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  • General website publishing questions involving domain forwarding issue

    - by Gorgeousyousuf
    Even though I have been having a certain level of knowledge and experience about web development I have never interested in obtaining a domain and publishing a website from my own server. Since today I have been struggling with getting my own domain and configuring it utilizing web sources. I started with learning the outline of web publishing process including web server installation, deploying a website for testing purpose,router port forwarding, getting a domain and forwarding domain to my router which will also forward http requests to my web server I am confused about some parts and so far could not get the web site accessed from outside of the network. All I try to do is just for learning purpose so I do not pay much attention to security issues for now. I have Server 2008 and IIS 7.5 installed. I use a laptop and have access to the modem over wireless and my modem is Zoom x6 5590. Well I will continue explaining what I have done so far and what I think will be after each action I did, I have successfully had access to my website on any local computer entering the internal ip address and port pair of the host machine in a browser. Next, I forwarded port 80 of my host machine creating a virtual server like 10.0.0.x(internal ip(static) of the host) - tcp - start port : 80 - end port : 80 in router options. Now I suppose every request that will come to the public Ip on port 80 will be forwarded to my host machine(10.0.0.x) over port 80. So If everyhing went as desired, the website listening on port 80 will accept the request and process the issue and finally respond bla bla bla... I suppose to access my website from outside of the network by entering http://MyPublicIp:80 in a browser but I couldn't accomplish this task by now despite using godady's domain forwarding tool,I see a small view of my website when I click the "preview" button that checks whether the address(http://publicip/Index.aspx) I entered where my domain will be forwarded is available or not. I am sure that configuring domain does not play a role in solving such a problem since using public ip and port matching does not help. So here is the first question, What is the fact that I face this problem? After that, I have couple of question regarding domain forwarding using godaddy tool. Can I forward my domain to a any port for example port 8080 other than default http port 80? Additionally, can I use a sub-domain to forward to a different port of the host? What I want to design is if the client enters www.mydomain.com, website1 will respond over a specified port and after when a client enters info.mydomain.com, another website which listens on different port will respond. I tried to add a sub-domain and forward it to a address like http://www.mydomain.com:8080/Index.aspx with no success. Can I really do that? Finally, what if I have a ftp site listening on the default port 21 and I create a domain like ftp.mydomain.com that will forward to that ftp site address. Is it possible to use sub-domains for ftp site access? I know I am more than confused but no matter whatever and however you reply to me, you will help me have a more clear view on this subject. Thank you very much from now.

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  • How can I get Firefox to update background-color on a:hover *before* a javascript routine is run?

    - by Rob
    I'm having a Firefox-specific issue with a script I wrote to create 3d layouts. The correct behavior is that the script pulls the background-color from an element and then uses that color to draw on the canvas. When a user mouses over a link and the background-color changes to the :hover rule, the color being drawn changes on the canvas changes as well. When the user mouses out, the color should revert back to non-hover color. This works as expected in Webkit browsers and Opera, but it seems like Firefox doesn't update the background-color in CSS immediately after a mouseout event occurs, so the current background-color doesn't get drawn if a mouseout occurs and it isn't followed up by another event that calls the draw() routine. It works just fine in Opera, Chrome, and Safari. How can I get Firefox to cooperate? I'm including the code that I believe is most relevant to my problem. Any advice on how I fix this problem and get a consistent effect would be very helpful. function drawFace(coord, mid, popColor,gs,x1,x2,side) { /*Gradients in our case run either up/down or left right. We have two algorithms depending on whether or not it's a sideways facing piece. Rather than parse the "rgb(r,g,b)" string(popColor) retrieved from elsewhere, it is simply offset with the gs variable to give the illusion that it starts at a darker color.*/ var canvas = document.getElementById('depth'); //This is for excanvas.js var G_vmlCanvasManager; if (G_vmlCanvasManager != undefined) { // ie IE G_vmlCanvasManager.initElement(canvas); } //Init canvas if (canvas.getContext) { var ctx = canvas.getContext('2d'); if (side) var lineargradient=ctx.createLinearGradient(coord[x1][0]+gs,mid[1],mid[0],mid[1]); else var lineargradient=ctx.createLinearGradient(coord[0][0],coord[2][1]+gs,coord[0][0],mid[1]); lineargradient.addColorStop(0,popColor); lineargradient.addColorStop(1,'black'); ctx.fillStyle=lineargradient; ctx.beginPath(); //Draw from one corner to the midpoint, then to the other corner, //and apply a stroke and a fill. ctx.moveTo(coord[x1][0],coord[x1][1]); ctx.lineTo(mid[0],mid[1]); ctx.lineTo(coord[x2][0],coord[x2][1]); ctx.stroke(); ctx.fill(); } } function draw(e) { var arr = new Array() var i = 0; var mid = new Array(2); $(".pop").each(function() { mid[0]=Math.round($(document).width()/2); mid[1]=Math.round($(document).height()/2); arr[arr.length++]=new getElemProperties(this,mid); i++; }); arr.sort(sortByDistance); clearCanvas(); for (a=0;a<i;a++) { /*In the following conditional statements, we're testing to see which direction faces should be drawn, based on a 1-point perspective drawn from the midpoint. In the first statement, we're testing to see if the lower-left hand corner coord[3] is higher on the screen than the midpoint. If so, we set it's gradient starting position to start at a point in space 60pixels higher(-60) than the actual side, and we also declare which corners make up our face, in this case the lower two corners, coord[3], and coord[2].*/ if (arr[a].bottomFace) drawFace(arr[a].coord,mid,arr[a].popColor,-60,3,2); if (arr[a].topFace) drawFace(arr[a].coord,mid,arr[a].popColor,60,0,1); if (arr[a].leftFace) drawFace(arr[a].coord,mid,arr[a].popColor,60,0,3,true); if (arr[a].rightFace) drawFace(arr[a].coord,mid,arr[a].popColor,-60,1,2,true); } } $("a.pop").bind("mouseenter mouseleave focusin focusout",draw); If you need to see the effect in action, or if you want the full javascript code, you can check it out here: http://www.robnixondesigns.com/strangematter/

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  • Why do I get "Sequence contains no elements"?

    - by Gary McGill
    NOTE: see edits at bottom. I am an idiot. I had the following code to process set of tag names and identify/process new ones: IEnumberable<string> tagNames = GetTagNames(); List<Tag> allTags = GetAllTags(); var newTagNames = tagNames.Where(n => !allTags.Any(t => t.Name == n)); foreach (var tagName in newTagNames) { // ... } ...and this worked fine, except that it failed to deal with cases where there's a tag called "Foo" and the list contains "foo". In other words, it wasn't doing a case-insensitive comparison. I changed the test to use a case-insensitive comparison, as follows: var newTagNames = tagNames.Where(n => !allTags.Any(t => t.Name.Equals(n, StringComparison.InvariantCultureIgnoreCase))); ... and suddenly I get an exception thrown when the foreach runs (and calls MoveNext on) newTagNames. The exception says: Sequence has no elements I'm confused by this. Why would foreach insist on the sequence being non-empty? I'd expect to see that error if I was calling First(), but not when using foreach? EDIT: more info. This is getting weirder by the minute. Because my code is in an async method, and I'm superstitious, I decided that there was too much "distance" between the point at which the exception is raised, and the point at which it's caught and reported. So, I put a try/catch around the offending code, in the hope of verifying that the exception being thrown really was what I thought it was. So now I can step through in the debugger to the foreach line, I can verify that the sequence is empty, and I can step right up to the bit where the debugger highlights the word "in". One more step, and I'm in my exception handler. But, not the exception handler I just added, no! It lands in my outermost exception handler, without visiting my recently-added one! It doesn't match catch (Exception ex) and nor does it match a plain catch. (I did also put in a finally, and verified that it does visit that on the way out). I've always taken it on faith that an Exception handler such as those would catch any exception. I'm scared now. I need an adult. EDIT 2: OK, so um, false alarm... The exception was not being caught by my local try/catch simply because it was not being raised by the code I thought. As I said above, I watched the execution in the debugger jump from the "in" of the foreach straight to the outer exception handler, hence my (wrong) assumption that that was where the error lay. However, with the empty enumeration, that was simply the last statement executed within the function, and for some reason the debugger did not show me the step out of the function or the execution of the next statement at the point of call - which was in fact the one causing the error. Apologies to all those who responded, and if you would like to create an answer saying that I am an idoit, I will gladly accept it. That is, if I ever show my face on SO again...

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  • How to directly rotate CVImageBuffer image in IOS 4 without converting to UIImage?

    - by Ian Charnas
    I am using OpenCV 2.2 on the iPhone to detect faces. I'm using the IOS 4's AVCaptureSession to get access to the camera stream, as seen in the code that follows. My challenge is that the video frames come in as CVBufferRef (pointers to CVImageBuffer) objects, and they come in oriented as a landscape, 480px wide by 300px high. This is fine if you are holding the phone sideways, but when the phone is held in the upright position I want to rotate these frames 90 degrees clockwise so that OpenCV can find the faces correctly. I could convert the CVBufferRef to a CGImage, then to a UIImage, and then rotate, as this person is doing: Rotate CGImage taken from video frame However that wastes a lot of CPU. I'm looking for a faster way to rotate the images coming in, ideally using the GPU to do this processing if possible. Any ideas? Ian Code Sample: -(void) startCameraCapture { // Start up the face detector faceDetector = [[FaceDetector alloc] initWithCascade:@"haarcascade_frontalface_alt2" withFileExtension:@"xml"]; // Create the AVCapture Session session = [[AVCaptureSession alloc] init]; // create a preview layer to show the output from the camera AVCaptureVideoPreviewLayer *previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:session]; previewLayer.frame = previewView.frame; previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill; [previewView.layer addSublayer:previewLayer]; // Get the default camera device AVCaptureDevice* camera = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; // Create a AVCaptureInput with the camera device NSError *error=nil; AVCaptureInput* cameraInput = [[AVCaptureDeviceInput alloc] initWithDevice:camera error:&error]; if (cameraInput == nil) { NSLog(@"Error to create camera capture:%@",error); } // Set the output AVCaptureVideoDataOutput* videoOutput = [[AVCaptureVideoDataOutput alloc] init]; videoOutput.alwaysDiscardsLateVideoFrames = YES; // create a queue besides the main thread queue to run the capture on dispatch_queue_t captureQueue = dispatch_queue_create("catpureQueue", NULL); // setup our delegate [videoOutput setSampleBufferDelegate:self queue:captureQueue]; // release the queue. I still don't entirely understand why we're releasing it here, // but the code examples I've found indicate this is the right thing. Hmm... dispatch_release(captureQueue); // configure the pixel format videoOutput.videoSettings = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithUnsignedInt:kCVPixelFormatType_32BGRA], (id)kCVPixelBufferPixelFormatTypeKey, nil]; // and the size of the frames we want // try AVCaptureSessionPresetLow if this is too slow... [session setSessionPreset:AVCaptureSessionPresetMedium]; // If you wish to cap the frame rate to a known value, such as 10 fps, set // minFrameDuration. videoOutput.minFrameDuration = CMTimeMake(1, 10); // Add the input and output [session addInput:cameraInput]; [session addOutput:videoOutput]; // Start the session [session startRunning]; } - (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection { // only run if we're not already processing an image if (!faceDetector.imageNeedsProcessing) { // Get CVImage from sample buffer CVImageBufferRef cvImage = CMSampleBufferGetImageBuffer(sampleBuffer); // Send the CVImage to the FaceDetector for later processing [faceDetector setImageFromCVPixelBufferRef:cvImage]; // Trigger the image processing on the main thread [self performSelectorOnMainThread:@selector(processImage) withObject:nil waitUntilDone:NO]; } }

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  • Mass Ball-to-Ball Collision Handling (as in, lots of balls)

