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• JEP 124: Enhance the Certificate Revocation-Checking API

  - by smullan

  Revocation checking is the mechanism to determine the revocation status of a certificate. If it is revoked, it is considered invalid and should not be used. Currently as of JDK 7, the PKIX implementation of java.security.cert.CertPathValidator  includes a revocation checking implementation that supports both OCSP and CRLs, the two main methods of checking revocation. However, there are very few options that allow you to configure the behavior. You can always implement your own revocation checker, but that's a lot of work. JEP 124 (Enhance the Certificate Revocation-Checking API) is one of the 11 new security features in JDK 8. This feature enhances the java.security.cert API to support various revocation settings such as best-effort checking, end-entity certificate checking, and mechanism-specific options and parameters. Let's describe each of these in more detail and show some examples. The features are provided through a new class named PKIXRevocationChecker. A PKIXRevocationChecker instance is returned by a PKIX CertPathValidator as follows: CertPathValidator cpv = CertPathValidator.getInstance("PKIX"); PKIXRevocationChecker prc = (PKIXRevocationChecker)cpv.getRevocationChecker(); You can now set various revocation options by calling different methods of the returned PKIXRevocationChecker object. For example, the best-effort option (called soft-fail) allows the revocation check to succeed if the status cannot be obtained due to a network connection failure or an overloaded server. It is enabled as follows: prc.setOptions(Enum.setOf(Option.SOFT_FAIL)); When the SOFT_FAIL option is specified, you can still obtain any exceptions that may have been thrown due to network issues. This can be useful if you want to log this information or treat it as a warning. You can obtain these exceptions by calling the getSoftFailExceptions method: List<CertPathValidatorException> exceptions = prc.getSoftFailExceptions(); Another new option called ONLY_END_ENTITY allows you to only check the revocation status of the end-entity certificate. This can improve performance, but you should be careful using this option, as the revocation status of CA certificates will not be checked. To set more than one option, simply specify them together, for example: prc.setOptions(Enum.setOf(Option.SOFT_FAIL, Option.ONLY_END_ENTITY)); By default, PKIXRevocationChecker will try to check the revocation status of a certificate using OCSP first, and then CRLs as a fallback. However, you can switch the order using the PREFER_CRLS option, or disable the fallback altogether using the NO_FALLBACK option. For example, here is how you would only use CRLs to check the revocation status: prc.setOptions(Enum.setOf(Option.PREFER_CRLS, Option.NO_FALLBACK)); There are also a number of other useful methods which allow you to specify various options such as the OCSP responder URI, the trusted OCSP responder certificate, and OCSP request extensions. However, one of the most useful features is the ability to specify a cached OCSP response with the setOCSPResponse method. This can be quite useful if the OCSPResponse has already been obtained, for example in a protocol that uses OCSP stapling. After you have set all of your preferred options, you must add the PKIXRevocationChecker to your PKIXParameters object as one of your custom CertPathCheckers before you validate the certificate chain, as follows: PKIXParameters params = new PKIXParameters(keystore); params.addCertPathChecker(prc); CertPathValidatorResult result = cpv.validate(path, params); Early access binaries of JDK 8 can be downloaded from http://jdk8.java.net/download.html

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• ADO and Two Way Storage Tiering

  - by Andy-Oracle

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 We get asked the following question about Automatic Data Optimization (ADO) storage tiering quite a bit. Can you tier back to the original location if the data gets hot again? The answer is yes but not with standard Automatic Data Optimization policies, at least not reliably. That's not how ADO is meant to operate. ADO is meant to mirror a traditional view of Information Lifecycle Management (ILM) where data will be very volatile when first created, will become less active or cool, and then will eventually cease to be accessed at all (i.e. cold). I think the reason this question gets asked is because customers realize that many of their business processes are cyclical and the thinking goes that those segments that only get used during month end or year-end cycles could sit on lower cost storage when not being used. Unfortunately this doesn't fit very well with the ADO storage tiering model. ADO storage tiering is based on the amount of free and used space in the source tablespace. There are two parameters that control this behavior, TBS_PERCENT_USED and TBS_PERCENT_FREE. When the space in the tablespace exceeds the TBS_PERCENT_USED value then segments specified in storage tiering clause(s) can be moved until the percent of free space reaches the TBS_PERCENT_FREE value. It is worth mentioning that no checks are made for available space in the target tablespace. Now, it is certainly possible to create custom functions to control storage tiering, but this can get complicated. The biggest problem is insuring that there is enough space to move the segment back to tier 1 storage, assuming that that's the goal. This isn't as much of a problem when moving from tier 1 to tier 2 storage because there is typically more tier 2 storage available. At least that's the premise since it is supposed to be less costly, lower performing and higher capacity storage. In either case though, if there isn't enough space then the operation fails. In the case of a customized function, the question becomes do you attempt to free the space so the move can be made or do you just stop and return false so that the move cannot take place? This is really the crux of the issue. Once you cross into this territory you're really going to have to implement two-way hierarchical storage and the whole point of ADO was to provide automatic storage tiering. You're probably better off using heat map and/or business access requirements and building your own hierarchical storage management infrastructure if you really want two way storage tiering. /* 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:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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• Use a custom value object or a Guid as an entity identifier in a distributed system?

  - by Kazark

  tl;dr I've been told that in domain-driven design, an identifier for an entity could be a custom value object, i.e. something other than Guid, string, int, etc. Can this really be advisable in a distributed system? Long version I will invent an situation analogous to the one I am currently facing. Say I have a distributed system in which a central concept is an egg. The system allows you to order eggs and see spending reports and inventory-centric data such as quantity on hand, usage, valuation and what have you. There area variety of services backing these behaviors. And say there is also another app which allows you to compose recipes that link to a particular egg type. Now egg type is broken down by the species—ostrich, goose, duck, chicken, quail. This is fine and dandy because it means that users don't end up with ostrich eggs when they wanted quail eggs and whatnot. However, we've been getting complaints because jumbo chicken eggs are not even close to equivalent to small ones. The price is different, and they really aren't substitutable in recipes. And here we thought we were doing users a favor by not overwhelming them with too many options. Currently each of the services (say, OrderSubmitter, EggTypeDefiner, SpendingReportsGenerator, InventoryTracker, RecipeCreator, RecipeTracker, or whatever) are identifying egg types with an industry-standard integer representation the species (let's call it speciesCode). We realize we've goofed up because this change could effect every service. There are two basic proposed solutions: Use a predefined identifier type like Guid as the eggTypeID throughout all the services, but make EggTypeDefiner the only service that knows that this maps to a speciesCode and eggSizeCode (and potentially to an isOrganic flag in the future, or whatever). Use an EggTypeID value object which is a combination of speciesCode and eggSizeCode in every service. I've proposed the first solution because I'm hoping it better encapsulates the definition of what an egg type is in the EggTypeDefiner and will be more resilient to changes, say if some people now want to differentiate eggs by whether or not they are "organic". The second solution is being suggested by some people who understand DDD better than I do in the hopes that less enrichment and lookup will be necessary that way, with the justification that in DDD using a value object as an ID is fine. Also, they are saying that EggTypeDefiner is not a domain and EggType is not an entity and as such should not have a Guid for an ID. However, I'm not sure the second solution is viable. This "value object" is going to have to be serialized into JSON and URLs for GET requests and used with a variety of technologies (C#, JavaScript...) which breaks encapsulation and thus removes any behavior of the identifier value object (is either of the fields optional? etc.) Is this a case where we want to avoid something that would normally be fine in DDD because we are trying to do DDD in a distributed fashion? Summary Can it be a good idea to use a custom value object as an identifier in a distributed system (solution #2)?

