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  • Which is Better - Paid Or Free Web Directories?

    There are thousands of human edited Web directories in the internet today although many are exiting this niche or business, new directories are being put up as each day passes by. Despite having so many Web directories to choose from at the end you will come up with two types of them, a paid and a free one and you might ask yourself which is better among them?

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  • High paid non-finance programming roles? [closed]

    - by Ian
    Besides finance (front-office/high frequency trading) developer roles, are there any other very well paid programming roles, specifically for C++ or Java? One particular industry I would find interesting is the energy industry? However, I completed an internship for one of the massive energy companies and their "IT department" was nothing more than Microsoft Access- they outsourced all the technical work to IBM and Accenture. EDIT: USD 110k+ Defense would sounds great except the fact I am not a US citizen :)

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  • Freelancing - Getting paid for the quote or estimate

    - by jah
    It is often necessary to spend time designing a solution, breaking down the design into tasks and sub tasks and estimating the time it will take to complete each task in order to produce a reasonable estimate or quote for a programming task. This process can be a serious investment of time, often without any guarantee that the estimate/quote will be acceptable to the potential client and more often that not the time was 'wasted' with no hope of getting paid for it (in the event of not winning the job). Is it the case that this is a cost of doing business and what can be done to minimise this unpaid time?

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  • How to publish paid Android apps if you're not from US/UK

    - by Sheikh Aman
    I was pretty excited while creating one of my apps but as it turns out you can't actually sign up for Google Checkout if you don't live either in the USA or in the UK. And since Google Checkout is the only way Android Market will pay you, all my efforts seem to be going in vain. So because I live in India, I can't sell my apps. I tried contacting Google by various means on this, but haven't got any response so far. I tried searching the web as well just to find out that one can't be paid via any other way. I am pretty sure that many people here might have gone through the same problem. How did you solve it? I have a PayPal account and an AdSense account as well. Can they help in any way? And if nothing works out, how am I supposed to be selling my app?

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  • Moving from building internal applications as WPF to ASP NET MVC?

    - by stuartmclark
    I have worked on quite a few internal applications for my work and I have always defaulted to using WPF, but I am considering re-writing existing ones into a web app. This is so that anyone in my company can use it without having to download anything from the network. I am just wondering if this is the way forward with any development of new internal applications? So, should I stop using WPF and start using ASP.NET MVC for internal applications that a lot of people need to use?

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  • Three Fusion Applications Communities are Now Live

    - by cwarticki
    The Fusion Application Support Team (FAST) launched three communities on the My Oracle Support Community.  These communities provide another channel for customers to get the information about Fusion Applications that they need. The three Fusion Applications communities are: ·     Technical - FA community -- covers all the Fusion Applications technology stack and technical questions from users. ·      Applications and Business Processes community -- covers all the functional questions and issues raised by users for all Fusion Applications except HCM. ·      Fusion Applications HCM community -- covers the functional questions and issues raised by users for Fusion HCM product family. Good for Our Customers Customers participating in these communities can ask questions and get timely responses from Oracle Fusion Applications experts who monitor the communities. The customers can search the Fusion Applications Community contents for information and answers. They also can collaborate with other customers and benefit from the collective experience of the community -- especially from people like you. All customers and partners are invited to join My Oracle Support Community for Fusion Applications. We believe that participating in the Fusion Applications communities can be a win-win option for everyone. We invite you to become an active part of the thriving Fusion Applications communities and experience how this interesting and insightful dialog can benefit you. How to Join the Community Navigate to http://communities.oracle.com. Click the Profile Tab to register yourself and edit your profile. ·         You can subscribe to the Fusion Applications communities by editing your Community Subscriptions. ·         You can get RSS feeds for each of your subscribed communities from the same section.

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  • Oracle Fusion Applications Design Patterns Now Available For Developers

    - by ultan o'broin
    The Oracle Fusion Applications user experience design patterns are published! These new, reusable usability solutions and best-practices, which will join the Oracle dashboard patterns and guidelines that are already available online, are used by Oracle to artfully bring to life a new standard in the user experience, or UX, of enterprise applications. Now, the Oracle applications development community can benefit from the science behind the Oracle Fusion Applications user experience, too. The design patterns are based on Oracle ADF components and easily implemented in Oracle JDeveloper. These Oracle Fusion Applications UX Design Patterns, or blueprints, enable Oracle applications developers and system implementers everywhere to leverage professional usability insight when: tailoring an Oracle Fusion application, creating coexistence solutions that existing users will be delighted with, thus enabling graceful user transitions to Oracle Fusion Applications down the road, or designing exciting, new, highly usable applications in the cloud or on-premise. Based on the Oracle Application Development Framework (ADF) components, the Oracle Fusion Applications patterns and guidelines are proven with real users and in the Applications UX usability labs, so you can get right to work coding productivity-enhancing designs that provide an advantage for your entire business. What’s the best way to get started? We’ve made that easy, too. The Design Filter Tool (DeFT) selects the best pattern for your user type and task. Simply adapt your selection for your own task flow and content, and you’re on your way to a really great applications user experience. More Oracle applications design patterns and training are coming your way in the future. To provide feedback on the sets that are currently available, let me know in the comments!.

