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  • Tips or techniques to use when you do't know how to code something?

    - by janoChen
    I have a background as UI designer. And I realized that it is a bit hard for me to write a pieces of logic. Sometimes I get it right, but most of the time, I end up with something hacky (and it usually takes a lot of time). And is not that I don't like programming, in fact, I'm starting to like it as much as design. It's just that sometimes I think that I'm better at dealing with colors an shapes, rather than numbers and logic (but I want to change that). What I usually do is to search the solution on the Internet, copy the example, and insert it into my app (I know this is not a very good practice). I've heard that one tip was to write the logic in common English as comment before writing the actual code. What other tips and techniques I can use?

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  • Come Aboard. We're Expecting You...

    - by KKline
    Those of us over a certain age (read - old as dirt) can remember the theme songs to certain TV shows better than we can the National Anthem. Try these lines out and see if you don't immediately remember the tune that goes along with them: Come and knock on our door | We've been waiting for you ... Makin' your way in the world today | Takes everything you've got ... Just some good ol' boys | Never meaning no harm ... Thank you for being a friend | Travel down the road and back again ... So when I...(read more)

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  • Software Design for Product Verticals and Service Verticals

    - by Rachel
    In every industry there are two verticals Product Vertical and Service Vertical, so my question is: How does design approach changes while designing Software for Product Vertical as compared to developing Software for Service Vertical ? What are the pros and cons for each case ? Also, in case of Product Vertical, How you go about designing Product or Features and what are steps involved ? Lastly, I was reading How Facebook Ships Code article and it appears that Product Managers have very little influence on how Product is developed and responsibility lies mainly with the Developer for the feature. So is this good practice and why one would go for this approach ? What would be your comment on this kind of approach ?

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  • MVC Pattern, ViewModels, Location of conversion.

    - by Pino
    I've been working with ASP.Net MVC for around a year now and have created my applications in the following way. X.Web - MVC Application Contains Controller and Views X.Lib - Contains Data Access, Repositories and Services. This allows us to drop the .Lib into any application that requires it. At the moment we are using Entity Framework, the conversion from EntityO to a more specific model is done in the controller. This set-up means if a service method returns an EntityO and then the Controller will do a conversion before the data is passed to a view. I'm interested to know if I should move the conversion to the Service so that the app doesn't have Entity Objects being passed around.

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  • Standard way of allowing general XML data

    - by Greg Jackson
    I'm writing a data gathering and reporting application that takes XML files as input, which will then be read, processed, and stored in a strongly-typed database. For example, an XML file for a "Job" might look like this: <Data type="Job"> <ID>12345</ID> <JobName>MyJob</JobName> <StartDate>04/07/2012 10:45:00 AM</StartDate> <Files> <File name="a.jpeg" path="images\" /> <File name="b.mp3" path="music\mp3\" /> </Files> </Data> I'd like to use a schema to have a standard format for these input files (depending on what type of data is being used, for example "Job", "User", "View"), but I'd also like to not fail validation if there is extra data provided. For example, perhaps a Job has additional properties such as "IsAutomated", "Requester", "EndDate", and so on. I don't particularly care about these extra properties. If they are included in the XML, I'll simply ignore them when I'm processing the XML file, and I'd like validation to do the same, without having to include in the schema every single possible property that a customer might provide me with. Is there a standard way of providing such a schema, or of allowing such a general XML file that can still be validated without resorting to something as naïve (and potentially difficult to deal with) as the below? <Data type="Job"> <Data name="ID">12345</Data> . . . <Data name="Files"> <Data name="File"> <Data name="Filename">a.jpeg</Data> <Data name="path">images</Data> . . . </Data> </Data>

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  • Next Quarterly Customer Update Webcast is July 24th (July 25th in Asia Pacific)

    - by R.Hunter
    Join Team Informatics, Kyle Hatlestad from the WebCenter Content “A-Team” and Oracle WebCenter Product Management for the next Oracle WebCenter Quarterly Customer Update Webcast scheduled for July 24th (July 25th in Asia Pacific). Get the latest product management updates and learn more about WebCenter Content and WebCenter Sites. Team Informatics will give an overview of the WebCenter Sites 11g Connector to WebCenter Content and Kyle Hatlestad will discuss best practices for WCC deployment and configuration. You can follow Kyle’s blog at: http://blogs.oracle.com/kyle/ Don't miss out, there will be two live sessions with Q&A. Further details and the registration links for the webcast can be found on our Oracle Technology Network Page.