    - by BlueThen
    Update: Found out that I was using the radius as the diameter, which was why the mtd was overcompensating. Hi, StackOverflow. I've written a Processing program awhile back simulating ball physics. Basically, I have a large number of balls (1000), with gravity turned on. Detection works great, but my issue is that they start acting weird when they're bouncing against other balls in all directions. I'm pretty confident this involves the handling. For the most part, I'm using Jay Conrod's code. One part that's different is if (distance > 1.0) return; which I've changed to if (distance < 1.0) return; because the collision wasn't even being performed with the first bit of code, I'm guessing that's a typo. The balls overlap when I use his code, which isn't what I was looking for. My attempt to fix it was to move the balls to the edge of each other: float angle = atan2(y - collider.y, x - collider.x); float distance = dist(x,y, balls[ID2].x,balls[ID2].y); x = collider.x + radius * cos(angle); y = collider.y + radius * sin(angle); This isn't correct, I'm pretty sure of that. I tried the correction algorithm in the previous ball-to-ball topic: // get the mtd Vector2d delta = (position.subtract(ball.position)); float d = delta.getLength(); // minimum translation distance to push balls apart after intersecting Vector2d mtd = delta.multiply(((getRadius() + ball.getRadius())-d)/d); // resolve intersection -- // inverse mass quantities float im1 = 1 / getMass(); float im2 = 1 / ball.getMass(); // push-pull them apart based off their mass position = position.add(mtd.multiply(im1 / (im1 + im2))); ball.position = ball.position.subtract(mtd.multiply(im2 / (im1 + im2))); except my version doesn't use vectors, and every ball's weight is 1. The resulting code I get is this: PVector delta = new PVector(collider.x - x, collider.y - y); float d = delta.mag(); PVector mtd = new PVector(delta.x * ((radius + collider.radius - d) / d), delta.y * ((radius + collider.radius - d) / d)); // push-pull apart based on mass x -= mtd.x * 0.5; y -= mtd.y * 0.5; collider.x += mtd.x * 0.5; collider.y += mtd.y * 0.5; This code seems to over-correct collisions. Which doesn't make sense to me because in no other way do I modify the x and y values of each ball, other than this. Some other part of my code could be wrong, but I don't know. Here's the snippet of the entire ball-to-ball collision handling I'm using: if (alreadyCollided.contains(new Integer(ID2))) // if the ball has already collided with this, then we don't need to reperform the collision algorithm return; Ball collider = (Ball) objects.get(ID2); PVector collision = new PVector(x - collider.x, y - collider.y); float distance = collision.mag(); if (distance == 0) { collision = new PVector(1,0); distance = 1; } if (distance < 1) return; PVector velocity = new PVector(vx,vy); PVector velocity2 = new PVector(collider.vx, collider.vy); collision.div(distance); // normalize the distance float aci = velocity.dot(collision); float bci = velocity2.dot(collision); float acf = bci; float bcf = aci; vx += (acf - aci) * collision.x; vy += (acf - aci) * collision.y; collider.vx += (bcf - bci) * collision.x; collider.vy += (bcf - bci) * collision.y; alreadyCollided.add(new Integer(ID2)); collider.alreadyCollided.add(new Integer(ID)); PVector delta = new PVector(collider.x - x, collider.y - y); float d = delta.mag(); PVector mtd = new PVector(delta.x * ((radius + collider.radius - d) / d), delta.y * ((radius + collider.radius - d) / d)); // push-pull apart based on mass x -= mtd.x * 0.2; y -= mtd.y * 0.2; collider.x += mtd.x * 0.2; collider.y += mtd.y * 0.2; Thanks. (Apologies for lack of sources, stackoverflow thinks I'm a spammer)

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  • jQuery .append() not working in IE, Safari, and Chrome

    - by mkmcdonald
    So I'm using jQuery's AJAX function to read some XML for me and it's worked just fine. But now I'm trying to manipulate the display property of 4 different dynamically generated divs. The size and x/y of the divs are determined by the XML and are parsed through. My problem lies in the face that these divs either aren't being generated or just don't show up in IE, Safari, and Chrome. In Firefox and Opera, they do work. I'm using jQuery's .append() to create the divs and then the .css() functino to manipulate them. Looking in Chrome's developer tools, I am seeing that the css property being changed in the script is being overridden by the property in the stylesheet. Any fixes? $(document).ready(function(){ $.ajax({ type: "GET", url: "generate?test", dataType: "xml", success: function(xml) { $(xml).find('template').each(function(){ var portion = $(this).attr('portion'); var select; var name = $(this).find('$(this):first').text(); var mutability = $(this).attr('mutability'); var x = (parseInt($(this).find('x:first').text())*96)/72; var y = (parseInt($(this).find('y:first').text())*96)/72; switch(portion){ case "stub": select = $('#StubTemplates'); select.append(""+name+""); break; case "body": select = $('#BodyTemplates'); select.append(""+name+""); y = y + 90; break; } switch(mutability){ case "dynamic": var width = (parseInt($(this).find('width:first').text())*96)/72; var height = (parseInt($(this).find('height:first').text())*96)/72; var n = name; switch(portion){ case "stub": $('.ticket').append("") break; case "body": $('.ticket').append(""); break; } var top = $('#'+n).position().top; var left = parseInt($('#'+n).css('margin-left')); $('#'+n).css('top', (y+top)+"px"); $('#'+n).css('margin-left', (x+left)+"px"); $('#'+n).css('width', width+"px"); $('#'+n).css('height', height+"px"); break; case "static": var n = name; switch(portion){ case "stub": $('.ticket').append(""); break; case "body": $('.ticket').append(""); break; } break; } }); var stubActive = false; var bodyActive = false; $('#StubTemplates').find('.ddindent').mouseup(function(){ var tVal = $(this).val(); var tTitle = $(this).attr('title'); if(!stubActive){ $('.stubEditable').css('display', 'none'); $('#'+tVal).css('display', 'block'); stubActive = true; }else{ $('.stubEditable').css('display', 'none'); $('#'+tVal).css('display', 'block'); stubActive = false; } }); $('#StubTemplates').find('#stubTempNone').mouseup(function(){ $('.stubEditable').css('display', 'none'); }); $('#BodyTemplates').find('.ddindent').mouseup(function(){ var tVal = $(this).val(); var tTitle = $(this).attr('title'); if(!bodyActive){ $('.bodyEditable').css('display', 'none'); $('#'+tVal).css('display', 'block'); bodyActive = true; }else{ $('.bodyEditable').css('display', 'none'); $('#'+tVal).css('display', 'block'); bodyActive = false; } }); $('#BodyTemplates').find('#bodyTempNone').mouseup(function(){ $('.bodyEditable').css('display', 'none'); }); } }); });

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  • Mysql 100% CPU + Slow query

    - by felipeclopes
    I'm using the RDS database from amazon with a some very big tables, and yesterday I started to face 100% CPU utilisation on the server and a bunch of slow query logs that were not happening before. I tried to check the queries that were running and faced this result from the explain command +----+-------------+-------------------------------+--------+----------------------------------------------------------------------------------------------+---------------------------------------+---------+-----------------------------------------------------------------+------+----------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------------------------------+--------+----------------------------------------------------------------------------------------------+---------------------------------------+---------+-----------------------------------------------------------------+------+----------------------------------------------+ | 1 | SIMPLE | businesses | const | PRIMARY | PRIMARY | 4 | const | 1 | Using index; Using temporary; Using filesort | | 1 | SIMPLE | activities_businesses | ref | PRIMARY,index_activities_users_on_business_id,index_tweets_users_on_tweet_id_and_business_id | index_activities_users_on_business_id | 9 | const | 2252 | Using index condition; Using where | | 1 | SIMPLE | activities_b_taggings_975e9c4 | ref | taggings_idx | taggings_idx | 782 | const,myapp_production.activities_businesses.id,const | 1 | Using index condition; Using where | | 1 | SIMPLE | activities | eq_ref | PRIMARY,index_activities_on_created_at | PRIMARY | 8 | myapp_production.activities_businesses.activity_id | 1 | Using where | +----+-------------+-------------------------------+--------+----------------------------------------------------------------------------------------------+---------------------------------------+---------+-----------------------------------------------------------------+------+----------------------------------------------+ Also checkin in the process list, I got something like this: +----+-----------------+-------------------------------------+----------------------------+---------+------+--------------+------------------------------------------------------------------------------------------------------+ | Id | User | Host | db | Command | Time | State | Info | +----+-----------------+-------------------------------------+----------------------------+---------+------+--------------+------------------------------------------------------------------------------------------------------+ | 1 | my_app | my_ip:57152 | my_app_production | Sleep | 0 | | NULL | | 2 | my_app | my_ip:57153 | my_app_production | Sleep | 2 | | NULL | | 3 | rdsadmin | localhost:49441 | NULL | Sleep | 9 | | NULL | | 6 | my_app | my_other_ip:47802 | my_app_production | Sleep | 242 | | NULL | | 7 | my_app | my_other_ip:47807 | my_app_production | Query | 231 | Sending data | SELECT my_fields... | | 8 | my_app | my_other_ip:47809 | my_app_production | Query | 231 | Sending data | SELECT my_fields... | | 9 | my_app | my_other_ip:47810 | my_app_production | Query | 231 | Sending data | SELECT my_fields... | | 10 | my_app | my_other_ip:47811 | my_app_production | Query | 231 | Sending data | SELECT my_fields... | | 11 | my_app | my_other_ip:47813 | my_app_production | Query | 231 | Sending data | SELECT my_fields... | ... So based on the numbers, it looks like there is no reason to have a slow query, since the worst execution plan is the one that goes through 2k rows which is not much. Edit 1 Another information that might be useful is the slow query_log SET timestamp=1401457485; SELECT my_query... # User@Host: myapp[myapp] @ ip-10-195-55-233.ec2.internal [IP] Id: 435 # Query_time: 95.830497 Lock_time: 0.000178 Rows_sent: 0 Rows_examined: 1129387 Edit 2 After profiling, I got this result. The result have approximately 250 rows with two columns each. +----------------------+----------+ | state | duration | +----------------------+----------+ | Sending data | 272 | | removing tmp table | 0 | | optimizing | 0 | | Creating sort index | 0 | | init | 0 | | cleaning up | 0 | | executing | 0 | | checking permissions | 0 | | freeing items | 0 | | Creating tmp table | 0 | | query end | 0 | | statistics | 0 | | end | 0 | | System lock | 0 | | Opening tables | 0 | | logging slow query | 0 | | Sorting result | 0 | | starting | 0 | | closing tables | 0 | | preparing | 0 | +----------------------+----------+ Edit 3 Adding query as requested SELECT activities.share_count, activities.created_at FROM `activities_businesses` INNER JOIN `businesses` ON `businesses`.`id` = `activities_businesses`.`business_id` INNER JOIN `activities` ON `activities`.`id` = `activities_businesses`.`activity_id` JOIN taggings activities_b_taggings_975e9c4 ON activities_b_taggings_975e9c4.taggable_id = activities_businesses.id AND activities_b_taggings_975e9c4.taggable_type = 'ActivitiesBusiness' AND activities_b_taggings_975e9c4.tag_id = 104 AND activities_b_taggings_975e9c4.created_at >= '2014-04-30 13:36:44' WHERE ( businesses.id = 1 ) AND ( activities.created_at > '2014-04-30 13:36:44' ) AND ( activities.created_at < '2014-05-30 12:27:03' ) ORDER BY activities.created_at; Edit 4 There may be a chance that the indexes are not being applied due to difference in column type between the taggings and the activities_businesses, on the taggable_id column. mysql> SHOW COLUMNS FROM activities_businesses; +-------------+------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | activity_id | bigint(20) | YES | MUL | NULL | | | business_id | bigint(20) | YES | MUL | NULL | | +-------------+------------+------+-----+---------+----------------+ 3 rows in set (0.01 sec) mysql> SHOW COLUMNS FROM taggings; +---------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | tag_id | int(11) | YES | MUL | NULL | | | taggable_id | bigint(20) | YES | | NULL | | | taggable_type | varchar(255) | YES | | NULL | | | tagger_id | int(11) | YES | | NULL | | | tagger_type | varchar(255) | YES | | NULL | | | context | varchar(128) | YES | | NULL | | | created_at | datetime | YES | | NULL | | +---------------+--------------+------+-----+---------+----------------+ So it is examining way more rows than it shows in the explain query, probably because some indexes are not being applied. Do you guys can help m with that?

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  • Help with specific Regex: need to match multiple instances of multiple formats in a single string.

