Search Results

Search found 8397 results on 336 pages for 'implementation'.

Page 284/336 | < Previous Page | 280 281 282 283 284 285 286 287 288 289 290 291  | Next Page >

• The long road to bug-free software

  - by Tony Davis

  The past decade has seen a burgeoning interest in functional programming languages such as Haskell or, in the Microsoft world, F#. Though still on the periphery of mainstream programming, functional programming concepts are gradually seeping into the imperative C# language (for example, Lambda expressions have their root in functional programming). One of the more interesting concepts from functional programming languages is the use of formal methods, the lofty ideal behind which is bug-free software. The idea is that we write a specification that describes exactly how our function (say) should behave. We then prove that our function conforms to it, and in doing so have proved beyond any doubt that it is free from bugs. All programmers already use one form of specification, specifically their programming language's type system. If a value has a specific type then, in a type-safe language, the compiler guarantees that value cannot be an instance of a different type. Many extensions to existing type systems, such as generics in Java and .NET, extend the range of programs that can be type-checked. Unfortunately, type systems can only prevent some bugs. To take a classic problem of retrieving an index value from an array, since the type system doesn't specify the length of the array, the compiler has no way of knowing that a request for the "value of index 4" from an array of only two elements is "unsafe". We restore safety via exception handling, but the ideal type system will prevent us from doing anything that is unsafe in the first place and this is where we start to borrow ideas from a language such as Haskell, with its concept of "dependent types". If the type of an array includes its length, we can ensure that any index accesses into the array are valid. The problem is that we now need to carry around the length of arrays and the values of indices throughout our code so that it can be type-checked. In general, writing the specification to prove a positive property, even for a problem very amenable to specification, such as a simple sorting algorithm, turns out to be very hard and the specification will be different for every program. Extend this to writing a specification for, say, Microsoft Word and we can see that the specification would end up being no simpler, and therefore no less buggy, than the implementation. Fortunately, it is easier to write a specification that proves that a program doesn't have certain, specific and undesirable properties, such as infinite loops or accesses to the wrong bit of memory. If we can write the specifications to prove that a program is immune to such problems, we could reuse them in many places. The problem is the lack of specification "provers" that can do this without a lot of manual intervention (i.e. hints from the programmer). All this might feel a very long way off, but computing power and our understanding of the theory of "provers" advances quickly, and Microsoft is doing some of it already. Via their Terminator research project they have started to prove that their device drivers will always terminate, and in so doing have suddenly eliminated a vast range of possible bugs. This is a huge step forward from saying, "we've tested it lots and it seems fine". What do you think? What might be good targets for specification and verification? SQL could be one: the cost of a bug in SQL Server is quite high given how many important systems rely on it, so there's a good incentive to eliminate bugs, even at high initial cost. [Many thanks to Mike Williamson for guidance and useful conversations during the writing of this piece] Cheers, Tony.

  Read the article

• Moving StarterSTS to the (Azure) Cloud

  - by Your DisplayName here!

  Quite some people asked me about an Azure version of StarterSTS. While I kinda knew what I had to do to make the move, I couldn’t find the time. Until recently. This blog post briefly documents the necessary changes and design decisions for the next version of StarterSTS which will work both on-premise and on Azure. Provider Fortunately StarterSTS is already based on the idea of “providers”. Authentication, roles and claims generation is based on the standard ASP.NET provider infrastructure. This makes the migration to different data stores less painful. In my case I simply moved the ASP.NET provider database to SQL Azure and still use the standard SQL Server based membership, roles and profile provider. In addition StarterSTS has its own providers to abstract resource access for certificates, relying party registration, client certificate registration and delegation. So I only had to provide new implementations. Signing and SSL keys now go in the Azure certificate store and user mappings (client certificates and delegation settings) have been moved to Azure table storage. The one thing I didn’t anticipate when I originally wrote StarterSTS was the need to also encapsulate configuration. Currently configuration is “locked” to the standard .NET configuration system. The new version will have a pluggable SettingsProvider with versions for .NET configuration as well as Azure service configuration. If you want to externalize these settings into e.g. a database, it is now just a matter of supplying a corresponding provider. Moving between the on-premise and Azure version will be just a matter of using different providers. URL Handling Another thing that’s substantially different on Azure (and load balanced scenarios in general) is the handling of URLs. In farm scenarios, the standard APIs like ASP.NET’s Request.Url return the current (internal) machine name, but you typically need the address of the external facing load balancer. There’s a hotfix for WCF 3.5 (included in v4) that fixes this for WCF metadata. This was accomplished by using the HTTP Host header to generate URLs instead of the local machine name. I now use the same approach for generating WS-Federation metadata as well as information card files. New Features I introduced a cache provider. Since we now have slightly more expensive lookups (e.g. relying party data from table storage), it makes sense to cache certain data in the front end. The default implementation uses the ASP.NET web cache and can be easily extended to use products like memcached or AppFabric Caching. Starting with the relying party provider, I now also provide a read/write interface. This allows building management interfaces on top of this provider. I also include a (very) simple web page that allows working with the relying party provider data. I guess I will use the same approach for other providers in the future as well. I am also doing some work on the tracing and health monitoring area. Especially important for the Azure version. Stay tuned.

  Read the article

• Dependency Injection Introduction

  - by MarkPearl

  I recently was going over a great book called “Dependency Injection in .Net” by Mark Seeman. So far I have really enjoyed the book and would recommend anyone looking to get into DI to give it a read. Today I thought I would blog about the first example Mark gives in his book to illustrate some of the benefits that DI provides. The ones he lists are Late binding Extensibility Parallel Development Maintainability Testability To illustrate some of these benefits he gives a HelloWorld example using DI that illustrates some of the basic principles. It goes something like this… class Program { static void Main(string[] args) { var writer = new ConsoleMessageWriter(); var salutation = new Salutation(writer); salutation.Exclaim(); Console.ReadLine(); } } public interface IMessageWriter { void Write(string message); } public class ConsoleMessageWriter : IMessageWriter { public void Write(string message) { Console.WriteLine(message); } } public class Salutation { private readonly IMessageWriter _writer; public Salutation(IMessageWriter writer) { _writer = writer; } public void Exclaim() { _writer.Write("Hello World"); } }   If you had asked me a few years ago if I had thought this was a good approach to solving the HelloWorld problem I would have resounded “No”. How could the above be better than the following…. class Program { static void Main(string[] args) { Console.WriteLine("Hello World"); Console.ReadLine(); } }  Today, my mind-set has changed because of the pain of past programs. So often we can look at a small snippet of code and make judgements when we need to keep in mind that we will most probably be implementing these patterns in projects with hundreds of thousands of lines of code and in projects that we have tests that we don’t want to break and that’s where the first solution outshines the latter. Let’s see if the first example achieves some of the outcomes that were listed as benefits of DI. Could I test the first solution easily? Yes… We could write something like the following using NUnit and RhinoMocks… [TestFixture] public class SalutationTests { [Test] public void ExclaimWillWriteCorrectMessageToMessageWriter() { var writerMock = MockRepository.GenerateMock<IMessageWriter>(); var sut = new Salutation(writerMock); sut.Exclaim(); writerMock.AssertWasCalled(x => x.Write("Hello World")); } }   This would test the existing code fine. Let’s say we then wanted to extend the original solution so that we had a secure message writer. We could write a class like the following… public class SecureMessageWriter : IMessageWriter { private readonly IMessageWriter _writer; private readonly string _secretPassword; public SecureMessageWriter(IMessageWriter writer, string secretPassword) { _writer = writer; _secretPassword = secretPassword; } public void Write(string message) { if (_secretPassword == "Mark") { _writer.Write(message); } else { _writer.Write("Unauthenticated"); } } }   And then extend our implementation of the program as follows… class Program { static void Main(string[] args) { var writer = new SecureMessageWriter(new ConsoleMessageWriter(), "Mark"); var salutation = new Salutation(writer); salutation.Exclaim(); Console.ReadLine(); } }   Our application has now been successfully extended and yet we did very little code change. In addition, our existing tests did not break and we would just need add tests for the extended functionality. Would this approach allow parallel development? Well, I am in two camps on parallel development but with some planning ahead of time it would allow for it as you would simply need to decide on the interface signature and could then have teams develop different sections programming to that interface. So,this was really just a quick intro to some of the basic concepts of DI that Mark introduces very successfully in his book. I am hoping to blog about this further as I continue through the book to list some of the more complex implementations of containers.

  Read the article

• Why is x=x++ undefined?

  - by ugoren

  It's undefined because the it modifies x twice between sequence points. The standard says it's undefined, therefore it's undefined. That much I know. But why? My understanding is that forbidding this allows compilers to optimize better. This could have made sense when C was invented, but now seems like a weak argument. If we were to reinvent C today, would we do it this way, or can it be done better? Or maybe there's a deeper problem, that makes it hard to define consistent rules for such expressions, so it's best to forbid them? So suppose we were to reinvent C today. I'd like to suggest simple rules for expressions such as x=x++, which seem to me to work better than the existing rules. I'd like to get your opinion on the suggested rules compared to the existing ones, or other suggestions. Suggested Rules: Between sequence points, order of evaluation is unspecified. Side effects take place immediately. There's no undefined behavior involved. Expressions evaluate to this value or that, but surely won't format your hard disk (strangely, I've never seen an implementation where x=x++ formats the hard disk). Example Expressions x=x++ - Well defined, doesn't change x. First, x is incremented (immediately when x++ is evaluated), then it's old value is stored in x. x++ + ++x - Increments x twice, evaluates to 2*x+2. Though either side may be evaluated first, the result is either x + (x+2) (left side first) or (x+1) + (x+1) (right side first). x = x + (x=3) - Unspecified, x set to either x+3 or 6. If the right side is evaluated first, it's x+3. It's also possible that x=3 is evaluated first, so it's 3+3. In either case, the x=3 assignment happens immediately when x=3 is evaluated, so the value stored is overwritten by the other assignment. x+=(x=3) - Well defined, sets x to 6. You could argue that this is just shorthand for the expression above. But I'd say that += must be executed after x=3, and not in two parts (read x, evaluate x=3, add and store new value). What's the Advantage? Some comments raised this good point. It's not that I'm after the pleasure of using x=x++ in my code. It's a strange and misleading expression. What I want is to be able to understand complicated expressions. Normally, a complicated expression is no more than the sum of its parts. If you understand the parts and the operators combining them, you can understand the whole. C's current behavior seems to deviate from this principle. One assignment plus another assignment suddenly doesn't make two assignments. Today, when I look at x=x++, I can't say what it does. With my suggested rules, I can, by simply examining its components and their relations.

