are not service domains. They use their I/O connectivity for performance for their own applications. However, there are some limitations and considerations: at this time, a domain using physical I/O cannot be live-migrated to another server. There is also a need to plan for security and introducing unneeded dependencies: if an I/O domain is also a service domain providing virtual I/O to guests, it has the ability to affect the correct operation of its client guest domains. This is even more relevant for the control domain. where the ldm command must be protected from unauthorized (or even mistaken) use that would affect other domains. As a general rule, running applications in the service domain or the control domain should be avoided. For reference, an excellent guide to secure deployment of domains by Stefan Hinker is at Secure Deployment of Oracle VM Server for SPARC. To recap: Guest domains with virtual I/O still provide the greatest operational flexibility, including features like live migration. They should be considered the default domain type to use unless there is a specific requirement that mandates an I/O domain. I/O domains can be used for applications with the highest performance requirements. Single Root I/O Virtualization (SR-IOV) makes this more attractive by giving direct I/O access to more domains, and by permitting dynamic reconfiguration of SR-IOV devices. Today's larger systems provide multiple PCIe buses - for example, 16 buses on the T5-8 - making it possible to configure multiple I/O domains each owning their own bus. Service domains should in general not be used for applications, because compromised security in the domain, or an outage, can affect domains that depend on it. This concern can be mitigated by providing guests' their virtual I/O from more than one service domain, so interruption of service in one service domain does not cause an application outage. The control domain should in general not be used to run applications, for the same reason. Oracle SuperCluster uses the control domain for applications, but it is an exception. It's not a general purpose environment; it's an engineered system with specifically configured applications and optimization for optimal performance. These are recommended "best practices" based on conversations with a number of Oracle architects. Keep in mind that "one size does not fit all", so you should evaluate these practices in the context of your own requirements. Summary Higher capacity servers that run Oracle VM Server for SPARC are attractive for applications with the most demanding resource requirements. New deployment models permit native I/O performance for demanding applications by running them in I/O domains with direct access to their devices. This is leveraged in SPARC SuperCluster, and can be leveraged in T-series servers to provision high-performance applications running in domains. Carefully planned, this can be used to provide peak performance for critical applications. That said, the improved virtual device performance in Oracle VM Server means that the default choice should still be guest domains with virtual I/O.

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  • Performance Optimization &ndash; It Is Faster When You Can Measure It