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• Can you/should you develop components for ASP.NET MVC?

  - by Vilx-

  Following from the previous question I've started to wonder - is it possible to implement "Components" in ASP.NET MVC (latest version)? And should you? Let's clarify what I mean with a "component". With that I mean a "control" (aka "widget"), similar to those that ASP.NET webforms is built upon. A gridview might be a good example. In webforms I can place on my form a datasource component (one line of code), a gridview component (another line of code) and bind them together (specify an attribute on the gridview). In the codebehind file I fill the datasource with data (a few lines of DB-querying code), and I'm all set. At this point the gridview is a fully functional standalone component. I can open the form, and I'll see all the data. I can sort it by clicking on the column headers; it is split into several pages; I can drag the column headers around and rearrange columns; I can turn on "grouping" mode; etc. And I don't need to write another line of code for any of it. The gridview, as a component, already has all the code tucked away in its classes and assemblies. I just place it on the form, initialize it, and it Just Works. At some times (like sorting or navigation to a different page) it will also perform ajax callbacks to the server, but those too will be handled internally, with my code having no knowledge at all about it. And then there are also events that I can attach if I want to get notified when something happens. In MVC I cannot see a way of doing this cleanly. Sure, there are the partial views, but those only handle half of the problem - they render the initial HTML. Some more can be achieved with client-side Javascript (like column re-arranging), but when the grid needs to do an ajax callback (say, to fetch the next page of data), my code will have to get involved and process that request. At best I guess I can provide some helper methods to process it, but I'll have to write the code that calls them, and also provide a controller method with signature matching the arguments of that callback. I guess that I could make some hacks with global events or special routes or something, but that just seems... hackish. Unelegant. Perhaps this is not the MVC way? Although I've completed one project in it, I'm still far from being an MVC expert. But then what is? In the intranet application that we're building there are dozens upon dozens of such grids. Naturally I want them all to have a unified look & behavior, and I don't want to repeat the same code all over the place. So what's the "MVC" approach to this problem?

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• Identity in .NET 4.5&ndash;Part 3: (Breaking) changes

  - by Your DisplayName here!

  I recently started porting a private build of Thinktecture.IdentityModel to .NET 4.5 and noticed a number of changes. The good news is that I can delete large parts of my library because many features are now in the box. Along the way I found some other nice additions. ClaimsIdentity now has methods to query the claims collection, e.g. HasClaim(), FindFirst(), FindAll(). ClaimsPrincipal has those methods as well. But they work across all contained identities. Nice! ClaimsPrincipal.Current retrieves the ClaimsPrincipal from Thread.CurrentPrincipal. Combined with the above changes, no casting necessary anymore. SecurityTokenHandler now has read and write methods that work directly with strings. This makes it much easier to deal with non-XML tokens like SWT or JWT. A new session security token handler that uses the ASP.NET machine key to protect the cookie. This makes it easier to get started in web farm scenarios. No need for a custom service host factory or the federation behavior anymore. WCF can be switched into “WIF mode” with the useIdentityConfiguration switch (odd name though). Tooling has become better and the new test STS makes it very easy to get started. On the other hand – and that was kind of expected – to bring claims into the core framework, there are also some breaking changes for WIF code. If you want to migrate (and I would recommend that), most changes to your code are mechanical. The following is a brain dump of the changes I encountered. Assembly Microsoft.IdentityModel is gone. The new functionality is now in mscorlib, System.IdentityModel(.Services) and System.ServiceModel. All the namespaces have changed as well. No IClaimsPrincipal and IClaimsIdentity anymore. Configuration section has been split into <system.identityModel /> and <system.identityModel.services />. WCF configuration story has changed as well. Claim.ClaimType is now Claim.Type. ClaimCollection is now IEnumerable<Claim>. IsSessionMode is now IsReferenceMode. Bootstrap token handling is different now. ClaimsPrincipalHttpModule is gone. This is not really needed anymore, apart from maybe claims transformation (see here). Various factory methods on ClaimsPrincipal are gone (e.g. ClaimsPrincipal.CreateFromIdentity()). SecurityTokenHandler.ValidateToken now returns a ReadOnlyCollection<ClaimsIdentity>. Some lower level helper classes are gone or internal now (e.g. KeyGenerator). The WCF WS-Trust bindings are gone. I think this is a pity. They were *really* useful when doing work with WSTrustChannelFactory. Since WIF is part of the Windows operating system and also supported in future versions of .NET, there is no urgent need to migrate to the 4.5 claims model. But obviously, going forward, at some point you want to make the move.

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• No access to Samba shares

  - by koanhead

  I have three shared folders in my local home directory- that is to say, on my Ubuntu desktop's /home/me/. All were set up using "Sharing Options" in Nautilus' right-click menu. The standard "Music" and "Videos" folders are configured identically: the "Guest Access" box is checked, but the "Allow others to create and delete" is not. The third folder, called "shared", is configured to not allow Guest access but to allow others to modify files. I have not altered /etc/samba/smb.conf by hand, I have only used Sharing Options to create and modify these so-called "shares". My roommates have two Windows 7 computers and one Ubuntu Netbook Remix netbook. I have the aforementioned desktop machine and laptop running 10.04. None of these machines can access any of the shares. Attempts to access the Guest shares result in the message \\machine\directory is not accessible. The network name could not be found. This is the error message generated by a VM running Windows 2000. The other Windows machines generate a similar error. The Ubuntu laptop gives the error Unable to mount location: Failed to mount Windows share. Hurrah, once again, for informative error messages. That really helps a lot. When attempting to browse the folder called "shared" from the laptop, I'm confronted with a password dialog. This behavior is the same will all machines I've tried in the situation. On entering my username and password for the account to which the shares belong, the password dialog briefly disappears and is replaced with an identical dialog. No error message, useful or not, appears. When attempting to browse this folder with the VM, the outcome is the same except that the password dialog helpfully states "incorrect username or password". My assumption is that the username and password in question is that of the user which owns the shares. I have tried all other username and password combinations available in this context and the outcome is the same. I would like to be able to share files. Sharing them with Windows machines is a nice feature, or would be if it was available. Really I consider sharing files between two machines with the same version of the same operating system kind of a minimum condition for network usability. Samba last functioned reliably for me more than ten years ago. I have attempted to use it on and off since then with only intermittent success. Oh, and "Personal File Sharing" from the Preferences menu does not result in an entry in Places → Network → my-server. In fact, the old entry "MY-SERVER" goes away and is replaced by "koanhead's public files on my-server", which when I attempt to open it from the laptop gives a "DBus.Error.NoReply: Message did not receive a reply." I know I come here and gripe about Ubuntu a lot, but on the other hand I spend literally hours every day trying to fix things in Ubuntu. It's a good system which aspires to greatness, which is why things like this either Need to work; or Be adequately documented. Ideally both would be the case. Anyway, rant over. Hopefully someone will have some insight on this issue. Thanks all who bother to read this wall o'text for your time.

