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• F# and the rose-tinted reflection

  - by CliveT

  We're already seeing increasing use of many cores on client desktops. It is a change that has been long predicted. It is not just a change in architecture, but our notions of efficiency in a program. No longer can we focus on the asymptotic complexity of an algorithm by counting the steps that a single core processor would take to execute it. Instead we'll soon be more concerned about the scalability of the algorithm and how well we can increase the performance as we increase the number of cores. This may even lead us to throw away our most efficient algorithms, and switch to less efficient algorithms that scale better. We might even be willing to waste cycles in order to speculatively execute at the algorithm rather than the hardware level. State is the big headache in this parallel world. At the hardware level, main memory doesn't necessarily contain the definitive value corresponding to a particular address. An update to a location might still be held in a CPU's local cache and it might be some time before the value gets propagated. To get the latest value, and the notion of "latest" takes a lot of defining in this world of rapidly mutating state, the CPUs may well need to communicate to decide who has the definitive value of a particular address in order to avoid lost updates. At the user program level, this means programmers will need to lock objects before modifying them, or attempt to avoid the overhead of locking by understanding the memory models at a very deep level. I think it's this need to avoid statefulness that has led to the recent resurgence of interest in functional languages. In the 1980s, functional languages started getting traction when research was carried out into how programs in such languages could be auto-parallelised. Sadly, the impracticality of some of the languages, the overheads of communication during this parallel execution, and rapid improvements in compiler technology on stock hardware meant that the functional languages fell by the wayside. The one thing that these languages were good at was getting rid of implicit state, and this single idea seems like a solution to the problems we are going to face in the coming years. Whether these languages will catch on is hard to predict. The mindset for writing a program in a functional language is really very different from the way that object-oriented problem decomposition happens - one has to focus on the verbs instead of the nouns, which takes some getting used to. There are a number of hybrid functional/object languages that have been becoming more popular in recent times. These half-way houses make it easy to use functional ideas for some parts of the program while still allowing access to the underlying object-focused platform without a great deal of impedance mismatch. One example is F# running on the CLR which, in Visual Studio 2010, has because a first class member of the pack. Inside Visual Studio 2010, the tooling for F# has improved to the point where it is easy to set breakpoints and watch values change while debugging at the source level. In my opinion, it is the tooling support that will enable the widespread adoption of functional languages - without this support, people will put off any transition into the functional world for as long as they possibly can. Without tool support it will make it hard to learn these languages. One tool that doesn't currently support F# is Reflector. The idea of decompiling IL to a functional language is daunting, but F# is potentially so important I couldn't dismiss the idea. As I'm currently developing Reflector 6.5, I thought it wise to take four days just to see how far I could get in doing so, even if it achieved little more than to be clearer on how much was possible, and how long it might take. You can read what happened here, and of the insights it gave us on ways to improve the tool.

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• Three Key Tenets of Optimal Social Collaboration

  - by kellsey.ruppel

  Today's blog post comes to us from John Bruswick! This post is an abridged version of John’s white paper in which he discusses three principals to optimize social collaboration within an enterprise.   By [email protected], Oracle Principal Sales Consultant Effective social collaboration is actionable, deeply contextual and inherently derives its value from business entities outside of itself. How does an organization begin the journey from traditional, siloed collaboration to natural, business entity based social collaboration? Successful enablement of enterprise social collaboration requires that organizations embrace the following tenets and understand that traditional collaborative functionality has inherent limits - it is innovation and integration in accordance with the following tenets that will provide net-new efficiency benefits. Key Tenets of Optimal Social Collaboration Leverage a Ubiquitous Social Fabric - Collaborative activities should be supported through a ubiquitous social fabric, providing a personalized experience, broadcasting key business events and connecting people and business processes.  This supports education of participants working in and around a specific business entity that will benefit from an implicit capture of tacit knowledge and provide continuity between participants.  In the absence of this ubiquitous platform activities can still occur but are essentially siloed causing frequent duplication of effort across similar tasks, with critical tacit knowledge eluding capture. Supply Continuous Context to Support Decision Making and Problem Solving - People generally engage in collaborative behavior to obtain a decision or the resolution for a specific issue.  The time to achieve resolution is referred to as "Solve Time".  Users have traditionally been forced to switch or "alt-tab" between business systems and synthesize their own context across disparate systems and processes.  The constant loss of context forces end users to exert a large amount of effort that could be spent on higher value problem solving. Extend the Collaborative Lifecycle into Back Office - Beyond the solve time from decision making efforts, additional time is expended formalizing the resolution that was generated from collaboration in a system of record.  Extending collaboration to result in the capture of an explicit decision maximizes efficiencies, creating a closed circuit for a particular thread.  This type of structured action may exist today within your organization's customer support system around opening, solving and closing support issues, but generally does not extend to Sales focused collaborative activities. Excelling in the Unstructured Future We will always have to deal with unstructured collaborative processes within our organizations.  Regardless of the participants and nature of the collaborate process, two things are certain – the origination and end points are generally known and relate to a business entity, perhaps a customer, opportunity, order, shipping location, product or otherwise. Imagine the benefits if an organization's key business systems supported a social fabric, provided continuous context and extended the lifecycle around the collaborative decision making to include output into back office systems of record.   The technical hurdle to embracing optimal social collaboration would fall away, leaving the company with an opportunity to focus on and refine how processes were approached.  Time and resources previously required could then be reallocated to focusing on innovation to support competitive differentiation unique to your business. How can you achieve optimal social collaboration? Oracle Social Network enables business users to collaborate with each other using a broad range of collaboration styles and integrates data from a variety of sources and business applications -- allowing you to achieve optimal social collaboration. Looking to learn more? Read John's white paper, where he discusses in further detail the three principals to optimize social collaboration within an enterprise. 

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• Windows Phone 8, possible tablets and what the latest update might mean

  - by Roger Hart

  Microsoft have just announced an update to Windows Phone 8. As one of the five, maybe six people who actually bought a WP8 handset I found this interesting. Then I read the blog post about it, and rushed off to write somewhat less than a thousand words about a single picture. The blog post announces an extra column of tiles on the start screen, and support for higher resolutions. If we ignore all the usual flummery about how this will make your life better, that (and the rotation lock) sounds a little like stage setting for tablets. Looking at the preview screenshot, I started to wonder. What it’s called Phablet_5F00_StartScreenProductivity_5F00_01_5F00_072A1240.jpg Pretty conclusive. If you can brand something a “phablet” and sleep at night you’re made of sterner stuff than I am, but that’s beside the point. It’s explicit in the post that Microsoft are expecting a broader range of form factors for WP8, but they stop short of quite calling out tablet size. The extra columns and resolution definitely back that up, so why stop at a 6 inch “phablet”? Sadly, the string of numbers there don’t really look like a Lumia model number – that would be a bit tendentious even for a speculative blog post about a single screenshot. “Productivity” is interesting too. I get into this a bit more below, but this is a pretty clear pitch for a business device. What it looks like Something that would look quite decent on a 7 inch screen, but something a bit too vertical to go toe-to-toe with the Surface. Certainly, it would look a lot better on a large-factor phone than any of the current models. Those tiles are going to get cramped and a bit ugly if the handsets aren’t getting bigger. What’s on it You have a bunch of missed calls, you rarely text, use a stocks app, and your budget spreadsheet and meeting notes are a thumb-reach away. Outlook is your main form of email. You care enough about LinkedIn to not only install its app but give it a huge live tile. There’s no beating about the bush here, the implicit persona is a corporate exec. With Nokia in the bag and Blackberry pushing daisies, that may not be a stupid play. There’s almost certainly a niche there if they can parlay their corporate credentials into filling it before BYOD (which functionally means an iPhone) reaches the late adopters. The really quite slick WP8 Office implementation ought to help here. This is the face they’ve chosen to present, the cultural milieu they’re normalizing for Windows Phone. It’s an iPhone for Serious Business Grown-ups. Could work, I guess. Does it mean anything? Is the latest WP8 update a sign that we can expect to see tablets running Windows Phone rather than WinRT? Well, WinRT tablets haven’t exactly taken off but I’m not quite going to make a leap like that just from a file name and a column of icons. I feel pretty safe, however, conjecturing that Microsoft would like to squeeze a WP8 “phablet” into the palm of every exec who’s ever grumbled about their Blackberry, and this release might get them a bit closer. If it works well incrementing up to larger devices, then that could be a fair hedge against WinRt crashing and burning any harder in the marketplace.

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• Python Coding standards vs. productivity

  - by Shroatmeister

  I work for a large humanitarian organisation, on a project building software that could help save lives in emergencies by speeding up the distribution of food. Many NGOs desperately need our software and we are weeks behind schedule. One thing that worries me in this project is what I think is an excessive focus on coding standards. We write in python/django and use a version of PEP0008, with various modifications e.g. line lengths can go up to 160 chars and all lines should go that long if possible, no blank lines between imports, line wrapping rules that apply only to certain kinds of classes, lots of templates that we must use, even if they aren't the best way to solve a problem etc. etc. One core dev spent a week rewriting a major part of the system to meet the then new coding standards, throwing away several suites of tests in the process, as the rewrite meant they were 'invalid'. We spent two weeks rewriting all the functionality that was lost, and fixing bugs. He is the lead dev and his word carries weight, so he has convinced the project manager that these standards are necessary. The junior devs do as they are told. I sense that the project manager has a strong feeling of cognitive dissonance about all this but nevertheless agrees with it vehemently as he feels unsure what else to do. Today I got in serious trouble because I had forgotten to put some spaces after commas in a keyword argument. I was literally shouted at by two other devs and the project manager during a Skype call. Personally I think coding standards are important but also think that we are wasting a lot of time obsessing with them, and when I verbalized this it provoked rage. I'm seen as a troublemaker in the team, a team that is looking for scapegoats for its failings. Since the introduction of the coding standards, the team's productivity has measurably plummeted, however this only reinforces the obsession, i.e. the lead dev simply blames our non-adherence to standards for the lack of progress. He believes that we can't read each other's code if we don't adhere to the conventions. This is starting to turn sticky. Now I am trying to modify various scripts, autopep8, pep8ify and PythonTidy to try to match the conventions. We also run pep8 against source code but there are so many implicit amendments to our standard that it's hard to track them all. The lead dev simple picks faults that the pep8 script doesn't pick up and shouts at us in the next stand-up meeting. Every week there are new additions to the coding standards that force us to rewrite existing, working, tested code. Thank heavens we still have tests, (I reverted some commits and fixed a bunch of the ones he removed). All the while there is increasing pressure to meet the deadline. I believe a fundamental issue is that the lead dev and another core dev refuse to trust other developers to do their job. But how to deal with that? We can't do our job because we are too busy rewriting everything. I've never encountered this dynamic in a software engineering team. Am I wrong to question their adherence to coding standards? Has anyone else experienced a similar situation and how have they dealt with it successfully? (I'm not looking for a discussion just actual solutions people have found)