  Read the article

• Should I expose IObservable<T> on my interfaces?

  - by Alex

  My colleague and I have dispute. We are writing a .NET application that processes massive amounts of data. It receives data elements, groups subsets of them into blocks according to some criterion and processes those blocks. Let's say we have data items of type Foo arriving some source (from the network, for example) one by one. We wish to gather subsets of related objects of type Foo, construct an object of type Bar from each such subset and process objects of type Bar. One of us suggested the following design. Its main theme is exposing IObservable objects directly from the interfaces of our components. // ********* Interfaces ********** interface IFooSource { // this is the event-stream of objects of type Foo IObservable<Foo> FooArrivals { get; } } interface IBarSource { // this is the event-stream of objects of type Bar IObservable<Bar> BarArrivals { get; } } / ********* Implementations ********* class FooSource : IFooSource { // Here we put logic that receives Foo objects from the network and publishes them to the FooArrivals event stream. } class FooSubsetsToBarConverter : IBarSource { IFooSource fooSource; IObservable<Bar> BarArrivals { get { // Do some fancy Rx operators on fooSource.FooArrivals, like Buffer, Window, Join and others and return IObservable<Bar> } } } // this class will subscribe to the bar source and do processing class BarsProcessor { BarsProcessor(IBarSource barSource); void Subscribe(); } // ******************* Main ************************ class Program { public static void Main(string[] args) { var fooSource = FooSourceFactory.Create(); var barsProcessor = BarsProcessorFactory.Create(fooSource) // this will create FooSubsetToBarConverter and BarsProcessor barsProcessor.Subscribe(); fooSource.Run(); // this enters a loop of listening for Foo objects from the network and notifying about their arrival. } } The other suggested another design that its main theme is using our own publisher/subscriber interfaces and using Rx inside the implementations only when needed. //********** interfaces ********* interface IPublisher<T> { void Subscribe(ISubscriber<T> subscriber); } interface ISubscriber<T> { Action<T> Callback { get; } } //********** implementations ********* class FooSource : IPublisher<Foo> { public void Subscribe(ISubscriber<Foo> subscriber) { /* ... */ } // here we put logic that receives Foo objects from some source (the network?) publishes them to the registered subscribers } class FooSubsetsToBarConverter : ISubscriber<Foo>, IPublisher<Bar> { void Callback(Foo foo) { // here we put logic that aggregates Foo objects and publishes Bars when we have received a subset of Foos that match our criteria // maybe we use Rx here internally. } public void Subscribe(ISubscriber<Bar> subscriber) { /* ... */ } } class BarsProcessor : ISubscriber<Bar> { void Callback(Bar bar) { // here we put code that processes Bar objects } } //********** program ********* class Program { public static void Main(string[] args) { var fooSource = fooSourceFactory.Create(); var barsProcessor = barsProcessorFactory.Create(fooSource) // this will create BarsProcessor and perform all the necessary subscriptions fooSource.Run(); // this enters a loop of listening for Foo objects from the network and notifying about their arrival. } } Which one do you think is better? Exposing IObservable and making our components create new event streams from Rx operators, or defining our own publisher/subscriber interfaces and using Rx internally if needed? Here are some things to consider about the designs: In the first design the consumer of our interfaces has the whole power of Rx at his/her fingertips and can perform any Rx operators. One of us claims this is an advantage and the other claims that this is a drawback. The second design allows us to use any publisher/subscriber architecture under the hood. The first design ties us to Rx. If we wish to use the power of Rx, it requires more work in the second design because we need to translate the custom publisher/subscriber implementation to Rx and back. It requires writing glue code for every class that wishes to do some event processing.

  Read the article

• PARTNER WEBCAST SERIES: INNOVATIONS IN APPLICATIONS - PROGRAM

  - by mseika

  Dear Partner, We are pleased to invite you to join the Innovations in Applications webcast series. Innovations in Applications will present Oracle Product's new functions and features including sales positioning. The key objectives of these webcasts are to inspire Partner's personnel to conduct successful sales, after sales and delivery at their Customer. Moreover, we aim to inspire you to conduct further Product Training and Certifications. And finally we'll provide you a chance to join Ecosystem's Product specific Community to learn and to contribute. Innovations in Applications will be presented as per the schedule below after the billable day (4:00 to 5:00 PM CET). The webcast is intended for Partner's Implementation Certified Specialists but Innovations in Applications is open for other Partner's personnel as well. At first, Oracle representative will discuss Oracle's contribution to partners. Then you will see product breakout session followed by Q&A with Oracle Experts. Each session will last for maximum 1 hour. A Q&A document covering all questions and answers will be made available after the webcast. What are the Benefits for partners? Find out how Innovations in Applications helps you to improve your sales, after sales and delivery Discover new functions and features so you can enrich your Customers's solution Learn more about Oracle products, especially sales positioning Hear crucial questions raised by colleague alike, learn from their interest Engage and present your questions to subject experts Be inspired of the richness of Oracle's product portfolio – for your and your customer's benefit. Be inspired to seek further Product Training and Certifications - Make your competence known and recognized! Brand yourself! Note: Should you already be familiar with a specific Product, then choose another one. Doing so you would expand your knowledge of the overall product portfolio. Some presentations contain product demonstration, although these presentations are not intended to be extremely detailed technical presentations. Useful Links for you to bookmark: To access previously presented Products presentations and Public Sector Value Proposition presentations, please go to the Recordings tab. You might want to bookmark the Enablement blog page Oracle Partner Enablement. Please check this regularly as we publish lots of good content here just for you. You might want to bookmark the Knowledge Zones page for solution-focused pages designed to jump start your path towards Specialization. You might want to bookmark the global event calendar page events.oracle.com. Delivery Format Innovations in Applications – program is a series of FREE prerecorded Oracle product presentations followed by Q&A. It will be delivered over the Web. Participants have the opportunity to submit questions during the web cast via chat and subject matter experts will provide verbal answers live. Innovations in Applications consists of several parallel prerecorded product breakout sessions, each lasting for max. 1 hour. At first, Oracle representative will discuss Oracle's contribution to Partners. Then you'll see the product breakout sessions followed by Q&A with Oracle Experts. A Q&A document covering all questions and answers will be made available after the webcast. You can also see Innovations in Applications afterwards as its content will be available online for the next 6-12 months. The next Innovations in Applications webcasts will be presented as follows: July 1st 2013 (please see Next Webcast tab) For more information please click here. Note: Depending on local network bandwidth please allow some seconds time the presentations to download. You might want to refresh your screen by pressing F5. DurationMaximum 1 hour For further information please contact Markku Rouhiainen.

  Read the article

• Can anybody help me in designing my UITableView into MVC Pattern ?

  - by user2877880

  I have written a ViewController in which i get data from the internet and display it in a UItableview using a json parser which uses object for key to identify its objects. What i would like your help in is to convert it into MVC pattern to make it less clumsy instead of including everything in the same controller class. Please try explaining it to me in terms of my code. THANKS IN ADVANCE. The code is as given below #import "ViewController.h" #import "AFNetworking.h" #import "ModelTableArray.h" @implementation ViewController @synthesize tableView = _tableView, activityIndicatorView = _activityIndicatorView, movies = _movies; - (void)viewDidLoad { [super viewDidLoad]; // Setting Up Table View self.tableView = [[UITableView alloc] initWithFrame:CGRectMake(0.0, 0.0, self.view.bounds.size.width, self.view.bounds.size.height) style:UITableViewStylePlain]; self.tableView.dataSource = self; self.tableView.delegate = self; self.tableView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight; self.tableView.hidden = YES; [self.view addSubview:self.tableView]; // Setting Up Activity Indicator View self.activityIndicatorView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray]; self.activityIndicatorView.hidesWhenStopped = YES; self.activityIndicatorView.center = self.view.center; [self.view addSubview:self.activityIndicatorView]; [self.activityIndicatorView startAnimating]; // Initializing Data Source self.movies = [[NSArray alloc] init]; NSURL *url = [[NSURL alloc] initWithString:@"http://itunes.apple.com/search?term=rocky&country=us&entity=movie"]; NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url]; UIRefreshControl *refreshControl = [[UIRefreshControl alloc] init]; [refreshControl addTarget:self action:@selector(refresh:) forControlEvents:UIControlEventValueChanged]; [self.tableView addSubview:refreshControl]; [refreshControl endRefreshing]; AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) { self.movies = [JSON objectForKey:@"results"]; [self.activityIndicatorView stopAnimating]; [self.tableView setHidden:NO]; [self.tableView reloadData]; } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) { NSLog(@"Request Failed with Error: %@, %@", error, error.userInfo); }]; [operation start]; } - (void)refresh:(UIRefreshControl *)sender { NSURL *url = [[NSURL alloc] initWithString:@"http://itunes.apple.com/search?term=rambo&country=us&entity=movie"]; NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url]; AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) { self.movies = [JSON objectForKey:@"results"]; [self.activityIndicatorView stopAnimating]; [self.tableView setHidden:NO]; [self.tableView reloadData]; } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) { NSLog(@"Request Failed with Error: %@, %@", error, error.userInfo); }]; [operation start]; [sender endRefreshing]; } - (void)viewDidUnload { [super viewDidUnload]; } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { return YES; } // Table View Data Source Methods - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { if (self.movies && self.movies.count) { return self.movies.count; } else { return 0; } } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *cellID = @"Cell Identifier"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellID]; if (!cell) { cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:cellID]; } NSDictionary *movie = [self.movies objectAtIndex:indexPath.row]; cell.textLabel.text = [movie objectForKey:@"trackName"]; cell.detailTextLabel.text = [movie objectForKey:@"artistName"]; NSURL *url = [[NSURL alloc] initWithString:[movie objectForKey:@"artworkUrl100"]]; [cell.imageView setImageWithURL:url placeholderImage:[UIImage imageNamed:@"placeholder"]]; return cell; } @end