    - by Alois Kraus
    Performance optimization in bigger systems is hard because the measured numbers can vary greatly depending on the measurement method of your choice. To measure execution timing of specific methods in your application you usually use Time Measurement Method Potential Pitfalls Stopwatch Most accurate method on recent processors. Internally it uses the RDTSC instruction. Since the counter is processor specific you can get greatly different values when your thread is scheduled to another core or the core goes into a power saving mode. But things do change luckily: Intel's Designer's vol3b, section 16.11.1 "16.11.1 Invariant TSC The time stamp counter in newer processors may support an enhancement, referred to as invariant TSC. Processor's support for invariant TSC is indicated by CPUID.80000007H:EDX[8]. The invariant TSC will run at a constant rate in all ACPI P-, C-. and T-states. This is the architectural behavior moving forward. On processors with invariant TSC support, the OS may use the TSC for wall clock timer services (instead of ACPI or HPET timers). TSC reads are much more efficient and do not incur the overhead associated with a ring transition or access to a platform resource." DateTime.Now Good but it has only a resolution of 16ms which can be not enough if you want more accuracy.   Reporting Method Potential Pitfalls Console.WriteLine Ok if not called too often. Debug.Print Are you really measuring performance with Debug Builds? Shame on you. Trace.WriteLine Better but you need to plug in some good output listener like a trace file. But be aware that the first time you call this method it will read your app.config and deserialize your system.diagnostics section which does also take time.   In general it is a good idea to use some tracing library which does measure the timing for you and you only need to decorate some methods with tracing so you can later verify if something has changed for the better or worse. In my previous article I did compare measuring performance with quantum mechanics. This analogy does work surprising well. When you measure a quantum system there is a lower limit how accurately you can measure something. The Heisenberg uncertainty relation does tell us that you cannot measure of a quantum system the impulse and location of a particle at the same time with infinite accuracy. For programmers the two variables are execution time and memory allocations. If you try to measure the timings of all methods in your application you will need to store them somewhere. The fastest storage space besides the CPU cache is the memory. But if your timing values do consume all available memory there is no memory left for the actual application to run. On the other hand if you try to record all memory allocations of your application you will also need to store the data somewhere. This will cost you memory and execution time. These constraints are always there and regardless how good the marketing of tool vendors for performance and memory profilers are: Any measurement will disturb the system in a non predictable way. Commercial tool vendors will tell you they do calculate this overhead and subtract it from the measured values to give you the most accurate values but in reality it is not entirely true. After falling into the trap to trust the profiler timings several times I have got into the habit to Measure with a profiler to get an idea where potential bottlenecks are. Measure again with tracing only the specific methods to check if this method is really worth optimizing. Optimize it Measure again. Be surprised that your optimization has made things worse. Think harder Implement something that really works. Measure again Finished! - Or look for the next bottleneck. Recently I have looked into issues with serialization performance. For serialization DataContractSerializer was used and I was not sure if XML is really the most optimal wire format. After looking around I have found protobuf-net which uses Googles Protocol Buffer format which is a compact binary serialization format. What is good for Google should be good for us. A small sample app to check out performance was a matter of minutes: using ProtoBuf; using System; using System.Diagnostics; using System.IO; using System.Reflection; using System.Runtime.Serialization; [DataContract, Serializable] class Data { [DataMember(Order=1)] public int IntValue { get; set; } [DataMember(Order = 2)] public string StringValue { get; set; } [DataMember(Order = 3)] public bool IsActivated { get; set; } [DataMember(Order = 4)] public BindingFlags Flags { get; set; } } class Program { static MemoryStream _Stream = new MemoryStream(); static MemoryStream Stream { get { _Stream.Position = 0; _Stream.SetLength(0); return _Stream; } } static void Main(string[] args) { DataContractSerializer ser = new DataContractSerializer(typeof(Data)); Data data = new Data { IntValue = 100, IsActivated = true, StringValue = "Hi this is a small string value to check if serialization does work as expected" }; var sw = Stopwatch.StartNew(); int Runs = 1000 * 1000; for (int i = 0; i < Runs; i++) { //ser.WriteObject(Stream, data); Serializer.Serialize<Data>(Stream, data); } sw.Stop(); Console.WriteLine("Did take {0:N0}ms for {1:N0} objects", sw.Elapsed.TotalMilliseconds, Runs); Console.ReadLine(); } } The results are indeed promising: Serializer Time in ms N objects protobuf-net   807 1000000 DataContract 4402 1000000 Nearly a factor 5 faster and a much more compact wire format. Lets use it! After switching over to protbuf-net the transfered wire data has dropped by a factor two (good) and the performance has worsened by nearly a factor two. How is that possible? We have measured it? Protobuf-net is much faster! As it turns out protobuf-net is faster but it has a cost: For the first time a type is de/serialized it does use some very smart code-gen which does not come for free. Lets try to measure this one by setting of our performance test app the Runs value not to one million but to 1. Serializer Time in ms N objects protobuf-net 85 1 DataContract 24 1 The code-gen overhead is significant and can take up to 200ms for more complex types. The break even point where the code-gen cost is amortized by its faster serialization performance is (assuming small objects) somewhere between 20.000-40.000 serialized objects. As it turned out my specific scenario involved about 100 types and 1000 serializations in total. That explains why the good old DataContractSerializer is not so easy to take out of business. The final approach I ended up was to reduce the number of types and to serialize primitive types via BinaryWriter directly which turned out to be a pretty good alternative. It sounded good until I measured again and found that my optimizations so far do not help much. After looking more deeper at the profiling data I did found that one of the 1000 calls did take 50% of the time. So how do I find out which call it was? Normal profilers do fail short at this discipline. A (totally undeserved) relatively unknown profiler is SpeedTrace which does unlike normal profilers create traces of your applications by instrumenting your IL code at runtime. This way you can look at the full call stack of the one slow serializer call to find out if this stack was something special. Unfortunately the call stack showed nothing special. But luckily I have my own tracing as well and I could see that the slow serializer call did happen during the serialization of a bool value. When you encounter after much analysis something unreasonable you cannot explain it then the chances are good that your thread was suspended by the garbage collector. If there is a problem with excessive GCs remains to be investigated but so far the serialization performance seems to be mostly ok.  When you do profile a complex system with many interconnected processes you can never be sure that the timings you just did measure are accurate at all. Some process might be hitting the disc slowing things down for all other processes for some seconds as well. There is a big difference between warm and cold startup. If you restart all processes you can basically forget the first run because of the OS disc cache, JIT and GCs make the measured timings very flexible. When you are in need of a random number generator you should measure cold startup times of a sufficiently complex system. After the first run you can try again getting different and much lower numbers. Now try again at least two times to get some feeling how stable the numbers are. Oh and try to do the same thing the next day. It might be that the bottleneck you found yesterday is gone today. Thanks to GC and other random stuff it can become pretty hard to find stuff worth optimizing if no big bottlenecks except bloatloads of code are left anymore. When I have found a spot worth optimizing I do make the code changes and do measure again to check if something has changed. If it has got slower and I am certain that my change should have made it faster I can blame the GC again. The thing is that if you optimize stuff and you allocate less objects the GC times will shift to some other location. If you are unlucky it will make your faster working code slower because you see now GCs at times where none were before. This is where the stuff does get really tricky. A safe escape hatch is to create a repro of the slow code in an isolated application so you can change things fast in a reliable manner. Then the normal profilers do also start working again. As Vance Morrison does point out it is much more complex to profile a system against the wall clock compared to optimize for CPU time. The reason is that for wall clock time analysis you need to understand how your system does work and which threads (if you have not one but perhaps 20) are causing a visible delay to the end user and which threads can wait a long time without affecting the user experience at all. Next time: Commercial profiler shootout.

