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  • PTLQueue : a scalable bounded-capacity MPMC queue

    - by Dave
    Title: Fast concurrent MPMC queue -- I've used the following concurrent queue algorithm enough that it warrants a blog entry. I'll sketch out the design of a fast and scalable multiple-producer multiple-consumer (MPSC) concurrent queue called PTLQueue. The queue has bounded capacity and is implemented via a circular array. Bounded capacity can be a useful property if there's a mismatch between producer rates and consumer rates where an unbounded queue might otherwise result in excessive memory consumption by virtue of the container nodes that -- in some queue implementations -- are used to hold values. A bounded-capacity queue can provide flow control between components. Beware, however, that bounded collections can also result in resource deadlock if abused. The put() and take() operators are partial and wait for the collection to become non-full or non-empty, respectively. Put() and take() do not allocate memory, and are not vulnerable to the ABA pathologies. The PTLQueue algorithm can be implemented equally well in C/C++ and Java. Partial operators are often more convenient than total methods. In many use cases if the preconditions aren't met, there's nothing else useful the thread can do, so it may as well wait via a partial method. An exception is in the case of work-stealing queues where a thief might scan a set of queues from which it could potentially steal. Total methods return ASAP with a success-failure indication. (It's tempting to describe a queue or API as blocking or non-blocking instead of partial or total, but non-blocking is already an overloaded concurrency term. Perhaps waiting/non-waiting or patient/impatient might be better terms). It's also trivial to construct partial operators by busy-waiting via total operators, but such constructs may be less efficient than an operator explicitly and intentionally designed to wait. A PTLQueue instance contains an array of slots, where each slot has volatile Turn and MailBox fields. The array has power-of-two length allowing mod/div operations to be replaced by masking. We assume sensible padding and alignment to reduce the impact of false sharing. (On x86 I recommend 128-byte alignment and padding because of the adjacent-sector prefetch facility). Each queue also has PutCursor and TakeCursor cursor variables, each of which should be sequestered as the sole occupant of a cache line or sector. You can opt to use 64-bit integers if concerned about wrap-around aliasing in the cursor variables. Put(null) is considered illegal, but the caller or implementation can easily check for and convert null to a distinguished non-null proxy value if null happens to be a value you'd like to pass. Take() will accordingly convert the proxy value back to null. An advantage of PTLQueue is that you can use atomic fetch-and-increment for the partial methods. We initialize each slot at index I with (Turn=I, MailBox=null). Both cursors are initially 0. All shared variables are considered "volatile" and atomics such as CAS and AtomicFetchAndIncrement are presumed to have bidirectional fence semantics. Finally T is the templated type. I've sketched out a total tryTake() method below that allows the caller to poll the queue. tryPut() has an analogous construction. Zebra stripping : alternating row colors for nice-looking code listings. See also google code "prettify" : https://code.google.com/p/google-code-prettify/ Prettify is a javascript module that yields the HTML/CSS/JS equivalent of pretty-print. -- pre:nth-child(odd) { background-color:#ff0000; } pre:nth-child(even) { background-color:#0000ff; } border-left: 11px solid #ccc; margin: 1.7em 0 1.7em 0.3em; background-color:#BFB; font-size:12px; line-height:65%; " // PTLQueue : Put(v) : // producer : partial method - waits as necessary assert v != null assert Mask = 1 && (Mask & (Mask+1)) == 0 // Document invariants // doorway step // Obtain a sequence number -- ticket // As a practical concern the ticket value is temporally unique // The ticket also identifies and selects a slot auto tkt = AtomicFetchIncrement (&PutCursor, 1) slot * s = &Slots[tkt & Mask] // waiting phase : // wait for slot's generation to match the tkt value assigned to this put() invocation. // The "generation" is implicitly encoded as the upper bits in the cursor // above those used to specify the index : tkt div (Mask+1) // The generation serves as an epoch number to identify a cohort of threads // accessing disjoint slots while s-Turn != tkt : Pause assert s-MailBox == null s-MailBox = v // deposit and pass message Take() : // consumer : partial method - waits as necessary auto tkt = AtomicFetchIncrement (&TakeCursor,1) slot * s = &Slots[tkt & Mask] // 2-stage waiting : // First wait for turn for our generation // Acquire exclusive "take" access to slot's MailBox field // Then wait for the slot to become occupied while s-Turn != tkt : Pause // Concurrency in this section of code is now reduced to just 1 producer thread // vs 1 consumer thread. // For a given queue and slot, there will be most one Take() operation running // in this section. // Consumer waits for producer to arrive and make slot non-empty // Extract message; clear mailbox; advance Turn indicator // We have an obvious happens-before relation : // Put(m) happens-before corresponding Take() that returns that same "m" for T v = s-MailBox if v != null : s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 // unlock slot to admit next producer and consumer return v Pause tryTake() : // total method - returns ASAP with failure indication for auto tkt = TakeCursor slot * s = &Slots[tkt & Mask] if s-Turn != tkt : return null T v = s-MailBox // presumptive return value if v == null : return null // ratify tkt and v values and commit by advancing cursor if CAS (&TakeCursor, tkt, tkt+1) != tkt : continue s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 return v The basic idea derives from the Partitioned Ticket Lock "PTL" (US20120240126-A1) and the MultiLane Concurrent Bag (US8689237). The latter