  Read the article

• What's new in Servlet 3.1 ? - Java EE 7 moving forward

  - by arungupta

  Servlet 3.0 was released as part of Java EE 6 and made huge changes focused at ease-of-use. The idea was to leverage the latest language features such as annotations and generics and modernize how Servlets can be written. The web.xml was made as optional as possible. Servet 3.1 (JSR 340), scheduled to be part of Java EE 7, is an incremental release focusing on couple of key features and some clarifications in the specification. The main features of Servlet 3.1 are explained below: Non-blocking I/O - Servlet 3.0 allowed asynchronous request processing but only traditional I/O was permitted. This can restrict scalability of your applications. Non-blocking I/O allow to build scalable applications. TOTD #188 provide more details about how non-blocking I/O can be done using Servlet 3.1. HTTP protocol upgrade mechanism - Section 14.42 in the HTTP 1.1 specification (RFC 2616) defines an upgrade mechanism that allows to transition from HTTP 1.1 to some other, incompatible protocol. The capabilities and nature of the application-layer communication after the protocol change is entirely dependent upon the new protocol chosen. After an upgrade is negotiated between the client and the server, the subsequent requests use the new chosen protocol for message exchanges. A typical example is how WebSocket protocol is upgraded from HTTP as described in Opening Handshake section of RFC 6455. The decision to upgrade is made in Servlet.service method. This is achieved by adding a new method: HttpServletRequest.upgrade and two new interfaces: javax.servlet.http.HttpUpgradeHandler and javax.servlet.http.WebConnection. TyrusHttpUpgradeHandler shows how WebSocket protocol upgrade is done in Tyrus (Reference Implementation for Java API for WebSocket). Security enhancements Applying run-as security roles to #init and #destroy methods Session fixation attack by adding HttpServletRequest.changeSessionId and a new interface HttpSessionIdListener. You can listen for any session id changes using these methods. Default security semantic for non-specified HTTP method in <security-constraint> Clarifying the semantics if a parameter is specified in the URI and payload Miscellaneous ServletResponse.reset clears any data that exists in the buffer as well as the status code, headers. In addition, Servlet 3.1 will also clears the state of calling getServletOutputStream or getWriter. ServletResponse.setCharacterEncoding: Sets the character encoding (MIME charset) of the response being sent to the client, for example, to UTF-8. Relative protocol URL can be specified in HttpServletResponse.sendRedirect. This will allow a URL to be specified without a scheme. That means instead of specifying "http://anotherhost.com/foo/bar.jsp" as a redirect address, "//anotherhost.com/foo/bar.jsp" can be specified. In this case the scheme of the corresponding request will be used. Clarification in HttpServletRequest.getPart and .getParts without multipart configuration. Clarification that ServletContainerInitializer is independent of metadata-complete and is instantiated per web application. A complete replay of What's New in Servlet 3.1: An Overview from JavaOne 2012 can be seen here (click on CON6793_mp4_6793_001 in Media). Each feature will be added to the JSR subject to EG approval. You can share your feedback to [email protected]. Here are some more references for you: Servlet 3.1 Public Review Candidate Downloads Servlet 3.1 PR Candidate Spec Servlet 3.1 PR Candidate Javadocs Servlet Specification Project JSR Expert Group Discussion Archive Java EE 7 Specification Status Several features have already been integrated in GlassFish 4 Promoted Builds. Have you tried any of them ? Here are some other Java EE 7 primers published so far: Concurrency Utilities for Java EE (JSR 236) Collaborative Whiteboard using WebSocket in GlassFish 4 (TOTD #189) Non-blocking I/O using Servlet 3.1 (TOTD #188) What's New in EJB 3.2 ? JPA 2.1 Schema Generation (TOTD #187) WebSocket Applications using Java (JSR 356) Jersey 2 in GlassFish 4 (TOTD #182) WebSocket and Java EE 7 (TOTD #181) Java API for JSON Processing (JSR 353) JMS 2.0 Early Draft (JSR 343) And of course, more on their way! Do you want to see any particular one first ?

  Read the article

• XNA - 3D AABB collision detection and response

  - by fastinvsqrt

  I've been fiddling around with 3D AABB collision in my voxel engine for the last couple of days, and every method I've come up with thus far has been almost correct, but each one never quite worked exactly the way I hoped it would. Currently what I do is get two bounding boxes for my entity, one modified by the X translation component and the other by the Z component, and check if each collides with any of the surrounding chunks (chunks have their own octrees that are populated only with blocks that support collision). If there is a collision, then I cast out rays into that chunk to get the shortest collision distance, and set the translation component to that distance if the component is greater than the distance. The problem is that sometimes collisions aren't even registered. Here's a video on YouTube that I created showing what I mean. I suspect the problem may be with the rays that I cast to get the collision distance not being where I think they are, but I'm not entirely sure what would be wrong with them if they are indeed the problem. Here is my code for collision detection and response in the X direction (the Z direction is basically the same): // create the XZ offset vector Vector3 offsXZ = new Vector3( ( _translation.X > 0.0f ) ? SizeX / 2.0f : ( _translation.X < 0.0f ) ? -SizeX / 2.0f : 0.0f, 0.0f, ( _translation.Z > 0.0f ) ? SizeZ / 2.0f : ( _translation.Z < 0.0f ) ? -SizeZ / 2.0f : 0.0f ); // X physics BoundingBox boxx = GetBounds( _translation.X, 0.0f, 0.0f ); if ( _translation.X > 0.0f ) { foreach ( Chunk chunk in surrounding ) { if ( chunk.Collides( boxx ) ) { float dist = GetShortestCollisionDistance( chunk, Vector3.Right, offsXZ ) - 0.0001f; if ( dist < _translation.X ) { _translation.X = dist; } } } } else if ( _translation.X < 0.0f ) { foreach ( Chunk chunk in surrounding ) { if ( chunk.Collides( boxx ) ) { float dist = GetShortestCollisionDistance( chunk, Vector3.Left, offsXZ ) - 0.0001f; if ( dist < -_translation.X ) { _translation.X = -dist; } } } } And here is my implementation for GetShortestCollisionDistance: private float GetShortestCollisionDistance( Chunk chunk, Vector3 rayDir, Vector3 offs ) { int startY = (int)( -SizeY / 2.0f ); int endY = (int)( SizeY / 2.0f ); int incY = (int)Cube.Size; float dist = Chunk.Size; for ( int y = startY; y <= endY; y += incY ) { // Position is the center of the entity's bounding box Ray ray = new Ray( new Vector3( Position.X + offs.X, Position.Y + offs.Y + y, Position.Z + offs.Z ), rayDir ); // Chunk.GetIntersections(Ray) returns Dictionary<Block, float?> foreach ( var pair in chunk.GetIntersections( ray ) ) { if ( pair.Value.HasValue && pair.Value.Value < dist ) { dist = pair.Value.Value; } } } return dist; } I realize some of this code can be consolidated to help with speed, but my main concern right now is to get this bit of physics programming to actually work.

  Read the article

• Validation and authorization in layered architecture

  - by SonOfPirate

  I know you are thinking (or maybe yelling), "not another question asking where validation belongs in a layered architecture?!?" Well, yes, but hopefully this will be a little bit of a different take on the subject. I am a firm believer that validation takes many forms, is context-based and varies at each level of the architecture. That is the basis for the post - helping to identify what type of validation should be performed in each layer. In addition, a question that often comes up is where authorization checks belong. The example scenario comes from an application for a catering business. Periodically during the day, a driver may turn in to the office any excess cash they've accumulated while taking the truck from site to site. The application allows a user to record the 'cash drop' by collecting the driver's ID, and the amount. Here's some skeleton code to illustrate the layers involved: public class CashDropApi // This is in the Service Facade Layer { [WebInvoke(Method = "POST")] public void AddCashDrop(NewCashDropContract contract) { // 1 Service.AddCashDrop(contract.Amount, contract.DriverId); } } public class CashDropService // This is the Application Service in the Domain Layer { public void AddCashDrop(Decimal amount, Int32 driverId) { // 2 CommandBus.Send(new AddCashDropCommand(amount, driverId)); } } internal class AddCashDropCommand // This is a command object in Domain Layer { public AddCashDropCommand(Decimal amount, Int32 driverId) { // 3 Amount = amount; DriverId = driverId; } public Decimal Amount { get; private set; } public Int32 DriverId { get; private set; } } internal class AddCashDropCommandHandler : IHandle<AddCashDropCommand> { internal ICashDropFactory Factory { get; set; } // Set by IoC container internal ICashDropRepository CashDrops { get; set; } // Set by IoC container internal IEmployeeRepository Employees { get; set; } // Set by IoC container public void Handle(AddCashDropCommand command) { // 4 var driver = Employees.GetById(command.DriverId); // 5 var authorizedBy = CurrentUser as Employee; // 6 var cashDrop = Factory.CreateCashDrop(command.Amount, driver, authorizedBy); // 7 CashDrops.Add(cashDrop); } } public class CashDropFactory { public CashDrop CreateCashDrop(Decimal amount, Employee driver, Employee authorizedBy) { // 8 return new CashDrop(amount, driver, authorizedBy, DateTime.Now); } } public class CashDrop // The domain object (entity) { public CashDrop(Decimal amount, Employee driver, Employee authorizedBy, DateTime at) { // 9 ... } } public class CashDropRepository // The implementation is in the Data Access Layer { public void Add(CashDrop item) { // 10 ... } } I've indicated 10 locations where I've seen validation checks placed in code. My question is what checks you would, if any, be performing at each given the following business rules (along with standard checks for length, range, format, type, etc): The amount of the cash drop must be greater than zero. The cash drop must have a valid Driver. The current user must be authorized to add cash drops (current user is not the driver). Please share your thoughts, how you have or would approach this scenario and the reasons for your choices.

  Read the article

• How to handle multi-processing of libraries which already spawn sub-processes?