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• Is this over-abstraction? (And is there a name for it?)

  - by mwhite

  I work on a large Django application that uses CouchDB as a database and couchdbkit for mapping CouchDB documents to objects in Python, similar to Django's default ORM. It has dozens of model classes and a hundred or two CouchDB views. The application allows users to register a "domain", which gives them a unique URL containing the domain name that gives them access to a project whose data has no overlap with the data of other domains. Each document that is part of a domain has its domain property set to that domain's name. As far as relationships between the documents go, all domains are effectively mutually exclusive subsets of the data, except for a few edge cases (some users can be members of more than one domain, and there are some administrative reports that include all domains, etc.). The code is full of explicit references to the domain name, and I'm wondering if it would be worth the added complexity to abstract this out. I'd also like to know if there's a name for the sort of bound property approach I'm taking here. Basically, I have something like this in mind: Before in models.py class User(Document): domain = StringProperty() class Group(Document): domain = StringProperty() name = StringProperty() user_ids = StringListProperty() # method that returns related document set def users(self): return [User.get(id) for id in self.user_ids] # method that queries a couch view optimized for a specific lookup @classmethod def by_name(cls, domain, name): # the view method is provided by couchdbkit and handles # wrapping json CouchDB results as Python objects, and # can take various parameters modifying behavior return cls.view('groups/by_name', key=[domain, name]) # method that creates a related document def get_new_user(self): user = User(domain=self.domain) user.save() self.user_ids.append(user._id) return user in views.py: from models import User, Group # there are tons of views like this, (request, domain, ...) def create_new_user_in_group(request, domain, group_name): group = Group.by_name(domain, group_name)[0] user = User(domain=domain) user.save() group.user_ids.append(user._id) group.save() in group/by_name/map.js: function (doc) { if (doc.doc_type == "Group") { emit([doc.domain, doc.name], null); } } After models.py class DomainDocument(Document): domain = StringProperty() @classmethod def domain_view(cls, *args, **kwargs): kwargs['key'] = [cls.domain.default] + kwargs['key'] return super(DomainDocument, cls).view(*args, **kwargs) @classmethod def get(cls, *args, **kwargs, validate_domain=True): ret = super(DomainDocument, cls).get(*args, **kwargs) if validate_domain and ret.domain != cls.domain.default: raise Exception() return ret def models(self): # a mapping of all models in the application. accessing one returns the equivalent of class BoundUser(User): domain = StringProperty(default=self.domain) class User(DomainDocument): pass class Group(DomainDocument): name = StringProperty() user_ids = StringListProperty() def users(self): return [self.models.User.get(id) for id in self.user_ids] @classmethod def by_name(cls, name): return cls.domain_view('groups/by_name', key=[name]) def get_new_user(self): user = self.models.User() user.save() views.py @domain_view # decorator that sets request.models to the same sort of object that is returned by DomainDocument.models and removes the domain argument from the URL router def create_new_user_in_group(request, group_name): group = request.models.Group.by_name(group_name) user = request.models.User() user.save() group.user_ids.append(user._id) group.save() (Might be better to leave the abstraction leaky here in order to avoid having to deal with a couchapp-style //! include of a wrapper for emit that prepends doc.domain to the key or some other similar solution.) function (doc) { if (doc.doc_type == "Group") { emit([doc.name], null); } } Pros and Cons So what are the pros and cons of this? Pros: DRYer prevents you from creating related documents but forgetting to set the domain. prevents you from accidentally writing a django view - couch view execution path that leads to a security breach doesn't prevent you from accessing underlying self.domain and normal Document.view() method potentially gets rid of the need for a lot of sanity checks verifying whether two documents whose domains we expect to be equal are. Cons: adds some complexity hides what's really happening requires no model modules to have classes with the same name, or you would need to add sub-attributes to self.models for modules. However, requiring project-wide unique class names for models should actually be fine because they correspond to the doc_type property couchdbkit uses to decide which class to instantiate them as, which should be unique. removes explicit dependency documentation (from group.models import Group)

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

  - by Michael Snow

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

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• No access to Samba shares

  - by koanhead

  I have three shared folders in my local home directory- that is to say, on my Ubuntu desktop's /home/me/. All were set up using "Sharing Options" in Nautilus' right-click menu. The standard "Music" and "Videos" folders are configured identically: the "Guest Access" box is checked, but the "Allow others to create and delete" is not. The third folder, called "shared", is configured to not allow Guest access but to allow others to modify files. I have not altered /etc/samba/smb.conf by hand, I have only used Sharing Options to create and modify these so-called "shares". My roommates have two Windows 7 computers and one Ubuntu Netbook Remix netbook. I have the aforementioned desktop machine and laptop running 10.04. None of these machines can access any of the shares. Attempts to access the Guest shares result in the message \\machine\directory is not accessible. The network name could not be found. This is the error message generated by a VM running Windows 2000. The other Windows machines generate a similar error. The Ubuntu laptop gives the error Unable to mount location: Failed to mount Windows share. Hurrah, once again, for informative error messages. That really helps a lot. When attempting to browse the folder called "shared" from the laptop, I'm confronted with a password dialog. This behavior is the same will all machines I've tried in the situation. On entering my username and password for the account to which the shares belong, the password dialog briefly disappears and is replaced with an identical dialog. No error message, useful or not, appears. When attempting to browse this folder with the VM, the outcome is the same except that the password dialog helpfully states "incorrect username or password". My assumption is that the username and password in question is that of the user which owns the shares. I have tried all other username and password combinations available in this context and the outcome is the same. I would like to be able to share files. Sharing them with Windows machines is a nice feature, or would be if it was available. Really I consider sharing files between two machines with the same version of the same operating system kind of a minimum condition for network usability. Samba last functioned reliably for me more than ten years ago. I have attempted to use it on and off since then with only intermittent success. Oh, and "Personal File Sharing" from the Preferences menu does not result in an entry in Places → Network → my-server. In fact, the old entry "MY-SERVER" goes away and is replaced by "koanhead's public files on my-server", which when I attempt to open it from the laptop gives a "DBus.Error.NoReply: Message did not receive a reply." I know I come here and gripe about Ubuntu a lot, but on the other hand I spend literally hours every day trying to fix things in Ubuntu. It's a good system which aspires to greatness, which is why things like this either Need to work; or Be adequately documented. Ideally both would be the case. Anyway, rant over. Hopefully someone will have some insight on this issue. Thanks all who bother to read this wall o'text for your time.