is essentially a circular ring-buffer where the elements themselves are queues or concurrent collections. You can think of the PTLQueue as a partitioned ticket lock "PTL" augmented to pass values from lock to unlock via the slots. Alternatively, you could conceptualize of PTLQueue as a degenerate MultiLane bag where each slot or "lane" consists of a simple single-word MailBox instead of a general queue. Each lane in PTLQueue also has a private Turn field which acts like the Turn (Grant) variables found in PTL. Turn enforces strict FIFO ordering and restricts concurrency on the slot mailbox field to at most one simultaneous put() and take() operation. PTL uses a single "ticket" variable and per-slot Turn (grant) fields while MultiLane has distinct PutCursor and TakeCursor cursors and abstract per-slot sub-queues. Both PTL and MultiLane advance their cursor and ticket variables with atomic fetch-and-increment. PTLQueue borrows from both PTL and MultiLane and has distinct put and take cursors and per-slot Turn fields. Instead of a per-slot queues, PTLQueue uses a simple single-word MailBox field. PutCursor and TakeCursor act like a pair of ticket locks, conferring "put" and "take" access to a given slot. PutCursor, for instance, assigns an incoming put() request to a slot and serves as a PTL "Ticket" to acquire "put" permission to that slot's MailBox field. To better explain the operation of PTLQueue we deconstruct the operation of put() and take() as follows. Put() first increments PutCursor obtaining a new unique ticket. That ticket value also identifies a slot. Put() next waits for that slot's Turn field to match that ticket value. This is tantamount to using a PTL to acquire "put" permission on the slot's MailBox field. Finally, having obtained exclusive "put" permission on the slot, put() stores the message value into the slot's MailBox. Take() similarly advances TakeCursor, identifying a slot, and then acquires and secures "take" permission on a slot by waiting for Turn. Take() then waits for the slot's MailBox to become non-empty, extracts the message, and clears MailBox. Finally, take() advances the slot's Turn field, which releases both "put" and "take" access to the slot's MailBox. Note the asymmetry : put() acquires "put" access to the slot, but take() releases that lock. At any given time, for a given slot in a PTLQueue, at most one thread has "put" access and at most one thread has "take" access. This restricts concurrency from general MPMC to 1-vs-1. We have 2 ticket locks -- one for put() and one for take() -- each with its own "ticket" variable in the form of the corresponding cursor, but they share a single "Grant" egress variable in the form of the slot's Turn variable. Advancing the PutCursor, for instance, serves two purposes. First, we obtain a unique ticket which identifies a slot. Second, incrementing the cursor is the doorway protocol step to acquire the per-slot mutual exclusion "put" lock. The cursors and operations to increment those cursors serve double-duty : slot-selection and ticket assignment for locking the slot's MailBox field. At any given time a slot MailBox field can be in one of the following states: empty with no pending operations -- neutral state; empty with one or more waiting take() operations pending -- deficit; occupied with no pending operations; occupied with one or more waiting put() operations -- surplus; empty with a pending put() or pending put() and take() operations -- transitional; or occupied with a pending take() or pending put() and take() operations -- transitional. The partial put() and take() operators can be implemented with an atomic fetch-and-increment operation, which may confer a performance advantage over a CAS-based loop. In addition we have independent PutCursor and TakeCursor cursors. Critically, a put() operation modifies PutCursor but does not access the TakeCursor and a take() operation modifies the TakeCursor cursor but does not access the PutCursor. This acts to reduce coherence traffic relative to some other queue designs. It's worth noting that slow threads or obstruction in one slot (or "lane") does not impede or obstruct operations in other slots -- this gives us some degree of obstruction isolation. PTLQueue is not lock-free, however. The implementation above is expressed with polite busy-waiting (Pause) but it's trivial to implement per-slot parking and unparking to deschedule waiting threads. It's also easy to convert the queue to a more general deque by replacing the PutCursor and TakeCursor cursors with Left/Front and Right/Back cursors that can move either direction. Specifically, to push and pop from the "left" side of the deque we would decrement and increment the Left cursor, respectively, and to push and pop from the "right" side of the deque we would increment and decrement the Right cursor, respectively. We used a variation of PTLQueue for message passing in our recent OPODIS 2013 paper. ul { list-style:none; padding-left:0; padding:0; margin:0; margin-left:0; } ul#myTagID { padding: 0px; margin: 0px; list-style:none; margin-left:0;} -- -- There's quite a bit of related literature in this area. I'll call out a few relevant references: Wilson's NYU Courant Institute UltraComputer dissertation from 1988 is classic and the canonical starting point : Operating System Data Structures for Shared-Memory MIMD Machines with Fetch-and-Add. Regarding provenance and priority, I think PTLQueue or queues effectively equivalent to PTLQueue have been independently rediscovered a number of times. See CB-Queue and BNPBV, below, for instance. But Wilson's dissertation anticipates the basic idea and seems to predate all the others. Gottlieb et al : Basic Techniques for the Efficient Coordination of Very Large Numbers of Cooperating Sequential Processors Orozco et al : CB-Queue in Toward high-throughput algorithms on many-core architectures which appeared in TACO 2012. Meneghin et al : BNPVB family in Performance evaluation of inter-thread communication mechanisms on multicore/multithreaded architecture Dmitry Vyukov : bounded MPMC queue (highly recommended) Alex Otenko : US8607249 (highly related). John Mellor-Crummey : Concurrent queues: Practical fetch-and-phi algorithms. Technical Report 229, Department of Computer Science, University of Rochester Thomasson : FIFO Distributed Bakery Algorithm (very similar to PTLQueue). Scott and Scherer : Dual Data Structures I'll propose an optimization left as an exercise for the reader. Say we wanted to reduce memory usage by eliminating inter-slot padding. Such padding is usually "dark" memory and otherwise unused and wasted. But eliminating the padding leaves us at risk of increased false sharing. Furthermore lets say it was usually the case that the PutCursor and TakeCursor were numerically close to each other. (That's true in some use cases). We might still reduce false sharing by incrementing the cursors by some value other than 1 that is not trivially small and is coprime with the number of slots. Alternatively, we might increment the cursor by one and mask as usual, resulting in a logical index. We then use that logical index value to index into a permutation table, yielding an effective index for use in the slot array. The permutation table would be constructed so that nearby logical indices would map to more distant effective indices. (Open question: what should that permutation look like? Possibly some perversion of a Gray code or De Bruijn sequence might be suitable). As an aside, say we need to busy-wait for some condition as follows : "while C == 0 : Pause". Lets say that C is usually non-zero, so we typically don't wait. But when C happens to be 0 we'll have to spin for some period, possibly brief. We can arrange for the code to be more machine-friendly with respect to the branch predictors by transforming the loop into : "if C == 0 : for { Pause; if C != 0 : break; }". Critically, we want to restructure the loop so there's one branch that controls entry and another that controls loop exit. A concern is that your compiler or JIT might be clever enough to transform this back to "while C == 0 : Pause". You can sometimes avoid this by inserting a call to a some type of very cheap "opaque" method that the compiler can't elide or reorder. On Solaris, for instance, you could use :"if C == 0 : { gethrtime(); for { Pause; if C != 0 : break; }}". It's worth noting the obvious duality between locks and queues. If you have strict FIFO lock implementation with local spinning and succession by direct handoff such as MCS or CLH,then you can usually transform that lock into a queue. Hidden commentary and annotations - invisible : * And of course there's a well-known duality between queues and locks, but I'll leave that topic for another blog post. * Compare and contrast : PTLQ vs PTL and MultiLane * Equivalent : Turn; seq; sequence; pos; position; ticket * Put = Lock; Deposit Take = identify and reserve slot; wait; extract & clear; unlock * conceptualize : Distinct PutLock and TakeLock implemented as ticket lock or PTL Distinct arrival cursors but share per-slot "Turn" variable provides exclusive role-based access to slot's mailbox field put() acquires exclusive access to a slot for purposes of "deposit" assigns slot round-robin and then acquires deposit access rights/perms to that slot take() acquires exclusive access to slot for purposes of "withdrawal" assigns slot round-robin and then acquires withdrawal access rights/perms to that slot At any given time, only one thread can have withdrawal access to a slot at any given time, only one thread can have deposit access to a slot Permissible for T1 to have deposit access and T2 to simultaneously have withdrawal access * round-robin for the purposes of; role-based; access mode; access role mailslot; mailbox; allocate/assign/identify slot rights; permission; license; access permission; * PTL/Ticket hybrid Asymmetric usage ; owner oblivious lock-unlock pairing K-exclusion add Grant cursor pass message m from lock to unlock via Slots[] array Cursor performs 2 functions : + PTL ticket + Assigns request to slot in round-robin fashion Deconstruct protocol : explication put() : allocate slot in round-robin fashion acquire PTL for "put" access store message into slot associated with PTL index take() : Acquire PTL for "take" access // doorway step seq = fetchAdd (&Grant, 1) s = &Slots[seq & Mask] // waiting phase while s-Turn != seq : pause Extract : wait for s-mailbox to be full v = s-mailbox s-mailbox = null Release PTL for both "put" and "take" access s-Turn = seq + Mask + 1 * Slot round-robin assignment and lock "doorway" protocol leverage the same cursor and FetchAdd operation on that cursor FetchAdd (&Cursor,1) + round-robin slot assignment and dispersal + PTL/ticket lock "doorway" step waiting phase is via "Turn" field in slot * PTLQueue uses 2 cursors -- put and take. Acquire "put" access to slot via PTL-like lock Acquire "take" access to slot via PTL-like lock 2 locks : put and take -- at most one thread can access slot's mailbox Both locks use same "turn" field Like multilane : 2 cursors : put and take slot is simple 1-capacity mailbox instead of queue Borrow per-slot turn/grant from PTL Provides strict FIFO Lock slot : put-vs-put take-vs-take at most one put accesses slot at any one time at most one put accesses take at any one time reduction to 1-vs-1 instead of N-vs-M concurrency Per slot locks for put/take Release put/take by advancing turn * is instrumental in ... * P-V Semaphore vs lock vs K-exclusion * See also : FastQueues-excerpt.java dice-etc/queue-mpmc-bounded-blocking-circular-xadd/ * PTLQueue is the same as PTLQB - identical * Expedient return; ASAP; prompt; immediately * Lamport's Bakery algorithm : doorway step then waiting phase Threads arriving at doorway obtain a unique ticket number Threads enter in ticket order * In the terminology of Reed and Kanodia a ticket lock corresponds to the busy-wait implementation of a semaphore using an eventcount and a sequencer It can also be thought of as an optimization of Lamport's bakery lock was designed for fault-tolerance rather than performance Instead of spinning on the release counter, processors using a bakery lock repeatedly examine the tickets of their peers --