    - by KevenK
    I apologize for the terrible title...it can be hard to try to summarize an entire situation into a single sentence. Let me start by saying that I'm asking because I'm just not a Regex expert. I've used it a bit here and there, but I just come up short with the correct way to meet the following requirements. The Regex that I'm attempting to write is for use in an XML schema for input validation, and used elsewhere in Javascript for the same purpose. There are two different possible formats that are supported. There is a literal string, which must be surrounded by quotation marks, and a Hex-value string which must be surrounded by braces. Some test cases: "this is a literal string" <-- Valid string, enclosed properly in "s "this should " still be correct" <-- Valid string, "s are allowed within (if possible, this requirement could be forgiven if necessary) "{00 11 22}" <-- Valid string, {}'s allow in strings. Another one that can be forgiven if necessary I am bad output <-- Invalid string, no "s "Some more problemss"you know <-- Invalid string, must be fully contained in "s {0A 68 4F 89 AC D2} <-- Valid string, hex characters enclosed in {}s {DDFF1234} <-- Valid string, spaces are ignored for Hex strings DEADBEEF <-- Invalid string, must be contained in either "s or {}s {0A 12 ZZ} <-- Invalid string, 'Z' is not a valid Hex character To satisfy these general requirements, I had come up with the following Regex that seems to work well enough. I'm still fairly new to Regex, so there could be a huge hole here that I'm missing.: &quot;.+&quot;|\{([0-9]|[a-f]|[A-F]| )+\} If I recall correctly, the XML Schema regex automatically assumes beginning and end of line (^ and $ respectively). So, essentially, this regex accepts any string that starts and ends with a ", or starts and ends with {}s and contains only valid Hexidecimal characters. This has worked well for me so far except that I had forgotten about another (although less common, and thus forgotten) input option that completely breaks my regex. Where I made my mistake: Valid input should also allow a user to separate valid strings (of either type, literal/hex) by a comma. This means that a single string should be able to contain more than one of the above valid strings, separated by commas. Luckily, however, a comma is not a supported character within a literal string (although I see that my existing regex does not care about commas). Example test cases: "some string",{0A F1} <-- Valid {1122},{face},"peanut butter" <-- Valid {0D 0A FF FE},"string",{FF FFAC19 85} <-- Valid (Spaces don't matter in Hex values) "Validation is allowed to break, if a comma is found not separating values",{0d 0a} <-- Invalid, comma is a delimiter, but "Validation is allowed to break" and "if a comma..." are not marked as separate strings with "s hi mom,"hello" <-- Invalid, String1 was not enclosed properly in "s or {}s My thoughts are that it is possible to use commas as a delimiter to check each "section" of the string to match a regex similar to the original, but I just am not that advanced in regex yet to come up with a solution on my own. Any help would be appreciated, but ultimately a final solution with an explanation would just stellar. Thanks for reading this huge wall of text!

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  • Spring MVC working with Web Designers

    - by jboyd
    When working with web-designers in a Spring-MVC and JSP environment, are there any tools or helpful patterns to reduce the pain of going back and forth from HTML to JSP and back? Project requirements dictate that views will change often, and it can be difficult to make changes efficiently because of the amount of Java code that leaks into the view layer. Ideally I'd like to remove almost all Java code from the view, but it does not seem like this works with the Spring/JSP philosophy where often the way to remove Java code is to replace that code with tag libraries, which will still have a similar problem. To provide a little clarity to my question I'm going to include some existing code (inherited by me) to show the kinds of problems I'm likely to face when change the look of our views: <%-- Begin looping through results --%> <% List memberList = memberSearchResults.getResults(); for(int i = start - 1; i < memberList.size() && i < end; i++) { Profile profile = (Profile)memberList.get(i); long profileId = profile.getProfileId(); String nickname = profile.getNickname(); String description = profile.getDescription(); Image image = profile.getAvatarImage(); String avatarImageSrc = null; int avatarImageWidthNum = 0; int avatarImageHeightNum = 0; if(null != image) { avatarImageSrc = image.getSrc(); avatarImageWidthNum = image.getWidth(); avatarImageHeightNum = image.getHeight(); } String bgColor = i % 2 == 1 ? "background-color:#FFF" : ""; %> <div style="float:left;clear:both;padding:5px 0 5px 5px;cursor:pointer;<%= bgColor %>" onclick='window.location="profile.sp?profileId=<%= profileId %>"'> <div style="float:right;clear:right;padding-left:10px;width:515px;font-size:10px;color:#7e7e7e"> <h6><%= nickname %></h6> <%= description %> </div> <img style="float:left;clear:left;" alt="Avatar Image" src="<%= null != avatarImageSrc && avatarImageSrc.trim().length() > 0 ? avatarImageSrc : "images/defaultUserImage.png" %>" <%= avatarImageWidthNum < avatarImageHeightNum ? "height='59'" : "width='92'" %> /> </div> <% } // End loop %> Now, ignoring some of the code smells there, it's obvious that if someone wants to change the look of that DIV it would be neccesary to re-place all the Java/JSP code into the new HTML given (the designers don't work in JSP files, they have their own HTML versions of the website). Which is tedious, and prone to errors.

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  • Why does this XSL fails to retrieve value from xml ?

    - by Pavitar
    Following is an extract of the XSL stylesheet that I have written. It says my '.xsl' is well formed but it somehow does not retrieve values from the xml,instead jus pastes the header and table headings. EDIT <?xml version="1.0" encoding="UTF-8"?> <xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:fn="http://www.w3.org/2005/xpath-functions"> <xsl:template match="/" > <html> <head> <title>GlenMark Pharma</title> </head> <h1 align="center"><font face="Monotype Corsiva" color="red">GlenMarkPharma</font></h1> <body> <table> <tbody> <tr> <th>ID</th> <th>ENAME</th> <th>Mobile</th> <th>EMAIL</th> <th>PWD</th> </tr> <xsl:for-each select="employees/employee"> <tr> <td><xsl:value-of select="@empID" /></td> <td><xsl:value-of select="name" /></td> <td><xsl:value-of select="mobile" /></td> <td><xsl:value-of select="email" /></td> <td><xsl:value-of select="pwd" /></td> </tr> </xsl:for-each> </tbody> </table> </body> </html> </xsl:template> </xsl:stylesheet> Here is my XML doc: <?xml version="1.0" encoding="UTF-8"?> <?xml-stylesheet type="text/xsl" href="MyfirstXsl.xsl"?> <!DOCTYPE employees SYSTEM "Mydtd.dtd"> <me:employees xmlns:me="[email protected]" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="[email protected] Mycomplex.xsd"> <me:employee empID="EMP101"> <me:name>Vicky</me:name> <me:mobile>9870582356</me:mobile> <me:email>[email protected]</me:email> <me:pwd>&defPWD;</me:pwd> </me:employee> </me:employees> I have also tried writing: <xsl:for-each select="employees/employee"> <tr> <td><xsl:value-of select="@empID" /></td> <td><xsl:value-of select="me:name" /></td> in the XSL since I have an alias to the namespace in my XML Doc.But it gives me an error of Invalid Pre-fix.I don't know what I'm doing wrong.

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  • How get <body> element from the html which one have as a string

    - by Oleg
    Hello! I have a stupid problem. An jQuery.ajax request return me a full HTML text as a string. I receive such response in an case of error on the server. The server give me an error description which I want to place inside of the corresponding place of my current page. So now the question: I have a string contains full HTML document (which is not an XML!!! see <hr> element inside). I need to have for example only BODY part as a jQuery object. Then I could append it to the corresponding part of my page. Here is an example of the string which I need to parse: <html> <head> <title>The resource cannot be found.</title> <style> body {font-family:"Verdana";font-weight:normal;font-size: .7em;color:black;} p {font-family:"Verdana";font-weight:normal;color:black;margin-top: -5px} // ... </style> </head> <body bgcolor="white"> <span><H1>Server Error in '/' Application.<hr width=100% size=1 color=silver></H1> <h2> <i>The resource cannot be found.</i> </h2></span> <font face="Arial, Helvetica, Geneva, SunSans-Regular, sans-serif "> <b> Description: </b>HTTP 404. The resource you are looking for ...bla bla.... <br><br> <b> Requested URL: </b>/ImportBPImagesInfos/Repository.svc/GetFullProfilimageSw<br><br> <hr width=100% size=1 color=silver> <b>Version Information:</b>&nbsp;Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1 </font> </body> </html> <!-- [HttpException]: A public action method &#39;.... at System.Web.Mvc.Controller.HandleUnknownAction(String actionName) at System.Web.Mvc.Controller.ExecuteCore() at System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) at System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) at System.Web.Mvc.MvcHandler.<>c__DisplayClass8.<BeginProcessRequest>b__4() at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass1.<MakeVoidDelegate>b__0() at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End() at System.Web.Mvc.Async.AsyncResultWrapper.End[TResult](IAsyncResult asyncResult, Object tag) at System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) at System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) at System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) -->

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  • reloading page while an ajax request in progress gives empty response and status as zero

    - by Jayapal Chandran
    Hi, Browser is firefox 3.0.10 I am requesting a page using ajax. The response is in progress may be in readyState less than 4. In this mean time i am trying to reload the page. What happens is the request ends giving an empty response. I used alert to find what string has been given as response text. I assume that by this time the ready state 4 is reached. why it is empty string. when i alert the xmlhttpobject.status it displayed 0. when i alert the xmlhttpobject.statusText an exception occurs stating that NOT AVAILABLE. when i read in the document http://www.devx.com/webdev/Article/33024/0/page/2 it said for 3 and 4 status and statusText are available but when i tested only status is available but not satausText Here is a sample code. consider that i have requested a page and my callback function is as follows function cb(rt) { if(rt.readyState==4) { alert(rt.status); alert(rt.statusText); // which throws an exception } } and my server side script is as follows sleep(30); //flushing little drop down code besides these i noticed the following... assume again i am requesting the above script using ajax. now there will be an idle time till 30 seconds is over before that 30 seconds i press refresh. i got xmlhttpobject.status as 0 but still the browser did not reload the page untill that 30 seconds. WHY? so what is happening when i refresh a page before an ajax request is complete is the status value is set to zero and the ready state is set to 4 but the page still waits for the response from the server to end... what is happening... THE REASON FOR ME TO FACE SOME THING LIKE THIS IS AS FOLLOWS. when ever i do an ajax request ... if the process succeeded like inserting some thing or deleting something i popup a div stating that updated successfully and i will reload the page. but if there is any error then i do not reload the page instead i just alert that unable to process this request. what happens if the user reloads the page before any of this request is complete is i get an empty response which in my calculation is there is a server error. so i was debugging the ajax response to filter out that the connection has been interrupted because the user had pressed reload. so in this time i don't want to display unable to process this request when the user reloads the page before the request has been complete. oh... a long story. IT IS A LONG DESCRIPTION SO THAT I CAN MAKE EXPERTS UNDERSTAND MY DOUBT. so what i want form the above. any type of answer would clear my mind. or i would like to say all type of answers. EDIT: 19 dec. If i did not get any correct answer then i would delete this question and will rewrite with examples. else i will accept after experimenting.

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  • 1136: Incorrect number of arguments. Expected 0.? AS3 Flash Cs4 (Round 2)

    - by charmaine
    (I have asked this before but I dont think I was direct enough with my question and therefore it did not get resolved so here goes again!) I am working through a book called Foundation Actionscript 3.0 Animation, making things move. I am now on Chapter 9 - Collision Detection. On two lines of my code I get the 1135 error, letting me know that I have an incorrect number of arguments. I have highlighted the two areas in which this occurs with asterisks: package { import flash.display.Sprite; import flash.events.Event; public class Bubbles extends Sprite { private var balls:Array; private var numBalls:Number = 10; private var centerBall:Ball; private var bounce:Number = -1; private var spring:Number = 0.2; public function Bubbles() { init(); } private function init():void { balls = new Array(); ***centerBall = new Ball(100, 0xcccccc);*** addChild(centerBall); centerBall.x = stage.stageWidth / 2; centerBall.y = stage.stageHeight / 2; for(var i:uint = 0; i < numBalls; i++) { ***var ball:Ball = new Ball(Math.random() * 40 + 5, Math.random() * 0xffffff);*** ball.x = Math.random() * stage.stageWidth; ball.y = Math.random() * stage.stageHeight; ball.vx = Math.random() * 6 - 3; ball.vy = Math.random() * 6 - 3; addChild(ball); balls.push(ball); } addEventListener(Event.ENTER_FRAME, onEnterFrame); } private function onEnterFrame(event:Event):void { for(var i:uint = 0; i < numBalls; i++) { var ball:Ball = balls[i]; move(ball); var dx:Number = ball.x - centerBall.x; var dy:Number = ball.y - centerBall.y; var dist:Number = Math.sqrt(dx * dx + dy * dy); var minDist:Number = ball.radius + centerBall.radius; if(dist < minDist) { var angle:Number = Math.atan2(dy, dx); var tx:Number = centerBall.x + Math.cos(angle) * minDist; var ty:Number = centerBall.y + Math.sin(angle) * minDist; ball.vx += (tx - ball.x) * spring; ball.vy += (ty - ball.y) * spring; } } } private function move(ball:Ball):void { ball.x += ball.vx; ball.y += ball.vy; if(ball.x + ball.radius > stage.stageWidth) { ball.x = stage.stageWidth - ball.radius; ball.vx *= bounce; } else if(ball.x - ball.radius < 0) { ball.x = ball.radius; ball.vx *= bounce; } if(ball.y + ball.radius > stage.stageHeight) { ball.y = stage.stageHeight - ball.radius; ball.vy *= bounce; } else if(ball.y - ball.radius < 0) { ball.y = ball.radius; ball.vy *= bounce; } } } } I think this is due to the non-existance of a Ball.as, when reading the tutorial I assumed it meant that I had to create a movie clip of a ball on stage and then export it for actionscript with the class name being Ball, however when flicking back through the book I saw that a Ball.as already existed, stating that I may need to use this again later on in the book, this read: package { import flash.display.Sprite; public class Ball extends Sprite { private var radius:Number; private var color:uint; public var vx:Number=0; public var vy:Number=0; public function Ball(radius:Number=40, color:uint=0xff0000) { this.radius=radius; this.color=color; init(); } public function init():void { graphics.beginFill(color); graphics.drawCircle(0, 0, radius); graphics.endFill(); } } } This managed to stop all the errors appearing however, it did not transmit any of the effects from Bubbles.as it just braught a Red Ball on the center of the stage. How would I alter this code in order to work in favour of Bubbles.as? Please Help! Thanks!