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• Concurrent Affairs

  - by Tony Davis

  I once wrote an editorial, multi-core mania, on the conundrum of ever-increasing numbers of processor cores, but without the concurrent programming techniques to get anywhere near exploiting their performance potential. I came to the.controversial.conclusion that, while the problem loomed for all procedural languages, it was not a big issue for the vast majority of programmers. Two years later, I still think most programmers don't concern themselves overly with this issue, but I do think that's a bigger problem than I originally implied. Firstly, is the performance boost from writing code that can fully exploit all available cores worth the cost of the additional programming complexity? Right now, with quad-core processors that, at best, can make our programs four times faster, the answer is still no for many applications. But what happens in a few years, as the number of cores grows to 100 or even 1000? At this point, it becomes very hard to ignore the potential gains from exploiting concurrency. Possibly, I was optimistic to assume that, by the time we have 100-core processors, and most applications really needed to exploit them, some technology would be around to allow us to do so with relative ease. The ideal solution would be one that allows programmers to forget about the problem, in much the same way that garbage collection removed the need to worry too much about memory allocation. From all I can find on the topic, though, there is only a remote likelihood that we'll ever have a compiler that takes a program written in a single-threaded style and "auto-magically" converts it into an efficient, correct, multi-threaded program. At the same time, it seems clear that what is currently the most common solution, multi-threaded programming with shared memory, is unsustainable. As soon as a piece of state can be changed by a different thread of execution, the potential number of execution paths through your program grows exponentially with the number of threads. If you have two threads, each executing n instructions, then there are 2^n possible "interleavings" of those instructions. Of course, many of those interleavings will have identical behavior, but several won't. Not only does this make understanding how a program works an order of magnitude harder, but it will also result in irreproducible, non-deterministic, bugs. And of course, the problem will be many times worse when you have a hundred or a thousand threads. So what is the answer? All of the possible alternatives require a change in the way we write programs and, currently, seem to be plagued by performance issues. Software transactional memory (STM) applies the ideas of database transactions, and optimistic concurrency control, to memory. However, working out how to break down your program into sufficiently small transactions, so as to avoid contention issues, isn't easy. Another approach is concurrency with actors, where instead of having threads share memory, each thread runs in complete isolation, and communicates with others by passing messages. It simplifies concurrent programs but still has performance issues, if the threads need to operate on the same large piece of data. There are doubtless other possible solutions that I haven't mentioned, and I would love to know to what extent you, as a developer, are considering the problem of multi-core concurrency, what solution you currently favor, and why. Cheers, Tony.

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• Webcast On-Demand: Building Java EE Apps That Scale

  - by jeckels

  With some awesome work by one of our architects, Randy Stafford, we recently completed a webcast on scaling Java EE apps efficiently. Did you miss it? No problem. We have a replay available on-demand for you. Just hit the '+' sign drop-down for access.Topics include: Domain object caching Service response caching Session state caching JSR-107 HotCache and more! Further, we had several interesting questions asked by our audience, and we thought we'd share a sampling of those here for you - just in case you had the same queries yourself. Enjoy! What is the largest Coherence deployment out there? We have seen deployments with over 500 JVMs in the Coherence cluster, and deployments with over 1000 JVMs using the Coherence jar file, in one system. On the management side there is an ecosystem of monitoring tools from Oracle and third parties with dashboards graphing values from Coherence's JMX instrumentation. For lifecycle management we have seen a lot of custom scripting over the years, but we've also integrated closely with WebLogic to leverage its management ecosystem for deploying Coherence-based applications and managing process life cycles. That integration introduces a new Java EE archive type, the Grid Archive or GAR, which embeds in an EAR and can be seen by a WAR in WebLogic. That integration also doesn't require any extra WebLogic licensing if Coherence is licensed. How is Coherence different from a NoSQL Database like MongoDB? Coherence can be considered a NoSQL technology. It pre-dates the NoSQL movement, having been first released in 2001 whereas the term "NoSQL" was coined in 2009. Coherence has a key-value data model primarily but can also be used for document data models. Coherence manages data in memory currently, though disk persistence is in a future release currently in beta testing. Where the data is managed yields a few differences from the most well-known NoSQL products: access latency is faster with Coherence, though well-known NoSQL databases can manage more data. Coherence also has features that well-known NoSQL database lack, such as grid computing, eventing, and data source integration. Finally Coherence has had 15 years of maturation and hardening from usage in mission-critical systems across a variety of industries, particularly financial services. Can I use Coherence for local caching? Yes, you get additional features beyond just a java.util.Map: you get expiration capabilities, size-limitation capabilities, eventing capabilites, etc. Are there APIs available for GoldenGate HotCache? It's mostly a black box. You configure it, and it just puts objects into your caches. However you can treat it as a glass box, and use Coherence event interceptors to enhance its behavior - and there are use cases for that. Are Coherence caches updated transactionally? Coherence provides several mechanisms for concurrency control. If a project insists on full-blown JTA / XA distributed transactions, Coherence caches can participate as resources. But nobody does that because it's a performance and scalability anti-pattern. At finer granularity, Coherence guarantees strict ordering of all operations (reads and writes) against a single cache key if the operations are done using Coherence's "EntryProcessor" feature. And Coherence has a unique feature called "partition-level transactions" which guarantees atomic writes of multiple cache entries (even in different caches) without requiring JTA / XA distributed transaction semantics.