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  • Webcast Replay Available: SOA Integration Options for E-Business Suite

    - by BillSawyer
    I am pleased to release the replay and presentation for the latest ATG Live Webcast: SOA Integration Options for E-Business Suite (Presentation)Abhishek Verma, Manager, Applications Technology Group and Rajesh Ghosh, Group Manager, ATG Development discussed the web service and SOA integration options for Oracle E-Business Suite. The presentation covered Oracle's integration tools and technologies, including the Oracle Applications Adapter and the Integrated SOA Gateway.Finding other recorded ATG webcastsThe catalog of ATG Live Webcast replays, presentations, and all ATG training materials is available in this blog's Webcasts and Training section.

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  • Why are exceptions considered better than explicit error testing?

    - by Richard Keller
    I often come across heated blog posts where the author uses the argument of "exceptions vs explicit error checking" to advocate their preferred language over some other language. The general consensus seems to be that languages which make use of exceptions are inherently better / cleaner than languages which rely heavily on error checking through explicit function calls. Is the use of exceptions considered better programming practice than explicit error checking, and if so, why?

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  • Deploying Data Mining Models using Model Export and Import, Part 2

    - by [email protected]
    In my last post, Deploying Data Mining Models using Model Export and Import, we explored using DBMS_DATA_MINING.EXPORT_MODEL and DBMS_DATA_MINING.IMPORT_MODEL to enable moving a model from one system to another. In this post, we'll look at two distributed scenarios that make use of this capability and a tip for easily moving models from one machine to another using only Oracle Database, not an external file transport mechanism, such as FTP. The first scenario, consider a company with geographically distributed business units, each collecting and managing their data locally for the products they sell. Each business unit has in-house data analysts that build models to predict which products to recommend to customers in their space. A central telemarketing business unit also uses these models to score new customers locally using data collected over the phone. Since the models recommend different products, each customer is scored using each model. This is depicted in Figure 1.Figure 1: Target instance importing multiple remote models for local scoring In the second scenario, consider multiple hospitals that collect data on patients with certain types of cancer. The data collection is standardized, so each hospital collects the same patient demographic and other health / tumor data, along with the clinical diagnosis. Instead of each hospital building it's own models, the data is pooled at a central data analysis lab where a predictive model is built. Once completed, the model is distributed to hospitals, clinics, and doctor offices who can score patient data locally.Figure 2: Multiple target instances importing the same model from a source instance for local scoring Since this blog focuses on model export and import, we'll only discuss what is necessary to move a model from one database to another. Here, we use the package DBMS_FILE_TRANSFER, which can move files between Oracle databases. The script is fairly straightforward, but requires setting up a database link and directory objects. We saw how to create directory objects in the previous post. To create a database link to the source database from the target, we can use, for example: create database link SOURCE1_LINK connect to <schema> identified by <password> using 'SOURCE1'; Note that 'SOURCE1' refers to the service name of the remote database entry in your tnsnames.ora file. From SQL*Plus, first connect to the remote database and export the model. Note that the model_file_name does not include the .dmp extension. This is because export_model appends "01" to this name.  Next, connect to the local database and invoke DBMS_FILE_TRANSFER.GET_FILE and import the model. Note that "01" is eliminated in the target system file name.  connect <source_schema>/<password>@SOURCE1_LINK; BEGIN  DBMS_DATA_MINING.EXPORT_MODEL ('EXPORT_FILE_NAME' || '.dmp',                                 'MY_SOURCE_DIR_OBJECT',                                 'name =''MY_MINING_MODEL'''); END; connect <target_schema>/<password>; BEGIN  DBMS_FILE_TRANSFER.GET_FILE ('MY_SOURCE_DIR_OBJECT',                               'EXPORT_FILE_NAME' || '01.dmp',                               'SOURCE1_LINK',                               'MY_TARGET_DIR_OBJECT',                               'EXPORT_FILE_NAME' || '.dmp' );  DBMS_DATA_MINING.IMPORT_MODEL ('EXPORT_FILE_NAME' || '.dmp',                                 'MY_TARGET_DIR_OBJECT'); END; To clean up afterward, you may want to drop the exported .dmp file at the source and the transferred file at the target. For example, utl_file.fremove('&directory_name', '&model_file_name' || '.dmp');

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  • How would you refactor nested IF Statements?