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  • How can I easily identify all keyboard shortcuts (hotkeys) on OS X and current running Applications

    - by Michael Prescott
    By default, the function keys on my MacBook Pro control various hardware features and native operating system applications like the brightness of the LCD, Expose, or iTunes. I like these buttons and can use the fn button to take advantage of application Function keys when working with certain applications. Some service-type, background applications also have useful keyboard shortcuts. I tend to forget which keys are active at the moment and sometimes launch the wrong processes. Is there an application or operating system, native way of identifying all of the currently available keyboard shortcuts?

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  • Developing Mobile Applications: Web, Native, or Hybrid?

    - by Michelle Kimihira
    Authors: Joe Huang, Senior Principal Product Manager, Oracle Mobile Application Development Framework  and Carlos Chang, Senior Principal Product Director The proliferation of mobile devices and platforms represents a game-changing technology shift on a number of levels. Companies must decide not only the best strategic use of mobile platforms, but also how to most efficiently implement them. Inevitably, this conversation devolves to the developers, who face the task of developing and supporting mobile applications—not a simple task in light of the number of devices and platforms. Essentially, developers can choose from the following three different application approaches, each with its own set of pros and cons. Native Applications: This refers to apps built for and installed on a specific platform, such as iOS or Android, using a platform-specific software development kit (SDK).  For example, apps for Apple’s iPhone and iPad are designed to run specifically on iOS and are written in Xcode/Objective-C. Android has its own variation of Java, Windows uses C#, and so on.  Native apps written for one platform cannot be deployed on another. Native apps offer fast performance and access to native-device services but require additional resources to develop and maintain each platform, which can be expensive and time consuming. Mobile Web Applications: Unlike native apps, mobile web apps are not installed on the device; rather, they are accessed via a Web browser.  These are server-side applications that render HTML, typically adjusting the design depending on the type of device making the request.  There are no program coding constraints for writing server-side apps—they can be written in Java, C, PHP, etc., it doesn’t matter.  Instead, the server detects what type of mobile browser is pinging the server and adjusts accordingly. For example, it can deliver fully JavaScript and CSS-enabled content to smartphone browsers, while downgrading gracefully to basic HTML for feature phone browsers. Mobile apps work across platforms, but are limited to what you can do through a browser and require Internet connectivity. For certain types of applications, these constraints may not be an issue. Oracle supports mobile web applications via ADF Faces (for tablets) and ADF Mobile browser (Trinidad) for smartphone and feature phones. Hybrid Applications: As the name implies, hybrid apps combine technologies from native and mobile Web apps to gain the benefits each. For example, these apps are installed on a device, like their pure native app counterparts, while the user interface (UI) is based on HTML5.  This UI runs locally within the native container, which usually leverages the device’s browser engine.  The advantage of using HTML5 is a consistent, cross-platform UI that works well on most devices.  Combining this with the native container, which is installed on-device, provides mobile users with access to local device services, such as camera, GPS, and local device storage.  Native apps may offer greater flexibility in integrating with device native services.  However, since hybrid applications already provide device integrations that typical enterprise applications need, this is typically less of an issue.  The new Oracle ADF Mobile release is an HTML5 and Java hybrid framework that targets mobile app development to iOS and Android from one code base. So, Which is the Best Approach? The short answer is – the best choice depends on the type of application you are developing.  For instance, animation-intensive apps such as games would favor native apps, while hybrid applications may be better suited for enterprise mobile apps because they provide multi-platform support. Just for starters, the following issues must be considered when choosing a development path. Application Complexity: How complex is the application? A quick app that accesses a database or Web service for some data to display?  