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  • ISE (Germany) and Techdata Azlan: Exadata win over IBM at Immonet

    - by Javier Puerta
    Immonet, a subsidiary of German media company Axel Springer, provides cross-media real estate marketing via the Internet, newspapers, and other channels. The Immonet.de website is the number two German property portal with approximately 1.8 million unique visitors per month and over than 950,000 current online offerings. Read here how ISE solved with Exadata the performance problems that Immonet was experiencing.

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  • Some notes from the Collaboration Summit

    <b>LWN.net:</b> "Your editor has just returned from the Linux Foundation's annual Collaboration Summit, held in San Francisco. LFCS is a unique event; despite becoming more developer-heavy over the years, it still pulls together an interesting combination of people from the wider Linux ecosystem."

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  • Eclipse vs. Aptana

    - by RPK
    I know that Eclipse is a universal IDE and variety of plugins are available to scale it. What is the difference between: The original Eclipse IDE, Aptana and NetBeans. I looked into Wikipedia and came to know that the latter two originate from the main Eclipse. For Aptana specially, what was the need to reproduce a new variant that resembles too much with its base IDE? If your preferred choice is Eclipse itself, what makes it unique as compared to the other two.

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  • Bad Data is Really the Monster

    - by Dain C. Hansen
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Bad Data is really the monster – is an article written by Bikram Sinha who I borrowed the title and the inspiration for this blog. Sinha writes: “Bad or missing data makes application systems fail when they process order-level data. One of the key items in the supply-chain industry is the product (aka SKU). Therefore, it becomes the most important data element to tie up multiple merchandising processes including purchase order allocation, stock movement, shipping notifications, and inventory details… Bad data can cause huge operational failures and cost millions of dollars in terms of time, resources, and money to clean up and validate data across multiple participating systems. Yes bad data really is the monster, so what do we do about it? Close our eyes and hope it stays in the closet? We’ve tacked this problem for some years now at Oracle, and with our latest introduction of Oracle Enterprise Data Quality along with our integrated Oracle Master Data Management products provides a complete, best-in-class answer to the bad data monster. What’s unique about it? Oracle Enterprise Data Quality also combines powerful data profiling, cleansing, matching, and monitoring capabilities while offering unparalleled ease of use. What makes it unique is that it has dedicated capabilities to address the distinct challenges of both customer and product data quality – [different monsters have different needs of course!]. And the ability to profile data is just as important to identify and measure poor quality data and identify new rules and requirements. Included are semantic and pattern-based recognition to accurately parse and standardize data that is poorly structured. Finally all of the data quality components are integrated with Oracle Master Data Management, including Oracle Customer Hub and Oracle Product Hub, as well as Oracle Data Integrator Enterprise Edition and Oracle CRM. Want to learn more? On Tuesday Nov 15th, I invite you to listen to our webcast on Reduce ERP consolidation risks with Oracle Master Data Management I’ll be joined by our partner iGate Patni and be talking about one specific way to deal with the bad data monster specifically around ERP consolidation. Look forward to seeing you there!