    - by saunderl
    I was cruising around the programming blogosphere when I happened upon this post about GOTO's: http://giuliozambon.blogspot.com/2010/12/programmers-tabu.html Here the writer talks about how "one must come to the conclusion that there are situations where GOTOs make for more readable and more maintainable code" and then goes on to show an example similar to this: if (Check#1) { CodeBlock#1 if (Check#2) { CodeBlock#2 if (Check#3) { CodeBlock#3 if (Check#4) { CodeBlock#4 if (Check#5) { CodeBlock#5 if (Check#6) { CodeBlock#6 if (Check#7) { CodeBlock#7 } else { rest - of - the - program } } } } } } } The writer then proposes that using GOTO's would make this code much easier to read and maintain. I personally can think of at least 3 different ways to flatten it out and make this code more readable without resorting to flow-breaking GOTO's. Here are my two favorites. 1 - Nested Small Functions. Take each if and its code block and turn it into a function. If the boolean check fails, just return. If it passes, then call the next function in the chain. (Boy, that sounds a lot like recursion, could you do it in a single loop with function pointers?) 2 - Sentinal Variable. To me this is the easyest. Just use a blnContinueProcessing variable and check to see if it is still true in your if check. Then if the check fails, set the variable to false. How many different ways can this type of coding problem be refactored to reduce nesting and increase maintainability?

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  • Third Party Applications and Other Acts of Violence Against Your SQL Server

    - by KKline
    I just got finished reading a great blog post from my buddy, Thomas LaRock ( t | b ), in which he describes a useful personal policy he used to track changes made to his SQL Servers when installing third-party products. Note that I'm talking about line-of-business applications here - your inventory management systems and help desk ticketing apps. I'm not talking about monitoring and tuning applications since they, by their very nature, need a different sort of access to your back-end server resources....(read more)

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  • Managing .NET External Dependencies

    - by Ben Griswold
    Noah and I continue our screencast series by sharing our approach to managing external dependencies referenced within a .NET solution.  This is another introductory episode but you might find a hidden gem in the short 4-minute clip.  ELMAH (Error Logging Modules and Handlers) is the external dependencies we are focusing on in the presentation.  If you are not familiar with ELMAH, this episode may be worth your time.   YouTube - Managing .NET External Dependencies This is one of our first screencasts.  If you have feedback, I’d love to hear it.

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  • What design patterns are the worst or most narrowly defined?

    - by Akku
    For every programming project, Managers with past programming experience try to shine when they recommend some design patterns for your project. I like design patterns when they make sense or if you need a scalbale solution. I've used Proxies, Observers and Command patterns in a positive way for example, and do so every day. But I'm really hesitant to use say a Factory pattern if there's only one way to create an object, as a factory might make it all easier in the future, but complicates the code and is pure overhead. So, my question is in respect to my future career and my answer to manager types throwing random pattern-names around: Which design patterns did you use, that threw you back overall? Which are the worst design patterns, that you shouldn't have a look at if it's not that only single situation where it makes sense (read: which design patterns are very narrowly defined)? (It's like I was looking for the negative reviews of an overall good product of amazon to see what bugged people most in using design patterns). And I'm not talking about Anti-Patterns here, but about Patterns that are usually thought of as "good" patterns. Edit: As some answered, the problem is most often that patterns are not "bad" but "used wrong". If you know patterns, that are often misused or even difficult to use, they would also fit as an answer.

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  • Better Programming By Programming Better?

    - by ahmed
    I am not convinced by the idea that developers are either born with it or they are not. Where’s the empirical evidence to support these types of claims? Can a programmer move from say the 50th to 90th percentile? However, most developers are not in the 99th or even 90th percentile (by definition), and thus still have room for improvement in programming ability, along with the important skills.The belief in innate talent is “lacking in hard evidence to substantiate it” as well.So how do I reconcile these seemingly contradictory statements? I think the lesson for software developers who wish to keep on top of their game and become experts is to keep exercising the mind via effortful studying. I read a lot technical books, but many of them aren’t making me better as a developer.