You can keep it simple, and a mobile Web app may suffice. However, for a mobile/field worker type of applications that supports mission critical functionality, hybrid or native applications are typically needed. Richness of User Interactivity: What type of user experience is required for the application?  Mobile browser-based app that’s optimized for mobile UI may suffice for quick lookup or productivity type of applications.  However, hybrid/native application would typically be required to deliver highly interactive user experiences needed for field-worker type of applications.  For example, interactive BI charts/graphs, maps, voice/email integration, etc.  In the most extreme case like gaming applications, native applications may be necessary to deliver the highly animated and graphically intensive user experience. Performance: What type of performance is required by the application functionality?  For instance, for real-time look up of data over the network, mobile app performance depends on network latency and server infrastructure capabilities.  If consistent performance is required, data would typically need to be cached, which is supported on hybrid or native applications only. Connectivity and Availability: What sort of connectivity will your application require? Does the app require Web access all the time in order to always retrieve the latest data from the server? Or do the requirements dictate offline support? While native and hybrid apps can be built to operate offline, Web mobile apps require Web connectivity. Multi-platform Requirements: The terms “consumerization of IT” and BYOD (bring your own device) effectively mean that the line between the consumer and the enterprise devices have become blurred. Employees are bringing their personal mobile devices to work and are often expecting that they work in the corporate network and access back-office applications.  Even if companies restrict access to the big dogs: (iPad, iPhone, Android phones and tablets, possibly Windows Phone and tablets), trying to support each platform natively will require increasing resources and domain expertise with each new language/platform. And let’s not forget the maintenance costs, involved in upgrading new versions of each platform.   Where multi-platform support is needed, Web mobile or hybrid apps probably have the advantage. Going native, and trying to support multiple operating systems may be cost prohibitive with existing resources and developer skills. Device-Services Access:  If your app needs to access local device services, such as the camera, contacts app, accelerometer, etc., then your choices are limited to native or hybrid applications.   Fragmentation: Apple controls Apple iOS and the only concern is what version iOS is running on any given device.   Not so Android, which is open source. There are many, many versions and variants of Android running on different devices, which can be a nightmare for app developers trying to support different devices running different flavors of Android.  (Is it an Amazon Kindle Fire? a Samsung Galaxy?  A Barnes & Noble Nook?) This is a nightmare scenario for native apps—on the other hand, a mobile Web or hybrid app, when properly designed, can shield you from these complexities because they are based on common frameworks.  Resources: How many developers can you dedicate to building and supporting mobile application development?  What are their existing skills sets?  If you’re considering native application development due to the complexity of the application under development, factor the costs of becoming proficient on a each platform’s OS and programming language. Add another platform, and that’s another language, another SDK. On the other side of the equation, Web mobile or hybrid applications are simpler to make, and readily support more platforms, but there may be performance trade-offs. Conclusion This only scratches the surface. However, I hope to have suggested some food for thought in choosing your mobile development strategy.  Do your due diligence, search the Web, read up on mobile, talk to peers, attend events. The development team at Oracle is working hard on mobile technologies to help customers extend enterprise applications to mobile faster and effectively.  To learn more on what Oracle has to offer, check out the Oracle ADF Mobile (hybrid) and ADF Faces/ADF Mobile browser (Web Mobile) solutions from Oracle.   Additional Information Blog: ADF Blog Product Information on OTN: ADF Mobile Product Information on Oracle.com: Oracle Fusion Middleware Follow us on Twitter and Facebook Subscribe to our regular Fusion Middleware Newsletter