  - by exhuma

  I am having some trouble coming up with a good solution to limit sub-processes in a script which uses a multi-processed library and the script itself is also multi-processed. Both, the library and script are modifiable by us. I believe the question is more about design than actual code, but for what it's worth, it's written in Python. The goal of the library is to hide implementation details of various internet routers. For that reason, the library has a "Proxy" factory method which takes the IP of a router as parameter. The factory then probes the device using a set of possible proxies. Usually, there is one proxy which immediately knows that is is able to send commands to this device. All others usually take some time to return (given a timeout). One thought was already to simply query the device for an identifier, and then select the proper proxy using that, but in order to do so, you would already need to know how to query the device. Abstracting this knowledge is one of the main purposes of the library, so that becomes a little bit of a "circular-requirement"/deadlock: To connect to a device, you need to know what proxy to use, and to know what proxy to create, you need to connect to a device. So probing the device is - as we can see - the best solution so far, apart from keeping a lookup-table somewhere. The library currently kills all remaining processes once a valid proxy has been found. And yes, there is always only one good proxy per device. Currently there are about 12 proxies. So if one create a proxy instance using the factory, 12 sub-processes are spawned. So far, this has been really useful and worked very well. But recently someone else wanted to use this library to "broadcast" a command to all devices. So he took the library, and wrote his own multi-processed script. This obviously spawned 12 * n processes where n is the number of IPs to which he broadcasted. This has given us two problems: The host on which the command was executed slowed down to a near halt. Aborting the script with CTRL+C ground the system to a total halt. Not even the hardware console responded anymore! This may be due to some Python strangeness which still needs to be investigated. Maybe related to http://bugs.python.org/issue8296 The big underlying question, is how to design a library which does multi-processing, so other applications which use this library and want to be multi-processed themselves do not run into system limitations. My first thought was to require a pool to be passed to the library, and execute all tasks in that pool. In that way, the person using the library has control over the usage of system resources. But my gut tells me that there must be a better solution. Disclaimer: My experience with multiprocessing is fairly limited. I have implemented a few straightforward which did not require access control to resources. So I have not yet any practical experience with semaphores or mutexes. p.s.: In the future, we may have enough information to do this without the probing. But the database which would contain the proper information is not yet operational. Also, the design about multiprocessing a multiprocessed library intrigues me :)

  Read the article

• Selective Suppression of Log Messages

  - by Duncan Mills

  Those of you who regularly read this blog will probably have noticed that I have a strange predilection for logging related topics, so why break this habit I ask?  Anyway here's an issue which came up recently that I thought was a good one to mention in a brief post.  The scenario really applies to production applications where you are seeing entries in the log files which are harmless, you know why they are there and are happy to ignore them, but at the same time you either can't or don't want to risk changing the deployed code to "fix" it to remove the underlying cause. (I'm not judging here). The good news is that the logging mechanism provides a filtering capability which can be applied to a particular logger to selectively "let a message through" or suppress it. This is the technique outlined below. First Create Your Filter  You create a logging filter by implementing the java.util.logging.Filter interface. This is a very simple interface and basically defines one method isLoggable() which simply has to return a boolean value. A return of false will suppress that particular log message and not pass it onto the handler. The method is passed the log record of type java.util.logging.LogRecord which provides you with access to everything you need to decide if you want to let this log message pass through or not, for example  getLoggerName(), getMessage() and so on. So an example implementation might look like this if we wanted to filter out all the log messages that start with the string "DEBUG" when the logging level is not set to FINEST:  public class MyLoggingFilter implements Filter {     public boolean isLoggable(LogRecord record) {         if ( !record.getLevel().equals(Level.FINEST) && record.getMessage().startsWith("DEBUG")){          return false;            }         return true;     } } Deploying   This code needs to be put into a JAR and added to your WebLogic classpath.  It's too late to load it as part of an application, so instead you need to put the JAR file into the WebLogic classpath using a mechanism such as the PRE_CLASSPATH setting in your domain setDomainEnv script. Then restart WLS of course. Using The final piece if to actually assign the filter.  The simplest way to do this is to add the filter attribute to the logger definition in the logging.xml file. For example, you may choose to define a logger for a specific class that is raising these messages and only apply the filter in that case.  <logger name="some.vendor.adf.ClassICantChange"         filter="oracle.demo.MyLoggingFilter"/> You can also apply the filter using WLST if you want a more script-y solution.

  Read the article

• Too complex/too many objects?

  - by Mike Fairhurst

  I know that this will be a difficult question to answer without context, but hopefully there are at least some good guidelines to share on this. The questions are at the bottom if you want to skip the details. Most are about OOP in general. Begin context. I am a jr dev on a PHP application, and in general the devs I work with consider themselves to use many more OO concepts than most PHP devs. Still, in my research on clean code I have read about so many ways of using OO features to make code flexible, powerful, expressive, testable, etc. that is just plain not in use here. The current strongly OO API that I've proposed is being called too complex, even though it is trivial to implement. The problem I'm solving is that our permission checks are done via a message object (my API, they wanted to use arrays of constants) and the message object does not hold the validation object accountable for checking all provided data. Metaphorically, if your perm containing 'allowable' and 'rare but disallowed' is sent into a validator, the validator may not know to look for 'rare but disallowed', but approve 'allowable', which will actually approve the whole perm check. We have like 11 validators, too many to easily track at such minute detail. So I proposed an AtomicPermission class. To fix the previous example, the perm would instead contain two atomic permissions, one wrapping 'allowable' and the other wrapping 'rare but disallowed'. Where previously the validator would say 'the check is OK because it contains allowable,' now it would instead say '"allowable" is ok', at which point the check ends...and the check fails, because 'rare but disallowed' was not specifically okay-ed. The implementation is just 4 trivial objects, and rewriting a 10 line function into a 15 line function. abstract class PermissionAtom { public function allow(); // maybe deny() as well public function wasAllowed(); } class PermissionField extends PermissionAtom { public function getName(); public function getValue(); } class PermissionIdentifier extends PermissionAtom { public function getIdentifier(); } class PermissionAction extends PermissionAtom { public function getType(); } They say that this is 'not going to get us anything important' and it is 'too complex' and 'will be difficult for new developers to pick up.' I respectfully disagree, and there I end my context to begin the broader questions. So the question is about my OOP, are there any guidelines I should know: is this too complicated/too much OOP? Not that I expect to get more than 'it depends, I'd have to see if...' when is OO abstraction too much? when is OO abstraction too little? how can I determine when I am overthinking a problem vs fixing one? how can I determine when I am adding bad code to a bad project? how can I pitch these APIs? I feel the other devs would just rather say 'its too complicated' than ask 'can you explain it?' whenever I suggest a new class.

  Read the article

• 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.

  Read the article

• The long road to bug-free software

  - by Tony Davis

  The past decade has seen a burgeoning interest in functional programming languages such as Haskell or, in the Microsoft world, F#. Though still on the periphery of mainstream programming, functional programming concepts are gradually seeping into the imperative C# language (for example, Lambda expressions have their root in functional programming). One of the more interesting concepts from functional programming languages is the use of formal methods, the lofty ideal behind which is bug-free software. The idea is that we write a specification that describes exactly how our function (say) should behave. We then prove that our function conforms to it, and in doing so have proved beyond any doubt that it is free from bugs. All programmers already use one form of specification, specifically their programming language's type system. If a value has a specific type then, in a type-safe language, the compiler guarantees that value cannot be an instance of a different type. Many extensions to existing type systems, such as generics in Java and .NET, extend the range of programs that can be type-checked. Unfortunately, type systems can only prevent some bugs. To take a classic problem of retrieving an index value from an array, since the type system doesn't specify the length of the array, the compiler has no way of knowing that a request for the "value of index 4" from an array of only two elements is "unsafe". We restore safety via exception handling, but the ideal type system will prevent us from doing anything that is unsafe in the first place and this is where we start to borrow ideas from a language such as Haskell, with its concept of "dependent types". If the type of an array includes its length, we can ensure that any index accesses into the array are valid. The problem is that we now need to carry around the length of arrays and the values of indices throughout our code so that it can be type-checked. In general, writing the specification to prove a positive property, even for a problem very amenable to specification, such as a simple sorting algorithm, turns out to be very hard and the specification will be different for every program. Extend this to writing a specification for, say, Microsoft Word and we can see that the specification would end up being no simpler, and therefore no less buggy, than the implementation. Fortunately, it is easier to write a specification that proves that a program doesn't have certain, specific and undesirable properties, such as infinite loops or accesses to the wrong bit of memory. If we can write the specifications to prove that a program is immune to such problems, we could reuse them in many places. The problem is the lack of specification "provers" that can do this without a lot of manual intervention (i.e. hints from the programmer). All this might feel a very long way off, but computing power and our understanding of the theory of "provers" advances quickly, and Microsoft is doing some of it already. Via their Terminator research project they have started to prove that their device drivers will always terminate, and in so doing have suddenly eliminated a vast range of possible bugs. This is a huge step forward from saying, "we've tested it lots and it seems fine". What do you think? What might be good targets for specification and verification? SQL could be one: the cost of a bug in SQL Server is quite high given how many important systems rely on it, so there's a good incentive to eliminate bugs, even at high initial cost. [Many thanks to Mike Williamson for guidance and useful conversations during the writing of this piece] Cheers, Tony.

  Read the article

• Javascript Inheritance Part 2

  - by PhubarBaz

  A while back I wrote about Javascript inheritance, trying to figure out the best and easiest way to do it (http://geekswithblogs.net/PhubarBaz/archive/2010/07/08/javascript-inheritance.aspx). That was 2 years ago and I've learned a lot since then. But only recently have I decided to just leave classical inheritance behind and embrace prototypal inheritance. For most of us, we were trained in classical inheritance, using class hierarchies in a typed language. Unfortunately Javascript doesn't follow that model. It is both classless and typeless, which is hard to fathom for someone who's been using classes the last 20 years. For the last two or three years since I've got into Javascript I've been trying to find the best way to force it into the class model without much success. It's clunky and verbose and hard to understand. I think my biggest problem was that it felt so wrong to add or change object members at run time. Every time I did it I felt like I needed a shower. That's the 20 years of classical inheritance in me. Finally I decided to embrace change and do something different. I decided to use the factory pattern to build objects instead of trying to use inheritance. Javascript was made for the factory pattern because of the way you can construct objects at runtime. In the factory pattern you have a factory function that you call and tell it to give you a certain type of object back. The factory function takes care of constructing the object to your specification. Here's an example. Say we want to have some shape objects and they have common attributes like id and area that we want to depend on in other parts of your application. So first thing to do is create a factory object and give it a factory method to create an abstract shape object. The factory method builds the object then returns it. var shapeFactory = { getShape: function(id){ var shape = { id: id, area: function() { throw "Not implemented"; } }; return shape; }}; Now we can add another factory method to get a rectangle. It calls the getShape() method first and then adds an implementation to it. getRectangle: function(id, width, height){ var rect = this.getShape(id); rect.width = width; rect.height = height; rect.area = function() { return this.width * this.height; }; return rect;} That's pretty simple right? No worrying about hooking up prototypes and calling base constructors or any of that crap I used to do. Now let's create a factory method to get a cuboid (rectangular cube). The cuboid object will extend the rectangle object. To get the area we will call into the base object's area method and then multiply that by the depth. getCuboid: function(id, width, height, depth){ var cuboid = this.getRectangle(id, width, height); cuboid.depth = depth; var baseArea = cuboid.area; cuboid.area = function() { var a = baseArea.call(this); return a * this.depth; } return cuboid;} See how we called the area method in the base object? First we save it off in a variable then we implement our own area method and use call() to call the base function. For me this is a lot cleaner and easier than trying to emulate class hierarchies in Javascript.