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  • Accenture Launches Smart Grid Data Management Platform

    - by caroline.yu
    Accenture announced today it has launched the Accenture Intelligent Network Data Enterprise (INDE), a data management platform to help utilities design, deploy and manage smart grids. INDE's functionality can be enabled by an array of third party technologies. In addition, Accenture plans to offer utilities the option of implementing the INDE solution based on a pre-configured suite of Oracle technologies. The Oracle-based version of INDE will accelerate the design of smart grids and help reduce the costs and risks associated with smart grid implementation. Stephan Scholl, Senior Vice President and General Manager of Oracle Utilities said, "Oracle and Accenture share a common vision of how the smart grid will enable more efficient energy choices for utilities and their customers. Our combined expertise in delivering mission-critical smart grid applications, security, data management and systems integration can help accelerate utilities toward a more intelligent network now and as future needs arise." For the full press release, click here.

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  • Laptops or Notebooks in a meeting? [closed]

    - by greengit
    Is taking the laptop to the meeting a good idea? Of course, the project leader needs to have one -- but the programmers -- especially those who only need to get straight instructions on what to do next on the project -- do they need to take laptops? I feel it takes longer to save notes in a software -- and it's lot easier to just jot down "things to do" in a simple note book. That way you can keep up with the discussion and not lose track of what someone else is saying by spending too much time entering text in the machine.

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  • Top 5 Sites and Activities in San Francisco to Experience During Oracle OpenWorld

    - by kgee
    While Oracle OpenWorld may provide solutions and information on topics like how to simplify your IT, the importance of cloud, and what types of storage may satisfy your enterprise needs, who is going to tell you more about San Francisco? Here are some suggested sites and activities to experience after OpenWorld that aren’t too far from the Moscone Center. It is recommended to take a cab for the sake of time, but the 6 square miles that make up San Francisco will make for a quick trek to any of the following destinations: The Golden Gate BridgeAn image often associated with San Francisco, this bridge is one of the most impressive in the world. Take a walk across it, or view it from nearby Crissy Field, it is a sight that floors even the most veteran of San Franciscans. The Ferry BuildingLocated at the end of Market Street in the Embarcadero, the Ferry Building once served as a hub of water transport and trade. The building has a bay front view and an array of food choices and restaurants. It is easily accessible via the Muni, BART, trolley or by cab. It is a must-see in San Francisco, and not too far from the Moscone Center. Ride the Trolley to the CastroFor only $2, you can get go back in history for a moment on the Trolley. Take the F-line from the Embarcadero and ride it all the way to the Castro district. During the ride, you will get an overview of the landscape and cultures that are prevalent in San Francisco, but be wary that some areas may beg for an open mind more than others. Golden Gate ParkWhen you tire of the concrete jungle, the lucky part of being in San Francisco is that you can escape to a natural refuge, this park being one of the favorites. This park is known for its hiking trails, cultural attractions, monuments, lakes and gardens. It is one good reason to bring your sneakers to San Francisco, and is also a great place to picnic. Please be wary that it is easy to get lost, and it is advisable to bring a map (just in case) if you go. Haight AshburyFor a complete change of scenery, Haight Ashbury is known as one of the places hippies used to live and the location of "The Summer of Love." It is now a more affluent neighborhood with boutique shops and the occasional drum circle. While it may be perceived as grungy in certain spots, it is one of the most photographed places in San Francisco and an integral part of San Franciscan history.

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  • ORA-7445 Troubleshooting