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

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

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  • Announcing the Fusion Applications Blog

    - by Theresa Hickman
    Want to learn more about Oracle's next generation applications, Fusion Applications, from key executives, strategy and development leaders? We have a Fusion Applications blog. Steve Miranda, Senior Vice President, Applications Development of Oracle kicks off the Fusion Applications blog series @blogs.oracle.com/applications. Content will vary; some content will be applicable to all Fusion Applications families, and some will focus on a particular family (HCM, CRM, Financials, etc.) You can also follow them on Facebook www.facebook.com/OracleApps.

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  • [MINI HOW-TO] Redeem Pre-paid Zune Card Points for Zune Marketplace Media

    - by Mysticgeek
    If you don’t want to pay the monthly fee for a Zune Pass, one option is buying a pre-paid Zune card. Here we take a look at how to redeem the Zune card points so you can get music for your Zune or Zune HD. Of course the first thing you will need to do is buy a Zune card. You can find them for different amounts at most retail locations that sell Zune’s like Walmart, Best Buy…etc. When you purchase the card make sure the cashier activates it.   Now open up your Zune desktop software and sign in if you aren’t already. Go into Settings \ Account and under Microsoft Points click on Redeem Code. Now enter the code from the back of the card that you scratch off and hit Next. After entering in your code successfully it asks for your contact information, which seems odd considering you’re using a prepaid card. You may want to enter in a fictitious address and phone number if concerned about privacy…then click Next. The only thing you might want to enter in legitimately is your email address to get a confirmation email. You’re given a Thank you message… And back in your Account Settings you’ll see the points have been added. Now you can go shopping for music, videos, TV shows, and more at the Zune Marketplace. If you don’t want to give up your credit card info and pay the monthly fee for the Zune Pass, using prepaid card to purchase music as you go is a good alternative. Similar Articles Productive Geek Tips Update Your Zune Player SoftwareUnofficial Windows XP Themes Created by MicrosoftSweet Black Theme for Windows XPMake Windows XP Use a Custom Theme for the Classic Logon ScreenListen to Local FM Radio in Windows 7 Media Center TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 PCmover Professional Easily Sync Files & Folders with Friends & Family Amazon Free Kindle for PC Download Stretch popurls.com with a Stylish Script (Firefox) OldTvShows.org – Find episodes of Hitchcock, Soaps, Game Shows and more Download Microsoft Office Help tab The Growth of Citibank

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  • Application to automatically switch between two applications in Windows

    - by OverloadUT
    Does an application exist that will cause the computer to switch (bring in to focus) between two different applications, on a timer? This is for Windows 7. I need this for a screen that will display publicly to customers. I want the screen to switch between two different applications every, say, 30 seconds. I figure there are enough businesses out there will customer-facing monitors these days that something simple like this must exist!

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  • get the list of open applications on windows

    - by noam
    I want to have a script that does the following thing: connect to a remote windows machine get the list of applications that are currently open on the machine, e.g exactly what I would get in the "applications" tab in the task manager, and print it. Is it possible to do that in batch? If not, what other options do I have?

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  • Oracle Fusion Applications Design Patterns Now Available

    - by Frank Nimphius
    "The Oracle Fusion Applications user experience design patterns are published! These new, reusable usability solutions and best-practices, which will join Oracle dashboard patterns and guidelines that are already available online, are used by Oracle to artfully bring to life a new standard in the user experience, or UX, of enterprise applications. Now, the Oracle applications development community can benefit from the science behind the Oracle Fusion Applications user experience, too.These Oracle Fusion Applications UX Design Patterns, or blueprints, enable Oracle applications developers and system implementers everywhere to leverage professional usability insight when [...]  designing exciting, new, highly usable applications -- in the cloud or on-premise.  Based on the Oracle Application Development Framework (ADF) components, the Oracle Fusion Applications patterns and guidelines are proven with real users and in the Applications UX usability labs, so you can get right to work coding productivity-enhancing designs that provide an advantage for your entire business.  What’s the best way to get started? We’ve made that easy, too. The Design Filter Tool (DeFT) selects the best pattern for your user type and task. Simply adapt your selection for your own task flow and content, and you’re on your way to a really great applications user experience. More Oracle applications design patterns and training are coming your way in the future. To provide feedback on the sets that are currently available, let us know in the comments section or use the contact form provided."

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  • Lesser known Ubuntu desktop applications

    - by becomingGuru
    So, this Ubuntu software center comes with 100s of applications of all types. In this version they have disabled rating, making it hard to find how good it is. I found gnome-shell today, that seemed awesome. There are other ones, less well known, For eg, Abiword is far better than Open Office Org Word processor in many ways. (Altho' I dont like word processors themselves.) What are the other less well known applications that you use and like. One application per answer.

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  • Examples of applications where messages are guaranteed to turn up imediately

    - by James Hay
    I'm trying to find an example to show where data is sent from somewhere, whether manually or automatically, and is received IMMEDIATELY by the recipient, (doesn't matter whether we're talking mobile, desktop or whatever). An even better example would be where there were multiple recipients for the same message. It doesn't matter what the data is or the context it's used in, only the immediacy of receiving it. I was thinking that there might be some example in finance and the stock markets, but I haven't been able to find any through googling. IM clients are a great example of this and I think I'm basically looking for examples of applications that communicate over sockets. If anyone works on applications of this nature or knows of particular implementations, can you give me a quick run down of the use case and if it's commercial software the name of the software. This is all basically for research purposes so doesn't have to be particularly detailed. If anyone can help, thanks.

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  • Staying focussed - Any applications to monitor what windows are open, record the titles and then tell you what you spend you day doing?

    - by Rory McCann
    I am bad at procrastination. I'm always opening new tabs to check out HackerNews or something. So I've installed StayFocussed on Chromium, so that I can't view more than X minutes of certain sites. Is there something like this for the Ubuntu Desktop? It would work with applications, not websites (obviously). I would like an application that would monitor what windows I have open or visible, and limit me to only certain applications. Maybe give warnings if I spend to much time looking at IRC or something. Is there any applications for that?

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

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

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