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  • WebCenter Customer Spotlight: College of American Pathologists

    - by me
    Author: Peter Reiser - Social Business Evangelist, Oracle WebCenter  Solution Summary College of American Pathologists Goes Live with OracleWebCenter - Imaging, AP Invoice Automation, and EBS Managed Attachment with Support for Imaging ContentThe College of American Pathologists (CAP), the leading organization of board-certified pathologists serving more then 18,000 physician members, 7,000 laboratories are accredited by the CAP, and approximately 22,000 laboratories are enrolled in the College’s proficiency testing programs. The business objective was to content-enable their Oracle E-Business Suite (EBS) enterprise application by combining the best of Imaging and Manage Attachment functionality providing a unique opportunity for the business to have unprecedented access to both structure and unstructured content from within their enterprise application. The solution improves customer services turnaround time, provides better compliance and improves maintenance and management of the technology infrastructure. Company OverviewThe College of American Pathologists (CAP), celebrating 50 years as the gold standard in laboratory accreditation, is a medical society serving more than 17,000 physician members and the global laboratory community. It is the world’s largest association composed exclusively of board certified pathologists and is the worldwide leader in laboratory quality assurance. The College advocates accountable, high-quality, and cost-effective patient care. The more than 17,000 pathologist members of the College of American Pathologists represent board-certified pathologists and pathologists in training worldwide. More than 7,000 laboratories are accredited by the CAP, and approximately 23,000 laboratories are enrolled in the College’s proficiency testing programs.  Business ChallengesThe CAP business objective was to content-enable their Oracle E-Business Suite (EBS) enterprise application by combining the best of Imaging and Manage Attachment functionality providing a unique opportunity for the business to have unprecedented access to both structure and unstructured content from within their enterprise application.  Bring more flexibility to systems and programs in order to adapt quickly Get a 360 degree view of the customer Reduce cost of running the business Solution DeployedWith the help of Oracle Consulting, the customer implemented Oracle WebCenter Content as the centralized E-Business Suite Document Repository.  The solution enables to capture, present and manage all unstructured content (PDFs,word processing documents, scanned images, etc.) related to Oracle E-Business Suite transactions and exposing the related content using the familiar EBS User Interface. Business ResultsThe CAP achieved following benefits from the implemented solution: Managed Attachment Solution Align with strategic Oracle Fusion Middleware platform Integrate with the CAP existing data capture capabilities Single user interface provided by the Managed Attachment solution for all content Better compliance and improved collaboration  Account Payables Invoice Processing Imaging Solution Automated invoice management eliminating dependency on paper materials and improving compliance, collaboration and accuracy A single repository to house and secure scanned invoices and all supplemental documents Greater management visibility of invoice entry process Additional Information CAP OpenWorld Presentation Oracle WebCenter Content Oracle Webcenter Capture Oracle WebCenter Imaging Oracle  Consulting

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  • Titan – The Mystery of the Missing Waves

    - by Akemi Iwaya
    The moon Titan holds a unique distinction…it is the only other known ‘object’ in our solar system with a dense atmosphere and stable bodies of surface liquid. Unlike Earth though, there are no waves on Titan. This mystery has planetary scientists baffled and on a quest to understand this incredible phenomenon. Titan: The Mystery of the Missing Waves [YouTube]     

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  • % new visitor vs. % returning visitor

    - by Torben Gundtofte-Bruun
    I'm not sure how to interpret the results in Google Analytics. I understand that some metrics should be high, and some should be low. But this one I don't get: % new visitor vs. % returning visitor: It's good that users are returning, but surely it's also good to get new, fresh visitors. How do I evaluate this %-vs-% ratio? The higher the better: visits unique visitors pageviews pages per visit avg. visit duration The lower the better: bounce rate drop-offs

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  • Google Analytics - Showing multiple site stats at once

    - by John
    Is there a way in google analytics to add multiple sites to and show all the stats together? So like the graphs and total visits/unique hits all combined for all the sites added to the google analytics account? For example if I have: site1.com site2.com site3.com Under one google analytics account, is there a way in google analytics tool to merge them together so I can see a sum of all traffic in one report?

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  • ASP.NET MVC: Using ProfileRequiredAttribute to restrict access to pages