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• Activation Error while testing Exception Handling Application Block

  - by CletusLoomis

  I'm getting the following error while testing my EHAB implementation: {"Activation error occured while trying to get instance of type ExceptionPolicyImpl, key "LogPolicy""} System.Exception Stack Trace: StackTrace " at Microsoft.Practices.ServiceLocation.ServiceLocatorImplBase.GetInstance(Type serviceType, String key) in c:\Home\Chris\Projects\CommonServiceLocator\main\Microsoft.Practices.ServiceLocation\ServiceLocatorImplBase.cs:line 53 at Microsoft.Practices.ServiceLocation.ServiceLocatorImplBase.GetInstance[TService](String key) in c:\Home\Chris\Projects\CommonServiceLocator\main\Microsoft.Practices.ServiceLocation\ServiceLocatorImplBase.cs:line 103 at Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicy.GetExceptionPolicy(Exception exception, String policyName) in e:\Builds\EntLib\Latest\Source\Blocks\ExceptionHandling\Src\ExceptionHandling\ExceptionPolicy.cs:line 131 at Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicy.HandleException(Exception exceptionToHandle, String policyName) in e:\Builds\EntLib\Latest\Source\Blocks\ExceptionHandling\Src\ExceptionHandling\ExceptionPolicy.cs:line 55 at Blackbox.Exception.ExceptionMain.LogException(Exception pException) in C:_Work_Black Box\Blackbox.Exception\ExceptionMain.vb:line 14 at BlackBox.Business.BusinessMain.TestExceptionHandling() in C:_Work_Black Box\BlackBox.Business\BusinessMain.vb:line 16 at Blackbox.Service.Service1.TestExceptionHandling() in C:_Work_Black Box\Blackbox.Service\Service.svc.vb:line 43" String Inner Exception: InnerException {"Resolution of the dependency failed, type = "Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyImpl", name = "LogPolicy". Exception occurred while: Calling constructor Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.FormattedEventLogTraceListener(System.String source, System.String log, System.String machineName, Microsoft.Practices.EnterpriseLibrary.Logging.Formatters.ILogFormatter formatter). Exception is: ArgumentException - Event log names must consist of printable characters and cannot contain \, *, ?, or spaces At the time of the exception, the container was: Resolving Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyImpl,LogPolicy Resolving parameter "policyEntries" of constructor Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyImpl(System.String policyName, System.Collections.Generic.IEnumerable1[[Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyEntry, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]] policyEntries) Resolving Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyEntry,LogPolicy.All Exceptions Resolving parameter "handlers" of constructor Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyEntry(System.Type exceptionType, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.PostHandlingAction postHandlingAction, System.Collections.Generic.IEnumerable1[[Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.IExceptionHandler, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]] handlers, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Instrumentation.IExceptionHandlingInstrumentationProvider instrumentationProvider) Resolving Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging.LoggingExceptionHandler,LogPolicy.All Exceptions.Logging Exception Handler (mapped from Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.IExceptionHandler, LogPolicy.All Exceptions.Logging Exception Handler) Resolving parameter "writer" of constructor Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging.LoggingExceptionHandler(System.String logCategory, System.Int32 eventId, System.Diagnostics.TraceEventType severity, System.String title, System.Int32 priority, System.Type formatterType, Microsoft.Practices.EnterpriseLibrary.Logging.LogWriter writer) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterImpl,LogWriter.default (mapped from Microsoft.Practices.EnterpriseLibrary.Logging.LogWriter, (none)) Resolving parameter "structureHolder" of constructor Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterImpl(Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterStructureHolder structureHolder, Microsoft.Practices.EnterpriseLibrary.Logging.Instrumentation.ILoggingInstrumentationProvider instrumentationProvider, Microsoft.Practices.EnterpriseLibrary.Logging.ILoggingUpdateCoordinator updateCoordinator) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterStructureHolder,LogWriterStructureHolder.default (mapped from Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterStructureHolder, (none)) Resolving parameter "traceSources" of constructor Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterStructureHolder(System.Collections.Generic.IEnumerable1[[Microsoft.Practices.EnterpriseLibrary.Logging.Filters.ILogFilter, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]] filters, System.Collections.Generic.IEnumerable1[[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] traceSourceNames, System.Collections.Generic.IEnumerable1[[Microsoft.Practices.EnterpriseLibrary.Logging.LogSource, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]] traceSources, Microsoft.Practices.EnterpriseLibrary.Logging.LogSource allEventsTraceSource, Microsoft.Practices.EnterpriseLibrary.Logging.LogSource notProcessedTraceSource, Microsoft.Practices.EnterpriseLibrary.Logging.LogSource errorsTraceSource, System.String defaultCategory, System.Boolean tracingEnabled, System.Boolean logWarningsWhenNoCategoriesMatch, System.Boolean revertImpersonation) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.LogSource,General Resolving parameter "traceListeners" of constructor Microsoft.Practices.EnterpriseLibrary.Logging.LogSource(System.String name, System.Collections.Generic.IEnumerable1[[System.Diagnostics.TraceListener, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] traceListeners, System.Diagnostics.SourceLevels level, System.Boolean autoFlush, Microsoft.Practices.EnterpriseLibrary.Logging.Instrumentation.ILoggingInstrumentationProvider instrumentationProvider) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.ReconfigurableTraceListenerWrapper,Event Log Listener (mapped from System.Diagnostics.TraceListener, Event Log Listener) Resolving parameter "wrappedTraceListener" of constructor Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.ReconfigurableTraceListenerWrapper(System.Diagnostics.TraceListener wrappedTraceListener, Microsoft.Practices.EnterpriseLibrary.Logging.ILoggingUpdateCoordinator coordinator) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.FormattedEventLogTraceListener,Event Log Listener?implementation (mapped from System.Diagnostics.TraceListener, Event Log Listener?implementation) Calling constructor Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.FormattedEventLogTraceListener(System.String source, System.String log, System.String machineName, Microsoft.Practices.EnterpriseLibrary.Logging.Formatters.ILogFormatter formatter) "} System.Exception My web.config is as follows: <?xml version="1.0"?> <configuration> <configSections> <section name="loggingConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Logging.Configuration.LoggingSettings, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="true" /> <section name="exceptionHandling" type="Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Configuration.ExceptionHandlingSettings, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="true" /> </configSections> <loggingConfiguration name="" tracingEnabled="true" defaultCategory="General"> <listeners> <add name="Event Log Listener" type="Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.FormattedEventLogTraceListener, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" listenerDataType="Microsoft.Practices.EnterpriseLibrary.Logging.Configuration.FormattedEventLogTraceListenerData, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" source="Enterprise Library Logging" formatter="Text Formatter" log="C:\Blackbox.log" machineName="." traceOutputOptions="LogicalOperationStack, DateTime, Timestamp, Callstack" /> </listeners> <formatters> <add type="Microsoft.Practices.EnterpriseLibrary.Logging.Formatters.TextFormatter, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" template="Timestamp: {timestamp}{newline}&#xA;Message: {message}{newline}&#xA;Category: {category}{newline}&#xA;Priority: {priority}{newline}&#xA;EventId: {eventid}{newline}&#xA;Severity: {severity}{newline}&#xA;Title:{title}{newline}&#xA;Machine: {localMachine}{newline}&#xA;App Domain: {localAppDomain}{newline}&#xA;ProcessId: {localProcessId}{newline}&#xA;Process Name: {localProcessName}{newline}&#xA;Thread Name: {threadName}{newline}&#xA;Win32 ThreadId:{win32ThreadId}{newline}&#xA;Extended Properties: {dictionary({key} - {value}{newline})}" name="Text Formatter" /> </formatters> <categorySources> <add switchValue="All" name="General"> <listeners> <add name="Event Log Listener" /> </listeners> </add> </categorySources> <specialSources> <allEvents switchValue="All" name="All Events" /> <notProcessed switchValue="All" name="Unprocessed Category" /> <errors switchValue="All" name="Logging Errors &amp; Warnings"> <listeners> <add name="Event Log Listener" /> </listeners> </errors> </specialSources> </loggingConfiguration> <exceptionHandling> <exceptionPolicies> <add name="LogPolicy"> <exceptionTypes> <add name="All Exceptions" type="System.Exception, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" postHandlingAction="NotifyRethrow"> <exceptionHandlers> <add name="Logging Exception Handler" type="Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging.LoggingExceptionHandler, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" logCategory="General" eventId="100" severity="Error" title="Enterprise Library Exception Handling" formatterType="Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.TextExceptionFormatter, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling" priority="0" /> </exceptionHandlers> </add> </exceptionTypes> </add> <add name="WcfExceptionShielding"> <exceptionTypes> <add name="InvalidOperationException" type="System.InvalidOperationException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" postHandlingAction="ThrowNewException"> <exceptionHandlers> <add type="Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.WCF.FaultContractExceptionHandler, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.WCF, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" exceptionMessageResourceType="" exceptionMessageResourceName="This is the message" exceptionMessage="This is the exception" faultContractType="Blackbox.Service.WCFFault, Blackbox.Service, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Fault Contract Exception Handler"> <mappings> <add source="{Guid}" name="Id" /> <add source="{Message}" name="MessageText" /> </mappings> </add> </exceptionHandlers> </add> </exceptionTypes> </add> </exceptionPolicies> </exceptionHandling> <connectionStrings> <add name="CompassEntities" connectionString="metadata=~\bin\CompassModel.csdl|~\bin\CompassModel.ssdl|~\bin\CompassModel.msl;provider=Devart.Data.Oracle;provider connection string=&quot;User Id=foo;Password=foo;Server=foo64mo;Home=OraClient11g_home1;Persist Security Info=True&quot;" providerName="System.Data.EntityClient" /> <add name="BlackboxEntities" connectionString="metadata=~\bin\BlackboxModel.csdl|~\bin\BlackboxModel.ssdl|~\bin\BlackboxModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=sqldev1\cps;Initial Catalog=FundServ;Integrated Security=True;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient" /> </connectionStrings> <system.web> <compilation debug="true" strict="false" explicit="true" targetFramework="4.0" /> </system.web> <system.serviceModel> <behaviors> <serviceBehaviors> <behavior> <!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment --> <serviceMetadata httpGetEnabled="true"/> <!-- To receive exception details in faults for debugging purposes, set the value below to true. Set to false before deployment to avoid disclosing exception information --> <serviceDebug includeExceptionDetailInFaults="false"/> </behavior> </serviceBehaviors> </behaviors> <serviceHostingEnvironment multipleSiteBindingsEnabled="true" /> </system.serviceModel> <system.webServer> <modules runAllManagedModulesForAllRequests="true"/> </system.webServer> </configuration> My code is as follows: Public Shared Function LogException(ByVal pException As System.Exception) As Boolean Return ExceptionPolicy.HandleException(pException, "LogPolicy") End Function Any assistance is appreciated.