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• JDK 7u25: Solutions to Issues caused by changes to Runtime.exec

  - by Devika Gollapudi

  The following examples were prepared by Java engineering for the benefit of Java developers who may have faced issues with Runtime.exec on the Windows platform. Background In JDK 7u21, the decoding of command strings specified to Runtime.exec(String), Runtime.exec(String,String[]) and Runtime.exec(String,String[],File) methods, has been made more strict. See JDK 7u21 Release Notes for more information. This caused several issues for applications. The following section describes some of the problems faced by developers and their solutions. Note: In JDK 7u25, the system property jdk.lang.Process.allowAmbigousCommands can be used to relax the checking process and helps as a workaround for some applications that cannot be changed. The workaround is only effective for applications that are run without a SecurityManager. See JDK 7u25 Release Notes for more information. Note: To understand the details of the Windows API CreateProcess call, see: http://msdn.microsoft.com/en-us/library/windows/desktop/ms682425%28v=vs.85%29.aspx There are two forms of Runtime.exec calls: with the command as string: "Runtime.exec(String command[, ...])" with the command as string array: "Runtime.exec(String[] cmdarray [, ...] )" The issues described in this section relate to the first form of call. With the first call form, developers expect the command to be passed "as is" to Windows where the command needs be split into its executable name and arguments parts first. But, in accordance with Java API, the command argument is split into executable name and arguments by spaces. Problem 1: "The file path for the command includes spaces" In the call: Runtime.getRuntime().exec("c:\\Program Files\\do.exe") the argument is split by spaces to an array of strings as: c:\\Program, Files\\do.exe The first element of parsed array is interpreted as the executable name, verified by SecurityManager (if present) and surrounded by quotations to avoid ambiguity in executable path. This results in the wrong command: "c:\\Program" "Files\\do.exe" which will fail. Solution: Use the ProcessBuilder class, or the Runtime.exec(String[] cmdarray [, ...] ) call, or quote the executable path. Where it is not possible to change the application code and where a SecurityManager is not used, the Java property jdk.lang.Process.allowAmbigousCommands could be used by setting its value to "true" from the command line: -Djdk.lang.Process.allowAmbigousCommands=true This will relax the checking process to allow ambiguous input. Examples: new ProcessBuilder("c:\\Program Files\\do.exe").start() Runtime.getRuntime().exec(new String[]{"c:\\Program Files\\do.exe"}) Runtime.getRuntime().exec("\"c:\\Program Files\\do.exe\"") Problem 2: "Shell command/.bat/.cmd IO redirection" The following implicit cmd.exe calls: Runtime.getRuntime().exec("dir temp.txt") new ProcessBuilder("foo.bat", "", "temp.txt").start() Runtime.getRuntime().exec(new String[]{"foo.cmd", "", "temp.txt"}) lead to the wrong command: "XXXX" "" temp.txt Solution: To specify the command correctly, use the following options: Runtime.getRuntime().exec("cmd /C \"dir temp.txt\"") new ProcessBuilder("cmd", "/C", "foo.bat temp.txt").start() Runtime.getRuntime().exec(new String[]{"cmd", "/C", "foo.cmd temp.txt"}) or Process p = new ProcessBuilder("cmd", "/C" "XXX").redirectOutput(new File("temp.txt")).start(); Problem 3: "Group execution of shell command and/or .bat/.cmd files" Due to enforced verification procedure, arguments in the following calls create the wrong commands.: Runtime.getRuntime().exec("first.bat && second.bat") new ProcessBuilder("dir", "&&", "second.bat").start() Runtime.getRuntime().exec(new String[]{"dir", "|", "more"}) Solution: To specify the command correctly, use the following options: Runtime.exec("cmd /C \"first.bat && second.bat\"") new ProcessBuilder("cmd", "/C", "dir && second.bat").start() Runtime.exec(new String[]{"cmd", "/C", "dir | more"}) The same scenario also works for the "&", "||", "^" operators of the cmd.exe shell. Problem 4: ".bat/.cmd with special DOS chars in quoted params” Due to enforced verification, arguments in the following calls will cause exceptions to be thrown.: Runtime.getRuntime().exec("log.bat \"error new ProcessBuilder("log.bat", "error Runtime.getRuntime().exec(new String[]{"log.bat", "error Solution: To specify the command correctly, use the following options: Runtime.getRuntime().exec("cmd /C log.bat \"error new ProcessBuilder("cmd", "/C", "log.bat", "error Runtime.getRuntime().exec(new String[]{"cmd", "/C", "log.bat", "error Examples: Complicated redirection for shell construction: cmd /c dir /b C:\ "my lovely spaces.txt" becomes Runtime.getRuntime().exec(new String[]{"cmd", "/C", "dir \b \"my lovely spaces.txt\"" }); The Golden Rule: In most cases, cmd.exe has two arguments: "/C" and the command for interpretation.

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• What's up with LDoms: Part 9 - Direct IO

  - by Stefan Hinker

  In the last article of this series, we discussed the most general of all physical IO options available for LDoms, root domains.  Now, let's have a short look at the next level of granularity: Virtualizing individual PCIe slots.  In the LDoms terminology, this feature is called "Direct IO" or DIO.  It is very similar to root domains, but instead of reassigning ownership of a complete root complex, it only moves a single PCIe slot or endpoint device to a different domain.  Let's look again at hardware available to mars in the original configuration: root@sun:~# ldm ls-io NAME TYPE BUS DOMAIN STATUS ---- ---- --- ------ ------ pci_0 BUS pci_0 primary pci_1 BUS pci_1 primary pci_2 BUS pci_2 primary pci_3 BUS pci_3 primary /SYS/MB/PCIE1 PCIE pci_0 primary EMP /SYS/MB/SASHBA0 PCIE pci_0 primary OCC /SYS/MB/NET0 PCIE pci_0 primary OCC /SYS/MB/PCIE5 PCIE pci_1 primary EMP /SYS/MB/PCIE6 PCIE pci_1 primary EMP /SYS/MB/PCIE7 PCIE pci_1 primary EMP /SYS/MB/PCIE2 PCIE pci_2 primary EMP /SYS/MB/PCIE3 PCIE pci_2 primary OCC /SYS/MB/PCIE4 PCIE pci_2 primary EMP /SYS/MB/PCIE8 PCIE pci_3 primary EMP /SYS/MB/SASHBA1 PCIE pci_3 primary OCC /SYS/MB/NET2 PCIE pci_3 primary OCC /SYS/MB/NET0/IOVNET.PF0 PF pci_0 primary /SYS/MB/NET0/IOVNET.PF1 PF pci_0 primary /SYS/MB/NET2/IOVNET.PF0 PF pci_3 primary /SYS/MB/NET2/IOVNET.PF1 PF pci_3 primary All of the "PCIE" type devices are available for SDIO, with a few limitations.  If the device is a slot, the card in that slot must support the DIO feature.  The documentation lists all such cards.  Moving a slot to a different domain works just like moving a PCI root complex.  Again, this is not a dynamic process and includes reboots of the affected domains.  The resulting configuration is nicely shown in a diagram in the Admin Guide: There are several important things to note and consider here: The domain receiving the slot/endpoint device turns into an IO domain in LDoms terminology, because it now owns some physical IO hardware. Solaris will create nodes for this hardware under /devices.  This includes entries for the virtual PCI root complex (pci_0 in the diagram) and anything between it and the actual endpoint device.  It is very important to understand that all of this PCIe infrastructure is virtual only!  Only the actual endpoint devices are true physical hardware. There is an implicit dependency between the guest owning the endpoint device and the root domain owning the real PCIe infrastructure: Only if the root domain is up and running, will the guest domain have access to the endpoint device. The root domain is still responsible for resetting and configuring the PCIe infrastructure (root complex, PCIe level configurations, error handling etc.) because it owns this part of the physical infrastructure. This also means that if the root domain needs to reset the PCIe root complex for any reason (typically a reboot of the root domain) it will reset and thus disrupt the operation of the endpoint device owned by the guest domain.  The result in the guest is not predictable.  I recommend to configure the resulting behaviour of the guest using domain dependencies as described in the Admin Guide in Chapter "Configuring Domain Dependencies". Please consult the Admin Guide in Section "Creating an I/O Domain by Assigning PCIe Endpoint Devices" for all the details! As you can see, there are several restrictions for this feature.  It was introduced in LDoms 2.0, mainly to allow the configuration of guest domains that need access to tape devices.  Today, with the higher number of PCIe root complexes and the availability of SR-IOV, the need to use this feature is declining.  I personally do not recommend to use it, mainly because of the drawbacks of the depencies on the root domain and because it can be replaced with SR-IOV (although then with similar limitations). This was a rather short entry, more for completeness.  I believe that DIO can usually be replaced by SR-IOV, which is much more flexible.  I will cover SR-IOV in the next section of this blog series.