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  • Internet Explorer Automation: how to suppress Open/Save dialog?

    - by Vladimir Dyuzhev
    When controlling IE instance via MSHTML, how to suppress Open/Save dialogs for non-HTML content? I need to get data from another system and import it into our one. Due to budget constraints no development (e.g. WS) can be done on the other side for some time, so my only option for now is to do web scrapping. The remote site is ASP.NET-based, so simple HTML requests won't work -- too much JS. I wrote a simple C# application that uses MSHTML and SHDocView to control an IE instance. So far so good: I can perform login, navigate to desired page, populate required fields and do submit. Then I face a couple of problems: First is that report is opening in another window. I suspect I can attach to that window too by enumerating IE windows in the system. Second, more troublesome, is that report itself is CSV file, and triggers Open/Save dialog. I'd like to avoid it and make IE save the file into given location OR I'm fine with programmatically clicking dialog buttons too (how?) I'm actually totally non-Windows guy (unix/J2EE), and hope someone with better knowledge would give me a hint how to do those tasks. Thanks! UPDATE I've found a promising document on MSDN: http://msdn.microsoft.com/en-ca/library/aa770041.aspx Control the kinds of content that are downloaded and what the WebBrowser Control does with them once they are downloaded. For example, you can prevent videos from playing, script from running, or new windows from opening when users click on links, or prevent Microsoft ActiveX controls from downloading or executing. Slowly reading through... UPDATE 2: MADE IT WORK, SORT OF... Finally I made it work, but in an ugly way. Essentially, I register a handler "before navigate", then, in the handler, if the URL is matching my target file, I cancel the navigation, but remember the URL, and use WebClient class to access and download that temporal URL directly. I cannot copy the whole code here, it contains a lot of garbage, but here are the essential parts: Installing handler: _IE2.FileDownload += new DWebBrowserEvents2_FileDownloadEventHandler(IE2_FileDownload); _IE.BeforeNavigate2 += new DWebBrowserEvents2_BeforeNavigate2EventHandler(IE_OnBeforeNavigate2); Recording URL and then cancelling download (thus preventing Save dialog to appear): public string downloadUrl; void IE_OnBeforeNavigate2(Object ob1, ref Object URL, ref Object Flags, ref Object Name, ref Object da, ref Object Head, ref bool Cancel) { Console.WriteLine("Before Navigate2 "+URL); if (URL.ToString().EndsWith(".csv")) { Console.WriteLine("CSV file"); downloadUrl = URL.ToString(); } Cancel = false; } void IE2_FileDownload(bool activeDocument, ref bool cancel) { Console.WriteLine("FileDownload, downloading "+downloadUrl+" instead"); cancel = true; } void IE_OnNewWindow2(ref Object o, ref bool cancel) { Console.WriteLine("OnNewWindow2"); _IE2 = new SHDocVw.InternetExplorer(); _IE2.BeforeNavigate2 += new DWebBrowserEvents2_BeforeNavigate2EventHandler(IE_OnBeforeNavigate2); _IE2.Visible = true; o = _IE2; _IE2.FileDownload += new DWebBrowserEvents2_FileDownloadEventHandler(IE2_FileDownload); _IE2.Silent = true; cancel = false; return; } And in the calling code using the found URL for direct download: ... driver.ClickButton(".*_btnRunReport"); driver.WaitForComplete(); Thread.Sleep(10000); WebClient Client = new WebClient(); Client.DownloadFile(driver.downloadUrl, "C:\\affinity.dump"); (driver is a simple wrapper over IE instance = _IE) Hope that helps someone.

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  • Clearcase - selective merge.

    - by Keshav
    Hi, I have a peculiar Clearcase doubt. I cannot fully describe why I'm doing such a confusing architecture, but I need to do it (thanks to the mistake done by someone long back). Ok, here's a bit of detail: B1 is a contaminated branch where both my group's changes and another group's changes got mixed together so badly that there is no way of finding which code is whose). So the solution proposed is to create a new branch called B2 (at the same level as B1) and put all the unmodified code of the other group on it (The way to do that would be to merge B1 with B2 and then go about removing all changes from it till it becomes original). Then create a CR branch on B1 and keep only my group's newly added files or modified files on that branch. Finally create an integration branch out of B2 and merge the changes from CR branch of B1 to integration branch of B2. So here is what I did: (The use case is where I have dir D where file a, b and c are there. My group ended up modifying file a while b and c are not modified at all). There is a branch B1 on which there are files a, b and c. There is another branch B2. A merge is done from B1 to B2. Now B2 also has a, b and c. At this point both branch B1 and B2 are same. Now I delete file a from branch B2 (rmname). Now B2 has b and c only. I put a label to this branch called Label1. This makes the code with label Label1 as the unmodified code from other group. Now I create a sub branch called CR1 from B1 and delete all the files that are there in B2 branch (i.e b and c) such that it contains only the modified code from original code on it. In my case it is file a. At this point branch B2 with label Label1 has files b and c (those are unmodified code) and branch CR1 coming off B1 has only a (that is modified by us). Now I create another branch called integration branch that comes off B2 Label1. And then I do a merge of CR branch on to that expecting that it will have all three files a, b and c for me. All I'd need to do is to do a version tree view and see who modified what. But the problem I face is that since I had done a rmname of file a on branch B2 earlier to putting Label. The merge does not really take the file a from CR branch. How to I get around that problem. I want to selectively merge. Is it possible? sorry if it is a bad design. I'm not really conversant with Clear case and have limited options and time to clear some one else's mess.

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  • Listing issue, GROUP mysql

    - by SethCodes
    Here is a mock-up example of Mysql table: | ID | Country | City | ________________________________ | 1 | Sweden | Stockholm | | 2 | Sweden | Stockholm | | 3 | Sweden | Lund | | 4 | Sweden | Lund | | 5 | Germany | Berlin | | 6 | Germany | Berlin | | 7 | Germany | Hamburg | | 8 | Germany | Hamburg | Notice how both rows Country and city have repeated values inside them. Using GROUP BY country, city in my PDO query, the values will not repeat while in loop. Here is PDO for this: $query = "SELECT id, city, country FROM table GROUP BY country, city"; $stmt = $db->query($query); while($row = $stmt->fetch(PDO::FETCH_ASSOC)) : The above code will result in an output like this (some editing in-between). GROUP BY works but the country repeats: Sweden - Stockholm Sweden - Lund Germany - Berlin Germany - Hamburg Using bootstrap collapse and above code, I separate the country from the city with a simple drop down collopase. Here is code: <li> <a data-toggle="collapse" data-target="#<?= $row['id']; ?>" href="search.php?country=<?= $row['country']; ?>"> <?= $row['country']; ?> </a> <div id ="<?= $row['id']; ?>" class="collapse in"> //collapse div here <a href="search.php?city=<?= $row['city']; ?>"> <?= $row['city']; ?><br></a> </div> //end </li> It then looks something like this (once collapse is initiated): Sweden > Stockholm Sweden > Lund Germany >Berlin Germany >Hamburg Here is where I face the problem. The above lists the values Sweden and Germany 2 times. I want Sweden and Germany to only list one time, and the cities listed below, so the desired look is to be this: Sweden // Lists one time > Stockholm > Lund Germany // Lists one time >Berlin >Hamburg I have tried using DISTINCT, GROUP_CONTACT and other methods, yet none get my desired output (above). Suggestions? Below is my current full code in action: <? $query = "SELECT id, city, country FROM table GROUP BY country, city"; $stmt = $db->query($query); while($row = $stmt->fetch(PDO::FETCH_ASSOC)) : ?> <li> <a data-toggle="collapse" data-target="#<?= $row['id']; ?>" href="search.php?country=<?= $row['country']; ?>"> <?= $row['country']; ?> </a> <div id ="<?= $row['id']; ?>" class="collapse in"> //collapse div here <a href="search.php?city=<?= $row['city']; ?>"> <?= $row['city']; ?><br></a> </div> //end </li> <? endwhile ?>

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  • How to implement this .NET client and PHP server synchronization scenario?

    - by pbean
    I have a PHP webserver and a .NET mobile application. The .NET application needs data from a database, which is provided (for now) by the php webserver. I'm fairly new to this kind of scenario so I'm not sure what the best practices are. I ran into a couple of problems and I am not certain how to overcome them. For now, I have the following setup. I run a PHP SOAP server which has a couple of operations which simply retrieve data from the database. For this web service I have created a WSDL file. In Visual Studio I added a web reference to my project using the WSDL file and it generated some classes for it. I simply call something like "MyWebService.GetItems();" and I get an array of items in my .NET application, which come straight from the database. Next I also serialize all these retrieved objects to local (permanent) storage. I face a couple of challenges which I don't know how to resolve properly. The idea is for the mobile client to synchronize the data once (at the start of the day), before working, and then use the local storage throughout the day, and synchronize it back at the end of the day. At the moment all data is downloaded through SOAP, and not a subset (only what is needed). How would I know which new information should be sent to the client? Only the server knows what is new, but only the client knows for sure which data it already has. I seem to be doing double work now. The data which is transferred with SOAP basically already are serialized objects. But at the moment I first retrieve all objects through SOAP and the .NET framework automatically deserializes it. Then I serialize all data again myself. It would be more efficient to simply download it to storage, and then deserialize it. The mobile device does not have a lot of memory. In my test data this is not really a problem, but with potentially tenths of thousands of records I can imagine this will become a problem. Currently when I call the SOAP method, it loads all data into memory (as an array) but as described above perhaps it would be better to have it stored into storage directly, and only retrieve from storage the objects that are needed. But how would I store this? An array would serialize to one big XML (or binary) file from which I cannot choose which objects to load. Would I make (possible tenths of thousands) separate files? Also at the end of the day when I want to send the changes back to the server, how would I know which objects to send... since they're not in memory? I hope my troubles are clear and I hope you are able to help me figure out how to implement this the best way. :) Some things are already fixed (like using .NET on the mobile device, using PHP and having a MySQL database server) but other things can most certainly be changed (like using SOAP).

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  • replaceAll() method using parameter from text file

    - by Herman Plani Ginting
    i have a collection of raw text in a table in database, i need to replace some words in this collection using a set of words. i put all the term to be replace and its substitutes in a text file as below min=admin lelet=lambat lemot=lambat nii=nih ntu=itu and so on. i have successfully initiate a variabel of File and Scanner to read the collection of the term and its substitutes. i loop all the dataset and save the raw text in a string in the same loop i loop all the term collection and save its row to a string name 'pattern', and split the pattern into two string named 'term' and 'replacer' in this loop i initiate a new string which its value is the string from the dataset modified by replaceAll(term,replacer) end loop for term collection then i insert the new string to another table in database end loop for dataset i do it manualy as below replaceAll("min","admin") and its works but its really something to code it manually for almost 2000 terms to be replace it. anyone ever face this kind of really something.. i really need a help now desperate :( package sentimenrepo; import javax.swing.*; import java.sql.*; import java.io.*; //import java.util.HashMap; import java.util.Scanner; //import java.util.Map; /** * * @author herman */ public class synonimReplaceV2 extends SwingWorker { protected Object doInBackground() throws Exception { new skripsisentimen.sentimenttwitter().setVisible(true); Integer row = 0; File synonimV2 = new File("synV2/catatan_kata_sinonim.txt"); String newTweet = ""; DB db = new DB(); Connection conn = db.dbConnect("jdbc:mysql://localhost:3306/tweet", "root", ""); try{ Statement select = conn.createStatement(); select.executeQuery("select * from synonimtweet"); ResultSet RS = select.getResultSet(); Scanner scSynV2 = new Scanner(synonimV2); while(RS.next()){ row++; String no = RS.getString("no"); String tweet = " "+ RS.getString("tweet"); String published = RS.getString("published"); String label = RS.getString("label"); clean2 cleanv2 = new clean2(); newTweet = cleanv2.cleanTweet(tweet); try{ Statement insert = conn.createStatement(); insert.executeUpdate("INSERT INTO synonimtweet_v2(no,tweet,published,label) values('" +no+"','"+newTweet+"','"+published+"','"+label+"')"); String current = skripsisentimen.sentimenttwitter.txtAreaResult.getText(); skripsisentimen.sentimenttwitter.txtAreaResult.setText(current+"\n"+row+"original : "+tweet+"\n"+newTweet+"\n______________________\n"); skripsisentimen.sentimenttwitter.lblStat.setText(row+" tweet read"); skripsisentimen.sentimenttwitter.txtAreaResult.setCaretPosition(skripsisentimen.sentimenttwitter.txtAreaResult.getText().length() - 1); }catch(Exception e){ skripsisentimen.sentimenttwitter.lblStat.setText(e.getMessage()); } skripsisentimen.sentimenttwitter.lblStat.setText(e.getMessage()); } }catch(Exception e){ skripsisentimen.sentimenttwitter.lblStat.setText(e.getMessage()); } return row; } class clean2{ public clean2(){} public String cleanTweet(String tweet){ File synonimV2 = new File("synV2/catatan_kata_sinonim.txt"); String pattern = ""; String term = ""; String replacer = ""; String newTweet=""; try{ Scanner scSynV2 = new Scanner(synonimV2); while(scSynV2.hasNext()){ pattern = scSynV2.next(); term = pattern.split("=")[0]; replacer = pattern.split("=")[1]; newTweet = tweet.replace(term, replacer); } }catch(Exception e){ e.printStackTrace(); } System.out.println(newTweet+"\n"+tweet); return newTweet; } } }