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• Reactive Extensions vs FileSystemWatcher

  - by Joel Mueller

  One of the things that has long bugged me about the FileSystemWatcher is the way it fires multiple events for a single logical change to a file. I know why it happens, but I don't want to have to care - I just want to reparse the file once, not 4-6 times in a row. Ideally, there would be an event that only fires when a given file is done changing, rather than every step along the way. Over the years I've come up with various solutions to this problem, of varying degrees of ugliness. I thought Reactive Extensions would be the ultimate solution, but there's something I'm not doing right, and I'm hoping someone can point out my mistake. I have an extension method: public static IObservable<IEvent<FileSystemEventArgs>> GetChanged(this FileSystemWatcher that) { return Observable.FromEvent<FileSystemEventArgs>(that, "Changed"); } Ultimately, I would like to get one event per filename, within a given time period - so that four events in a row with a single filename are reduced to one event, but I don't lose anything if multiple files are modified at the same time. BufferWithTime sounds like the ideal solution. var bufferedChange = watcher.GetChanged() .Select(e => e.EventArgs.FullPath) .BufferWithTime(TimeSpan.FromSeconds(1)) .Where(e => e.Count > 0) .Select(e => e.Distinct()); When I subscribe to this observable, a single change to a monitored file triggers my subscription method four times in a row, which rather defeats the purpose. If I remove the Distinct() call, I see that each of the four calls contains two identical events - so there is some buffering going on. Increasing the TimeSpan passed to BufferWithTime seems to have no effect - I went as high as 20 seconds without any change in behavior. This is my first foray into Rx, so I'm probably missing something obvious. Am I doing it wrong? Is there a better approach? Thanks for any suggestions...

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• RadGrid nestedview sort makes nestedview disappear?

  - by lance

  When I click on the header of my detail table, it disappears entirely, leaving empty white space in the browser where it used to be. The Ajax postback caused by my clicking on the header does fire FooGridNeedDataSource and FooGridItemCommand, but I've used the debugger to skip the code inside those handlers (after clicking the header of the column I'm trying to sort, in the detail table), and I still get the same behavior. I'm hoping someone can tell me what I'm doing wrong? The MasterTableView sorts just fine (my real markup enables that with AllowSorting="true" on MasterTableView). <telerik:RadGrid ID="FooGrid" runat="server" AutoGenerateColumns="false" OnNeedDataSource="FooGridNeedDataSource" OnItemCommand="FooGridItemCommand" > <MasterTableView ClientDataKeyNames="FooData" DataKeyNames="FooData"> <Columns> <telerik:GridBoundColumn DataField="FooData" HeaderText="Foo"></telerik:GridBoundColumn> </Columns> <DetailTables> <telerik:GridTableView AllowSorting="true"> <Columns> <telerik:GridBoundColumn DataField="FooDetailData" HeaderText="Foo Detail" ></telerik:GridBoundColumn> </Columns> </telerik:GridTableView> </DetailTables> </MasterTableView> </telerik:RadGrid>

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• Is it OK to set "Cache-Control: public" when sending “304 Not Modified” for images stored in the dat

  - by Emilien

  After asking a question about sending “304 Not Modified” for images stored in the in the Google App Engine datastore, I now have a question about Cache-Control. My app now sends Last-Modified and Etag, but by default GAE alsto sends Cache-Control: no-cache. According to this page: The “no-cache” directive, according to the RFC, tells the browser that it should revalidate with the server before serving the page from the cache. [...] In practice, IE and Firefox have started treating the no-cache directive as if it instructs the browser not to even cache the page. As I DO want browsers to cache the image, I've added the following line to my code: self.response.headers['Cache-Control'] = "public" According to the same page as before: The “cache-control: public” directive [...] tells the browser and proxies [...] that the page may be cached. This is good for non-sensitive pages, as caching improves performance. The question is if this could be harmful to the application in some way? Would it be best to send Cache-Control: must-revalidate to "force" the browser to revalidate (I suppose that is the behavior that was originally the reason behind sending Cache-Control: no-cache) This directive insists that the browser must revalidate the page against the server before serving it from cache. Note that it implicitly lets the browser cache the page.