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• ArchBeat Link-o-Rama for 2012-08-30

  - by Bob Rhubart

  Next Generation Mobile Clients for Oracle Applications & the role of Oracle Fusion Middleware | Manish Palaparthy Manish Palaparthy examines some of Oracle's mobile applications, and takes a look at the underlying technology. Master Data Management: A Foundation for Big Data Analysis | Manouj Tahiliani "Businesses that have embraced MDM to get a single, enriched and unified view of Master data by resolving semantic discrepancies and augmenting the explicit master data information from within the enterprise with implicit data from outside the enterprise like social profiles will have a leg up in embracing Big Data solutions. This is especially true for large and medium-sized businesses in industries like Retail, Communications, Financial Services, etc that would find it very challenging to get comprehensive analytical coverage and derive long-term success without resolving the limitations of the heterogeneous topology that leads to disparate, fragmented and incomplete master data." — Manouj Tahiliani Architect Day: Boston - Agenda Update Here's the latest updated information on the session schedule and content for Oracle Technology Network Architect Day in Boston, MA on September 12, 2012. Registration is open, but seating is limited. OTN Architect Day: Boston is being held on Wednesday September 12, 2012, 8:00 a.m. – 5:00 p.m., at the Boston Marriott Burlington, One Burlington Mall Road, Burlington, MA 01803. Integrating Coherence & Java EE 6 Applications using ActiveCache | Ricardo Ferreira The seamless integration between Oracle Coherence and Oracle WebLogic Server "provides a comprehensive environment to develop applications without the complexity of extra Java code to manage cache as a dependency," explains Ricardo Ferreira, "since Oracle provides a DI (Dependency Injection) mechanism for Coherence, the same DI mechanism available in standard Java EE applications. This feature is called ActiveCache." Ricardo shows you how to configure ActiveCache in WebLogic and your Java EE application. Cloud Infrastructure has a new standard from the DMTF "Unlike a de facto standard where typically one vendor has change control over the interface, and everyone else has to reverse engineer the inner workings of it, [Cloud Infrastructure Management Interface (CIMI)] is a de jure standard that is under change control of a standards body. One reason the standard took two years to create is that we factored in use cases, requirements and contributed APIs from multiple vendors. These vendors have products shipping today and as a result CIMI has a strong foundation in real world experience." Oracle GoldenGate 11g Release Launch Webcast- September 12 The new release of Oracle GoldenGate 11g is now available for major databases and platforms. Register for this webcast and live Q&A with product experts to learn about the solution's new features. September 12, 2012. 8:00am AM and 10:00AM PT. Speakers: Doug Reid (Director, Product Management, Oracle GoldenGate), Irem Radzik (Director, Product Marketing, Oracle Data Integration Products) Thought for the Day "[When] asking skilled architects…what they do when confronted with highly complex problems… [they] would most likely answer, 'Just use Common Sense.' [A] better expression than 'common sense' is 'contextual sense'—a knowledge of what is reasonable within a given context. Practicing architects through eduction, experience and examples accumulate a considerable body of contextual sense by the time they're entrusted with solving a system-level problem…" — Eberhardt Rechtin (January 16, 1926 – April 14, 2006) Source: SoftwareQuotes.com

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• Why is there no service-oriented language?

  - by Wolfgang

  Edit: To avoid further confusion: I am not talking about web services and such. I am talking about structuring applications internally, it's not about how computers communicate. It's about programming languages, compilers and how the imperative programming paradigm is extended. Original: In the imperative programming field, we saw two paradigms in the past 20 years (or more): object-oriented (OO), and service-oriented (SO) aka. component-based (CB). Both paradigms extend the imperative programming paradigm by introducing their own notion of modules. OO calls them objects (and classes) and lets them encapsulates both data (fields) and procedures (methods) together. SO, in contrast, separates data (records, beans, ...) from code (components, services). However, only OO has programming languages which natively support its paradigm: Smalltalk, C++, Java and all other JVM-compatibles, C# and all other .NET-compatibles, Python etc. SO has no such native language. It only comes into existence on top of procedural languages or OO languages: COM/DCOM (binary, C, C++), CORBA, EJB, Spring, Guice (all Java), ... These SO frameworks clearly suffer from the missing native language support of their concepts. They start using OO classes to represent services and records. This leads to designs where there is a clear distinction between classes that have methods only (services) and those that have fields only (records). Inheritance between services or records is then simulated by inheritance of classes. Technically, its not kept so strictly but in general programmers are adviced to make classes to play only one of the two roles. They use additional, external languages to represent the missing parts: IDL's, XML configurations, Annotations in Java code, or even embedded DSL like in Guice. This is especially needed, but not limited to, since the composition of services is not part of the service code itself. In OO, objects create other objects so there is no need for such facilities but for SO there is because services don't instantiate or configure other services. They establish an inner-platform effect on top of OO (early EJB, CORBA) where the programmer has to write all the code that is needed to "drive" SO. Classes represent only a part of the nature of a service and lots of classes have to be written to form a service together. All that boiler plate is necessary because there is no SO compiler which would do it for the programmer. This is just like some people did it in C for OO when there was no C++. You just pass the record which holds the data of the object as a first parameter to the procedure which is the method. In a OO language this parameter is implicit and the compiler produces all the code that we need for virtual functions etc. For SO, this is clearly missing. Especially the newer frameworks extensively use AOP or introspection to add the missing parts to a OO language. This doesn't bring the necessary language expressiveness but avoids the boiler platform code described in the previous point. Some frameworks use code generation to produce the boiler plate code. Configuration files in XML or annotations in OO code is the source of information for this. Not all of the phenomena that I mentioned above can be attributed to SO but I hope it clearly shows that there is a need for a SO language. Since this paradigm is so popular: why isn't there one? Or maybe there are some academic ones but at least the industry doesn't use one.

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• Crime Scene Investigation: SQL Server

  - by Rodney Landrum

  “The packages are running slower in Prod than they are in Dev” My week began with this simple declaration from one of our lead BI developers, quickly followed by an emailed spreadsheet demonstrating that, over 5 executions, an extensive ETL process was running average 630 seconds faster on Dev than on Prod. The situation needed some scientific investigation to determine why the same code, the same data, the same schema would yield consistently slower results on a more powerful server. Prod had yet to be officially christened with a “Go Live” date so I had the time, and having recently been binge watching CSI: New York, I also had the inclination. An inspection of the two systems, Prod and Dev, revealed the first surprise: although Prod was indeed a “bigger” system, with double the amount of RAM of Dev, the latter actually had twice as many processor cores. On neither system did I see much sign of resources being heavily taxed, while the ETL process was running. Without any real supporting evidence, I jumped to a conclusion that my years of performance tuning should have helped me avoid, and that was that the hardware differences explained the better performance on Dev. We spent time setting up a Test system, similarly scoped to Prod except with 4 times the cores, and ported everything across. The results of our careful benchmarks left us truly bemused; the ETL process on the new server was slower than on both other systems. We burned more time tweaking server configurations, monitoring IO and network latency, several times believing we’d uncovered the smoking gun, until the results of subsequent test runs pitched us back into confusion. Finally, I decided, enough was enough. Hadn’t I learned very early in my DBA career that almost all bottlenecks were caused by code and database design, not hardware? It was time to get back to basics. With over 100 SSIS packages and hundreds of queries, each handling specific tasks such as file loads, bulk inserts, transforms, logging, and so on, the task seemed formidable. And yet, after barely an hour spent with Profiler, Extended Events, and wait statistics DMVs, I had a lead in the shape of a query that joined three tables, containing millions of rows, returned 3279 results, but performed 239K logical reads. As soon as I looked at the execution plans for the query in Dev and Test I saw the culprit, an implicit conversion warning on a join predicate field that was numeric in one table and a varchar(50) in another! I turned this information over to the BI developers who quickly resolved the data type mismatches and found and fixed “several” others as well. After the schema changes the same query with the same databases ran in under 1 second on all systems and reduced the logical reads down to fewer than 300. The analysis also revealed that on Dev, the ETL task was pulling data across a LAN, whereas Prod and Test were connected across slower WAN, in large part explaining why the same process ran slower on the latter two systems. Loading the data locally on Prod delivered a further 20% gain in performance. As we progress through our DBA careers we learn valuable lessons. Sometimes, with a project deadline looming and pressure mounting, we choose to forget them. I was close to giving into the temptation to throw more hardware at the problem. I’m pleased at least that I resisted, though I still kick myself for not looking at the code on day one. It can seem a daunting prospect to return to the fundamentals of the code so close to roll out, but with the right tools, and surprisingly little time, you can collect the evidence that reveals the true problem. It is a lesson I trust I will remember for my next 20 years as a DBA, if I’m ever again tempted to bypass the evidence.

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• Know Your Service Request Status

  - by Get Proactive Customer Adoption Team

  Untitled Document To monitor a Service Request or not to monitor a Service Request... That should never be the question Monitoring the Service Requests you create is an essential part of the process to resolve your issue when you work with a Support Engineer. If you monitor your Service Request, you know at all times where it is in the process, or to be more specific, you know at all times what action the Support Engineer has taken on your request and what the next step is. When you think about it, it is rather simple... Oracle Support is working the issue, Oracle Development is working the issue, or you are. When you check on the status, you may find that the Support Engineer has a question for you or the engineer is waiting for more information to resolve the issue. If you monitor the Service Request, and respond quickly, the process keeps moving, and you’ll get your answer more quickly. Monitoring a Service Request is easy. All you need to do is check the status codes that the Support Engineer or the system assigns to your Service Request. These status codes are not static. You will see that during the life of your Service request, it will go through a variety of status codes. The best advice I can offer you when you monitor your Service Request is to watch the codes. If the status is not changing, or if you are not getting responses back within the agreed timeframes, you should review the action plan the Support Engineer has outlined or talk about a new action plan. Here are the most common status codes: Work in Progress indicates that your Support Engineer is researching and working the issue. Development Working means that you have a code related issue and Oracle Support has submitted a bug to Development. Please pay a particular attention to the following statuses; they indicate that the Support Engineer is waiting for a response from you: Customer Working usually means that your Support Engineer needs you to collect additional information, needs you to try something or to apply a patch, or has more questions for you. Solution Offered indicates that the Support Engineer has identified the problem and has provided you with a solution. Auto-Close or Close Initiated are statuses you don’t want to see. Monitoring your Service Request helps prevent your issues from reaching these statuses. They usually indicate that the Support Engineer did not receive the requested information or action from you. This is important. If you fail to respond, the Support Engineer will attempt to contact you three times over a two-week period. If these attempts are unsuccessful, he or she will initiate the Auto-Close process. At the end of this additional two-week period, if you have not updated the Service Request, your Service Request is considered abandoned and the Support Engineer will assign a Customer Abandoned status. A Support Engineer doesn’t like to see this status, since he or she has been working to solve your issue, but we know our customers dislike it even more, since it means their issue is not moving forward. You can avoid delays in resolving your issue by monitoring your Service Request and acting quickly when you see the status change. Respond to the request from the engineer to answer questions, collect information, or to try the offered solution. Then the Support Engineer can continue working the issue and the Service Request keeps moving forward towards resolution. Keep in mind that if you take an extended period of time to respond to a request or to provide the information requested, the Support Engineer cannot take the next step. You may inadvertently send an implicit message about the problem’s urgency that may not match the Service Request priority, and your need for an answer. Help us help you. We want to get you the answer as quickly as possible so you can stay focused on your company’s objectives. Now, back to our initial question. To monitor Service Requests or not to monitor Service Requests? I think the answer is clear: yes, monitor your Service Request to resolve the issue as quickly as possible.