    - by DigiMortal
    If you are using AppFabric Access Control Services to authenticate users when they log in to your community site using Live ID, Google or some other popular identity provider, you need more than AuthorizeAttribute to make sure that users can access the content that is there for authenticated users only. In this posting I will show you hot to extend the AuthorizeAttribute so users must also have user profile filled. Semi-authorized users When user is authenticated through external identity provider then not all identity providers give us user name or other information we ask users when they join with our site. What all identity providers have in common is unique ID that helps you identify the user. Example. Users authenticated through Windows Live ID by AppFabric ACS have no name specified. Google’s identity provider is able to provide you with user name and e-mail address if user agrees to publish this information to you. They both give you unique ID of user when user is successfully authenticated in their service. There is logical shift between ASP.NET and my site when considering user as authorized. For ASP.NET MVC user is authorized when user has identity. For my site user is authorized when user has profile and row in my users table. Having profile means that user has unique username in my system and he or she is always identified by this username by other users. My solution is simple: I created my own action filter attribute that makes sure if user has profile to access given method and if user has no profile then browser is redirected to join page. Illustrating the problem Usually we restrict access to page using AuthorizeAttribute. Code is something like this. [Authorize] public ActionResult Details(string id) {     var profile = _userRepository.GetUserByUserName(id);     return View(profile); } If this page is only for site users and we have user profiles then all users – the ones that have profile and all the others that are just authenticated – can access the information. It is okay because all these users have successfully logged in in some service that is supported by AppFabric ACS. In my site the users with no profile are in grey spot. They are on half way to be users because they have no username and profile on my site yet. So looking at the image above again we need something that adds profile existence condition to user-only content. [ProfileRequired] public ActionResult Details(string id) {     var profile = _userRepository.GetUserByUserName(id);     return View(profile); } Now, this attribute will solve our problem as soon as we implement it. ProfileRequiredAttribute: Profiles are required to be fully authorized Here is my implementation of ProfileRequiredAttribute. It is pretty new and right now it is more like working draft but you can already play with it. public class ProfileRequiredAttribute : AuthorizeAttribute {     private readonly string _redirectUrl;       public ProfileRequiredAttribute()     {         _redirectUrl = ConfigurationManager.AppSettings["JoinUrl"];         if (string.IsNullOrWhiteSpace(_redirectUrl))             _redirectUrl = "~/";     }              public override void OnAuthorization(AuthorizationContext filterContext)     {         base.OnAuthorization(filterContext);           var httpContext = filterContext.HttpContext;         var identity = httpContext.User.Identity;           if (!identity.IsAuthenticated || identity.GetProfile() == null)             if(filterContext.Result == null)                 httpContext.Response.Redirect(_redirectUrl);          } } All methods with this attribute work as follows: if user is not authenticated then he or she is redirected to AppFabric ACS identity provider selection page, if user is authenticated but has no profile then user is by default redirected to main page of site but if you have application setting with name JoinUrl then user is redirected to this URL. First case is handled by AuthorizeAttribute and the second one is handled by custom logic in ProfileRequiredAttribute class. GetProfile() extension method To get user profile using less code in places where profiles are needed I wrote GetProfile() extension method for IIdentity interface. There are some more extension methods that read out user and identity provider identifier from claims and based on this information user profile is read from database. If you take this code with copy and paste I am sure it doesn’t work for you but you get the idea. public static User GetProfile(this IIdentity identity) {     if (identity == null)         return null;       var context = HttpContext.Current;     if (context.Items["UserProfile"] != null)         return context.Items["UserProfile"] as User;       var provider = identity.GetIdentityProvider();     var nameId = identity.GetNameIdentifier();       var rep = ObjectFactory.GetInstance<IUserRepository>();     var profile = rep.GetUserByProviderAndNameId(provider, nameId);       context.Items["UserProfile"] = profile;       return profile; } To avoid round trips to database I cache user profile to current request because the chance that profile gets changed meanwhile is very minimal. The other reason is maybe more tricky – profile objects are coming from Entity Framework context and context has also HTTP request as lifecycle. Conclusion This posting gave you some ideas how to finish user profiles stuff when you use AppFabric ACS as external authentication provider. Although there was little shift between us and ASP.NET MVC with interpretation of “authorized” we were easily able to solve the problem by extending AuthorizeAttribute to get all our requirements fulfilled. We also write extension method for IIdentity that returns as user profile based on username and caches the profile in HTTP request scope.

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  • Catch AutoVue at the COE 2010 PLM Conference

    - by [email protected]
    It's a busy tradeshow season! The AutoVue team will be exhibiting at next week's COE 2010 PLM Conference and Technifair in Las Vegas, NV. This will be a unique opportunity to meet with AutoVue visualization experts and discuss how to leverage visualization throughout your engineering organization to capitalize on product and engineering information to improve business processes, such as design reviews, change management and design revisions. If you plan on attending, be sure to stop by Oracle's AutoVue booth (#508). Click here for more details about the show.

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  • Effective SEO Article Tutorials and Guide For Newbie Web Content Creators

    Getting updated knowledge for how to write SEO articles is essential because of the steady changes occurring in the search engine algorithms. There are certain challenges that most newbie content writers are facing when it comes to dealing with the issues like website content creation. With the introduction of Web 2.0, it is necessary to use high quality unique content in marketing products or services on the internet.

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  • Why Simplicity is the Best Custom Logo Design Rule?

    When it comes to custom logo design everyone wants a unique and effective logo design. The main purpose of a logo design is to give a business / organization a visual identity. Now if we are talking ... [Author: Emily Matthew - Web Design and Development - March 31, 2010]

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  • Customer Experience Management : A conversation with world experts RTD

    - by David lefranc
    A conversation with world experts in Customer Experience Management in Rome, Italy - Wed, June 20, 2012 It is our pleasure to share the registration link below for your chance to meet active members of the Oracle Real-Time Decisions Customer Advisory Board. Join us to hear how leading brands across the world have achieved tremendous return on investment through their Oracle Real-Time Decisions deployments and do not miss this unique opportunity to ask them specific questions directly during our customer roundtable. Please share this information with anyone interested in real-time decision management and cross-channel predictive process optimization.http://www.oracle.com/goto/RealTimeDecisions

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  • Customer Experience Management : A conversation with world experts RTD