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  • Step by Step:How to use Web Services in ASP.NET AJAX

    - by Yousef_Jadallah
    In my Article Preventing Duplicate Date With ASP.NET AJAX I’ve used ASP.NET AJAX With Web Service Technology, Therefore I add this topic as an introduction how to access Web services from client script in AJAX-enabled ASP.NET Web pages. As well I write this topic to answer the common questions which most of the developers face while working with ASP.NET Ajax Web Services especially in Microsoft ASP.NET official forum http://forums.asp.net/. ASP.NET enables you to create Web services can be accessed from client script in Web pages by using AJAX technology to make Web service calls. Data is exchanged asynchronously between client and server, typically in JSON format.   Lets go a head with the steps :   1-Create a new project , if you are using VS 2005 you have to create ASP.NET Ajax Enabled Web site.   2-Add new Item , Choose Web Service file .     3-To make your Web Services accessible from script, first it must be an .asmx Web service whose Web service class is qualified with the ScriptServiceAttribute attribute and every method you are using to be called from Client script must be qualified with the WebMethodAttribute attribute. On other hand you can use your Web page( CS or VB files) to add static methods accessible from Client Script , just you need to add WebMethod Attribute and set the EnablePageMethods attribute of the ScriptManager control to true..   The other condition is to register the ScriptHandlerFactory HTTP handler, which processes calls made from script to .asmx Web services : <system.web> <httpHandlers> <remove verb="*" path="*.asmx"/> <add verb="*" path="*.asmx" type="System.Web.Script.Services.ScriptHandlerFactory" validate="false"/> </httpHandlers> <system.web> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } but this already added automatically for any Web.config file of any ASP.NET AJAX Enabled WebSite or Project, So you don’t need to add it.   4-Avoid the default Method HelloWorld, then add your method in your asmx file lets say  OurServerOutput , As a consequence your Web service will be like this : using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Services;     [WebService(Namespace = "http://tempuri.org/")] [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)] [System.Web.Script.Services.ScriptService] public class WebService : System.Web.Services.WebService {     [WebMethod] public string OurServerOutput() { return "The Server Date and Time is : " + DateTime.Now.ToString(); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   5-Add ScriptManager Contol to your aspx file then reference the Web service by adding an asp:ServiceReference child element to the ScriptManager control and setting its path attribute to point to the Web service, That generate a JavaScript proxy class for calling the specified Web service from client script.   <asp:ScriptManager runat="server" ID="scriptManager"> <Services> <asp:ServiceReference Path="WebService.asmx" /> </Services> </asp:ScriptManager> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Basically ,to enable your application to call Web services(.asmx files) by using client script, the server asynchronous communication layer automatically generates JavaScript proxy classes. A proxy class is generated for each Web service for which an <asp:ServiceReference> element is included under the <asp:ScriptManager> control in the page.   6-Create new button to call the JavaSciprt function and a label to display the returned value . <input id="btnCallDateTime" type="button" value="Call Web Service" onclick="CallDateTime()"/> <asp:Label ID="lblOutupt" runat="server" Text="Label"></asp:Label> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   7-Define the JavaScript code to call the Web Service : <script language="javascript" type="text/javascript">   function CallDateTime() {   WebService.OurServerOutput(OnSucceeded); }   function OnSucceeded(result) { var lblOutput = document.getElementById("lblOutupt"); lblOutput.innerHTML = result; } </script> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } CallDateTime function calls the Web Service Method OurServerOutput… OnSucceeded function Used as the callback function that processes the Web Service return value. which the result parameter is a simple parameter contain the Server Date Time value returned from the Web Service . Finally , when you complete these steps and run your application you can press the button and retrieve Server Date time without postback.   Conclusion: In this topic I describes how to access Web services from client script in AJAX-enabled ASP.NET Web pages With a full .NET Framework/JSON serialize, direct integration with the familiar .asmx Web services ,Using  simple example,Also you can connect with the database to return value by create WebMethod in your Web Service file and the same steps you can use. Next time I will show you more complex example which returns a complex type like objects.   Hope this help.

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  • Oracle Coherence, Split-Brain and Recovery Protocols In Detail