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• WiX, MSDeploy and an appealing configuration/deployment paradigm

  - by alexhildyard

  I do a lot of application and server configuration; I've done this for many years and have tended to view the complexity of this strictly in terms of the complexity of the ultimate configuration to be deployed. For example, specific APIs aside, I would tend to regard installing a server certificate as a more complex activity than, say, copying a file or adding a Registry entry.My prejudice revolved around the idea of a sequential deployment script that not only had the explicit prescription to apply a specific server configuration, but also made the implicit presumption that the server in question was in a good known state. Scripts like this fail for hundreds of reasons -- the Default Website didn't exist; the application had already been deployed; the application had already been partially deployed and failed to rollback fully, and so on. And so the problem is that the more complex the configuration activity, the more scope for error in any individual part of that activity, and therefore the greater the chance the server in question will not end up at exactly the desired configuration level.Recently I was introduced to a completely different mindset, which, for want of a better turn of phrase, I will call the "make it so" mindset. It's extremely simple both to explain and to implement. In place of the head-down, imperative script you used to use, you substitute a set of checks -- much like exception handlers -- around each configuration activity, starting with a check of the current system state. Thus the configuration logic becomes: "IF these services aren't started then start them, and IF XYZ website doesn't exist then create it, and IF these shares don't exist then create them, and IF these shares aren't permissioned in some particular way, then permission them so." This works. Really well, in my experience. Scenario 1: You want to get a system into a good known state; it's already in a good known state; you quickly realise there is nothing to do.Scenario 2: You want to get the system into a good known state; your script is flawed or the system is bust; it cannot be put into that state. You know exactly where (at least part of) the problem is and why.Scenario 3: You want to get the system into a good known state; people are fiddling around with the system just now. That's fine. You do what you can, and later you come back and try it againScenario 4: No one wants to deploy anything; they want you to prove that the previous deployment was successful. So you re-run the deployment script with the "-WhatIf" flag. It reports that there was nothing to change. There's your proof.I mentioned two technologies in the title -- MSI and MSDeploy. I am thinking specifically of the conversation that took place here. Having worked with both technologies, I think Rob Mensching's response is appropriately nuanced, and in essence the difference is this: sometimes your target is either to achieve a specific new server state, or to rollback to a known good one. Then again, your target may be to configure what you can, and to understand what you can't. Implicitly MSDeploy's "rollback" is simply to redeploy the previous version, whereas a well-crafted MSI will actively put your system into that state without further intervention. Either way, if all goes well it will leave you with a system in one of two states, whereas MSDeploy could leave your system in one of many states. The key is that MSDeploy and MSI are complementary technologies; which suits you best depends as much on Operational guidance as your Configuration remit.What I wanted to say was that I have always been for atomic, transactional-based configuration, but having worked with the "make it so" paradigm, I have been favourably impressed by the actual results. I'm tempted to put a more technical post up on this in due course.

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• Multichannel Digital Engagement: Find Out How Your Organization Measures Up

  - by Michael Snow

  This article was originally published in the September 2013 Edition of the Oracle Information InDepth Newsletter ORACLE WEBCENTER EDITION Thanks to mobile and social technologies, interactive online experiences are now commonplace. Not only that, they give consumers more choices, influence, and control than ever before. So how can you make your organization stand out? The key building blocks for delivering exceptional cross-channel digital experiences are outlined below. Also, a new assessment tool is available to help you measure your organization's ability to deliver such experiences. A clearly defined digital strategy. The customer journey is growing increasingly complex, encompassing multiple touchpoints and channels. It used to be easy to map marketing efforts to specific offline channels; for example, a direct mail piece with an offer to visit a store for a discounted purchase. Now it is more difficult to cultivate and track such clear cause-and-effect relationships. To deliver an integrated digital experience in this more complex world, organizations need a clearly defined and comprehensive digital marketing strategy that is backed up by an integrated set of software, middleware, and hardware solutions. Strong support for business agility and speed-to-market. As both IT and marketing executives know, speed-to-market and business agility are key to competitive advantage. That means marketers need solutions to support the rapid implementation of online marketing initiatives—plus the flexibility to adapt quickly to a changing marketplace. And IT needs tools with the performance, scalability, and ease of integration to support marketing efforts. Both teams benefit when business users are empowered to implement marketing initiatives on their own, with minimal IT intervention. The ability to deliver relevant, personalized content. Delivering a one-size-fits-all online customer experience is no longer acceptable. Customers expect you to know who they are, including their preferences and past relationship with your brand. That means delivering the most relevant content from the moment a visitor enters your site. To make that happen, you need a powerful rules engine so that marketers and business users can easily define site visitor segments and deliver content accordingly. That includes both implicit targeting that is based on the user’s behavior, and explicit targeting that takes a user’s profile information into account. Ideally, the rules engine can also intelligently weight recommendations when multiple segments apply to a specific customer. Support for social interactivity. With the advent of Facebook and LinkedIn, visitors expect to participate in and contribute to your web presence—and share their experience on their own social networks. That requires easy incorporation of user-generated content such as comments, ratings, reviews, polls, and blogs; seamless integration with third-party social networking sites; and support for social login, which helps to remove barriers to social participation. The ability to deliver connected, multichannel experiences that include powerful, flexible mobile capabilities. By 2015, mobile usage is projected to surpass that of PCs and other wired devices. In other words, mobile is an essential element in delivering exceptional online customer experiences. This requires the creation and management of mobile experiences that are optimized for delivery to the thousands of different devices that are in use today. Just as important, organizations must be able to easily extend their traditional web presence to the mobile channel and deliver highly personalized and relevant multichannel marketing initiatives while also managing to minimize the time and effort required to manage mobile sites. Are you curious to know how your organization measures up when it comes to delivering an engaging, multichannel digital experience? If so, take this brief, 15-question online assessment and see how your organization scores in the areas of digital strategy, digital agility, relevance and personalization, social interactivity, and multichannel experience.

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• Error with postgres and Rails in Bundle Install on Ubuntu 12.10

  - by jason328

  I'm trying to install postgres onto Ubuntu. When running the Bundle Install in terminal I'm receiving this message at the end of the running code. How do I get pg to install properly? Libpq-dev is installed as well. Using coffee-rails (3.2.2) Using diff-lcs (1.1.3) Using jquery-rails (2.0.2) Installing pg (0.12.2) with native extensions Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension. /usr/bin/ruby1.9.1 extconf.rb checking for pg_config... yes Using config values from /usr/bin/pg_config checking for libpq-fe.h... yes checking for libpq/libpq-fs.h... yes checking for PQconnectdb() in -lpq... yes checking for PQconnectionUsedPassword()... yes checking for PQisthreadsafe()... yes checking for PQprepare()... yes checking for PQexecParams()... yes checking for PQescapeString()... yes checking for PQescapeStringConn()... yes checking for PQgetCancel()... yes checking for lo_create()... yes checking for pg_encoding_to_char()... yes checking for PQsetClientEncoding()... yes checking for rb_encdb_alias()... yes checking for rb_enc_alias()... no checking for struct pgNotify.extra in libpq-fe.h... yes checking for unistd.h... yes checking for ruby/st.h... yes creating extconf.h creating Makefile make compiling compat.c compiling pg.c pg.c: In function ‘pgconn_wait_for_notify’: pg.c:2117:3: warning: ‘rb_thread_select’ is deprecated (declared at /usr/include/ruby- 1.9.1/ruby/intern.h:379) [-Wdeprecated-declarations] pg.c: In function ‘pgconn_block’: pg.c:2592:3: error: format not a string literal and no format arguments [-Werror=format- security] pg.c:2598:3: warning: ‘rb_thread_select’ is deprecated (declared at /usr/include/ruby- 1.9.1/ruby/intern.h:379) [-Wdeprecated-declarations] pg.c:2607:4: error: format not a string literal and no format arguments [-Werror=format- security] pg.c: In function ‘pgconn_locreate’: pg.c:2866:11: warning: variable ‘lo_oid’ set but not used [-Wunused-but-set-variable] pg.c: In function ‘find_or_create_johab’: pg.c:3947:3: warning: implicit declaration of function ‘rb_encdb_alias’ [-Wimplicit- function-declaration] cc1: some warnings being treated as errors make: *** [pg.o] Error 1 Gem files will remain installed in /home/jason/.bundler/tmp/10083/gems/pg-0.12.2 for inspection. Results logged to /home/jason/.bundler/tmp/10083/gems/pg-0.12.2/ext/gem_make.out An error occurred while installing pg (0.12.2), and Bundler cannot continue. Make sure that `gem install pg -v '0.12.2'` succeeds before bundling.

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• Need help making site available externally

  - by White Island

  I'm trying to open a hole in the firewall (ASA 5505, v8.2) to allow external access to a Web application. Via ASDM (6.3?), I've added the server as a Public Server, which creates a static NAT entry [I'm using the public IP that is assigned to 'dynamic NAT--outgoing' for the LAN, after confirming on the Cisco forums that it wouldn't bring everyone's access crashing down] and an incoming rule "any... public_ip... https... allow" but traffic is still not getting through. When I look at the log viewer, it says it's denied by access-group outside_access_in, implicit rule, which is "any any ip deny" I haven't had much experience with Cisco management. I can't see what I'm missing to allow this connection through, and I'm wondering if there's anything else special I have to add. I tried adding a rule (several variations) within that access-group to allow https to the server, but it never made a difference. Maybe I haven't found the right combination? :P I also made sure the Windows firewall is open on port 443, although I'm pretty sure the current problem is Cisco, because of the logs. :) Any ideas? If you need more information, please let me know. Thanks Edit: First of all, I had this backward. (Sorry) Traffic is being blocked by access-group "inside_access_out" which is what confused me in the first place. I guess I confused myself again in the midst of typing the question. Here, I believe, is the pertinent information. Please let me know what you see wrong. access-list acl_in extended permit tcp any host PUBLIC_IP eq https access-list acl_in extended permit icmp CS_WAN_IPs 255.255.255.240 any access-list acl_in remark Allow Vendor connections to LAN access-list acl_in extended permit tcp host Vendor any object-group RemoteDesktop access-list acl_in remark NetworkScanner scan-to-email incoming (from smtp.mail.microsoftonline.com to PCs) access-list acl_in extended permit object-group TCPUDP any object-group Scan-to-email host NetworkScanner object-group Scan-to-email access-list acl_out extended permit icmp any any access-list acl_out extended permit tcp any any access-list acl_out extended permit udp any any access-list SSLVPNSplitTunnel standard permit LAN_Subnet 255.255.255.0 access-list nonat extended permit ip VPN_Subnet 255.255.255.0 LAN_Subnet 255.255.255.0 access-list nonat extended permit ip LAN_Subnet 255.255.255.0 VPN_Subnet 255.255.255.0 access-list inside_access_out remark NetworkScanner Scan-to-email outgoing (from scanner to Internet) access-list inside_access_out extended permit object-group TCPUDP host NetworkScanner object-group Scan-to-email any object-group Scan-to-email access-list inside_access_out extended permit tcp any interface outside eq https static (inside,outside) PUBLIC_IP LOCAL_IP[server object] netmask 255.255.255.255 I wasn't sure if I needed to reverse that "static" entry, since I got my question mixed up... and also with that last access-list entry, I tried interface inside and outside - neither proved successful... and I wasn't sure about whether it should be www, since the site is running on https. I assumed it should only be https.