    - by [email protected]
        QUICKLINK: Note 153788.1 ORA-600/ORA-7445 Lookup tool Note 1082674.1 : A Video To Demonstrate The Usage Of The ORA-600/ORA-7445 Lookup Tool [Video]   Have you observed an ORA-07445 error reported in your alert log? While the ORA-600 error is "captured" as a handled exception in the Oracle source code, the ORA-7445 is an unhandled exception error due to an OS exception which should result in the creation of a core file.  An ORA-7445 is a generic error, and can occur from anywhere in the Oracle code. The precise location of the error is identified by the core file and/or trace file it produces.  Looking for the best way to diagnose? Whenever an ORA-7445 error is raised a core file is generated.  There may be a trace file generated with the error as well.   Prior to 11g, the core files are located in the CORE_DUMP_DEST directory.   Starting with 11g, there is a new advanced fault diagnosability infrastructure to manage trace data.  Diagnostic files are written into a root directory for all diagnostic data called the ADR home.   Core files at 11g will go to the ADR HOME/cdump directory.   For more information on the Oracle 11g Diagnosability feature see Note 453125.1 11g Diagnosability Frequently Asked Questions Note 443529.1 11g Quick Steps to Package and Send Critical Error Diagnostic Information to Support[Video]   NOTE:  While the core file is captured in the Diagnosability infrastructure, the file may not be included with a diagnostic package.1.  Check the Alert LogThe alert log may indicate additional errors or other internal errors at the time of the problem.   In some cases, the ORA-7445 error will occur along with ORA-600, ORA-3113, ORA-4030 errors.  The ORA-7445 error can be side effects of the other problems and you should review the first error and associated core file or trace file and work down the list of errors.   Note 1020463.6 DIAGNOSING ORA-3113 ERRORS Note 1812.1 TECH:  Getting a Stack Trace from a CORE file Note 414966.1 RDA Documentation Index   If the ORA-7445 errors are not associated with other error conditions, ensure the trace data is not truncated. If you see a message at the end of the file   "MAX DUMP FILE SIZE EXCEEDED"   the MAX_DUMP_FILE_SIZE parameter is not setup high enough or to 'unlimited'. There could be vital diagnostic information missing in the file and discovering the root issue may be very difficult.  Set the MAX_DUMP_FILE_SIZE appropriately and regenerate the error for complete trace information. For pointers on deeper analysis of these errors see   Note 390293.1 Introduction to 600/7445 Internal Error Analysis Note 211909.1 Customer Introduction to ORA-7445 Errors 2.  Search 600/7445 Lookup Tool Visit My Oracle Support to access the ORA-00600 Lookup tool (Note 153788.1). The ORA-600/ORA-7445 Lookup tool may lead you to applicable content in My Oracle Support on the problem and can be used to investigate the problem with argument data from the error message or you can pull out key stack pointers from the associated trace file to match up against known bugs.3.  "Fine tune" searches in Knowledge Base As the ORA-7445 error indicates an unhandled exception in the Oracle source code, your search in the Oracle Knowledge Base will need to focus on the stack data from the core file or the trace file. Keep in mind that searches on generic argument data will bring back a large result set.  The more you can learn about the environment and code leading to the errors, the easier it will be to narrow the hit list to match your problem. Note 153788.1 ORA-600/ORA-7445 TroubleshooterNote 1082674.1 A Video To Demonstrate The Usage Of The ORA-600/ORA-7445 Lookup Tool [Video] NOTE:  If no trace file is captured, see Note 1812.1 TECH:  Getting a Stack Trace from a CORE file.  Core files are managed through 11g Diagnosability, but are not packaged with other diagnostic data automatically.  The core files can be quite large, but may be useful during analysis within Oracle Support.4.  If assistance is required from Oracle Should it become necessary to get assistance from Oracle Support on an ORA-7445 problem, please provide at a minimum, the Alert log  Associated tracefile(s) or incident package at 11g Patch level  information Core file(s)  Information about changes in configuration and/or application prior to  issues  If error is reproducible, a self-contained reproducible testcase: Note.232963.1 How to Build a Testcase for Oracle Data Server Support to Reproduce ORA-600 and ORA-7445 Errors RDA report or Oracle Configuration Manager information Oracle Configuration Manager Quick Start Guide Note 548815.1 My Oracle Support Configuration Management FAQ Note 414966.1 RDA Documentation Index ***For reference to the content in this blog, refer to Note.1092832.1 Master Note for Diagnosing ORA-600

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  • Should one always know what an API is doing just by looking at the code?

    - by markmnl
    Recently I have been developing my own API and with that invested interest in API design I have been keenly interested how I can improve my API design. One aspect that has come up a couple times is (not by users of my API but in my observing discussion about the topic): one should know just by looking at the code calling the API what it is doing. For example see this discussion on GitHub for the discourse repo, it goes something like: foo.update_pinned(true, true); Just by looking at the code (without knowing the parameter names, documentation etc.) one cannot guess what it is going to do - what does the 2nd argument mean? The suggested improvement is to have something like: foo.pin() foo.unpin() foo.pin_globally() And that clears things up (the 2nd arg was whether to pin foo globally, I am guessing), and I agree in this case the later would certainly be an improvement. However I believe there can be instances where methods to set different but logically related state would be better exposed as one method call rather than separate ones, even though you would not know what it is doing just by looking at the code. (So you would have to resort to looking at the parameter names and documentation to find out - which personally I would always do no matter what if I am unfamiliar with an API). For example I expose one method SetVisibility(bool, string, bool) on a FalconPeer and I acknowledge just looking at the line: falconPeer.SetVisibility(true, "aerw3", true); You would have no idea what it is doing. It is setting 3 different values that control the "visibility" of the falconPeer in the logical sense: accept join requests, only with password and reply to discovery requests. Splitting this out into 3 method calls could lead to a user of the API to set one aspect of "visibility" forgetting to set others that I force them to think about by only exposing the one method to set all aspects of "visibility". Furthermore when the user wants to change one aspect they almost always will want to change another aspect and can now do so in one call.