  Read the article

• Reading graph inputs for a programming puzzle and then solving it

  - by Vrashabh

  I just took a programming competition question and I absolutely bombed it. I had trouble right at the beginning itself from reading the input set. The question was basically a variant of this puzzle http://codercharts.com/puzzle/evacuation-plan but also had an hour component in the first line(say 3 hours after start of evacuation). It reads like this This puzzle is a tribute to all the people who suffered from the earthquake in Japan. The goal of this puzzle is, given a network of road and locations, to determine the maximum number of people that can be evacuated. The people must be evacuated from evacuation points to rescue points. The list of road and the number of people they can carry per hour is provided. Input Specifications Your program must accept one and only one command line argument: the input file. The input file is formatted as follows: the first line contains 4 integers n r s t n is the number of locations (each location is given by a number from 0 to n-1) r is the number of roads s is the number of locations to be evacuated from (evacuation points) t is the number of locations where people must be evacuated to (rescue points) the second line contains s integers giving the locations of the evacuation points the third line contains t integers giving the locations of the rescue points the r following lines contain to the road definitions. Each road is defined by 3 integers l1 l2 width where l1 and l2 are the locations connected by the road (roads are one-way) and width is the number of people per hour that can fit on the road Now look at the sample input set 5 5 1 2 3 0 3 4 0 1 10 0 2 5 1 2 4 1 3 5 2 4 10 The 3 in the first line is the additional component and is defined as the number of hours since the resuce has started which is 3 in this case. Now my solution was to use Dijisktras algorithm to find the shortest path between each of the rescue and evac nodes. Now my problem started with how to read the input set. I read the first line in python and stored the values in variables. But then I did not know how to store the values of the distance between the nodes and what DS to use and how to input it to say a standard implementation of dijikstras algorithm. So my question is two fold 1.) How do I take the input of such problems? - I have faced this problem in quite a few competitions recently and I hope I can get a simple code snippet or an explanation in java or python to read the data input set in such a way that I can input it as a graph to graph algorithms like dijikstra and floyd/warshall. Also a solution to the above problem would also help. 2.) How to solve this puzzle? My algorithm was: Find shortest path between evac points (in the above example it is 14 from 0 to 3) Multiply it by number of hours to get maximal number of saves Also the answer given for the variant for the input set was 24 which I dont understand. Can someone explain that also. UPDATE: I get how the answer is 14 in the given problem link - it seems to be just the shortest path between node 0 and 3. But with the 3 hour component how is the answer 24 UPDATE I get how it is 24 - its a complete graph traversal at every hour and this is how I solve it Hour 1 Node 0 to Node 1 - 10 people Node 0 to Node 2- 5 people TotalRescueCount=0 Node 1=10 Node 2= 5 Hour 2 Node 1 to Node 3 = 5(Rescued) Node 2 to Node 4 = 5(Rescued) Node 0 to Node 1 = 10 Node 0 to Node 2 = 5 Node 1 to Node 2 = 4 TotalRescueCount = 10 Node 1 = 10 Node 2= 5+4 = 9 Hour 3 Node 1 to Node 3 = 5(Rescued) Node 2 to Node 4 = 5+4 = 9(Rescued) TotalRescueCount = 9+5+10 = 24 It hard enough for this case , for multiple evac and rescue points how in the world would I write a pgm for this ?

  Read the article

• ?SPARC T4?????????????·???? : Netra SPARC T4-1

  - by user13138700

  ?SPARC T4???????????????·??????? Netra SPARC T4-1 ???? Netra SPARC T4-2 ?2012?1?10??????????3?15??????????????(????) ?????????? Netra SPARC T4-1 ? 4core ???( T4 ???????? 4core ???)(*)???????????????????????????(*)( Netra SPARC T4-1 ?????? 4core ???? 8core ????????) ??? prtdiag ????? pginfo ??????????????? 8????/1core ???? prtdiag ????????4core=32???????????????pginfo ?????????????????core ???????????????????? # ./prtdiag -v System Configuration: Oracle Corporation sun4v Netra SPARC T4-1 ???????: 130560 M ??? ================================ ?? CPU ================================ CPU ID Frequency Implementation Status ------ --------- ---------------------- ------- 0 2848 MHz SPARC-T4 on-line 1 2848 MHz SPARC-T4 on-line 2 2848 MHz SPARC-T4 on-line 3 2848 MHz SPARC-T4 on-line 4 2848 MHz SPARC-T4 on-line 5 2848 MHz SPARC-T4 on-line 6 2848 MHz SPARC-T4 on-line 7 2848 MHz SPARC-T4 on-line 8 2848 MHz SPARC-T4 on-line 9 2848 MHz SPARC-T4 on-line 10 2848 MHz SPARC-T4 on-line 11 2848 MHz SPARC-T4 on-line 12 2848 MHz SPARC-T4 on-line 13 2848 MHz SPARC-T4 on-line 14 2848 MHz SPARC-T4 on-line 15 2848 MHz SPARC-T4 on-line 16 2848 MHz SPARC-T4 on-line 17 2848 MHz SPARC-T4 on-line 18 2848 MHz SPARC-T4 on-line 19 2848 MHz SPARC-T4 on-line 20 2848 MHz SPARC-T4 on-line 21 2848 MHz SPARC-T4 on-line 22 2848 MHz SPARC-T4 on-line 23 2848 MHz SPARC-T4 on-line 24 2848 MHz SPARC-T4 on-line 25 2848 MHz SPARC-T4 on-line 26 2848 MHz SPARC-T4 on-line 27 2848 MHz SPARC-T4 on-line 28 2848 MHz SPARC-T4 on-line 29 2848 MHz SPARC-T4 on-line 30 2848 MHz SPARC-T4 on-line 31 2848 MHz SPARC-T4 on-line ======================= Physical Memory Configuration ======================== ???? # pginfo -p -T 0 (System [system,chip]) CPUs: 0-31 `-- 3 (Data_Pipe_to_memory [system,chip]) CPUs: 0-31 |-- 2 (Floating_Point_Unit [core]) CPUs: 0-7 | `-- 1 (Integer_Pipeline [core]) CPUs: 0-7 |-- 5 (Floating_Point_Unit [core]) CPUs: 8-15 | `-- 4 (Integer_Pipeline [core]) CPUs: 8-15 |-- 7 (Floating_Point_Unit [core]) CPUs: 16-23 | `-- 6 (Integer_Pipeline [core]) CPUs: 16-23 `-- 9 (Floating_Point_Unit [core]) CPUs: 24-31 `-- 8 (Integer_Pipeline [core]) CPUs: 24-31 T4 ????????????????????????????????????????????????? T3 ?????(S2 core)?????T4 ?????(S3 core)?????????????5???????????? T3 ?????(S2 core)?????????????????????????(????????)?????????????????????????????????????????????·???????????????????????????????????????? ????T4 ????????????????????????????T4 ??????????·??????? Netra SPARC T4-1 4core ????????????????????????????????????T3 ???????????????????????????? ?????????Netra SPARC T4-1 ??????????????? Netra SPARC T4-1 ?? Computing 1 x SPARC T4 4?? 32???? or 8 ?? 64 ???? 2.85GHz CPU (1?????8????) 16 x DDR3 DIMM (?? 256GB ?????16GB DIMM ???) I/O and Storage 3 x Low Profile PCI-Express Gen2 ???? (2 x 10Gb Ethernet XAUI ???????) 2 x Full-height Half-length PCI-Express Gen2 ???? 4 x 10/100/1000 Ethernet ???????? 4 x 2.5” SAS2 HDD 4 x USB ??? (?? 2, ?? 2) RAS and Management and Power Supply ???? (RAID????), ????PSU ?????????? ILOM?????????????? 2N (1+1) , AC ???? DC ?? Support OS Oracle Solaris 10 10/9, 9/10, 8/11, Oracle Solaris 11 11/11 Oracle VM Server for SPARC 2.1 (LDoms) ???? ??? NEBS Level3?? ??????21” 19”(EIA-310D),23”,24”,600mm????? ?????(?????)????????? ????SPARC T4 ????????SPARC T4 ?????????????????????????(4???)???????????? Oracle OpenWorld Tokyo 2012 ?3??(4/4(?)?4/5(?)?4/6(?))?????????????????????&?????????????????SPARC T4 ?????????????????????????????????·?????????????????SPARC T4 ???????????????????!? Oracle OpenWorld Tokyo 2012 http://www.oracle.com/openworld/jp-ja/index.html ????·???????????? 4/6(?) Develop D3-13 (14:00 - 14:45) ???????????49 ??? ?????? 7264 ???????????????

  Read the article

• OpenSSL Handshake Failure (14094410) - Erroneous Client Certificate Check from Mobile Phone