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• innobackupex - after restoring - quit without updating PID file

  - by clarkk

  After restoring a backup the server can't start.. restoring # tar -izxf /var/www/bak/db/2013-11-10-1437_mysql.tar.gz -C /var/www/bak/db_import # innobackupex --use-memory=1G --apply-log /var/www/bak/db_import # service mysql stop # mv /var/lib/mysql /var/lib/mysql-old # mkdir /var/lib/mysql # innobackupex --copy-back /var/www/bak/db_import # chown -R mysql:mysql /var/lib/mysql # service mysql start error log 131110 21:24:20 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql 2013-11-10 21:24:21 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details). 2013-11-10 21:24:21 6194 [Warning] Using pre 5.5 semantics to load error messages from /opt/mysql/server-5.6/share/english/. 2013-11-10 21:24:21 6194 [Warning] If this is not intended, refer to the documentation for valid usage of --lc-messages-dir and --language parameters. 2013-11-10 21:24:21 6194 [Note] Plugin 'FEDERATED' is disabled. /usr/local/mysql/bin/mysqld: Table 'mysql.plugin' doesn't exist 2013-11-10 21:24:21 6194 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it. 2013-11-10 21:24:21 6194 [Note] InnoDB: The InnoDB memory heap is disabled 2013-11-10 21:24:21 6194 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins 2013-11-10 21:24:21 6194 [Note] InnoDB: Compressed tables use zlib 1.2.3 2013-11-10 21:24:21 6194 [Note] InnoDB: Using Linux native AIO 2013-11-10 21:24:21 6194 [Note] InnoDB: Not using CPU crc32 instructions 2013-11-10 21:24:21 6194 [Note] InnoDB: Initializing buffer pool, size = 128.0M 2013-11-10 21:24:21 6194 [Note] InnoDB: Completed initialization of buffer pool 2013-11-10 21:24:21 6194 [Note] InnoDB: Highest supported file format is Barracuda. 2013-11-10 21:24:22 6194 [Note] InnoDB: 128 rollback segment(s) are active. 2013-11-10 21:24:22 6194 [Note] InnoDB: Waiting for purge to start 2013-11-10 21:24:22 6194 [Note] InnoDB: 5.6.12 started; log sequence number 636992658 2013-11-10 21:24:22 6194 [Note] Server hostname (bind-address): '127.0.0.1'; port: 3306 2013-11-10 21:24:22 6194 [Note] - '127.0.0.1' resolves to '127.0.0.1'; 2013-11-10 21:24:22 6194 [Note] Server socket created on IP: '127.0.0.1'. 2013-11-10 21:24:22 6194 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.user' doesn't exist 131110 21:24:22 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended mysql_upgrade /opt/mysql/server-5.6/bin/mysql_upgrade -u root -pxxxxx -P 3308 Warning: Using a password on the command line interface can be insecure. Looking for 'mysql' as: /opt/mysql/server-5.6/bin/mysql Looking for 'mysqlcheck' as: /opt/mysql/server-5.6/bin/mysqlcheck FATAL ERROR: Upgrade failed

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• Establishing a web page bookmarking process - looking for ideas to improve

  - by Matt

  Like many others, I have a process for bookmarking web pages to read later. My requirements for web page bookmarking are: Ability to bookmark pages must be available from all (within reason) platforms - PC/browser, mobile device, etc. Bookmarks must be centrally stored (implicit from #2) so that I can read the bookmarks from anywhere/any device Full text of web pages must be stored Bonus features would be: Bookmarks and page content should be full text searchable Maintain an archive indefinitely Distinguish between what's read vs. unread Bookmarked page content is cleaned up, e.g. ads eliminated, unnecessary html removed, pages better formatted for reading My current process (which addresses most of these requirements) is as follows: I set up a Gmail account with 2 labels, "Bookmarks Unread" and "Bookmarks Read" Gmail filters set up such that depending on the form of the address (using Gmail's '+string' functionality in addresses), the incoming bookmark gets labeled appropriately On each of my browsers/devices, I have an address book entry for [email protected] and [email protected]. If I want to clean up the page content, I use the Readability bookmarklet which does a great job of giving me the essential content only Anywhere I have Firefox, I use the Send Page by Email extension which, with 2 clicks, allows me to send the cleaned-up Readability page URL and content to one of the above email addresses. Where I don't have Firefox (e.g. iPhone or other mobile device) I use the native ability to send the current link via email (most/all apps have them, including the browser, RSS readers, NYTimes, etc.). In most cases (unless it's built into the particular app), this won't include the page body. The process is almost perfect. I've got the central access and ubiquitous access of Gmail as the storage mechanism, full text searchability (due to Gmail, but of course only for the URLs I send from that Firefox extension), a cleaned up page due to Readability, ability to read offline (assuming I use an IMAP client against Gmail) and permanent archiving of content, including what's been read vs. unread. The missing pieces are: The Send Page by Email Firefox extension seems to only send X bytes of a web page. Or some portion. So it limits my full text searchability. Where I don't have Firefox, I can only send the link, so no full text search at all in those cases. Instapaper looks like it meets most of my requirements (and bonus items). The only downside to me (personal preference) is that central storage is based on Instapaper vs. something more broad like Gmail, which as a generalized service and with Google behind it pretty much means it's permanent. I'm not too hung up on this, but I would definitely prefer to keep Gmail if possible. An upside of Instapaper is that it does the page clean-up as well as stores the entire page content, unlike my Firefox extension. Thoughts on addressing the gaps and improving this process further?

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• Apache proxy pass in nginx

  - by summerbulb

  I have the following configuration in Apache: RewriteEngine On #APP ProxyPass /abc/ http://remote.com/abc/ ProxyPassReverse /abc/ http://remote.com/abc/ #APP2 ProxyPass /efg/ http://remote.com/efg/ ProxyPassReverse /efg/ http://remote.com/efg/ I am trying to have the same configuration in nginx. After reading some links, this is what I have : server { listen 8081; server_name localhost; proxy_redirect http://localhost:8081/ http://remote.com/; location ^~/abc/ { proxy_set_header X-Forwarded-Host $host; proxy_set_header X-Forwarded-Server $host; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_pass http://remote.com/abc/; } location ^~/efg/ { proxy_set_header X-Forwarded-Host $host; proxy_set_header X-Forwarded-Server $host; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_pass http://remote.com/efg/; } } I already have the following configuration: server { listen 8080; server_name localhost; location / { root html; index index.html index.htm; } location ^~/myAPP { alias path/to/app; index main.html; } location ^~/myAPP/images { alias another/path/to/images autoindex on; } } The idea here is to overcome a same-origin-policy problem. The main pages are on localhost:8080 but we need ajax calls to http://remote.com/abc. Both domains are under my control. Using the above configuration, the ajax calls either don't reach the remote server or get cut off because of the cross origin. The above solution worked in Apache and isn't working in nginx, so I am assuming it's a configuration problem. I think there is an implicit question here: should I have two server declarations or should I somehow merge them into one? EDIT: Added some more information EDIT2: I've moved all the proxy_pass configuration into the main server declaration and changed all the ajax calls to go through port 8080. I am now getting a new error: 502 Connection reset by peer. Wireshark shows packets going out to http://remote.com with a bad IP header checksum.

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• Why is Windows 7 not following all routes?

  - by GigabyteProductions

  My computer is connected to my secondary router that's running the 192.168.42.0/24 network and my computer also has a route that directs anything on that network to the router, but for anything on that network other than the router itself, it get's the ICMP response of Reply from 192.168.42.194: Destination host unreachable. (with 192.168.42.194 being my computer). Every other network works, like all of the internet, or addresses on my primary router like 192.168.1.*, just not on the 192.168.42.0/24 network... route print returns: IPv4 Route Table =========================================================================== Active Routes: Network Destination Netmask Gateway Interface Metric 0.0.0.0 0.0.0.0 192.168.42.1 192.168.42.194 276 127.0.0.0 255.0.0.0 On-link 127.0.0.1 306 127.0.0.1 255.255.255.255 On-link 127.0.0.1 306 127.255.255.255 255.255.255.255 On-link 127.0.0.1 306 192.168.42.0 255.255.255.0 On-link 192.168.42.194 276 192.168.42.194 255.255.255.255 On-link 192.168.42.194 276 192.168.42.255 255.255.255.255 On-link 192.168.42.194 276 224.0.0.0 240.0.0.0 On-link 127.0.0.1 306 224.0.0.0 240.0.0.0 On-link 192.168.42.194 276 255.255.255.255 255.255.255.255 On-link 127.0.0.1 306 255.255.255.255 255.255.255.255 On-link 192.168.42.194 276 =========================================================================== Persistent Routes: Network Address Netmask Gateway Address Metric 0.0.0.0 0.0.0.0 192.168.42.1 Default =========================================================================== The only time anything is supposed to send an ICMP Host Unreachable response is when there's no route to it, right? So, why is my own computer sending that to ping or tracert when I have the route of 192.168.42.0 with the mask of 255.255.255.0? An IP address of 192.168.42.2 surely fits into that route. If I explicitly add a route for the IP address i am trying to access, it works, like: route add 192.168.42.2 mask 255.255.255.255 192.168.42.1 (the 192.168.42.1 right after mask is gateway, or the device to send the packet to so it can route it further), but why wont it work for the implicit route that's automatically on the table? I disabled my firewall, too (I use Comodo if anyone thinks this still serves as a problem). I'v even tried explicitly adding the gateway of 192.168.42.1 to the 192.168.42.0/24 route instead of it routing through 0.0.0.0's gateway, which is what On-link does. but that didn't work either, so it's not a gateway specification problem. If the host was really unreachable, it would be the router's IP address (192.168.42.1) sending that to me... This network is all of my creation, so there's no problem such as an administrator locking me out, because i am the administrator.