    - by David lefranc
    A conversation with world experts in Customer Experience Management in Rome, Italy - Wed, June 20, 2012 It is our pleasure to share the registration link below for your chance to meet active members of the Oracle Real-Time Decisions Customer Advisory Board. Join us to hear how leading brands across the world have achieved tremendous return on investment through their Oracle Real-Time Decisions deployments and do not miss this unique opportunity to ask them specific questions directly during our customer roundtable. Please share this information with anyone interested in real-time decision management and cross-channel predictive process optimization.http://www.oracle.com/goto/RealTimeDecisions

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  • The environment that is uniquely Oracle by Phillip Yi

    - by Nadiya
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 In the past month, I have been given the exclusive opportunity to hire a Legal graduate/intern for Oracle’s in-house Legal Counsel based here in North Ryde, Sydney. Whilst talking to various applicants, I am asked the same, broad question – what are we looking for? Time and time I have spoken about targeting the best, or targeting the best fit. I am an advocate of the latter, hence when approaching this question I answer very simply – ‘we are looking for the individual, that will fit into the culture and environment that is uniquely Oracle’. So, what is the environment/culture like here at Oracle? What makes Oracle so unique and a great place to work, especially as a graduate? Much like our business model, we are forward and innovative thinkers – we are not afraid to try new things, whether it is a success or failure. We are all highly driven, motivated and successful individuals – Oracle is a firm believer that in order to be driven, motivated and successful, you need to be surrounded by like minded people. And last, we are all autonomous and independent, self starters – at Oracle you are treated as an adult. We are not in the business of continually micro managing, nor constantly spoon feeding or holding your hand. Oracle has an amazing support, resource and training network – if you need support, extra training or resources it is there for your taking. And of course, if you do it on your own accord, you will learn it much quicker. For those reasons, Oracle is unique in its environment – we ensure and set up everyone for success. With such a great working environment/culture, why wouldn’t you choose Oracle? /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-family:"Calibri","sans-serif"; mso-ascii- mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi- mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • Website Design Customization

    Website design can be of two types- General or customized. If you are really serious and want to offer something new and unique through your website design, then customized services can fulfill this ... [Author: Alan Smith - Web Design and Development - May 18, 2010]

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  • On-Demand Webcast: Managing Oracle Exadata with Oracle Enterprise Manager 11g

    - by Scott McNeil
    Watch this on-demand webcast and discover how Oracle Enterprise Manager 11g's unique management capabilities allow you to efficiently manage all stages of Oracle Exadata's lifecycle, from testing applications on Exadata to deployment. You'll learn how to: Maximize and predict database performance Drive down IT operational costs through automation Ensure service quality with proactive management Register today and unlock the potential of Oracle Exadata for your enterprise. Register Now!

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  • Amazing Secret Monitor (How-To Trick)

    - by Akemi Iwaya
    If you have an extra monitor sitting around and love the idea of making it a bit more unique, then this monitor hack may be the perfect ‘trick’ to use for your next DIY project. Here is extra footage compiled during the making of the video above that you can enjoy watching. Amazing Secret Monitor! (How To) [YouTube] Amazing Secret Monitor – (Extra Footage) [YouTube]     

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  • Data Structures for Logic Games / Deduction Rules / Sufficient Set of Clues?

    - by taserian
    I've been cogitating about developing a logic game similar to Einstein's Puzzle , which would have different sets of clues for every new game replay. What data structures would you use to handle the different entities (pets, colors of houses, nationalities, etc.), deduction rules, etc. to guarantee that the clues you provide point to a unique solution? I'm having a hard time thinking about how to get the deduction rules to play along with the possible clues; any insight would be appreciated.

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  • Agile PLM Highlights from Oracle OpenWorld 2012

    - by Kerrie Foy
    Thank you to everyone who joined us at Oracle OpenWorld this year, either in person or virtually (thanks for tweeting #oowplm)!  From customer presentations to after-hours networking opportunities, there was a lot to see and do during the entire conference. Sessions It was our pleasure to feature several customer speakers during our PLM sessions at OpenWorld from such companies as Starbucks, Coca-Cola, Facebook, Eli Lilly, and many more.  Each had a unique perspective to share and fascinating insight into how they successfully leverage Agile PLM to facilitate profitable innovation, protect brand integrity, streamline operations, manage compliance, launch faster, etc.  For example, during the Product Value Chain keynote session, CIO Chris Bedi of JDSU shared how they implemented Agile PLM to support business imperatives around rapid innovation, centralizing product information, collaboration, and eliminate the “Excel gymnastics” required to obtain global portfolio visibility. In just 120 days after implementing, JDSU employees reported significant improvements around product record management, new product introduction, engineering collaboration and more, which created a better work environment to enable critical innovation. I could write on and on about the almost 20 sessions! So to spare yourselves, please visit launch.oracle.com/?plmopenworld2012; it’s a curated selection of PLM presentations from the OpenWorld Content Catalog and available on-demand. Enjoy! Agile Innovation Management During OpenWorld, we announced an exciting new addition to the Agile PLM applications called Innovation Management that redefines the industry’s scope of product lifecycle management.  Our broad vision of complete enterprise PLM for the entire Product Value Chain already broke new ground by helping organizations extend PLM disciplines downstream by connecting product design to commercialization processes; now we are helping executives look farther upstream in the early innovation phases to ultimately close the gap between strategy and execution that so commonly nags innovation initiatives.  More on this coming soon so stay tuned! Unique Networking Opportunities  We know it can be challenging during OpenWorld to find time to productively connect and network with your industry peers, so we hosted an Agile PLM “Birds of a Feather” networking brunch for the second year in a row.  At a fine restaurant close to Moscone we hosted nine tables, each with only ten seats to encourage active conversation.  Furthermore, guests could select from a list of predetermined table topics sponsored by a specialized PLM partner to guarantee – even more so – that they were seated with like-minded company and optimizing their time at the conference.  Everyone enjoyed the opportunity to easily connect with other PLM users during OpenWorld in a more casual setting. What’s Next? Thank you again to all who joined us!  If you haven't yet, mark your calendar to join us for the next Oracle Agile PLM conference at the Value Chain Summit in San Francisco, February 4-6 in 2013!  We’ll have 40 sessions of PLM content in four tracks. Don’t miss it! You can sign up to be notified when official registration opens by visiting www.oracle.com/goto/vcs. 