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• Random DNS Client Issue with BIND9/Windows Server 2003 DNS

  - by upkels

  Within our office, we have a local server running DNS, for internal related "domains", (e.g. .internal, .office, .lan, .vpn, etc.). Randomly, only the hosts configured with those extensions will stop resolving on the Windows-based workstations. Sometimes it'll work for a couple weeks without issue on one machine, then suddenly stop working, or it'll happen on another 15 times per day. It's completely random for all workstations. When troubleshooting, I have opened up a command prompt, and issued various nslookup commands for some of these hosts, and they resolve, however I've been told that nslookup uses different "libraries" for name resolution than other applications such as web browsers, email clients, etc. The only solution thus far, is manually restarting the Windows DNS Client on each workstation when this happens. Issuing the ipconfig /flushdns command multiple times helps every now and then, but is not successful enough to even attempt before restarting the DNS Client. I have tried two different DNS servers; BIND9, and Windows Server 2003 R2 DNS, and the behavior is the same. We have a single Netgear JGS524 switch all workstations and servers are connected to within the office, and a Linksys SR224G switch in another department with workstations attached.

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• Managing Dependency Hell with WiX and C#

  - by Tom the Junglist

  We are on the eve of product launch, and at the last minute I am being bombarded with crash reports that appear to be related to our installer, which is a WiX3 project with separate outputs for x86 and x64 builds. These have been an ongoing problem that I always thought were fixed, only to find out that they were still lurking. The product itself is a collection of binaries that communicate with each other via .Net remoting, including a Windows Service and a small COM component that is loaded as an addon in another app. The service runs as SYSTEM, the COM piece runs in a low-rights context, while the other pieces run in normal user contexts. Other pieces include an third-party COM object library DLL and a shared DLL with the .net Remoting interfaces. I've observed flat-out weird behavior with MSI, particularly on version upgrades. Between MS' anal strong-name implementation (specifically, the exact version check before loading a given assembly), a documented WiX/MSI bug that sees critical files erased on upgrades (essentially, if a file in the upgrade MSI has the same version number as the existing install, that file is deleted), and having to work around Wow64 virtualization (x86 MSI can only write to registry/HD locations via Wow64, yet x64 MSIs cannot run on x86 computers...), I am about ready to trash the whole thing and port it over to a different install system. What I am looking for on tips + tricks, techniques, or suggestions on how to properly do things so that I am not fighting with Windows Installer's twisted sense of logic. I am tired of fighting with WiX/MSI/Windows Installer. All it needs to do is place files and registry keys where I tell it to, upgrade them when appropriate, and don't delete anything until the user uninstalls. Instead, dependencies are deleted willy-nilly, bringing up a whole bunch of uncatchable exceptions (can't wrap a try{} block around function declarations) and GPF'ing the whole app. I am particularly interested in 'best practices' and examples regarding shared and dependency DLLs, and any tips on making sure if a file needs to go to GAC, that it actually goes to the GAC and stays there until it is appropriate to remove it. Thanks! Tom

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• ExtJS: Combobox in EditorGridPanel not selecting the desired item (with test case)

  - by TomH

  I'm using ExtJS to create an EditorGridPanel with a combobox for an editor in a cell. The combobox in my EditorGridPanel that is not working as I'd expect it to. When the user types the first letter of an item in the drop down list, the combobox seems to ignore it and select the first item in the list. I can reproduce the error consistently and have put together a test case here: http://cluebucket.com/dev/testcase/testcase.html Load the page and reproduce the behavior by the following -- note that this is all done using the keyboard, no mouse clicks: Click 'Add Record' (A new row is added to the grid) enter text in the text field. TAB to the Priority field without selecting anything (None will remain selected) TAB out of the Priority field. (A new row is added to the grid) enter text and TAB to the Priority field TYPE v (Very High is selected) TAB out of the priority field (A new row is added to the grid) enter text and TAB to the Priority field Type v (None is selected, but Very High should have been) TAB out of the priority field Enter text and TAB to the priority field Type l ('el') (Low is selected) TAB out, enter text, TAB to priority Type l (None is selected) It appears that whenever the user attempts to select the same value that was selected in the previous row, the combobox selects None. Any ideas? The code is available at cluebucket.com/dev/testcase/js/testcase.js Thoughts/Pointers/Corrections are appreciated!! thanks tom

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• Css trick to conjoin divs.

  - by Jronny

  Is there a way we could conjoin three divs together? Hello <div class="mainContainer"> <div class="LeftDiv"></div> <div class="CenterDiv"> <input id="txtTest" type="text"/> </div> <div class="RightDiv"></div> </div> World! what we need here is to present the code this way: Hello<*LeftDiv*><*CenterDiv with the textbox*><*RightDiv*>World I tried to use float:left on LeftDiv, CenterDiv and RightDiv but the css also affects the mainContainer. I also need to set the LeftDiv's and RightDiv's height and width on the css but I just can't do it without the float. Thanks in advance. Edit: Added question - when LeftDiv, CenterDiv and RightDiv are floated-left, why is mainContainer affected? i just want to have the three inner divs conjoined without affecting the parent div's behavior...

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• How to get only one rounded corner with border-radius htc hack and MSIE v:roundrect?

  - by aarreoskari

  I have a problem with partially rounded corners. See the first working example for most browsers: .box { display: block; width: 100px; height: 100px; border: 1px solid black; background-color: yellow; -moz-border-radius-bottomright: 10px; -webkit-border-bottom-right-radius: 10px; } You can see that only bottom right corner should be rounded. Natural choice would be adding a border-radius.htc hack inside a conditional IE statement: .box { border-bottom-right-radius: 20px; behavior:url(border-radius.htc); } This is not working because border-radius.htc file is only accessing normal border-radius value (this.currentStyle['border-radius']). VML used by the hack is roundrect which only supports one percentage value for arcsize. So I was wondering if there is any other way around the problem by using some other VML elements? Another problem is that htc-file doesnt's support borders but that can be fixed with VML's stroked attribute. Nifty corners for example doesn't work well with corners at all.