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• Silverlight 5 Hosting :: Features in Silverlight 5 and Release Date

  - by mbridge

  Silverlight 5 is finally announced in the Silverlight FireStarter Event on the 2nd December, 2010. This new version of Silverlight which was earlier labeled as 'Future of Microsoft Silverlight' has now come much closer to go live as the first Silverlight 5 Beta version is expected to be shipped during the early months of 2011. However for the full fledged and the final release of Silverlight 5, we have to wait many more months as the same is likely to be made available within the Q3 2011. As would have been usually expected, this latest edition would feature many new capabilities thereby extending the developer productivity to a whole new dimension of premium media experience and feature-rich business applications. It comes along with many new feature updates as well as the inclusion of new technologies to improve the standard of the Silverlight applications which are now fine-tuned to produce next generation business and media solutions that is capable to meet the requirements of the advanced web-based app development. The Silverlight 5 is all set to replace the previous fourth version which now includes more than forty new features while also dropping various deprecated elements that was prevalent earlier. It has brought around some major performance enhancements and also included better support for various other tools and technologies. Following are some of the changes that are registered to be available under the Silverlight 5 Beta edition which is scheduled to be launched during the Q1 2011. Silverlight 5 : Premium Media Experiences The media features of Silverlight 5 has seen some major enhancements with a lot of optimizations being made to deliver richer solutions. It's capability has now been extended to make things easier, faster and capable of performing the desired tasks in the most efficient manner. The Silverlight media solutions has already been a part of many companies in the recent days where various on-demand Silverlight services were featured but with the arrival of the next generation premium media solution of Silverlight 5, it is expected to register new heights of success and global user acclamation for using it with many esteemed web-based projects and media solutions. - The most happening element in the new Silverlight 5 will be its support for utilizing the GPU based hardware acceleration which is intended to lower down the CPU load to a significant extent and thereby allowing faster rendering of media contents without consuming much resources. This feature is believed to be particularly helpful for low configured machines to run full HD media content without any lagging caused due to processor load. It will hence be one great feature to revolutionize the new generation high quality media contents to be available within the web in a more efficient manner with its hardware decoded video playback capabilities. - With the inclusion of hardware video decoding to minimize the processor load, the Silverlight 5 also comes with another optimization enhancement to also reduce the power consumption level by making new methods to deal with the power-saver settings. With this optimization in effect, the computer would be automatically allowed to switch to sleep mode while no video playback is in progress and also to prevent any screensavers to popup and cause annoyances during any video playback. There would also be other power saver options which will be made available to best suit the users requirements and purpose. - The Silverlight trickplay feature is another great way to tweak any silverlight powered media content as is used for many video tutorial sites or for dealing with any sort of presentations. This feature enables the user to modify the playback speed to either slowdown or speedup during the playback durations based on the requirements without compromising on the quality of output. Normally such manipulations always makes the content's audio to go off-pitch, but the same will not be the case with TrickPlay and the audio would seamlessly progress with the video without skipping any of its part. - In addition to all of the above, the new Silverlight 5 will be featuring wireless control of all the media contents by making use of remote controllers. With the use of such remote devices, it will be easier to handle the various media playback controls thereby providing more freedom while experiencing the premium media services. Silverlight 5 : Business Application Development The application development standard has been extended with more possibilities by bringing forth new and useful technologies and also reviving the existing methods to work better than what it was used to. From the UI improvements to advanced technical aspects, the Silverlight 5 scores high on all grounds to produce great next generation business delivered applications by putting in more creativity and resourceful touch to all the apps being produced with it. - The WPF feature of Silverlight is made more effective by introducing new standards of Databinding which is intended to improve the productivity standards of the Silverlight application developer. It brings in a lot of convenience in debugging the databinding components or expressions and hence making things work in a flawless manner. Some additional features related to databinding includes that of Ancestor RelativeSource, Implicit DataTemplates and Model View ViewModel (MVVM) support with DataContextChanged event and many other new features relating it. - It now comes with a refined text and printing service which facilitates better clarity of the text rendering and also many positive changes which are being applied to the layout pattern. New supports has been added to include OpenType font, multi-column text, linked-text containers and character leading support to name a few among the available features.This also includes some important printing aspects like that of Postscript Vector Printing API which allows to program our printing tasks in a user defined way and Pivot functionality for visualization concerns of informations. - The Graphics support is the key improvements being incorporated which now enables to utilize three dimensional graphics pattern using GPU acceleration. It can manage to provide some really cool visualizations being curved to provide media contents within the business apps with also the support for full HD contents at 1080p quality. - Silverlight 5 includes the support for 64-bit operating systems and relevant browsers and is also optimized to provide better performance. It can support the background thread for the networking which can reduce the latency of the network to a considerable extent. The Out-of-Browser functionality adds the support for utilizing various libraries and also the Win32 API. It also comes with testing support with VS 2010 which is mostly an automated procedure and has also enabled increased security aspects of all the Silverlight 5 developed applications by using the improved version of group policy support.

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• Difference between LASTDATE and MAX for semi-additive measures in #DAX

  - by Marco Russo (SQLBI)

  I recently wrote an article on SQLBI about the semi-additive measures in DAX. I included the formulas common calculations and there is an interesting point that worth a longer digression: the difference between LASTDATE and MAX (which is similar to FIRSTDATE and MIN – I just describe the former, for the latter just replace the correspondent names). LASTDATE is a dax function that receives an argument that has to be a date column and returns the last date active in the current filter context. Apparently, it is the same value returned by MAX, which returns the maximum value of the argument in the current filter context. Of course, MAX can receive any numeric type (including date), whereas LASTDATE only accepts a column of type date. But overall, they seems identical in the result. However, the difference is a semantic one. In fact, this expression: LASTDATE ( 'Date'[Date] ) could be also rewritten as: FILTER ( VALUES ( 'Date'[Date] ), 'Date'[Date] = MAX ( 'Date'[Date] ) ) LASTDATE is a function that returns a table with a single column and one row, whereas MAX returns a scalar value. In DAX, any expression with one row and one column can be automatically converted into the corresponding scalar value of the single cell returned. The opposite is not true. So you can use LASTDATE in any expression where a table or a scalar is required, but MAX can be used only where a scalar expression is expected. Since LASTDATE returns a table, you can use it in any expression that expects a table as an argument, such as COUNTROWS. In fact, you can write this expression: COUNTROWS ( LASTDATE ( 'Date'[Date] ) ) which will always return 1 or BLANK (if there are no dates active in the current filter context). You cannot pass MAX as an argument of COUNTROWS. You can pass to LASTDATE a reference to a column or any table expression that returns a column. The following two syntaxes are semantically identical: LASTDATE ( 'Date'[Date] ) LASTDATE ( VALUES ( 'Date'[Date] ) ) The result is the same and the use of VALUES is not required because it is implicit in the first syntax, unless you have a row context active. In that case, be careful that using in a row context the LASTDATE function with a direct column reference will produce a context transition (the row context is transformed into a filter context) that hides the external filter context, whereas using VALUES in the argument preserve the existing filter context without applying the context transition of the row context (see the columns LastDate and Values in the following query and result). You can use any other table expressions (including a FILTER) as LASTDATE argument. For example, the following expression will always return the last date available in the Date table, regardless of the current filter context: LASTDATE ( ALL ( 'Date'[Date] ) ) The following query recap the result produced by the different syntaxes described. EVALUATE     CALCULATETABLE(         ADDCOLUMNS(              VALUES ('Date'[Date] ),             "LastDate", LASTDATE( 'Date'[Date] ),             "Values", LASTDATE( VALUES ( 'Date'[Date] ) ),             "Filter", LASTDATE( FILTER ( VALUES ( 'Date'[Date] ), 'Date'[Date] = MAX ( 'Date'[Date] ) ) ),             "All", LASTDATE( ALL ( 'Date'[Date] ) ),             "Max", MAX( 'Date'[Date] )         ),         'Date'[Calendar Year] = 2008     ) ORDER BY 'Date'[Date] The LastDate columns repeat the current date, because the context transition happens within the ADDCOLUMNS. The Values column preserve the existing filter context from being replaced by the context transition, so the result corresponds to the last day in year 2008 (which is filtered in the external CALCULATETABLE). The Filter column works like the Values one, even if we use the FILTER instead of the LASTDATE approach. The All column shows the result of LASTDATE ( ALL ( ‘Date’[Date] ) ) that ignores the filter on Calendar Year (in fact the date returned is in year 2010). Finally, the Max column shows the result of the MAX formula, which is the easiest to use and only don’t return a table if you need it (like in a filter argument of CALCULATE or CALCULATETABLE, where using LASTDATE is shorter). I know that using LASTDATE in complex expressions might create some issue. In my experience, the fact that a context transition happens automatically in presence of a row context is the main reason of confusion and unexpected results in DAX formulas using this function. For a reference of DAX formulas using MAX and LASTDATE, read my article about semi-additive measures in DAX.