    - by Ricardo Ferreira
    This article provides a high level conceptual overview of Split-Brain scenarios in distributed systems. It will focus on a specific example of cluster communication failure and recovery in Oracle Coherence. This includes a discussion on the witness protocol (used to remove failed cluster members) and the panic protocol (used to resolve Split-Brain scenarios). Note that the removal of cluster members does not necessarily indicate a Split-Brain condition. Oracle Coherence does not (and cannot) detect a Split-Brain as it occurs, the condition is only detected when cluster members that previously lost contact with each other regain contact. Cluster Topology and Configuration In order to create an good didactic for the article, let's assume a cluster topology and configuration. In this example we have a six member cluster, consisting of one JVM on each physical machine. The member IDs are as follows: Member ID  IP Address  1  10.149.155.76  2  10.149.155.77  3  10.149.155.236  4  10.149.155.75  5  10.149.155.79  6  10.149.155.78 Members 1, 2, and 3 are connected to a switch, and members 4, 5, and 6 are connected to a second switch. There is a link between the two switches, which provides network connectivity between all of the machines. Member 1 is the first member to join this cluster, thus making it the senior member. Member 6 is the last member to join this cluster. Here is a log snippet from Member 6 showing the complete member set: 2010-02-26 15:27:57.390/3.062 Oracle Coherence GE 3.5.3/465p2 <Info> (thread=main, member=6): Started DefaultCacheServer... SafeCluster: Name=cluster:0xDDEB Group{Address=224.3.5.3, Port=35465, TTL=4} MasterMemberSet ( ThisMember=Member(Id=6, Timestamp=2010-02-26 15:27:58.635, Address=10.149.155.78:8088, MachineId=1102, Location=process:228, Role=CoherenceServer) OldestMember=Member(Id=1, Timestamp=2010-02-26 15:27:06.931, Address=10.149.155.76:8088, MachineId=1100, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:511, Role=CoherenceServer) ActualMemberSet=MemberSet(Size=6, BitSetCount=2 Member(Id=1, Timestamp=2010-02-26 15:27:06.931, Address=10.149.155.76:8088, MachineId=1100, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:511, Role=CoherenceServer) Member(Id=2, Timestamp=2010-02-26 15:27:17.847, Address=10.149.155.77:8088, MachineId=1101, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:296, Role=CoherenceServer) Member(Id=3, Timestamp=2010-02-26 15:27:24.892, Address=10.149.155.236:8088, MachineId=1260, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:32459, Role=CoherenceServer) Member(Id=4, Timestamp=2010-02-26 15:27:39.574, Address=10.149.155.75:8088, MachineId=1099, Location=process:800, Role=CoherenceServer) Member(Id=5, Timestamp=2010-02-26 15:27:49.095, Address=10.149.155.79:8088, MachineId=1103, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:3229, Role=CoherenceServer) Member(Id=6, Timestamp=2010-02-26 15:27:58.635, Address=10.149.155.78:8088, MachineId=1102, Location=process:228, Role=CoherenceServer) ) RecycleMillis=120000 RecycleSet=MemberSet(Size=0, BitSetCount=0 ) ) At approximately 15:30, the connection between the two switches is severed: Thirty seconds later (the default packet timeout in development mode) the logs indicate communication failures across the cluster. In this example, the communication failure was caused by a network failure. In a production setting, this type of communication failure can have many root causes, including (but not limited to) network failures, excessive GC, high CPU utilization, swapping/virtual memory, and exceeding maximum network bandwidth. In addition, this type of failure is not necessarily indicative of a split brain. Any communication failure will be logged in this fashion. Member 2 logs a communication failure with Member 5: 2010-02-26 15:30:32.638/196.928 Oracle Coherence GE 3.5.3/465p2 <Warning> (thread=PacketPublisher, member=2): Timeout while delivering a packet; requesting the departure confirmation for Member(Id=5, Timestamp=2010-02-26 15:27:49.095, Address=10.149.155.79:8088, MachineId=1103, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:3229, Role=CoherenceServer) by MemberSet(Size=2, BitSetCount=2 Member(Id=1, Timestamp=2010-02-26 15:27:06.931, Address=10.149.155.76:8088, MachineId=1100, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:511, Role=CoherenceServer) Member(Id=4, Timestamp=2010-02-26 15:27:39.574, Address=10.149.155.75:8088, MachineId=1099, Location=process:800, Role=CoherenceServer) ) The Coherence clustering protocol (TCMP) is a reliable transport mechanism built on UDP. In order for the protocol to be reliable, it requires an acknowledgement (ACK) for each packet delivered. If a packet fails to be acknowledged within the configured timeout period, the Coherence cluster member will log a packet timeout (as seen in the log message above). When this occurs, the cluster member will consult with other members to determine who is at fault for the communication failure. If the witness members agree that the suspect member is at fault, the suspect is removed from the cluster. If the witnesses unanimously disagree, the accuser is removed. This process is known as the witness protocol. Since Member 2 cannot communicate with Member 5, it selects two witnesses (Members 1 and 4) to determine if the communication issue is with Member 5 or with itself (Member 2). However, Member 4 is on the switch that is no longer accessible by Members 1, 2 and 3; thus a packet timeout for member 4 is recorded as well: 2010-02-26 15:30:35.648/199.938 Oracle Coherence GE 3.5.3/465p2 <Warning> (thread=PacketPublisher, member=2): Timeout while delivering a packet; requesting the departure confirmation for Member(Id=4, Timestamp=2010-02-26 15:27:39.574, Address=10.149.155.75:8088, MachineId=1099, Location=process:800, Role=CoherenceServer) by MemberSet(Size=2, BitSetCount=2 Member(Id=1, Timestamp=2010-02-26 15:27:06.931, Address=10.149.155.76:8088, MachineId=1100, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:511, Role=CoherenceServer) Member(Id=6, Timestamp=2010-02-26 15:27:58.635, Address=10.149.155.78:8088, MachineId=1102, Location=process:228, Role=CoherenceServer) ) Member 1 has the ability to confirm the departure of member 4, however Member 6 cannot as it is also inaccessible. At the same time, Member 3 sends a request to remove Member 6, which is followed by a report from Member 3 indicating that Member 6 has departed the cluster: 2010-02-26 15:30:35.706/199.996 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=Cluster, member=2): MemberLeft request for Member 6 received from Member(Id=3, Timestamp=2010-02-26 15:27:24.892, Address=10.149.155.236:8088, MachineId=1260, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:32459, Role=CoherenceServer) 2010-02-26 15:30:35.709/199.999 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=Cluster, member=2): MemberLeft notification for Member 6 received from Member(Id=3, Timestamp=2010-02-26 15:27:24.892, Address=10.149.155.236:8088, MachineId=1260, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:32459, Role=CoherenceServer) The log for Member 3 determines how Member 6 departed the cluster: 2010-02-26 15:30:35.161/191.694 Oracle Coherence GE 3.5.3/465p2 <Warning> (thread=PacketPublisher, member=3): Timeout while delivering a packet; requesting the departure confirmation for Member(Id=6, Timestamp=2010-02-26 15:27:58.635, Address=10.149.155.78:8088, MachineId=1102, Location=process:228, Role=CoherenceServer) by MemberSet(Size=2, BitSetCount=2 Member(Id=1, Timestamp=2010-02-26 15:27:06.931, Address=10.149.155.76:8088, MachineId=1100, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:511, Role=CoherenceServer) Member(Id=2, Timestamp=2010-02-26 15:27:17.847, Address=10.149.155.77:8088, MachineId=1101, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:296, Role=CoherenceServer) ) 2010-02-26 15:30:35.165/191.698 Oracle Coherence GE 3.5.3/465p2 <Info> (thread=Cluster, member=3): Member departure confirmed by MemberSet(Size=2, BitSetCount=2 Member(Id=1, Timestamp=2010-02-26 15:27:06.931, Address=10.149.155.76:8088, MachineId=1100, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:511, Role=CoherenceServer) Member(Id=2, Timestamp=2010-02-26 15:27:17.847, Address=10.149.155.77:8088, MachineId=1101, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:296, Role=CoherenceServer) ); removing Member(Id=6, Timestamp=2010-02-26 15:27:58.635, Address=10.149.155.78:8088, MachineId=1102, Location=process:228, Role=CoherenceServer) In this case, Member 3 happened to select two witnesses that it still had connectivity with (Members 1 and 2) thus resulting in a simple decision to remove Member 6. Given the departure of Member 6, Member 2 is left with a single witness to confirm the departure of Member 4: 2010-02-26 15:30:35.713/200.003 Oracle Coherence GE 3.5.3/465p2 <Info> (thread=Cluster, member=2): Member departure confirmed by MemberSet(Size=1, BitSetCount=2 Member(Id=1, Timestamp=2010-02-26 15:27:06.931, Address=10.149.155.76:8088, MachineId=1100, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:511, Role=CoherenceServer) ); removing Member(Id=4, Timestamp=2010-02-26 15:27:39.574, Address=10.149.155.75:8088, MachineId=1099, Location=process:800, Role=CoherenceServer) In the meantime, Member 4 logs a missing heartbeat from the senior member. This message is also logged on Members 5 and 6. 2010-02-26 15:30:07.906/150.453 Oracle Coherence GE 3.5.3/465p2 <Info> (thread=PacketListenerN, member=4): Scheduled senior member heartbeat is overdue; rejoining multicast group. Next, Member 4 logs a TcpRing failure with Member 2, thus resulting in the termination of Member 2: 2010-02-26 15:30:21.421/163.968 Oracle Coherence GE 3.5.3/465p2 <D4> (thread=Cluster, member=4): TcpRing: Number of socket exceptions exceeded maximum; last was "java.net.SocketTimeoutException: connect timed out"; removing the member: 2 For quick process termination detection, Oracle Coherence utilizes a feature called TcpRing which is a sparse collection of TCP/IP-based connections between different members in the cluster. Each member in the cluster is connected to at least one other member, which (if at all possible) is running on a different physical box. This connection is not used for any data transfer, only heartbeat communications are sent once a second per each link. If a certain number of exceptions are thrown while trying to re-establish a connection, the member throwing the exceptions is removed from the cluster. Member 5 logs a packet timeout with Member 3 and cites witnesses Members 4 and 6: 2010-02-26 15:30:29.791/165.037 Oracle Coherence GE 3.5.3/465p2 <Warning> (thread=PacketPublisher, member=5): Timeout while delivering a packet; requesting the departure confirmation for Member(Id=3, Timestamp=2010-02-26 15:27:24.892, Address=10.149.155.236:8088, MachineId=1260, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:32459, Role=CoherenceServer) by MemberSet(Size=2, BitSetCount=2 Member(Id=4, Timestamp=2010-02-26 15:27:39.574, Address=10.149.155.75:8088, MachineId=1099, Location=process:800, Role=CoherenceServer) Member(Id=6, Timestamp=2010-02-26 15:27:58.635, Address=10.149.155.78:8088, MachineId=1102, Location=process:228, Role=CoherenceServer) ) 2010-02-26 15:30:29.798/165.044 Oracle Coherence GE 3.5.3/465p2 <Info> (thread=Cluster, member=5): Member departure confirmed by MemberSet(Size=2, BitSetCount=2 Member(Id=4, Timestamp=2010-02-26 15:27:39.574, Address=10.149.155.75:8088, MachineId=1099, Location=process:800, Role=CoherenceServer) Member(Id=6, Timestamp=2010-02-26 15:27:58.635, Address=10.149.155.78:8088, MachineId=1102, Location=process:228, Role=CoherenceServer) ); removing Member(Id=3, Timestamp=2010-02-26 15:27:24.892, Address=10.149.155.236:8088, MachineId=1260, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:32459, Role=CoherenceServer) Eventually we are left with two distinct clusters consisting of Members 1, 2, 3 and Members 4, 5, 6, respectively. In the latter cluster, Member 4 is promoted to senior member. The connection between the two switches is restored at 15:33. Upon the restoration of the connection, the cluster members immediately receive cluster heartbeats from the two senior members. In the case of Members 1, 2, and 3, the following is logged: 2010-02-26 15:33:14.970/369.066 Oracle Coherence GE 3.5.3/465p2 <Warning> (thread=Cluster, member=1): The member formerly known as Member(Id=4, Timestamp=2010-02-26 15:30:35.341, Address=10.149.155.75:8088, MachineId=1099, Location=process:800, Role=CoherenceServer) has been forcefully evicted from the cluster, but continues to emit a cluster heartbeat; henceforth, the member will be shunned and its messages will be ignored. Likewise for Members 4, 5, and 6: 2010-02-26 15:33:14.343/336.890 Oracle Coherence GE 3.5.3/465p2 <Warning> (thread=Cluster, member=4): The member formerly known as Member(Id=1, Timestamp=2010-02-26 15:30:31.64, Address=10.149.155.76:8088, MachineId=1100, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:511, Role=CoherenceServer) has been forcefully evicted from the cluster, but continues to emit a cluster heartbeat; henceforth, the member will be shunned and its messages will be ignored. This message indicates that a senior heartbeat is being received from members that were previously removed from the cluster, in other words, something that should not be possible. For this reason, the recipients of these messages will initially ignore them. After several iterations of these messages, the existence of multiple clusters is acknowledged, thus triggering the panic protocol to reconcile this situation. When the presence of more than one cluster (i.e. Split-Brain) is detected by a Coherence member, the panic protocol is invoked in order to resolve the conflicting clusters and consolidate into a single cluster. The protocol consists of the removal of smaller clusters until there is one cluster remaining. In the case of equal size clusters, the one with the older Senior Member will survive. Member 1, being the oldest member, initiates the protocol: 2010-02-26 15:33:45.970/400.066 Oracle Coherence GE 3.5.3/465p2 <Warning> (thread=Cluster, member=1): An existence of a cluster island with senior Member(Id=4, Timestamp=2010-02-26 15:27:39.574, Address=10.149.155.75:8088, MachineId=1099, Location=process:800, Role=CoherenceServer) containing 3 nodes have been detected. Since this Member(Id=1, Timestamp=2010-02-26 15:27:06.931, Address=10.149.155.76:8088, MachineId=1100, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:511, Role=CoherenceServer) is the senior of an older cluster island, the panic protocol is being activated to stop the other island's senior and all junior nodes that belong to it. Member 3 receives the panic: 2010-02-26 15:33:45.803/382.336 Oracle Coherence GE 3.5.3/465p2 <Error> (thread=Cluster, member=3): Received panic from senior Member(Id=1, Timestamp=2010-02-26 15:27:06.931, Address=10.149.155.76:8088, MachineId=1100, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:511, Role=CoherenceServer) caused by Member(Id=4, Timestamp=2010-02-26 15:27:39.574, Address=10.149.155.75:8088, MachineId=1099, Location=process:800, Role=CoherenceServer) Member 4, the senior member of the younger cluster, receives the kill message from Member 3: 2010-02-26 15:33:44.921/367.468 Oracle Coherence GE 3.5.3/465p2 <Error> (thread=Cluster, member=4): Received a Kill message from a valid Member(Id=3, Timestamp=2010-02-26 15:27:24.892, Address=10.149.155.236:8088, MachineId=1260, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:32459, Role=CoherenceServer); stopping cluster service. In turn, Member 4 requests the departure of its junior members 5 and 6: 2010-02-26 15:33:44.921/367.468 Oracle Coherence GE 3.5.3/465p2 <Error> (thread=Cluster, member=4): Received a Kill message from a valid Member(Id=3, Timestamp=2010-02-26 15:27:24.892, Address=10.149.155.236:8088, MachineId=1260, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:32459, Role=CoherenceServer); stopping cluster service. 2010-02-26 15:33:43.343/349.015 Oracle Coherence GE 3.5.3/465p2 <Error> (thread=Cluster, member=6): Received a Kill message from a valid Member(Id=4, Timestamp=2010-02-26 15:27:39.574, Address=10.149.155.75:8088, MachineId=1099, Location=process:800, Role=CoherenceServer); stopping cluster service. Once Members 4, 5, and 6 restart, they rejoin the original cluster with senior member 1. The log below is from Member 4. Note that it receives a different member id when it rejoins the cluster. 2010-02-26 15:33:44.921/367.468 Oracle Coherence GE 3.5.3/465p2 <Error> (thread=Cluster, member=4): Received a Kill message from a valid Member(Id=3, Timestamp=2010-02-26 15:27:24.892, Address=10.149.155.236:8088, MachineId=1260, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:32459, Role=CoherenceServer); stopping cluster service. 2010-02-26 15:33:46.921/369.468 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=Cluster, member=4): Service Cluster left the cluster 2010-02-26 15:33:47.046/369.593 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=Invocation:InvocationService, member=4): Service InvocationService left the cluster 2010-02-26 15:33:47.046/369.593 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=OptimisticCache, member=4): Service OptimisticCache left the cluster 2010-02-26 15:33:47.046/369.593 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=ReplicatedCache, member=4): Service ReplicatedCache left the cluster 2010-02-26 15:33:47.046/369.593 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=DistributedCache, member=4): Service DistributedCache left the cluster 2010-02-26 15:33:47.046/369.593 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=Invocation:Management, member=4): Service Management left the cluster 2010-02-26 15:33:47.046/369.593 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=Cluster, member=4): Member 6 left service Management with senior member 5 2010-02-26 15:33:47.046/369.593 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=Cluster, member=4): Member 6 left service DistributedCache with senior member 5 2010-02-26 15:33:47.046/369.593 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=Cluster, member=4): Member 6 left service ReplicatedCache with senior member 5 2010-02-26 15:33:47.046/369.593 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=Cluster, member=4): Member 6 left service OptimisticCache with senior member 5 2010-02-26 15:33:47.046/369.593 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=Cluster, member=4): Member 6 left service InvocationService with senior member 5 2010-02-26 15:33:47.046/369.593 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=Cluster, member=4): Member(Id=6, Timestamp=2010-02-26 15:33:47.046, Address=10.149.155.78:8088, MachineId=1102, Location=process:228, Role=CoherenceServer) left Cluster with senior member 4 2010-02-26 15:33:49.218/371.765 Oracle Coherence GE 3.5.3/465p2 <Info> (thread=main, member=n/a): Restarting cluster 2010-02-26 15:33:49.421/371.968 Oracle Coherence GE 3.5.3/465p2 <D5> (thread=Cluster, member=n/a): Service Cluster joined the cluster with senior service member n/a 2010-02-26 15:33:49.625/372.172 Oracle Coherence GE 3.5.3/465p2 <Info> (thread=Cluster, member=n/a): This Member(Id=5, Timestamp=2010-02-26 15:33:50.499, Address=10.149.155.75:8088, MachineId=1099, Location=process:800, Role=CoherenceServer, Edition=Grid Edition, Mode=Development, CpuCount=2, SocketCount=1) joined cluster "cluster:0xDDEB" with senior Member(Id=1, Timestamp=2010-02-26 15:27:06.931, Address=10.149.155.76:8088, MachineId=1100, Location=site:usdhcp.oraclecorp.com,machine:dhcp-burlington6-4fl-east-10-149,process:511, Role=CoherenceServer, Edition=Grid Edition, Mode=Development, CpuCount=2, SocketCount=2) Cool isn't it?