  - by Clayton Sims

  I'm running a proxy server through Apache with modssl, which we're using to proxy POSTs from mobile devices to another internal server. This works successfully for most clients, but requests from a specific phone model (Nokia 2690) are showing a bizarre handshake failure. It looks as though OpenSSL is either requesting (or attempting to read an unsolicited) client certificate from the phone (which is especially bizarre because j2me's kssl implementation doesn't support client certs). I've disabled client certificates with the SSLVerifyClient none directive in both the virtual host conf and the modssl conf. The trace from error.log on debug level is (details redacted): [client 41.220.207.10] Connection to child 0 established (server www.myserver.org:443) [info] Seeding PRNG with 656 bytes of entropy [debug] ssl_engine_kernel.c(1866): OpenSSL: Handshake: start [debug] ssl_engine_kernel.c(1874): OpenSSL: Loop: before/accept initialization [debug] ssl_engine_io.c(1882): OpenSSL: read 11/11 bytes from BIO#7fe3fbaf17a0 [mem: 7fe3fbaf90d0] (BIO dump follows) [debug] ssl_engine_io.c(1815): +-------------------------------------------------------------------------+ [debug] ssl_engine_io.c(1860): +-------------------------------------------------------------------------+ [debug] ssl_engine_io.c(1882): OpenSSL: read 49/49 bytes from BIO#7fe3fbaf17a0 [mem: 7fe3fbaf90db] (BIO dump follows) [debug] ssl_engine_io.c(1815): +-------------------------------------------------------------------------+ [debug] ssl_engine_io.c(1860): +-------------------------------------------------------------------------+ [debug] ssl_engine_kernel.c(1874): OpenSSL: Loop: SSLv3 read client hello A [debug] ssl_engine_kernel.c(1874): OpenSSL: Loop: SSLv3 write server hello A [debug] ssl_engine_kernel.c(1874): OpenSSL: Loop: SSLv3 write certificate A [debug] ssl_engine_kernel.c(1874): OpenSSL: Loop: SSLv3 write server done A [debug] ssl_engine_kernel.c(1874): OpenSSL: Loop: SSLv3 flush data [debug] ssl_engine_io.c(1882): OpenSSL: read 5/5 bytes from BIO#7fe3fbaf17a0 [mem: 7fe3fbaf90d0] (BIO dump follows) [debug] ssl_engine_io.c(1815): +-------------------------------------------------------------------------+ [debug] ssl_engine_io.c(1860): +-------------------------------------------------------------------------+ [debug] ssl_engine_io.c(1882): OpenSSL: read 2/2 bytes from BIO#7fe3fbaf17a0 [mem: 7fe3fbaf90d5] (BIO dump follows) [debug] ssl_engine_io.c(1815): +-------------------------------------------------------------------------+ [debug] ssl_engine_io.c(1860): +-------------------------------------------------------------------------+ [debug] ssl_engine_kernel.c(1879): OpenSSL: Read: SSLv3 read client certificate A [debug] ssl_engine_kernel.c(1898): OpenSSL: Exit: failed in SSLv3 read client certificate A [client 41.220.207.10] SSL library error 1 in handshake (server www.myserver.org:443) [info] SSL Library Error: 336151568 error:14094410:SSL routines:SSL3_READ_BYTES:sslv3 alert handshake failure [client 41.220.207.10] Connection closed to child 0 with abortive shutdown (server www.myserver.org:443) I've tried enabling all ciphers and all protocols temporarily with modssl, neither of which seemed to be the issue. The phone should be using RSA_RC4_128_MD5 and SSLv3, all of which are available. Am I missing something more fundamental about what's failing here? It seemed like the certificate request might have been part of a renegotiation failure. I tried enabling SSLInsecureRenegotiation On on the virtual host, in case it was an issue of the phone's SSL not supporting the new protocol, but to no avail. Currently running: Apache/2.2.16 (Ubuntu) mod_ssl/2.2.16 OpenSSL/0.9.8o Apache proxy_html/3.0.1

  Read the article

• Bidirectional real-time sync of large file tree between two distant linux servers

  - by dlo

  By large file tree I mean about 200k files, and growing all the time. A relatively small number of files are being changed in any given hour though. By bidirectional I mean that changes may occur on either server and need to be pushed to the other, so rsync doesn't seem appropriate. By distant I mean that the servers are both in data centers, but geographically remote from each other. Currently there are only 2 servers, but that may expand over time. By real-time, it's ok for there to be a little latency between syncing, but running a cron every 1-2 minutes doesn't seem right, since a very small fraction of files may change in any given hour, let alone minute. EDIT: This is running on VPS's so I might be limited on the kinds of kernel-level stuff I can do. Also, the VPS's are not resource-rich, so I'd shy away from solutions that require lots of ram (like Gluster?). What's the best / most "accepted" approach to get this done? This seems like it would be a common need, but I haven't been able to find a generally accepted approach yet, which was surprising. (I'm seeking the safety of the masses. :) I've come across lsyncd to trigger a sync at the filesystem change level. That seems clever though not super common, and I'm a bit confused by the various lsyncd approaches. There's just using lsyncd with rsync, but it seems this could be fragile for bidirectionality since rsync doesn't have a notion of memory (eg- to know whether a deleted file on A should be deleted on B or whether it's a new file on B that should be copied to A). lipsync appears to be just a lsyncd+rsync implementation, right? Then there's using lsyncd with csync2, like this: http://www.axivo.com/community/threads/lightning-fast-synchronization-with-csync2-and-lsyncd.121/ ... I'm leaning towards this approach, but csync2 is a little quirky, though I did do a successful test of it. I'm mostly concerned that I haven't been able to find a lot of community confirmation of this method. People on here seem to like Unison a lot, but it seems that it is no longer under active development and it's not clear that it has an automatic trigger like lsyncd. I've seen Gluster mentioned, but maybe overkill for what I need? UPDATE: fyi- I ended up going with the original solution I mentioned: lsyncd+csync2. It seems to work quite well, and I like the architectural approach of having the servers be very loosely joined, so that each server can operate indefinitely on its own regardless of the link quality between them.

  Read the article

• An alternative to Google Talk, AIM, MSN, et al [closed]

  - by mkaito

  I'm not entirely sure whether this part of stack exchange is the most adequate for my question, but it would seem to me that people sharing this kind of concern would converge either here, or possibly on a more unix-specific sub site. Either way, here goes. Background Feel free to skip to The Question, below. This should, however, help those interested understand where I'm coming from, and where I expect to get, messaging-wise. My online talking place-to-go has been IRC for the last fifteen years. I think it's a great protocol, and clients out there are very good. I still use, and will always continue to use IRC for most of my chat needs. But then, there is private instant messaging. While IRC can solve this with queries and DCC chats, the protocol just isn't meant to work too well on intermittent connections, such as a mobile device, where you can often walk around places with low signal. I used MSN for a while, but didn't like it. The concept was awesome, but I think Microsoft didn't get the implementation quite right. When they started adding all that eye candy, and my buddies started flooding me with custom icons and buzzing my screen to it's knees, I shut my account and told folks that missed me to just email or call me. Much whining happened, I got called many weird things for not using MSN, but folks eventually got over it. Next, Google Talk came along, and seemed to be a lot better than MSN ever was. The protocol was open, so I could use whatever client I felt a fancy for. With the advent of smart phones, I just got myself a gtalk client on the phone, and have had a really decent integrated mostly-universal IM solution. Over the last few months, all Google services have been feeling flaky. IMs will often arrive anywhere between twenty minutes and one hour after being sent, clients will randomly disconnect, client priorities seem to work sometimes, and sometimes just a random device of those connected will get an IM. I think the time has come to look for greener grass. The Question It's rather hard to put what I'm looking for into precise words. I guess I just want something that is kind of like MSN/Gtalk, but that doesn't let me down when I need it. IRC is pretty much perfect, but the protocol just isn't designed to work well on mobile devices. Really, at this point I'm considering sticking to IRC for desktop messaging, and SMS/email on the phone, but I hope that in this day and age there is something better out there.

  Read the article

• Persistent Issues on small business network using Cisco 871W and Catalyst Express 500

  - by Ben Campbell

  Being the most qualified (read: still not qualified) to solve our persistant network issues, I've turned to serverfault for guidance. I've done some searching, reading related documentation on cisco.com and tried a bit of troubleshooting. Here is the config: 100mb synchronous connection from a business internet provider (tested multiple times at 100meg at the source) Cisco 871W wireless point & router is where the WAN connection starts (this serves all our wireless). The only wired connection in the 871W is the Catalyst switch listed below. Cisco Catalyst Express 500 (24TT) is where all the wired connections terminate. About 20 Windows workstations and servers (AD/Webservers only). Some services in EC2 including mail and other web servers/apps. I've been TOLD cabling internally should be gigabit-ready. Here are the problems: generally slow download rates from the internet to the desktop/laptop frequent "page cannot be displayed" errors in browsers-sometimes 3 or 4 reloads are necessary... often times CSS wont load or other content requiring the browser to connect to a different server. slow speed within the LAN from workstation to workstation copying files. I would expect extremely fast data transfer workstation to workstation / server to workstation in this simple network. Several things I need to admit: I'm not primarily a network guy. Funding is relatively low, I need to be the guy that finds the solution. I understand most of the terminology and most of the technology. Implementation is where I fail due to lack of experience. Getting to the point: I'm wondering whether experienced network admins think that our small network should be sufficiently served with our current hardware if configured properly... or if we should purchase new equipment and start fresh? If starting fresh is the plan, whatever that new equipment may be is a likely different question entirely. If I haven't provided enough information, I will happily do some troubleshooting and update with the results. I have experience using wireshark and some other tools. Please let me know what you think would be most helpful and thanks in advance. EDIT: I forgot to add that the Cisco applicance will not finish loading the SDM Express console. It hangs every time at the "populating modules... DHCP". It eventually crashes and closes. I've rebooted the hardware and this still happens.

  Read the article

• Snmpd update interface counters slowly or something like this

  - by Korjavin Ivan

  I update one my freebsd box to 9-stable (totally new installation) and install net-snmp for monitoring. uname -r 9.1-PRERELEASE pkg_info net-snmp-5.7.1_7 Information for net-snmp-5.7.1_7: Comment: An extendable SNMP implementation .... cat /var/db/ports/net-snmp/options # This file is auto-generated by 'make config'. # Options for net-snmp-5.7.1_7 _OPTIONS_READ=net-snmp-5.7.1_7 _FILE_COMPLETE_OPTIONS_LIST= IPV6 MFD_REWRITES PERL PERL_EMBEDDED PYTHON DUMMY TKMIB DMALLOC MYSQL AX_SOCKONLY UNPRIVILEGED OPTIONS_FILE_UNSET+=IPV6 OPTIONS_FILE_UNSET+=MFD_REWRITES OPTIONS_FILE_SET+=PERL OPTIONS_FILE_SET+=PERL_EMBEDDED OPTIONS_FILE_UNSET+=PYTHON OPTIONS_FILE_SET+=DUMMY OPTIONS_FILE_UNSET+=TKMIB OPTIONS_FILE_SET+=DMALLOC OPTIONS_FILE_UNSET+=MYSQL OPTIONS_FILE_UNSET+=AX_SOCKONLY OPTIONS_FILE_UNSET+=UNPRIVILEGED I have about 500 vlan on this machine, and collect info about interface through snmpd to 2 different software, zabbix and cacti. And both of them plot the graphs with blank fields. I tryed change polling time in zabbix, from 15, sec to 30,60,90,120,10. And anyway i have blank fields. snmpd.conf is empty - only a access controls. This configuration worked fine on freebsd 8. Where is my fault? How fix this graphs? UPD: Changing pooling time, switch off one of agent, doesnt help. I look at zabbix log (recieved data from snmpd) and see that: sorry for russian locale, just look at numbers: and thats is not true, as my "iftop" show speed was about 90Mbits, but snmpd return 2Mbits. I understand that snmpd doesnt return speed, it return just a counter. But how its possible? why 2Mbit/s ? I tryed recompile snmpd with 64-bit counters, and without it. In both variants this blank fields present. So i think its my OS (freebsd) doesnt update interface counters well. I still collect tcpdump for found this request/response. But have problem with that, to much trash. UPD2: I decrypt tcpdump-ed file, and public this as google doc at gdocfile Timediff looks strange.. Like zabbix sometimes "forget" do request, and then do twice at row, ehh UPD3: I parse log from command "while true; do netstat -bin -I vlan4008 /var/log/netstat; sleep 300; done" and load as google docs, and add formula for speed : link Looks like all counters in OS are good. Now i think problem in : 1. zabbix get request twice at row (and what about cacti) 2. snmpd use counter32