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  • .NET 4.0 Dynamic object used statically?

    - by Kevin Won
    I've gotten quite sick of XML configuration files in .NET and want to replace them with a format that is more sane. Therefore, I'm writing a config file parser for C# applications that will take a custom config file format, parse it, and create a Python source string that I can then execute in C# and use as a static object (yes that's right--I want a static (not the static type dyanamic) object in the end). Here's an example of what my config file looks like: // my custom config file format GlobalName: ExampleApp Properties { ExternalServiceTimeout: "120" } Python { // this allows for straight python code to be added to handle custom config def MyCustomPython: return "cool" } Using ANTLR I've created a Lexer/Parser that will convert this format to a Python script. So assume I have that all right and can take the .config above and run my Lexer/Parser on it to get a Python script out the back (this has the added benefit of giving me a validation tool for my config). By running the resultant script in C# // simplified example of getting the dynamic python object in C# // (not how I really do it) ScriptRuntime py = Python.CreateRuntime(); dynamic conf = py.UseFile("conftest.py"); dynamic t = conf.GetConfTest("test"); I can get a dynamic object that has my configuration settings. I can now get my config file settings in C# by invoking a dynamic method on that object: //C# calling a method on the dynamic python object var timeout = t.GetProperty("ExternalServiceTimeout"); //the config also allows for straight Python scripting (via the Python block) var special = t.MyCustonPython(); of course, I have no type safety here and no intellisense support. I have a dynamic representation of my config file, but I want a static one. I know what my Python object's type is--it is actually newing up in instance of a C# class. But since it's happening in python, it's type is not the C# type, but dynamic instead. What I want to do is then cast the object back to the C# type that I know the object is: // doesn't work--can't cast a dynamic to a static type (nulls out) IConfigSettings staticTypeConfig = t as IConfigSettings Is there any way to figure out how to cast the object to the static type? I'm rather doubtful that there is... so doubtful that I took another approach of which I'm not entirely sure about. I'm wondering if someone has a better way... So here's my current tactic: since I know the type of the python object, I am creating a C# wrapper class: public class ConfigSettings : IConfigSettings that takes in a dynamic object in the ctor: public ConfigSettings(dynamic settings) { this.DynamicProxy = settings; } public dynamic DynamicProxy { get; private set; } Now I have a reference to the Python dynamic object of which I know the type. So I can then just put wrappers around the Python methods that I know are there: // wrapper access to the underlying dynamic object // this makes my dynamic object appear 'static' public string GetSetting(string key) { return this.DynamicProxy.GetProperty(key).ToString(); } Now the dynamic object is accessed through this static proxy and thus can obviously be passed around in the static C# world via interface, etc: // dependency inject the dynamic object around IBusinessLogic logic = new BusinessLogic(IConfigSettings config); This solution has the benefits of all the static typing stuff we know and love while at the same time giving me the option of 'bailing out' to dynamic too: // the DynamicProxy property give direct access to the dynamic object var result = config.DynamicProxy.MyCustomPython(); but, man, this seems rather convoluted way of getting to an object that is a static type in the first place! Since the whole dynamic/static interaction world is new to me, I'm really questioning if my solution is optimal or if I'm missing something (i.e. some way of casting that dynamic object to a known static type) about how to bridge the chasm between these two universes.