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• NET Math Libraries

  - by JoshReuben

  NET Mathematical Libraries   .NET Builder for Matlab The MathWorks Inc. - http://www.mathworks.com/products/netbuilder/ MATLAB Builder NE generates MATLAB based .NET and COM components royalty-free deployment creates the components by encrypting MATLAB functions and generating either a .NET or COM wrapper around them. .NET/Link for Mathematica www.wolfram.com a product that 2-way integrates Mathematica and Microsoft's .NET platform call .NET from Mathematica - use arbitrary .NET types directly from the Mathematica language. use and control the Mathematica kernel from a .NET program. turns Mathematica into a scripting shell to leverage the computational services of Mathematica. write custom front ends for Mathematica or use Mathematica as a computational engine for another program comes with full source code. Leverages MathLink - a Wolfram Research's protocol for sending data and commands back and forth between Mathematica and other programs. .NET/Link abstracts the low-level details of the MathLink C API. Extreme Optimization http://www.extremeoptimization.com/ a collection of general-purpose mathematical and statistical classes built for the.NET framework. It combines a math library, a vector and matrix library, and a statistics library in one package. download the trial of version 4.0 to try it out. Multi-core ready - Full support for Task Parallel Library features including cancellation. Broad base of algorithms covering a wide range of numerical techniques, including: linear algebra (BLAS and LAPACK routines), numerical analysis (integration and differentiation), equation solvers. Mathematics leverages parallelism using .NET 4.0's Task Parallel Library. Basic math: Complex numbers, 'special functions' like Gamma and Bessel functions, numerical differentiation. Solving equations: Solve equations in one variable, or solve systems of linear or nonlinear equations. Curve fitting: Linear and nonlinear curve fitting, cubic splines, polynomials, orthogonal polynomials. Optimization: find the minimum or maximum of a function in one or more variables, linear programming and mixed integer programming. Numerical integration: Compute integrals over finite or infinite intervals, over 2D and higher dimensional regions. Integrate systems of ordinary differential equations (ODE's). Fast Fourier Transforms: 1D and 2D FFT's using managed or fast native code (32 and 64 bit) BigInteger, BigRational, and BigFloat: Perform operations with arbitrary precision. Vector and Matrix Library Real and complex vectors and matrices. Single and double precision for elements. Structured matrix types: including triangular, symmetrical and band matrices. Sparse matrices. Matrix factorizations: LU decomposition, QR decomposition, singular value decomposition, Cholesky decomposition, eigenvalue decomposition. Portability and performance: Calculations can be done in 100% managed code, or in hand-optimized processor-specific native code (32 and 64 bit). Statistics Data manipulation: Sort and filter data, process missing values, remove outliers, etc. Supports .NET data binding. Statistical Models: Simple, multiple, nonlinear, logistic, Poisson regression. Generalized Linear Models. One and two-way ANOVA. Hypothesis Tests: 12 14 hypothesis tests, including the z-test, t-test, F-test, runs test, and more advanced tests, such as the Anderson-Darling test for normality, one and two-sample Kolmogorov-Smirnov test, and Levene's test for homogeneity of variances. Multivariate Statistics: K-means cluster analysis, hierarchical cluster analysis, principal component analysis (PCA), multivariate probability distributions. Statistical Distributions: 25 29 continuous and discrete statistical distributions, including uniform, Poisson, normal, lognormal, Weibull and Gumbel (extreme value) distributions. Random numbers: Random variates from any distribution, 4 high-quality random number generators, low discrepancy sequences, shufflers. New in version 4.0 (November, 2010) Support for .NET Framework Version 4.0 and Visual Studio 2010 TPL Parallellized – multicore ready sparse linear program solver - can solve problems with more than 1 million variables. Mixed integer linear programming using a branch and bound algorithm. special functions: hypergeometric, Riemann zeta, elliptic integrals, Frensel functions, Dawson's integral. Full set of window functions for FFT's. Product  Price Update subscription Single Developer License $999  $399  Team License (3 developers) $1999  $799  Department License (8 developers) $3999  $1599  Site License (Unlimited developers in one physical location) $7999  $3199    NMath http://www.centerspace.net .NET math and statistics libraries matrix and vector classes random number generators Fast Fourier Transforms (FFTs) numerical integration linear programming linear regression curve and surface fitting optimization hypothesis tests analysis of variance (ANOVA) probability distributions principal component analysis cluster analysis built on the Intel Math Kernel Library (MKL), which contains highly-optimized, extensively-threaded versions of BLAS (Basic Linear Algebra Subroutines) and LAPACK (Linear Algebra PACKage). Product  Price Update subscription Single Developer License $1295 $388 Team License (5 developers) $5180 $1554   DotNumerics http://www.dotnumerics.com/NumericalLibraries/Default.aspx free DotNumerics is a website dedicated to numerical computing for .NET that includes a C# Numerical Library for .NET containing algorithms for Linear Algebra, Differential Equations and Optimization problems. The Linear Algebra library includes CSLapack, CSBlas and CSEispack, ports from Fortran to C# of LAPACK, BLAS and EISPACK, respectively. Linear Algebra (CSLapack, CSBlas and CSEispack). Systems of linear equations, eigenvalue problems, least-squares solutions of linear systems and singular value problems. Differential Equations. Initial-value problem for nonstiff and stiff ordinary differential equations ODEs (explicit Runge-Kutta, implicit Runge-Kutta, Gear's BDF and Adams-Moulton). Optimization. Unconstrained and bounded constrained optimization of multivariate functions (L-BFGS-B, Truncated Newton and Simplex methods).   Math.NET Numerics http://numerics.mathdotnet.com/ free an open source numerical library - includes special functions, linear algebra, probability models, random numbers, interpolation, integral transforms. A merger of dnAnalytics with Math.NET Iridium in addition to a purely managed implementation will also support native hardware optimization. constants & special functions complex type support real and complex, dense and sparse linear algebra (with LU, QR, eigenvalues, ... decompositions) non-uniform probability distributions, multivariate distributions, sample generation alternative uniform random number generators descriptive statistics, including order statistics various interpolation methods, including barycentric approaches and splines numerical function integration (quadrature) routines integral transforms, like fourier transform (FFT) with arbitrary lengths support, and hartley spectral-space aware sequence manipulation (signal processing) combinatorics, polynomials, quaternions, basic number theory. parallelized where appropriate, to leverage multi-core and multi-processor systems fully managed or (if available) using native libraries (Intel MKL, ACMS, CUDA, FFTW) provides a native facade for F# developers

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• C++ Little Wonders: The C++11 auto keyword redux

  - by James Michael Hare

  I’ve decided to create a sub-series of my Little Wonders posts to focus on C++.  Just like their C# counterparts, these posts will focus on those features of the C++ language that can help improve code by making it easier to write and maintain.  The index of the C# Little Wonders can be found here. This has been a busy week with a rollout of some new website features here at my work, so I don’t have a big post for this week.  But I wanted to write something up, and since lately I’ve been renewing my C++ skills in a separate project, it seemed like a good opportunity to start a C++ Little Wonders series.  Most of my development work still tends to focus on C#, but it was great to get back into the saddle and renew my C++ knowledge.  Today I’m going to focus on a new feature in C++11 (formerly known as C++0x, which is a major move forward in the C++ language standard).  While this small keyword can seem so trivial, I feel it is a big step forward in improving readability in C++ programs. The auto keyword If you’ve worked on C++ for a long time, you probably have some passing familiarity with the old auto keyword as one of those rarely used C++ keywords that was almost never used because it was the default. That is, in the code below (before C++11): 1: int foo() 2: { 3: // automatic variables (allocated and deallocated on stack) 4: int x; 5: auto int y; 6:  7: // static variables (retain their value across calls) 8: static int z; 9:  10: return 0; 11: } The variable x is assumed to be auto because that is the default, thus it is unnecessary to specify it explicitly as in the declaration of y below that.  Basically, an auto variable is one that is allocated and de-allocated on the stack automatically.  Contrast this to static variables, that are allocated statically and exist across the lifetime of the program. Because auto was so rarely (if ever) used since it is the norm, they decided to remove it for this purpose and give it new meaning in C++11.  The new meaning of auto: implicit typing Now, if your compiler supports C++ 11 (or at least a good subset of C++11 or 0x) you can take advantage of type inference in C++.  For those of you from the C# world, this means that the auto keyword in C++ now behaves a lot like the var keyword in C#! For example, many of us have had to declare those massive type declarations for an iterator before.  Let’s say we have a std::map of std::string to int which will map names to ages: 1: std::map<std::string, int> myMap; And then let’s say we want to find the age of a given person: 1: // Egad that's a long type... 2: std::map<std::string, int>::const_iterator pos = myMap.find(targetName); Notice that big ugly type definition to declare variable pos?  Sure, we could shorten this by creating a typedef of our specific map type if we wanted, but now with the auto keyword there’s no need: 1: // much shorter! 2: auto pos = myMap.find(targetName); The auto now tells the compiler to determine what type pos should be based on what it’s being assigned to.  This is not dynamic typing, it still determines the type as if it were explicitly declared and once declared that type cannot be changed.  That is, this is invalid: 1: // x is type int 2: auto x = 42; 3:  4: // can't assign string to int 5: x = "Hello"; Once the compiler determines x is type int it is exactly as if we typed int x = 42; instead, so don’t' confuse it with dynamic typing, it’s still very type-safe. An interesting feature of the auto keyword is that you can modify the inferred type: 1: // declare method that returns int* 2: int* GetPointer(); 3:  4: // p1 is int*, auto inferred type is int 5: auto *p1 = GetPointer(); 6:  7: // ps is int*, auto inferred type is int* 8: auto p2 = GetPointer(); Notice in both of these cases, p1 and p2 are determined to be int* but in each case the inferred type was different.  because we declared p1 as auto *p1 and GetPointer() returns int*, it inferred the type int was needed to complete the declaration.  In the second case, however, we declared p2 as auto p2 which means the inferred type was int*.  Ultimately, this make p1 and p2 the same type, but which type is inferred makes a difference, if you are chaining multiple inferred declarations together.  In these cases, the inferred type of each must match the first: 1: // Type inferred is int 2: // p1 is int* 3: // p2 is int 4: // p3 is int& 5: auto *p1 = GetPointer(), p2 = 42, &p3 = p2; Note that this works because the inferred type was int, if the inferred type was int* instead: 1: // syntax error, p1 was inferred to be int* so p2 and p3 don't make sense 2: auto p1 = GetPointer(), p2 = 42, &p3 = p2; You could also use const or static to modify the inferred type: 1: // inferred type is an int, theAnswer is a const int 2: const auto theAnswer = 42; 3:  4: // inferred type is double, Pi is a static double 5: static auto Pi = 3.1415927; Thus in the examples above it inferred the types int and double respectively, which were then modified to const and static. Summary The auto keyword has gotten new life in C++11 to allow you to infer the type of a variable from it’s initialization.  This simple little keyword can be used to cut down large declarations for complex types into a much more readable form, where appropriate.   Technorati Tags: C++, C++11, Little Wonders, auto

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• How-to filter table filter input to only allow numeric input