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  • Single paging Meta Tag Duplication [duplicate]

    - by Dominic Reigns
    This question already has an answer here: Should paginated content have unique meta tags? 1 answer How to make Google understand about single paging content issue ? A single page has got above 100 paging ? 1-10 of 199 Go to Page 12345678910 ... like this as mentioned above, Do I need to put fresh meta tag on each page ??? Help me out from this issue ?

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  • Card deck and sparse matrix interview questions

    - by MrDatabase
    I just had a technical phone screen w/ a start-up. Here's the technical questions I was asked ... and my answers. What do think of these answers? Feel free to post better answers :-) Question 1: how would you represent a standard 52 card deck in (basically any language)? How would you shuffle the deck? Answer: use an array containing a "Card" struct or class. Each instance of card has some unique identifier... either it's position in the array or a unique integer member variable in the range [0, 51]. Shuffle the cards by traversing the array once from index zero to index 51. Randomly swap ith card with "another card" (I didn't remember how this shuffle algorithm works exactly). Watch out for using the same probability for each card... that's a gotcha in this algorithm. I mentioned the algorithm is from Programming Pearls. Question 2: how to represent a large sparse matrix? the matrix can be very large... like 1000x1000... but only a relatively small number (~20) of the entries are non-zero. Answer: condense the array into a list of the non-zero entries. for a given entry (i,j) in the array... "map" (i,j) to a single integer k... then use k as a key into a dictionary or hashtable. For the 1000x1000 sparse array map (i,j) to k using something like f(i, j) = i + j * 1001. 1001 is just one plus the maximum of all i and j. I didn't recall exactly how this mapping worked... but the interviewer got the idea (I think). Are these good answers? I'm wondering because after I finished the second question the interviewer said the dreaded "well that's all the questions I have for now." Cheers!

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  • Own a KINECT for MS-XBOX before anyone does

    Following is the announced by Richik Nandi from Microsoft team. Dear Customer, We believe that our privileged customers shouldn't have to wait for good things. So, here's a special offer exclusively for you. Be one of the first in India to own and experience Kinect for XBOX 360, few days before it is even launched in stores. Introducing the new Kinect for XBOX 360®. Kinect needs no controllers. You are the controller. Kinect brings games and entertainment to life in extraordinary new ways without using a controller. The sensor recognizes your face, eyes and body movements to deliver a superb gaming experience. Easy to use and great fun, Kinect gets everyone off the couch. See a ball? Kick it. Want to join a friend in the fun? Simply jump in. Imagine controlling movies and music with the wave of a hand or the sound of your voice! Kinect is all about fun for you and your family. And the best part is Kinect works with every Xbox 360®. There are two options you can choose from: •  Kinect sensor + 4GB Xbox 360 bundle + Kinect Adventures game at Rs 22,990/-and get Dance Central game worth Rs 1999 from Redington, 20% discount voucher from Starwood on food and beverages, T-shirt from PUMA and a Kinect adventure live card absolutely free using your unique promo code : XbTXXZl2Sb •  Kinect Sensor at Rs 9,500/-and get 20% discount voucher from Starwood on food and beverages, T-shirt from PUMA and a Kinect adventure live card absolutely free using your unique promo code : lDg6o8SuYh We want you to own your Kinect before the official launch. The promotion closes by 10th November. To know more about Kinect click here. To book your Kinect PRE-ORDER now! Enter your details along with the above mentioned promo code to avail of the free gifts offer. We will have your Kinect delivered by 19th November 2010. Enjoy being the controller. Enjoy the Kinect. span.fullpost {display:none;}

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  • Basic Web Design Practices

    When the web designing concept was initially introduced, just having online website made a company unique from others and pushed it ahead of competition in the market. This is not the case anymore. A... [Author: Alan Smith - Web Design and Development - June 08, 2010]

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