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  • php script gets two ajax requests, only returns one?

    - by Dan.StackOverflow
    I'll start from the beginning. I'm building a wordpress plugin that does double duty, in that it can be inserted in to a post via a shortcode, or added as a sidebar widget. All it does is output some js to make jquery.post requests to a local php file. The local php file makes a request to a webservice for some data. (I had to do it this way instead of directly querying the web service with jquery.ajax because the url contains a license key that would be public if put in the js). Anyway, When I am viewing a page in the wordpress blog that has both the sidebar widget and the plugin output via shortcode only one of the requests work. I mean it works in that it gets a response back from the php script. Once the page is loaded they both work normally when manually told to. Webpage view - send 2 post requests to my php script - both elements should be filed in, but only one is. My php script is just: <?php if(isset($_POST["zip"])) { // build a curl object, execute the request, // and basically just echo what the curl request returns. } ?> Pretty basic. here is some js some people wanted to see: function widget_getActivities( zip ){ jQuery("#widget_active_list").text(""); jQuery.post("http://localhost/wordpress/wp-content/ActiveAjax.php", { zip: zip}, function(text) { jQuery(text).find("asset").each(function(j, aval){ var html = ""; html += "<a href='" + jQuery(aval).find("trackback").text() + "' target='new'> " + jQuery(aval).find("assetName").text() + "</a><b> at </b>"; jQuery("location", aval).each(function(i, val){ html += jQuery("locationName", val).text() + " <b> on </b>"; }); jQuery("date", aval).each(function(){ html += jQuery("startDate", aval).text(); <!--jQuery("#widget_active_list").append("<div id='ActivityEntry'>" + html + " </div>");--> jQuery("#widget_active_list") .append(jQuery("<div>") .addClass("widget_ActivityEntry") .html(html) .bind("mouseenter", function(){ jQuery(this).animate({ fontSize: "20px", lineHeight: "1.2em" }, 50); }) .bind("mouseleave", function(){ jQuery(this).animate({ fontSize: "10px", lineHeight: "1.2em" }, 50); }) ); }); }); }); } Now imagine there is another function identical to this one except everything that is prepended with 'widget_' isn't prepended. These two functions get called separately via: jQuery(document).ready(function(){ w_zip = jQuery("#widget_zip").val(); widget_getActivities( w_zip ); jQuery("#widget_updateZipLink").click(function() { //start function when any update link is clicked widget_c_zip = jQuery("#widget_zip").val(); if (undefined == widget_c_zip || widget_c_zip == "" || widget_c_zip.length != 5) jQuery("#widget_zipError").text("Bad zip code"); else widget_getActivities( widget_c_zip ); }); }) I can see in my apache logs that both requests are being made. I'm guessing it is some sort of race condition but that doesn't make ANY sense. I'm new to all this, any ideas? EDIT: I've come up with a sub-optimal solution. I have my widget detect if the plugin is also being used on the page, and if so it waits for 3 seconds before performing the request. But I have a feeling this same thing is going to happen if multiple clients perform a page request at the same time that triggers one of the requests to my php script, because I believe the problem is in the php script, which is scary.

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