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  • A Taxonomy of Numerical Methods v1

    - by JoshReuben
    Numerical Analysis – When, What, (but not how) Once you understand the Math & know C++, Numerical Methods are basically blocks of iterative & conditional math code. I found the real trick was seeing the forest for the trees – knowing which method to use for which situation. Its pretty easy to get lost in the details – so I’ve tried to organize these methods in a way that I can quickly look this up. I’ve included links to detailed explanations and to C++ code examples. I’ve tried to classify Numerical methods in the following broad categories: Solving Systems of Linear Equations Solving Non-Linear Equations Iteratively Interpolation Curve Fitting Optimization Numerical Differentiation & Integration Solving ODEs Boundary Problems Solving EigenValue problems Enjoy – I did ! Solving Systems of Linear Equations Overview Solve sets of algebraic equations with x unknowns The set is commonly in matrix form Gauss-Jordan Elimination http://en.wikipedia.org/wiki/Gauss%E2%80%93Jordan_elimination C++: http://www.codekeep.net/snippets/623f1923-e03c-4636-8c92-c9dc7aa0d3c0.aspx Produces solution of the equations & the coefficient matrix Efficient, stable 2 steps: · Forward Elimination – matrix decomposition: reduce set to triangular form (0s below the diagonal) or row echelon form. If degenerate, then there is no solution · Backward Elimination –write the original matrix as the product of ints inverse matrix & its reduced row-echelon matrix à reduce set to row canonical form & use back-substitution to find the solution to the set Elementary ops for matrix decomposition: · Row multiplication · Row switching · Add multiples of rows to other rows Use pivoting to ensure rows are ordered for achieving triangular form LU Decomposition http://en.wikipedia.org/wiki/LU_decomposition C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-lu-decomposition-for-solving.html Represent the matrix as a product of lower & upper triangular matrices A modified version of GJ Elimination Advantage – can easily apply forward & backward elimination to solve triangular matrices Techniques: · Doolittle Method – sets the L matrix diagonal to unity · Crout Method - sets the U matrix diagonal to unity Note: both the L & U matrices share the same unity diagonal & can be stored compactly in the same matrix Gauss-Seidel Iteration http://en.wikipedia.org/wiki/Gauss%E2%80%93Seidel_method C++: http://www.nr.com/forum/showthread.php?t=722 Transform the linear set of equations into a single equation & then use numerical integration (as integration formulas have Sums, it is implemented iteratively). an optimization of Gauss-Jacobi: 1.5 times faster, requires 0.25 iterations to achieve the same tolerance Solving Non-Linear Equations Iteratively find roots of polynomials – there may be 0, 1 or n solutions for an n order polynomial use iterative techniques Iterative methods · used when there are no known analytical techniques · Requires set functions to be continuous & differentiable · Requires an initial seed value – choice is critical to convergence à conduct multiple runs with different starting points & then select best result · Systematic - iterate until diminishing returns, tolerance or max iteration conditions are met · bracketing techniques will always yield convergent solutions, non-bracketing methods may fail to converge Incremental method if a nonlinear function has opposite signs at 2 ends of a small interval x1 & x2, then there is likely to be a solution in their interval – solutions are detected by evaluating a function over interval steps, for a change in sign, adjusting the step size dynamically. Limitations – can miss closely spaced solutions in large intervals, cannot detect degenerate (coinciding) solutions, limited to functions that cross the x-axis, gives false positives for singularities Fixed point method http://en.wikipedia.org/wiki/Fixed-point_iteration C++: http://books.google.co.il/books?id=weYj75E_t6MC&pg=PA79&lpg=PA79&dq=fixed+point+method++c%2B%2B&source=bl&ots=LQ-5P_taoC&sig=lENUUIYBK53tZtTwNfHLy5PEWDk&hl=en&sa=X&ei=wezDUPW1J5DptQaMsIHQCw&redir_esc=y#v=onepage&q=fixed%20point%20method%20%20c%2B%2B&f=false Algebraically rearrange a solution to isolate a variable then apply incremental method Bisection method http://en.wikipedia.org/wiki/Bisection_method C++: http://numericalcomputing.wordpress.com/category/algorithms/ Bracketed - Select an initial interval, keep bisecting it ad midpoint into sub-intervals and then apply incremental method on smaller & smaller intervals – zoom in Adv: unaffected by function gradient à reliable Disadv: slow convergence False Position Method http://en.wikipedia.org/wiki/False_position_method C++: http://www.dreamincode.net/forums/topic/126100-bisection-and-false-position-methods/ Bracketed - Select an initial interval , & use the relative value of function at interval end points to select next sub-intervals (estimate how far between the end points the solution might be & subdivide based on this) Newton-Raphson method http://en.wikipedia.org/wiki/Newton's_method C++: http://www-users.cselabs.umn.edu/classes/Summer-2012/csci1113/index.php?page=./newt3 Also known as Newton's method Convenient, efficient Not bracketed – only a single initial guess is required to start iteration – requires an analytical expression for the first derivative of the function as input. Evaluates the function & its derivative at each step. Can be extended to the Newton MutiRoot method for solving multiple roots Can be easily applied to an of n-coupled set of non-linear equations – conduct a Taylor Series expansion of a function, dropping terms of order n, rewrite as a Jacobian matrix of PDs & convert to simultaneous linear equations !!! Secant Method http://en.wikipedia.org/wiki/Secant_method C++: http://forum.vcoderz.com/showthread.php?p=205230 Unlike N-R, can estimate first derivative from an initial interval (does not require root to be bracketed) instead of inputting it Since derivative is approximated, may converge slower. Is fast in practice as it does not have to evaluate the derivative at each step. Similar implementation to False Positive method Birge-Vieta Method http://mat.iitm.ac.in/home/sryedida/public_html/caimna/transcendental/polynomial%20methods/bv%20method.html C++: http://books.google.co.il/books?id=cL1boM2uyQwC&pg=SA3-PA51&lpg=SA3-PA51&dq=Birge-Vieta+Method+c%2B%2B&source=bl&ots=QZmnDTK3rC&sig=BPNcHHbpR_DKVoZXrLi4nVXD-gg&hl=en&sa=X&ei=R-_DUK2iNIjzsgbE5ID4Dg&redir_esc=y#v=onepage&q=Birge-Vieta%20Method%20c%2B%2B&f=false combines Horner's method of polynomial evaluation (transforming into lesser degree polynomials that are more computationally efficient to process) with Newton-Raphson to provide a computational speed-up Interpolation Overview Construct new data points for as close as possible fit within range of a discrete set of known points (that were obtained via sampling, experimentation) Use Taylor Series Expansion of a function f(x) around a specific value for x Linear Interpolation http://en.wikipedia.org/wiki/Linear_interpolation C++: http://www.hamaluik.com/?p=289 Straight line between 2 points à concatenate interpolants between each pair of data points Bilinear Interpolation http://en.wikipedia.org/wiki/Bilinear_interpolation C++: http://supercomputingblog.com/graphics/coding-bilinear-interpolation/2/ Extension of the linear function for interpolating functions of 2 variables – perform linear interpolation first in 1 direction, then in another. Used in image processing – e.g. texture mapping filter. Uses 4 vertices to interpolate a value within a unit cell. Lagrange Interpolation http://en.wikipedia.org/wiki/Lagrange_polynomial C++: http://www.codecogs.com/code/maths/approximation/interpolation/lagrange.php For polynomials Requires recomputation for all terms for each distinct x value – can only be applied for small number of nodes Numerically unstable Barycentric Interpolation http://epubs.siam.org/doi/pdf/10.1137/S0036144502417715 C++: http://www.gamedev.net/topic/621445-barycentric-coordinates-c-code-check/ Rearrange the terms in the equation of the Legrange interpolation by defining weight functions that are independent of the interpolated value of x Newton Divided Difference Interpolation http://en.wikipedia.org/wiki/Newton_polynomial C++: http://jee-appy.blogspot.co.il/2011/12/newton-divided-difference-interpolation.html Hermite Divided Differences: Interpolation polynomial approximation for a given set of data points in the NR form - divided differences are used to approximately calculate the various differences. For a given set of 3 data points , fit a quadratic interpolant through the data Bracketed functions allow Newton divided differences to be calculated recursively Difference table Cubic Spline Interpolation http://en.wikipedia.org/wiki/Spline_interpolation C++: https://www.marcusbannerman.co.uk/index.php/home/latestarticles/42-articles/96-cubic-spline-class.html Spline is a piecewise polynomial Provides smoothness – for interpolations with significantly varying data Use weighted coefficients to bend the function to be smooth & its 1st & 2nd derivatives are continuous through the edge points in the interval Curve Fitting A generalization of interpolating whereby given data points may contain noise à the curve does not necessarily pass through all the points Least Squares Fit http://en.wikipedia.org/wiki/Least_squares C++: http://www.ccas.ru/mmes/educat/lab04k/02/least-squares.c Residual – difference between observed value & expected value Model function is often chosen as a linear combination of the specified functions Determines: A) The model instance in which the sum of squared residuals has the least value B) param values for which model best fits data Straight Line Fit Linear correlation between independent variable and dependent variable Linear Regression http://en.wikipedia.org/wiki/Linear_regression C++: http://www.oocities.org/david_swaim/cpp/linregc.htm Special case of statistically exact extrapolation Leverage least squares Given a basis function, the sum of the residuals is determined and the corresponding gradient equation is expressed as a set of normal linear equations in matrix form that can be solved (e.g. using LU Decomposition) Can be weighted - Drop the assumption that all errors have the same significance –-> confidence of accuracy is different for each data point. Fit the function closer to points with higher weights Polynomial Fit - use a polynomial basis function Moving Average http://en.wikipedia.org/wiki/Moving_average C++: http://www.codeproject.com/Articles/17860/A-Simple-Moving-Average-Algorithm Used for smoothing (cancel fluctuations to highlight longer-term trends & cycles), time series data analysis, signal processing filters Replace each data point with average of neighbors. Can be simple (SMA), weighted (WMA), exponential (EMA). Lags behind latest data points – extra weight can be given to more recent data points. Weights can decrease arithmetically or exponentially according to distance from point. Parameters: smoothing factor, period, weight basis Optimization Overview Given function with multiple variables, find Min (or max by minimizing –f(x)) Iterative approach Efficient, but not necessarily reliable Conditions: noisy data, constraints, non-linear models Detection via sign of first derivative - Derivative of saddle points will be 0 Local minima Bisection method Similar method for finding a root for a non-linear equation Start with an interval that contains a minimum Golden Search method http://en.wikipedia.org/wiki/Golden_section_search C++: http://www.codecogs.com/code/maths/optimization/golden.php Bisect intervals according to golden ratio 0.618.. Achieves reduction by evaluating a single function instead of 2 Newton-Raphson Method Brent method http://en.wikipedia.org/wiki/Brent's_method C++: http://people.sc.fsu.edu/~jburkardt/cpp_src/brent/brent.cpp Based on quadratic or parabolic interpolation – if the function is smooth & parabolic near to the minimum, then a parabola fitted through any 3 points should approximate the minima – fails when the 3 points are collinear , in which case the denominator is 0 Simplex Method http://en.wikipedia.org/wiki/Simplex_algorithm C++: http://www.codeguru.com/cpp/article.php/c17505/Simplex-Optimization-Algorithm-and-Implemetation-in-C-Programming.htm Find the global minima of any multi-variable function Direct search – no derivatives required At each step it maintains a non-degenerative simplex – a convex hull of n+1 vertices. Obtains the minimum for a function with n variables by evaluating the function at n-1 points, iteratively replacing the point of worst result with the point of best result, shrinking the multidimensional simplex around the best point. Point replacement involves expanding & contracting the simplex near the worst value point to determine a better replacement point Oscillation can be avoided by choosing the 2nd worst result Restart if it gets stuck Parameters: contraction & expansion factors Simulated Annealing http://en.wikipedia.org/wiki/Simulated_annealing C++: http://code.google.com/p/cppsimulatedannealing/ Analogy to heating & cooling metal to strengthen its structure Stochastic method – apply random permutation search for global minima - Avoid entrapment in local minima via hill climbing Heating schedule - Annealing schedule params: temperature, iterations at each temp, temperature delta Cooling schedule – can be linear, step-wise or exponential Differential Evolution http://en.wikipedia.org/wiki/Differential_evolution C++: http://www.amichel.com/de/doc/html/ More advanced stochastic methods analogous to biological processes: Genetic algorithms, evolution strategies Parallel direct search method against multiple discrete or continuous variables Initial population of variable vectors chosen randomly – if weighted difference vector of 2 vectors yields a lower objective function value then it replaces the comparison vector Many params: #parents, #variables, step size, crossover constant etc Convergence is slow – many more function evaluations than simulated annealing Numerical Differentiation Overview 2 approaches to finite difference methods: · A) approximate function via polynomial interpolation then differentiate · B) Taylor series approximation – additionally provides error estimate Finite Difference methods http://en.wikipedia.org/wiki/Finite_difference_method C++: http://www.wpi.edu/Pubs/ETD/Available/etd-051807-164436/unrestricted/EAMPADU.pdf Find differences between high order derivative values - Approximate differential equations by finite differences at evenly spaced data points Based on forward & backward Taylor series expansion of f(x) about x plus or minus multiples of delta h. Forward / backward difference - the sums of the series contains even derivatives and the difference of the series contains odd derivatives – coupled equations that can be solved. Provide an approximation of the derivative within a O(h^2) accuracy There is also central difference & extended central difference which has a O(h^4) accuracy Richardson Extrapolation http://en.wikipedia.org/wiki/Richardson_extrapolation C++: http://mathscoding.blogspot.co.il/2012/02/introduction-richardson-extrapolation.html A sequence acceleration method applied to finite differences Fast convergence, high accuracy O(h^4) Derivatives via Interpolation Cannot apply Finite Difference method to discrete data points at uneven intervals – so need to approximate the derivative of f(x) using the derivative of the interpolant via 3 point Lagrange Interpolation Note: the higher the order of the derivative, the lower the approximation precision Numerical Integration Estimate finite & infinite integrals of functions More accurate procedure than numerical differentiation Use when it is not possible to obtain an integral of a function analytically or when the function is not given, only the data points are Newton Cotes Methods http://en.wikipedia.org/wiki/Newton%E2%80%93Cotes_formulas C++: http://www.siafoo.net/snippet/324 For equally spaced data points Computationally easy – based on local interpolation of n rectangular strip areas that is piecewise fitted to a polynomial to get the sum total area Evaluate the integrand at n+1 evenly spaced points – approximate definite integral by Sum Weights are derived from Lagrange Basis polynomials Leverage Trapezoidal Rule for default 2nd formulas, Simpson 1/3 Rule for substituting 3 point formulas, Simpson 3/8 Rule for 4 point formulas. For 4 point formulas use Bodes Rule. Higher orders obtain more accurate results Trapezoidal Rule uses simple area, Simpsons Rule replaces the integrand f(x) with a quadratic polynomial p(x) that uses the same values as f(x) for its end points, but adds a midpoint Romberg Integration http://en.wikipedia.org/wiki/Romberg's_method C++: http://code.google.com/p/romberg-integration/downloads/detail?name=romberg.cpp&can=2&q= Combines trapezoidal rule with Richardson Extrapolation Evaluates the integrand at equally spaced points The integrand must have continuous derivatives Each R(n,m) extrapolation uses a higher order integrand polynomial replacement rule (zeroth starts with trapezoidal) à a lower triangular matrix set of equation coefficients where the bottom right term has the most accurate approximation. The process continues until the difference between 2 successive diagonal terms becomes sufficiently small. Gaussian Quadrature http://en.wikipedia.org/wiki/Gaussian_quadrature C++: http://www.alglib.net/integration/gaussianquadratures.php Data points are chosen to yield best possible accuracy – requires fewer evaluations Ability to handle singularities, functions that are difficult to evaluate The integrand can include a weighting function determined by a set of orthogonal polynomials. Points & weights are selected so that the integrand yields the exact integral if f(x) is a polynomial of degree <= 2n+1 Techniques (basically different weighting functions): · Gauss-Legendre Integration w(x)=1 · Gauss-Laguerre Integration w(x)=e^-x · Gauss-Hermite Integration w(x)=e^-x^2 · Gauss-Chebyshev Integration w(x)= 1 / Sqrt(1-x^2) Solving ODEs Use when high order differential equations cannot be solved analytically Evaluated under boundary conditions RK for systems – a high order differential equation can always be transformed into a coupled first order system of equations Euler method http://en.wikipedia.org/wiki/Euler_method C++: http://rosettacode.org/wiki/Euler_method First order Runge–Kutta method. Simple recursive method – given an initial value, calculate derivative deltas. Unstable & not very accurate (O(h) error) – not used in practice A first-order method - the local error (truncation error per step) is proportional to the square of the step size, and the global error (error at a given time) is proportional to the step size In evolving solution between data points xn & xn+1, only evaluates derivatives at beginning of interval xn à asymmetric at boundaries Higher order Runge Kutta http://en.wikipedia.org/wiki/Runge%E2%80%93Kutta_methods C++: http://www.dreamincode.net/code/snippet1441.htm 2nd & 4th order RK - Introduces parameterized midpoints for more symmetric solutions à accuracy at higher computational cost Adaptive RK – RK-Fehlberg – estimate the truncation at each integration step & automatically adjust the step size to keep error within prescribed limits. At each step 2 approximations are compared – if in disagreement to a specific accuracy, the step size is reduced Boundary Value Problems Where solution of differential equations are located at 2 different values of the independent variable x à more difficult, because cannot just start at point of initial value – there may not be enough starting conditions available at the end points to produce a unique solution An n-order equation will require n boundary conditions – need to determine the missing n-1 conditions which cause the given conditions at the other boundary to be satisfied Shooting Method http://en.wikipedia.org/wiki/Shooting_method C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-shooting-method-for-solving.html Iteratively guess the missing values for one end & integrate, then inspect the discrepancy with the boundary values of the other end to adjust the estimate Given the starting boundary values u1 & u2 which contain the root u, solve u given the false position method (solving the differential equation as an initial value problem via 4th order RK), then use u to solve the differential equations. Finite Difference Method For linear & non-linear systems Higher order derivatives require more computational steps – some combinations for boundary conditions may not work though Improve the accuracy by increasing the number of mesh points Solving EigenValue Problems An eigenvalue can substitute a matrix when doing matrix multiplication à convert matrix multiplication into a polynomial EigenValue For a given set of equations in matrix form, determine what are the solution eigenvalue & eigenvectors Similar Matrices - have same eigenvalues. Use orthogonal similarity transforms to reduce a matrix to diagonal form from which eigenvalue(s) & eigenvectors can be computed iteratively Jacobi method http://en.wikipedia.org/wiki/Jacobi_method C++: http://people.sc.fsu.edu/~jburkardt/classes/acs2_2008/openmp/jacobi/jacobi.html Robust but Computationally intense – use for small matrices < 10x10 Power Iteration http://en.wikipedia.org/wiki/Power_iteration For any given real symmetric matrix, generate the largest single eigenvalue & its eigenvectors Simplest method – does not compute matrix decomposition à suitable for large, sparse matrices Inverse Iteration Variation of power iteration method – generates the smallest eigenvalue from the inverse matrix Rayleigh Method http://en.wikipedia.org/wiki/Rayleigh's_method_of_dimensional_analysis Variation of power iteration method Rayleigh Quotient Method Variation of inverse iteration method Matrix Tri-diagonalization Method Use householder algorithm to reduce an NxN symmetric matrix to a tridiagonal real symmetric matrix vua N-2 orthogonal transforms     Whats Next Outside of Numerical Methods there are lots of different types of algorithms that I’ve learned over the decades: Data Mining – (I covered this briefly in a previous post: http://geekswithblogs.net/JoshReuben/archive/2007/12/31/ssas-dm-algorithms.aspx ) Search & Sort Routing Problem Solving Logical Theorem Proving Planning Probabilistic Reasoning Machine Learning Solvers (eg MIP) Bioinformatics (Sequence Alignment, Protein Folding) Quant Finance (I read Wilmott’s books – interesting) Sooner or later, I’ll cover the above topics as well.