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• resizing row's height in QTreeWidget/QTreeView

  - by serge

  Hi everyone, I have some problems with sizing row's height in QTreeWidget. I use QStyledItemDelegate with QPlainTextEdit. During editing text in QPlainTextEdit i check for changes with a help of: rect = self.blockBoundingRect(self.firstVisibleBlock()) and if text's height changes i resize editor size and need row in QTreeWidget also resizing. But i don't know how to inform TreeWidget or a Delegate about changes. I tried to initialize editor with index, that i could use in a future, but Delegate creates new editor every time and i failed to use signals. Also I used following function to catch resize event, but it' doesn't: bool QAbstractItemDelegate::editorEvent ( QEvent * event, QAbstractItemModel * model, const QStyleOptionViewItem & option, const QModelIndex & index ) How can i bound editor's size changes with TreeWidget? And one more thing, by default all items (cells) in TreeWidget have -1 or some big value as default width. I need whole text in cell to be visible, so how can i limit cells width only by visible range and make it expand in height? I want for it the same behavior as in instance a table in MSWord. Thank you in advance, Serge

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• jQuery UI dialog on ASP.NET page (inside user control)

  - by marc_s

  I have a really odd behavior here: I created a little popup dialog in jQuery UI, and in my test HTML page, it works flawlessly. When I click on the button, the popup comes up, covers the background, and remains on screen until I click on one of the two buttons (OK or Cancel) provided. So now I wanted to add this into my ASP.NET 3.5 app. I wanted to add it to a GridView inside a user controls (ASCX), which is on a page (ASPX) contained inside a master page. The jQuery 1.4.2 and jQuery UI 1.8.1 scripts are referenced on the master page: <body> <form id="XXXXXX" runat="server"> <Ajax:ScriptManager ID="masterScriptManager" runat="server" ScriptMode="Auto"> <Scripts> <asp:ScriptReference Path="~/Scripts/jquery-1.4.2.min.js" /> <asp:ScriptReference Path="~/Scripts/jquery-ui-1.8.1.custom.min.js" /> </Scripts> </Ajax:ScriptManager> I had to change this to use the Ajax script manager, since adding them to the as never worked. So in my gridview, I have a column with image buttons, and when the user clicks on those, I am calling a little javascript function to show the jQuery UI dialog: function showDialog() { $("#dlg-discount").dialog('open'); $("#txtAmount").focus(); } When I run this page in MS IE 8, I get a separate page, and at the top of the page, I get the contents of my , with proper background color and all. In Firefox 3.5.6, I do get the dialog as a popup. In both cases, the dialog page/popup disappears again after a second or less - without me clicking anything! It seems similar to this question but the solution provided there doesn't work in my case. This one here also seems similar but again: the solution presented doesn't seem to work in my case... Any ideas / hints / tips on what the h** is going on here?? Thanks!

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• ASP.NET MVC DropDownList SelectedValue works on Edit action, but not Create action

  - by davekaro

  I have the following code in my controller (for Edit and Create): model.Templates = new SelectList(PageManagementService.PageTemplateFetchList(), "PageId", "Title", 213); the "213" is an Id for one of the pages - just using it for testing. And this is in my view (for Edit and Create): <%= this.Html.DropDownListFor(model => model.Page.TemplateId, this.Model.Templates)%> <%= this.Model.Templates.SelectedValue %> When I go to the Create form, I see the dropdown list, but the tag with value="213" is not selected. I even output the SelectedValue to make sure it's 213 - and I see 213. When I go to the Edit form, I see the dropdown list, and the tag with value="213" is selected. On the Create form, none of the tags have a "selected" attribute. On the Edit form, the tag with value="213" has the "selected" attribute. Am I missing something? What could be causing this? Anyone see this behavior before?

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• How do I solve column width problems in a SSRS Tablix?

  - by David Stein

  I'm creating a simple report from Microsoft Dynamics CRM. When I pull in the following dataset: SELECT FQD.productidname , FQD.NEW_PRICEBREAKS , FQD.NEW_WEEKSARO , ltrim(rtrim(FP.NEW_PRODUCTNAME)) AS NewProductDesc , FQD.productdescription , FQD.quoteid , FQD.quantity , FQD.productiddsc , FQD.baseamount , FQD.lineitemnumber , FQD.priceperunit , FQD.extendedamount , ISNULL(FP.productnumber, '') AS productnumber , ISNULL(FQD.uomidname, '-') AS Unit , FQD.tax AS Tax , FQD.volumediscountamount * FQD.quantity AS Discount , FQD.manualdiscountamount AS MDiscount , FQD.quotedetailid , FQD.crm_moneyformatstring , FQD.NEW_PRICEPERUNIT , FQD.NEW_PRICEPERUNIT_BASE FROM FilteredQuoteDetail FQD LEFT OUTER JOIN FilteredProduct FP ON FQD.productid = FP.productid WHERE (FQD.quoteid = @CRM_QuoteId) The NewProductDesc field is too wide. If I shorted it in design view, it still comes out too wide in the presentation. I think the field is coming out that wide because the database field probably has a bunch of blank spaces at the end of every description. I could not find a way to force that field in the Tablix not to grow horizontally, so I attempted to remedy it in the dataset by replacing the NewProductDesc line with: ltrim(rtrim(FP.NEW_PRODUCTNAME)) AS NewProductDesc However, that has no effect either. Can anyone suggest why this behavior is occuring? Can anyone tell me how I can force the field not to grow horizontally?

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• {PHP} Fatal error: Using $this when not in object context (Joomla)

  - by Asher

  Hi all, i don't really know php and have hit a brick wall. The problem is that my site is showing the following error... Fatal error: Using $this when not in object context in /hermes/web07/b2350/pow.thefoodie/htdocs/index.php on line 11 This is the begining of my index.php file... // no direct access define( 'YOURBASEPATH', dirname(FILE) ); ? language; ?" lang="language; ?" main_body ul li { behavior: url(baseurl; ?/templates/template ?/css/iepngfix.htc) } baseurl; ?/templates/template ?/js/pngfix.js" baseurl; ?/templates/template ?/css/template_css.css" rel="stylesheet" type="text/css" media="all" / baseurl; ?/templates/template ?/js/fx_styles.js" baseurl; ?/templates/template ?/js/accordion.js" // *************************** // // Template Parameters // // *************************** $h1 = $this-params-get("logo"); $linked_h1 = ($this-params-get("logoLinked", 1) == 0)?"false":"true"; $h1_title = $this-params-get("logoTitle"); $h2_motto = $this-params-get("logoMotto"); // Please do NOT change this unless you know what you doing. $template_path = $this-baseurl.'/templates/'.$this-template; // template path $default_font = "default"; // **************************** ? Any help would be great as i am completely lost.

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