  Read the article

• Disable .htaccess from apache allowoverride none, still reads .htaccess files

  - by John Magnolia

  I have moved all of our .htaccess config into <Directory> blocks and set AllowOverride None in the default and default-ssl. Although after restarting apache it is still reading the .htaccess files. How can I completely turn off reading these files? Update of all files with "AllowOverride" /etc/apache2/mods-available/userdir.conf <IfModule mod_userdir.c> UserDir public_html UserDir disabled root <Directory /home/*/public_html> AllowOverride FileInfo AuthConfig Limit Indexes Options MultiViews Indexes SymLinksIfOwnerMatch IncludesNoExec <Limit GET POST OPTIONS> Order allow,deny Allow from all </Limit> <LimitExcept GET POST OPTIONS> Order deny,allow Deny from all </LimitExcept> </Directory> </IfModule> /etc/apache2/mods-available/alias.conf <IfModule alias_module> # # Aliases: Add here as many aliases as you need (with no limit). The format is # Alias fakename realname # # Note that if you include a trailing / on fakename then the server will # require it to be present in the URL. So "/icons" isn't aliased in this # example, only "/icons/". If the fakename is slash-terminated, then the # realname must also be slash terminated, and if the fakename omits the # trailing slash, the realname must also omit it. # # We include the /icons/ alias for FancyIndexed directory listings. If # you do not use FancyIndexing, you may comment this out. # Alias /icons/ "/usr/share/apache2/icons/" <Directory "/usr/share/apache2/icons"> Options Indexes MultiViews AllowOverride None Order allow,deny Allow from all </Directory> </IfModule> /etc/apache2/httpd.conf # # Directives to allow use of AWStats as a CGI # Alias /awstatsclasses "/usr/share/doc/awstats/examples/wwwroot/classes/" Alias /awstatscss "/usr/share/doc/awstats/examples/wwwroot/css/" Alias /awstatsicons "/usr/share/doc/awstats/examples/wwwroot/icon/" ScriptAlias /awstats/ "/usr/share/doc/awstats/examples/wwwroot/cgi-bin/" # # This is to permit URL access to scripts/files in AWStats directory. # <Directory "/usr/share/doc/awstats/examples/wwwroot"> Options None AllowOverride None Order allow,deny Allow from all </Directory> Alias /awstats-icon/ /usr/share/awstats/icon/ <Directory /usr/share/awstats/icon> Options None AllowOverride None Order allow,deny Allow from all </Directory> /etc/apache2/sites-available/default-ssl <IfModule mod_ssl.c> <VirtualHost _default_:443> ServerAdmin webmaster@localhost DocumentRoot /var/www <Directory /> Options FollowSymLinks AllowOverride None </Directory> <Directory /var/www/> Options Indexes FollowSymLinks MultiViews AllowOverride None </Directory> ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory> ErrorLog ${APACHE_LOG_DIR}/error.log # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. LogLevel warn CustomLog ${APACHE_LOG_DIR}/ssl_access.log combined # SSL Engine Switch: # Enable/Disable SSL for this virtual host. SSLEngine on # A self-signed (snakeoil) certificate can be created by installing # the ssl-cert package. See # /usr/share/doc/apache2.2-common/README.Debian.gz for more info. # If both key and certificate are stored in the same file, only the # SSLCertificateFile directive is needed. SSLCertificateFile /etc/ssl/certs/ssl-cert-snakeoil.pem SSLCertificateKeyFile /etc/ssl/private/ssl-cert-snakeoil.key # Server Certificate Chain: # Point SSLCertificateChainFile at a file containing the # concatenation of PEM encoded CA certificates which form the # certificate chain for the server certificate. Alternatively # the referenced file can be the same as SSLCertificateFile # when the CA certificates are directly appended to the server # certificate for convinience. #SSLCertificateChainFile /etc/apache2/ssl.crt/server-ca.crt # Certificate Authority (CA): # Set the CA certificate verification path where to find CA # certificates for client authentication or alternatively one # huge file containing all of them (file must be PEM encoded) # Note: Inside SSLCACertificatePath you need hash symlinks # to point to the certificate files. Use the provided # Makefile to update the hash symlinks after changes. #SSLCACertificatePath /etc/ssl/certs/ #SSLCACertificateFile /etc/apache2/ssl.crt/ca-bundle.crt # Certificate Revocation Lists (CRL): # Set the CA revocation path where to find CA CRLs for client # authentication or alternatively one huge file containing all # of them (file must be PEM encoded) # Note: Inside SSLCARevocationPath you need hash symlinks # to point to the certificate files. Use the provided # Makefile to update the hash symlinks after changes. #SSLCARevocationPath /etc/apache2/ssl.crl/ #SSLCARevocationFile /etc/apache2/ssl.crl/ca-bundle.crl # Client Authentication (Type): # Client certificate verification type and depth. Types are # none, optional, require and optional_no_ca. Depth is a # number which specifies how deeply to verify the certificate # issuer chain before deciding the certificate is not valid. #SSLVerifyClient require #SSLVerifyDepth 10 # Access Control: # With SSLRequire you can do per-directory access control based # on arbitrary complex boolean expressions containing server # variable checks and other lookup directives. The syntax is a # mixture between C and Perl. See the mod_ssl documentation # for more details. #<Location /> #SSLRequire ( %{SSL_CIPHER} !~ m/^(EXP|NULL)/ \ # and %{SSL_CLIENT_S_DN_O} eq "Snake Oil, Ltd." \ # and %{SSL_CLIENT_S_DN_OU} in {"Staff", "CA", "Dev"} \ # and %{TIME_WDAY} >= 1 and %{TIME_WDAY} <= 5 \ # and %{TIME_HOUR} >= 8 and %{TIME_HOUR} <= 20 ) \ # or %{REMOTE_ADDR} =~ m/^192\.76\.162\.[0-9]+$/ #</Location> # SSL Engine Options: # Set various options for the SSL engine. # o FakeBasicAuth: # Translate the client X.509 into a Basic Authorisation. This means that # the standard Auth/DBMAuth methods can be used for access control. The # user name is the `one line' version of the client's X.509 certificate. # Note that no password is obtained from the user. Every entry in the user # file needs this password: `xxj31ZMTZzkVA'. # o ExportCertData: # This exports two additional environment variables: SSL_CLIENT_CERT and # SSL_SERVER_CERT. These contain the PEM-encoded certificates of the # server (always existing) and the client (only existing when client # authentication is used). This can be used to import the certificates # into CGI scripts. # o StdEnvVars: # This exports the standard SSL/TLS related `SSL_*' environment variables. # Per default this exportation is switched off for performance reasons, # because the extraction step is an expensive operation and is usually # useless for serving static content. So one usually enables the # exportation for CGI and SSI requests only. # o StrictRequire: # This denies access when "SSLRequireSSL" or "SSLRequire" applied even # under a "Satisfy any" situation, i.e. when it applies access is denied # and no other module can change it. # o OptRenegotiate: # This enables optimized SSL connection renegotiation handling when SSL # directives are used in per-directory context. #SSLOptions +FakeBasicAuth +ExportCertData +StrictRequire <FilesMatch "\.(cgi|shtml|phtml|php)$"> SSLOptions +StdEnvVars </FilesMatch> <Directory /usr/lib/cgi-bin> SSLOptions +StdEnvVars </Directory> # SSL Protocol Adjustments: # The safe and default but still SSL/TLS standard compliant shutdown # approach is that mod_ssl sends the close notify alert but doesn't wait for # the close notify alert from client. When you need a different shutdown # approach you can use one of the following variables: # o ssl-unclean-shutdown: # This forces an unclean shutdown when the connection is closed, i.e. no # SSL close notify alert is send or allowed to received. This violates # the SSL/TLS standard but is needed for some brain-dead browsers. Use # this when you receive I/O errors because of the standard approach where # mod_ssl sends the close notify alert. # o ssl-accurate-shutdown: # This forces an accurate shutdown when the connection is closed, i.e. a # SSL close notify alert is send and mod_ssl waits for the close notify # alert of the client. This is 100% SSL/TLS standard compliant, but in # practice often causes hanging connections with brain-dead browsers. Use # this only for browsers where you know that their SSL implementation # works correctly. # Notice: Most problems of broken clients are also related to the HTTP # keep-alive facility, so you usually additionally want to disable # keep-alive for those clients, too. Use variable "nokeepalive" for this. # Similarly, one has to force some clients to use HTTP/1.0 to workaround # their broken HTTP/1.1 implementation. Use variables "downgrade-1.0" and # "force-response-1.0" for this. BrowserMatch "MSIE [2-6]" \ nokeepalive ssl-unclean-shutdown \ downgrade-1.0 force-response-1.0 # MSIE 7 and newer should be able to use keepalive BrowserMatch "MSIE [17-9]" ssl-unclean-shutdown </VirtualHost> </IfModule> /etc/apache2/sites-available/default <VirtualHost *:80> ServerAdmin webmaster@localhost DocumentRoot /var/www <Directory /> Options FollowSymLinks AllowOverride None </Directory> <Directory /var/www/> Options -Indexes FollowSymLinks MultiViews AllowOverride None Order allow,deny allow from all </Directory> ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory> Alias /delboy /usr/share/phpmyadmin <Directory /usr/share/phpmyadmin> # Restrict phpmyadmin access Order Deny,Allow Allow from all </Directory> ErrorLog ${APACHE_LOG_DIR}/error.log # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. LogLevel warn CustomLog ${APACHE_LOG_DIR}/access.log combined Alias /doc/ "/usr/share/doc/" <Directory "/usr/share/doc/"> Options Indexes MultiViews FollowSymLinks AllowOverride None Order deny,allow Deny from all Allow from 127.0.0.0/255.0.0.0 ::1/128 </Directory> </VirtualHost> /etc/apache2/conf.d/security # # Disable access to the entire file system except for the directories that # are explicitly allowed later. # # This currently breaks the configurations that come with some web application # Debian packages. # #<Directory /> # AllowOverride None # Order Deny,Allow # Deny from all #</Directory> # Changing the following options will not really affect the security of the # server, but might make attacks slightly more difficult in some cases. # # ServerTokens # This directive configures what you return as the Server HTTP response # Header. The default is 'Full' which sends information about the OS-Type # and compiled in modules. # Set to one of: Full | OS | Minimal | Minor | Major | Prod # where Full conveys the most information, and Prod the least. # #ServerTokens Minimal ServerTokens OS #ServerTokens Full # # Optionally add a line containing the server version and virtual host # name to server-generated pages (internal error documents, FTP directory # listings, mod_status and mod_info output etc., but not CGI generated # documents or custom error documents). # Set to "EMail" to also include a mailto: link to the ServerAdmin. # Set to one of: On | Off | EMail # #ServerSignature Off ServerSignature On # # Allow TRACE method # # Set to "extended" to also reflect the request body (only for testing and # diagnostic purposes). # # Set to one of: On | Off | extended # TraceEnable Off #TraceEnable On /etc/apache2/apache2.conf # # Based upon the NCSA server configuration files originally by Rob McCool. # # This is the main Apache server configuration file. It contains the # configuration directives that give the server its instructions. # See http://httpd.apache.org/docs/2.2/ for detailed information about # the directives. # # Do NOT simply read the instructions in here without understanding # what they do. They're here only as hints or reminders. If you are unsure # consult the online docs. You have been warned. # # The configuration directives are grouped into three basic sections: # 1. Directives that control the operation of the Apache server process as a # whole (the 'global environment'). # 2. Directives that define the parameters of the 'main' or 'default' server, # which responds to requests that aren't handled by a virtual host. # These directives also provide default values for the settings # of all virtual hosts. # 3. Settings for virtual hosts, which allow Web requests to be sent to # different IP addresses or hostnames and have them handled by the # same Apache server process. # # Configuration and logfile names: If the filenames you specify for many # of the server's control files begin with "/" (or "drive:/" for Win32), the # server will use that explicit path. If the filenames do *not* begin # with "/", the value of ServerRoot is prepended -- so "foo.log" # with ServerRoot set to "/etc/apache2" will be interpreted by the # server as "/etc/apache2/foo.log". # ### Section 1: Global Environment # # The directives in this section affect the overall operation of Apache, # such as the number of concurrent requests it can handle or where it # can find its configuration files. # # # ServerRoot: The top of the directory tree under which the server's # configuration, error, and log files are kept. # # NOTE! If you intend to place this on an NFS (or otherwise network) # mounted filesystem then please read the LockFile documentation (available # at <URL:http://httpd.apache.org/docs/2.2/mod/mpm_common.html#lockfile>); # you will save yourself a lot of trouble. # # Do NOT add a slash at the end of the directory path. # #ServerRoot "/etc/apache2" # # The accept serialization lock file MUST BE STORED ON A LOCAL DISK. # LockFile ${APACHE_LOCK_DIR}/accept.lock # # PidFile: The file in which the server should record its process # identification number when it starts. # This needs to be set in /etc/apache2/envvars # PidFile ${APACHE_PID_FILE} # # Timeout: The number of seconds before receives and sends time out. # Timeout 300 # # KeepAlive: Whether or not to allow persistent connections (more than # one request per connection). Set to "Off" to deactivate. # KeepAlive On # # MaxKeepAliveRequests: The maximum number of requests to allow # during a persistent connection. Set to 0 to allow an unlimited amount. # We recommend you leave this number high, for maximum performance. # MaxKeepAliveRequests 100 # # KeepAliveTimeout: Number of seconds to wait for the next request from the # same client on the same connection. # KeepAliveTimeout 4 ## ## Server-Pool Size Regulation (MPM specific) ## # prefork MPM # StartServers: number of server processes to start # MinSpareServers: minimum number of server processes which are kept spare # MaxSpareServers: maximum number of server processes which are kept spare # MaxClients: maximum number of server processes allowed to start # MaxRequestsPerChild: maximum number of requests a server process serves <IfModule mpm_prefork_module> StartServers 5 MinSpareServers 5 MaxSpareServers 10 MaxClients 150 MaxRequestsPerChild 500 </IfModule> # worker MPM # StartServers: initial number of server processes to start # MaxClients: maximum number of simultaneous client connections # MinSpareThreads: minimum number of worker threads which are kept spare # MaxSpareThreads: maximum number of worker threads which are kept spare # ThreadLimit: ThreadsPerChild can be changed to this maximum value during a # graceful restart. ThreadLimit can only be changed by stopping # and starting Apache. # ThreadsPerChild: constant number of worker threads in each server process # MaxRequestsPerChild: maximum number of requests a server process serves <IfModule mpm_worker_module> StartServers 2 MinSpareThreads 25 MaxSpareThreads 75 ThreadLimit 64 ThreadsPerChild 25 MaxClients 150 MaxRequestsPerChild 0 </IfModule> # event MPM # StartServers: initial number of server processes to start # MaxClients: maximum number of simultaneous client connections # MinSpareThreads: minimum number of worker threads which are kept spare # MaxSpareThreads: maximum number of worker threads which are kept spare # ThreadsPerChild: constant number of worker threads in each server process # MaxRequestsPerChild: maximum number of requests a server process serves <IfModule mpm_event_module> StartServers 2 MaxClients 150 MinSpareThreads 25 MaxSpareThreads 75 ThreadLimit 64 ThreadsPerChild 25 MaxRequestsPerChild 0 </IfModule> # These need to be set in /etc/apache2/envvars User ${APACHE_RUN_USER} Group ${APACHE_RUN_GROUP} # # AccessFileName: The name of the file to look for in each directory # for additional configuration directives. See also the AllowOverride # directive. # AccessFileName .htaccess # # The following lines prevent .htaccess and .htpasswd files from being # viewed by Web clients. # <Files ~ "^\.ht"> Order allow,deny Deny from all Satisfy all </Files> # # DefaultType is the default MIME type the server will use for a document # if it cannot otherwise determine one, such as from filename extensions. # If your server contains mostly text or HTML documents, "text/plain" is # a good value. If most of your content is binary, such as applications # or images, you may want to use "application/octet-stream" instead to # keep browsers from trying to display binary files as though they are # text. # DefaultType text/plain # # HostnameLookups: Log the names of clients or just their IP addresses # e.g., www.apache.org (on) or 204.62.129.132 (off). # The default is off because it'd be overall better for the net if people # had to knowingly turn this feature on, since enabling it means that # each client request will result in AT LEAST one lookup request to the # nameserver. # HostnameLookups Off # ErrorLog: The location of the error log file. # If you do not specify an ErrorLog directive within a <VirtualHost> # container, error messages relating to that virtual host will be # logged here. If you *do* define an error logfile for a <VirtualHost> # container, that host's errors will be logged there and not here. # ErrorLog ${APACHE_LOG_DIR}/error.log # # LogLevel: Control the number of messages logged to the error_log. # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. # LogLevel warn # Include module configuration: Include mods-enabled/*.load Include mods-enabled/*.conf # Include all the user configurations: Include httpd.conf # Include ports listing Include ports.conf # # The following directives define some format nicknames for use with # a CustomLog directive (see below). # If you are behind a reverse proxy, you might want to change %h into %{X-Forwarded-For}i # LogFormat "%v:%p %h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" vhost_combined LogFormat "%h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" combined LogFormat "%h %l %u %t \"%r\" %>s %O" common LogFormat "%{Referer}i -> %U" referer LogFormat "%{User-agent}i" agent # Include of directories ignores editors' and dpkg's backup files, # see README.Debian for details. # Include generic snippets of statements Include conf.d/ # Include the virtual host configurations: Include sites-enabled/