  - by frank.nimphius

  In a previous ADF Code Corner post, I explained how to change the table filter behavior by intercepting the query condition in a query filter. See sample #30 at http://www.oracle.com/technetwork/developer-tools/adf/learnmore/index-101235.html In this OTN Harvest post I explain how to prevent users from providing invalid character entries as table filter criteria to avoid problems upon re-querying the table. In the example shown next, only numeric values are allowed for a table column filter. To create a table that allows data filtering, drag a View Object – or a data collection of a Web Service or JPA business service – from the DataControls panel and drop it as a table. Choose the Enable Filtering option in the Edit Table Columns dialog so the table renders with the column filter boxes displayed. The table filter fields are created using implicit af:inputText components that need to be customized for you to apply a custom filter input component, or to change the input behavior. To change the input filter, so only a defined set of input keys is allowed, you need to change the default filter field with your own af:inputText field to which you apply an af:clientListener tag that filters user keyboard entries. For this, in the Oracle JDeveloper visual editor, select the column which filter you want to change and expand the column node in the Oracle JDeveloper Structure Window. Part of the column definition is the Column facet node. Expand the facets so you see the filter facet entry. The filter facet is grayed out as there is no custom facet defined. In a next step, open theComponent Palette (ctrl+shift+P) and drag an Input Text component onto the facet. This demarks the first part in the filter customization. To make the custom filter component work, you need to map the af:inputText component value property to the ADF filter criteria that is exposed in the Expression Builder. Open the Expression Builder for the filter input component value property by clicking the arrow icon to its right. In the Expression Builder expand the JSP Objects | vs | filterCriteria node to select the attribute name represented by the table column. The vs entry is the name of a variable that is defined on the table and that grants you access to the table attributes. Now that the filter works as before – though using a custom filter input component – you can add the af:clientListener tag to your custom filter component – af:inputText – to call out to JavaScript when users type in the column filter field Point the client filter method property to a JavaScript function that you reference or add through using the af:resource tag and set the type property value to keyDown. <af:document id="d1">     <af:resource type="javascript" source="/js/filterHandler.js"/> … The filter definition looks as shown below <af:inputText label="Label 1" id="it1"                         value="#{vs.filterCriteria.Employe        <af:clientListener method="suppressCharacterInput"                                     type="keyDown"/> </af:inputText> The JavaScript code that you can use to either filter character inputs or numeric inputs is shown below. Just store this code in an external JavaScript (.js) file and reference it from the af:resource tag. //Allow numbers, cursor control keys and delete keys function suppressCharacterInput(evt) {     var _keyCode = evt.getKeyCode();     var _filterField = evt.getCurrentTarget();     var _oldValue = _filterField.getValue();     if (!((_keyCode < 57) ||(_keyCode > 96 && _keyCode < 105))) {         _filterField.setValue(_oldValue);         evt.cancel();     } } //Allow characters, cursor control keys and delete keys function suppressNumericInput(evt) {  var _keyCode = evt.getKeyCode();  var _filterField = evt.getCurrentTarget();  var _oldValue = _filterField.getValue();  //check for numbers  if ((_keyCode < 57 && _keyCode > 47) ||      (_keyCode > 96 && _keyCode < 105)){     _filterField.setValue(_oldValue);     evt.cancel();   } } But what if browsers don't allow JavaScript ? Don't worry about this. If browsers would not support JavaScript then ADF Faces as a whole would not work and you had a different problem.

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• How do I prove or disprove "god" objects are wrong?

  - by honestduane

  Problem Summary: Long story short, I inherited a code base and an development team I am not allowed to replace and the use of God Objects is a big issue. Going forward, I want to have us re-factor things but I am getting push-back from the teams who want to do everything with God Objects "because its easier" and this means I would not be allowed to re-factor. I pushed back citing my years of dev experience, that I'm the new boss who was hired to know these things, etc, and so did the third party offshore companies account sales rep, and this is now at the executive level and my meeting is tomorrow and I want to go in with a lot of technical ammo to advocate best practices because I feel it will be cheaper in the long run (And I personally feel that is what the third party is worried about) for the company. My issue is from a technical level, I know its good long term but I'm having trouble with the ultra short term and 6 months term, and while its something I "know" I cant prove it with references and cited resources outside of one person (Robert C. Martin, aka Uncle Bob), as that is what I am being asked to do as I have been told having data from one person and only one person (Robert C Martin) is not good enough of an argument. Question: What are some resources I can cite directly (Title, year published, page number, quote) by well known experts in the field that explicitly say this use of "God" Objects/Classes/Systems is bad (or good, since we are looking for the most technically valid solution)? Research I have already done: I have a number of books here and I have searched their indexes for the use of the words "god object" and "god class". I found that oddly its almost never used and the copy of the GoF book I have for example, never uses it (At least according to the index in front of me) but I have found it in 2 books per the below, but I want more I can use. I checked the Wikipedia page for "God Object" and its currently a stub with little reference links so although I personally agree with that it says, It doesn't have much I can use in an environment where personal experience is not considered valid. The book cited is also considered too old to be valid by the people I am debating these technical points with as the argument they are making is that "it was once thought to be bad but nobody could prove it, and now modern software says "god" objects are good to use". I personally believe that this statement is incorrect, but I want to prove the truth, whatever it is. In Robert C Martin's "Agile Principles, Patterns, and Practices in C#" (ISBN: 0-13-185725-8, hardcover) where on page 266 it states "Everybody knows that god classes are a bad idea. We don't want to concentrate all the intelligence of a system into a single object or a single function. One of the goals of OOD is the partitioning and distribution of behavior into many classes and many function." -- And then goes on to say sometimes its better to use God Classes anyway sometimes (Citing micro-controllers as an example). In Robert C Martin's "Clean Code: A Handbook of Agile Software Craftsmanship" page 136 (And only this page) talks about the "God class" and calls it out as a prime example of a violation of the "classes should be small" rule he uses to promote the Single Responsibility Principle" starting on on page 138. The problem I have is all my references and citations come from the same person (Robert C. Martin), and am from the same single person/source. I am being told that because he is just one guy, my desire to not use "God Classes" is invalid and not accepted as a standard best practice in the software industry. Is this true? Am I doing things wrong from a technical perspective by trying to keep to the teaching of Uncle Bob? God Objects and Object Oriented Programming and Design: The more I think of this the more I think this is more something you learn when you study OOP and its never explicitly called out; Its implicit to good design is my thinking (Feel free to correct me, please, as I want to learn), The problem is I "know" this, but but not everybody does, so in this case its not considered a valid argument because I am effectively calling it out as universal truth when in fact most people are statistically ignorant of it since statistically most people are not programmers. Conclusion: I am at a loss on what to search for to get the best additional results to cite, since they are making a technical claim and I want to know the truth and be able to prove it with citations like a real engineer/scientist, even if I am biased against god objects due to my personal experience with code that used them. Any assistance or citations would be deeply appreciated.

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• Why enumerator structs are a really bad idea

  - by Simon Cooper

  If you've ever poked around the .NET class libraries in Reflector, I'm sure you would have noticed that the generic collection classes all have implementations of their IEnumerator as a struct rather than a class. As you will see, this design decision has some rather unfortunate side effects... As is generally known in the .NET world, mutable structs are a Very Bad Idea; and there are several other blogs around explaining this (Eric Lippert's blog post explains the problem quite well). In the BCL, the generic collection enumerators are all mutable structs, as they need to keep track of where they are in the collection. This bit me quite hard when I was coding a wrapper around a LinkedList<int>.Enumerator. It boils down to this code: sealed class EnumeratorWrapper : IEnumerator<int> { private readonly LinkedList<int>.Enumerator m_Enumerator; public EnumeratorWrapper(LinkedList<int> linkedList) { m_Enumerator = linkedList.GetEnumerator(); } public int Current { get { return m_Enumerator.Current; } } object System.Collections.IEnumerator.Current { get { return Current; } } public bool MoveNext() { return m_Enumerator.MoveNext(); } public void Reset() { ((System.Collections.IEnumerator)m_Enumerator).Reset(); } public void Dispose() { m_Enumerator.Dispose(); } } The key line here is the MoveNext method. When I initially coded this, I thought that the call to m_Enumerator.MoveNext() would alter the enumerator state in the m_Enumerator class variable and so the enumeration would proceed in an orderly fashion through the collection. However, when I ran this code it went into an infinite loop - the m_Enumerator.MoveNext() call wasn't actually changing the state in the m_Enumerator variable at all, and my code was looping forever on the first collection element. It was only after disassembling that method that I found out what was going on The MoveNext method above results in the following IL: .method public hidebysig newslot virtual final instance bool MoveNext() cil managed { .maxstack 1 .locals init ( [0] bool CS$1$0000, [1] valuetype [System]System.Collections.Generic.LinkedList`1/Enumerator CS$0$0001) L_0000: nop L_0001: ldarg.0 L_0002: ldfld valuetype [System]System.Collections.Generic.LinkedList`1/Enumerator EnumeratorWrapper::m_Enumerator L_0007: stloc.1 L_0008: ldloca.s CS$0$0001 L_000a: call instance bool [System]System.Collections.Generic.LinkedList`1/Enumerator::MoveNext() L_000f: stloc.0 L_0010: br.s L_0012 L_0012: ldloc.0 L_0013: ret } Here, the important line is 0002 - m_Enumerator is accessed using the ldfld operator, which does the following: Finds the value of a field in the object whose reference is currently on the evaluation stack. So, what the MoveNext method is doing is the following: public bool MoveNext() { LinkedList<int>.Enumerator CS$0$0001 = this.m_Enumerator; bool CS$1$0000 = CS$0$0001.MoveNext(); return CS$1$0000; } The enumerator instance being modified by the call to MoveNext is the one stored in the CS$0$0001 variable on the stack, and not the one in the EnumeratorWrapper class instance. Hence why the state of m_Enumerator wasn't getting updated. Hmm, ok. Well, why is it doing this? If you have a read of Eric Lippert's blog post about this issue, you'll notice he quotes a few sections of the C# spec. In particular, 7.5.4: ...if the field is readonly and the reference occurs outside an instance constructor of the class in which the field is declared, then the result is a value, namely the value of the field I in the object referenced by E. And my m_Enumerator field is readonly! Indeed, if I remove the readonly from the class variable then the problem goes away, and the code works as expected. The IL confirms this: .method public hidebysig newslot virtual final instance bool MoveNext() cil managed { .maxstack 1 .locals init ( [0] bool CS$1$0000) L_0000: nop L_0001: ldarg.0 L_0002: ldflda valuetype [System]System.Collections.Generic.LinkedList`1/Enumerator EnumeratorWrapper::m_Enumerator L_0007: call instance bool [System]System.Collections.Generic.LinkedList`1/Enumerator::MoveNext() L_000c: stloc.0 L_000d: br.s L_000f L_000f: ldloc.0 L_0010: ret } Notice on line 0002, instead of the ldfld we had before, we've got a ldflda, which does this: Finds the address of a field in the object whose reference is currently on the evaluation stack. Instead of loading the value, we're loading the address of the m_Enumerator field. So now the call to MoveNext modifies the enumerator stored in the class rather than on the stack, and everything works as expected. Previously, I had thought enumerator structs were an odd but interesting feature of the BCL that I had used in the past to do linked list slices. However, effects like this only underline how dangerous mutable structs are, and I'm at a loss to explain why the enumerators were implemented as structs in the first place. (interestingly, the SortedList<TKey, TValue> enumerator is a struct but is private, which makes it even more odd - the only way it can be accessed is as a boxed IEnumerator!). I would love to hear people's theories as to why the enumerators are implemented in such a fashion. And bonus points if you can explain why LinkedList<int>.Enumerator.Reset is an explicit implementation but Dispose is implicit... Note to self: never ever ever code a mutable struct.

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