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  • Experiencing the New Social Enterprise

    - by kellsey.ruppel(at)oracle.com
    Social media and networking tools, popularly known as Web 2.0 technologies, are rapidly transforming user expectations of enterprise systems. Many organizations are investing in these new tools to cultivate a modern user experience in an "Enterprise 2.0" environment that unlocks the full potential of traditional IT systems and fosters collaboration in key business processes. Is your organization a social enterprise? How are you using Web 2.0 and Enterprise 2.0 technologies? Read this white paper to learn how Oracle WebCenter Suite enables organizations to become social enterprises and is the modern user experience platform for the enterprise and the Web.

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  • What is your unique programming problem-solving style? [closed]

    - by gcc
    Everyone has their own styles and technique for approaching and solving real world problems. These distinguish us from other people or other programmers. (Actually, I think it make us more desirable as programmers and improves computer science) To improve, we read a lot of books; for example, programming style, how to solve problems, how to approach problems, software and algorithms, et al. Can I learn your technique? In other words, if someone gives you a problem, at first step, what are you doing to solve it? I want learn the style in which you approach, analyze, and solve a problem. EDIT: every programmer is a unique instance; each of us approach problems and converge on solutions in our own... idiomatic manner. This manner is sometimes a quirk of training, a bias of tools, but often it is an insightful nugget, a little golden hammer that cracks nuts just slightly faster then others. When answering, give your general approaches but also take a moment to identify how you look at things in ways that your peers do not. Let's call this your Unique Solving Perspective, or USP.

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  • How to document/verify consistent layering?

    - by Morten
    I have recently moved to the dark side: I am now a CUSTOMER of software development -- mainly websites. With this new role comes new concerns. As a programmer i know how solid an application becomes when it is properly layered, and I want to use this knowledge in my new job. I don't want business logic in my presentation layer, and certainly not presentation stuff in my data layer. Thus, I want to be able to demand from my supllier that they document the level of layering, and how neat and consistent the layering is. The big question is: How is the level of layering documented to me as a customer, and is that a reasonable demmand for me to have, so I don't have to look in the code (I'm not supposed to do that anymore)?

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  • Design patterns to avoiding breaking the SRP while performing heavy data logging

    - by Kazark
    A class that performs both computations and data logging seems to have at least two responsibilities. Given a system for which the specifications require heavy data logging, what kind of design patterns or architectural patterns can be used to avoid bloating all the classes with logging calls every time they compute something? The decorator pattern be used (e.g. Interpolator decorated to LoggingInterpolator), but it seems that would result in a situation hardly more desirable in which almost every major class would need to be decorated with logging.

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  • Boost your infrastructure with Coherence into the Cloud