  Read the article

• Spanning-tree setup with incompatible switches

  - by wfaulk

  I have a set of eight HP ProCurve 2910al-48G Ethernet switches at my datacenter that are set up in a star topology with no physical loops. I want to partially mesh the switches for redundancy and manage the loops with a spanning-tree protocol. However, our connection to the datacenter is provided by two uplinks, each to a Cisco 3750. The datacenter's switches are handling the redundant connection using PVST spanning-tree, which is a Cisco-proprietary spanning-tree implementation that my HP switches do not support. It appears that my switches are not participating in the datacenter's spanning-tree domain, but are blindly passing the BPDUs between the two switchports on my side, which enables the datacenter's switches to recognize the loop and put one of the uplinks into the Blocking state. This is somewhat supposition, but I can confirm that, while my switches say that both of the uplink ports are forwarding, only one is passing any real quantity of data. (I am assuming that I cannot get the datacenter to move away from PVST. I don't know that I'd want them to make that significant of a change anyway.) The datacenter has also sent me this output from their switches (which I have expurgated of any identifiable info): 3750G-1#sh spanning-tree vlan nnn VLAN0nnn Spanning tree enabled protocol ieee Root ID Priority 10 Address 00d0.0114.xxxx Cost 4 Port 5 (GigabitEthernet1/0/5) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 32mmm (priority 32768 sys-id-ext nnn) Address 0018.73d3.yyyy Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300 sec Interface Role Sts Cost Prio.Nbr Type ------------------- ---- --- --------- -------- -------------------------------- Gi1/0/5 Root FWD 4 128.5 P2p Gi1/0/6 Altn BLK 4 128.6 P2p Gi1/0/8 Altn BLK 4 128.8 P2p and: 3750G-2#sh spanning-tree vlan nnn VLAN0nnn Spanning tree enabled protocol ieee Root ID Priority 10 Address 00d0.0114.xxxx Cost 4 Port 6 (GigabitEthernet1/0/6) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 32mmm (priority 32768 sys-id-ext nnn) Address 000f.f71e.zzzz Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300 sec Interface Role Sts Cost Prio.Nbr Type ------------------- ---- --- --------- -------- -------------------------------- Gi1/0/1 Desg FWD 4 128.1 P2p Gi1/0/5 Altn BLK 4 128.5 P2p Gi1/0/6 Root FWD 4 128.6 P2p Gi1/0/8 Desg FWD 4 128.8 P2p The uplinks to my switches are on Gi1/0/8 on both of their switches. The uplink ports are configured with a single tagged VLAN. I am also using a number of other tagged VLANs in my switch infrastructure. And, to be clear, I am passing the tagged VLAN I'm receiving from the datacenter to other ports on other switches in my infrastructure. My question is: how do I configure my switches so that I can use a spanning tree protocol inside my switch infrastructure without breaking the datacenter's spanning tree that I cannot participate in?

  Read the article

< Previous Page | 280 281 282 283 284 285 286 287 288 289 290 291  | Next Page >