    - by Nino Guarnacci
    Authors: Nino Guarnacci & Francesco Scarano,  at this URL could be found the original article:  http://blogs.oracle.com/slc/coherence_into_the_cloud_boost. Thinking about the enterprise cloud, come to mind many possible configurations and new opportunities in enterprise environments. Various customers needs that serve as guides to this new trend are often very different, but almost always united by two main objectives: Elasticity of infrastructure both Hardware and Software Investments related to the progressive needs of the current infrastructure Characteristics of innovation and economy. A concrete use case that I worked on recently demanded the fulfillment of two basic requirements of economy and innovation.The client had the need to manage a variety of data cache, which can process complex queries and parallel computational operations, maintaining the caches in a consistent state on different server instances, on which the application was installed.In addition, the customer was looking for a solution that would allow him to manage the likely situations in load peak during certain times of the year.For this reason, the customer requires a replication site, on which convey part of the requests during periods of peak; the desire was, however, to prevent the immobilization of investments in owned hardware-software architectures; so, to respond to this need, it was requested to seek a solution based on Cloud technologies and architectures already offered by the market. Coherence can already now address the requirements of large cache between different nodes in the cluster, providing further technology to search and parallel computing, with the simultaneous use of all hardware infrastructure resources. Moreover, thanks to the functionality of "Push Replication", which can replicate and update the information contained in the cache, even to a site hosted in the cloud, it is satisfied the need to make resilient infrastructure that can be based also on nodes temporarily housed in the Cloud architectures. There are different types of configurations that can be realized using the functionality "Push-Replication" of Coherence. Configurations can be either: Active - Passive  Hub and Spoke Active - Active Multi Master Centralized Replication Whereas the architecture of this particular project consists of two sites (Site 1 and Site Cloud), between which only Site 1 is enabled to write into the cache, it was decided to adopt an Active-Passive Configuration type (Hub and Spoke). If, however, the requirement should change over time, it will be particularly easy to change this configuration in an Active-Active configuration type. Although very simple, the small sample in this post, inspired by the specific project is effective, to better understand the features and capabilities of Coherence and its configurations. Let's create two distinct coherence cluster, located at miles apart, on two different domain contexts, one of them "hosted" at home (on-premise) and the other one hosted by any cloud provider on the network (or just the same laptop to test it :)). These two clusters, which we call Site 1 and Site Cloud, will contain the necessary information, so a simple client can insert data only into the Site 1. On both sites will be subscribed a listener, who listens to the variations of specific objects within the various caches. To implement these features, you need 4 simple classes: CachedResponse.java Represents the POJO class that will be inserted into the cache, and fulfills the task of containing useful information about the hypothetical links navigation ResponseSimulatorHelper.java Represents a link simulator, which has the task of randomly creating objects of type CachedResponse that will be added into the caches CacheCommands.java Represents the model of our example, because it is responsible for receiving instructions from the controller and performing basic operations against the cache, such as insert, delete, update, listening, objects within the cache Shell.java It is our controller, which give commands to be executed within the cache of the two Sites So, summarily, we execute the java class "Shell", asking it to put into the cache 100 objects of type "CachedResponse" through the java class "CacheCommands", then the simulator "ResponseSimulatorHelper" will randomly create new instances of objects "CachedResponse ". Finally, the Shell class will listen to for events occurring within the cache on the Site Cloud, while insertions and deletions are performed on Site 1. Now, we realize the two configurations of two respective sites / cluster: Site 1 and Site Cloud.For the Site 1 we define a cache of type "distributed" with features of "read and write", using the cache class store for the "push replication", a functionality offered by the project "incubator" of Oracle Coherence.For the "Site Cloud" we expect even the definition of “distributed” cache type with tcp proxy feature enabled, so it can receive updates from Site 1.  Coherence Cache Config XML file for "storage node" on "Site 1" site1-prod-cache-config.xml Coherence Cache Config XML file for "storage node" on "Site Cloud" site2-prod-cache-config.xml For two clients "Shell" which will connect respectively to the two clusters we have provided two easy access configurations.  Coherence Cache Config XML file for Shell on "Site 1" site1-shell-prod-cache-config.xml Coherence Cache Config XML file for Shell on "Site Cloud" site2-shell-prod-cache-config.xml Now, we just have to get everything and run our tests. To start at least one "storage" node (which holds the data) for the "Cloud Site", we can run the standard class  provided OOTB by Oracle Coherence com.tangosol.net.DefaultCacheServer with the following parameters and values:-Xmx128m-Xms64m-Dcom.sun.management.jmxremote -Dtangosol.coherence.management=all -Dtangosol.coherence.management.remote=true -Dtangosol.coherence.distributed.localstorage=true -Dtangosol.coherence.cacheconfig=config/site2-prod-cache-config.xml-Dtangosol.coherence.clusterport=9002-Dtangosol.coherence.site=SiteCloud To start at least one "storage" node (which holds the data) for the "Site 1", we can perform again the standard class provided by Coherence  com.tangosol.net.DefaultCacheServer with the following parameters and values:-Xmx128m-Xms64m-Dcom.sun.management.jmxremote -Dtangosol.coherence.management=all -Dtangosol.coherence.management.remote=true -Dtangosol.coherence.distributed.localstorage=true -Dtangosol.coherence.cacheconfig=config/site1-prod-cache-config.xml-Dtangosol.coherence.clusterport=9001-Dtangosol.coherence.site=Site1 Then, we start the first client "Shell" for the "Cloud Site", launching the java class it.javac.Shell  using these parameters and values: -Xmx64m-Xms64m-Dcom.sun.management.jmxremote -Dtangosol.coherence.management=all -Dtangosol.coherence.management.remote=true -Dtangosol.coherence.distributed.localstorage=false -Dtangosol.coherence.cacheconfig=config/site2-shell-prod-cache-config.xml-Dtangosol.coherence.clusterport=9002-Dtangosol.coherence.site=SiteCloud Finally, we start the second client "Shell" for the "Site 1", re-launching a new instance of class  it.javac.Shell  using  the following parameters and values: -Xmx64m-Xms64m-Dcom.sun.management.jmxremote -Dtangosol.coherence.management=all -Dtangosol.coherence.management.remote=true -Dtangosol.coherence.distributed.localstorage=false -Dtangosol.coherence.cacheconfig=config/site1-shell-prod-cache-config.xml-Dtangosol.coherence.clusterport=9001-Dtangosol.coherence.site=Site1  And now, let’s execute some tests to validate and better understand our configuration. TEST 1The purpose of this test is to load the objects into the "Site 1" cache and seeing how many objects are cached on the "Site Cloud". Within the "Shell" launched with parameters to access the "Site 1", let’s write and run the command: load test/100 Within the "Shell" launched with parameters to access the "Site Cloud" let’s write and run the command: size passive-cache Expected result If all is OK, the first "Shell" has uploaded 100 objects into a cache named "test"; consequently the "push-replication" functionality has updated the "Site Cloud" by sending the 100 objects to the second cluster where they will have been posted into a respective cache, which we named "passive-cache". TEST 2The purpose of this test is to listen to deleting and adding events happening on the "Site 1" and that are replicated within the cache on "Cloud Site". In the "Shell" launched with parameters to access the "Site Cloud" let’s write and run the command: listen passive-cache/name like '%' or a "cohql" query, with your preferred parameters In the "Shell" launched with parameters to access the "Site 1" let’s write and run the following commands: load test/10 load test2/20 delete test/50 Expected result If all is OK, the "Shell" to Site Cloud let us to listen to all the add and delete events within the cache "cache-passive", whose objects satisfy the query condition "name like '%' " (ie, every objects in the cache; you could change the tests and create different queries).Through the Shell to "Site 1" we launched the commands to add and to delete objects on different caches (test and test2). With the "Shell" running on "Site Cloud" we got the evidence (displayed or printed, or in a log file) that its cache has been filled with events and related objects generated by commands executed from the" Shell "on" Site 1 ", thanks to "push-replication" feature.  Other tests can be performed, such as, for example, the subscription to the events on the "Site 1" too, using different "cohql" queries, changing the cache configuration,  to effectively demonstrate both the potentiality and  the versatility produced by these different configurations, even in the cloud, as in our case. More information on how to configure Coherence "Push Replication" can be found in the Oracle Coherence Incubator project documentation at the following link: http://coherence.oracle.com/display/INC10/Home More information on Oracle Coherence "In Memory Data Grid" can be found at the following link: http://www.oracle.com/technetwork/middleware/coherence/overview/index.html To download and execute the whole sources and configurations of the example explained in the above post,  click here to download them; After download the last available version of the Push-Replication Pattern library implementation from the Oracle Coherence Incubator site, and download also the related and required version of Oracle Coherence. For simplicity the required .jarS to execute the example (that can be found into the Push-Replication-Pattern  download and Coherence Distribution download) are: activemq-core-5.3.1.jar activemq-protobuf-1.0.jar aopalliance-1.0.jar coherence-commandpattern-2.8.4.32329.jar coherence-common-2.2.0.32329.jar coherence-eventdistributionpattern-1.2.0.32329.jar coherence-functorpattern-1.5.4.32329.jar coherence-messagingpattern-2.8.4.32329.jar coherence-processingpattern-1.4.4.32329.jar coherence-pushreplicationpattern-4.0.4.32329.jar coherence-rest.jar coherence.jar commons-logging-1.1.jar commons-logging-api-1.1.jar commons-net-2.0.jar geronimo-j2ee-management_1.0_spec-1.0.jar geronimo-jms_1.1_spec-1.1.1.jar http.jar jackson-all-1.8.1.jar je.jar jersey-core-1.8.jar jersey-json-1.8.jar jersey-server-1.8.jar jl1.0.jar kahadb-5.3.1.jar miglayout-3.6.3.jar org.osgi.core-4.1.0.jar spring-beans-2.5.6.jar spring-context-2.5.6.jar spring-core-2.5.6.jar spring-osgi-core-1.2.1.jar spring-osgi-io-1.2.1.jar At this URL could be found the original article: http://blogs.oracle.com/slc/coherence_into_the_cloud_boost Authors: Nino Guarnacci & Francesco Scarano

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