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  • Internationalize WebCenter Portal - Content Presenter

    - by Stefan Krantz
    Lately we have been involved in engagements where internationalization has been holding the project back from success. In this post we are going to explain how to get Content Presenter and its editorials to comply with the current selected locale for the WebCenter Portal session. As you probably know by now WebCenter Portal leverages the Localization support from Java Server Faces (JSF), in this post we will assume that the localization is controlled and enforced by switching the current browsers locale between English and Spanish. There is two main scenarios in internationalization of a content enabled pages, since Content Presenter offers both presentation of information as well as contribution of information, in this post we will look at how to enable seamless integration of correct localized version of the back end content file and how to enable the editor/author to edit the correct localized version of the file based on the current browser locale. Solution Scenario 1 - Localization aware content presentation Due to the amount of steps required to implement the enclosed solution proposal I have decided to share the solution with you in group components for each facet of the solution. If you want to get more details on each step, you can review the enclosed components. This post will guide you through the steps of enabling each component and what it enables/changes in each section of the system. Enable Content Presenter Customization By leveraging a predictable naming convention of the data files used to hold the content for the Content Presenter instance we can easily develop a component that will dynamically switch the name out before presenting the information. The naming convention we have leverage is the industry best practice by having a shared identifier as prefix (ContentABC) and a language enabled suffix (_EN) (_ES). So the assumption is that each file pair in above example should look like following:- English version - (ContentABC_EN)- Spanish version - (ContentABC_ES) Based on above theory we can now easily regardless of the primary version assigned to the content presenter instance switch the language out by using the localization support from JSF. Below java bean (oracle.webcenter.doclib.internal.view.presenter.NLSHelperBean) is enclosed in the customization project available for download at the bottom of the post: 1: public static final String CP_D_DOCNAME_FORMAT = "%s_%s"; 2: public static final int CP_UNIQUE_ID_INDEX = 0; 3: private ContentPresenter presenter = null; 4:   5:   6: public NLSHelperBean() { 7: super(); 8: } 9:   10: /** 11: * This method updates the configuration for the pageFlowScope to have the correct datafile 12: * for the current Locale 13: */ 14: public void initLocaleForDataFile() { 15: String dataFile = null; 16: // Checking that state of presenter is present, also make sure the item is eligible for localization by locating the "_" in the name 17: if(presenter.getConfiguration().getDatasource() != null && 18: presenter.getConfiguration().getDatasource().isNodeDatasource() && 19: presenter.getConfiguration().getDatasource().getNodeIdDatasource() != null && 20: !presenter.getConfiguration().getDatasource().getNodeIdDatasource().equals("") && 21: presenter.getConfiguration().getDatasource().getNodeIdDatasource().indexOf("_") > 0) { 22: dataFile = presenter.getConfiguration().getDatasource().getNodeIdDatasource(); 23: FacesContext fc = FacesContext.getCurrentInstance(); 24: //Leveraging the current faces contenxt to get current localization language 25: String currentLocale = fc.getViewRoot().getLocale().getLanguage().toUpperCase(); 26: String newDataFile = dataFile; 27: String [] uniqueIdArr = dataFile.split("_"); 28: if(uniqueIdArr.length > 0) { 29: newDataFile = String.format(CP_D_DOCNAME_FORMAT, uniqueIdArr[CP_UNIQUE_ID_INDEX], currentLocale); 30: } 31: //Replacing the current Node datasource with localized datafile. 32: presenter.getConfiguration().getDatasource().setNodeIdDatasource(newDataFile); 33: } 34: } With this bean code available to our WebCenter Portal implementation we can start the next step, by overriding the standard behavior in content presenter by applying a MDS Taskflow customization to the content presenter taskflow, following taskflow customization has been applied to the customization project attached to this post:- Library: WebCenter Document Library Service View- Path: oracle.webcenter.doclib.view.jsf.taskflows.presenter- File: contentPresenter.xml Changes made in above customization view:1. A new method invocation activity has been added (initLocaleForDataFile)2. The method invocation invokes the new NLSHelperBean3. The default activity is moved to the new Method invocation (initLocaleForDataFile)4. The outcome from the method invocation goes to determine-navigation (original default activity) The above changes concludes the presentation modification to support a compatible localization scenario for a content driven page. In addition this customization do not limit or disables the out of the box capabilities of WebCenter Portal. Steps to enable above customization Start JDeveloper and open your WebCenter Portal Application Select "Open Project" and include the extracted project you downloaded (CPNLSCustomizations.zip) Make sure the build out put from CPNLSCustomizations project is a dependency to your Portal project Deploy your Portal Application to your WC_CustomPortal managed server Make sure your naming convention of the two data files follow above recommendation Example result of the solution: Solution Scenario 2 - Localization aware content creation and authoring As you could see from Solution Scenario 1 we require the naming convention to be strictly followed, this means in the hands of a user with limited technology knowledge this can be one of the failing links in this solutions. Therefore I strongly recommend that you also follow this part since this will eliminate this risk and also increase the editors/authors usability with a magnitude. The current WebCenter Portal Architecture leverages WebCenter Content today to maintain, publish and manage content, therefore we need to make few efforts in making sure this part of the architecture is on board with our new naming practice and also simplifies the creation of content for our end users. As you probably remember the naming convention required a prefix to be common so I propose we enable a new component that help you auto name the content items dDocName (this means that the readable title can still be in a human readable format). The new component (WCP-LocalizationSupport.zip) built for this scenario will enable a couple of things: 1. A new service where a sequential number can be generate on request - service name: GET_WCP_LOCALE_CONTENTID 2. The content presenter is leveraging a specific function when launching the content creation wizard from within Content Presenter. Assumption is that users will create the content by clicking "Create Web Content" button. When clicking the button the wizard opened is actually running in side of WebCenter Content server, file executed (contentwizard.hcsp). This file uses JSON commands that will generate operations in the content server, I have extend this file to create two identical data files instead of one.- First it creates the English version by leveraging the new Service and a Global Rule to set the dDocName on the original check in screen, this global rule is available in a configuration package attached to this blog (NLSContentProfileRule.zip)- Secondly we run a set of JSON javascripts to create the Spanish version with the same details except for the name where we replace the suffix with (_ES)- Then content creation wizard ends with its out of the box behavior and assigns the Content Presenter instance the English versionSee Javascript markup below - this can be changed in the (WCP-LocalizationSupport.zip/component/WCP-LocalizationSupport/publish/webcenter) 1: //---------------------------------------A-TEAM--------------------------------------- 2: WCM.ContentWizard.CheckinContentPage.OnCheckinComplete = function(returnParams) 3: { 4: var callback = WCM.ContentWizard.CheckinContentPage.checkinCompleteCallback; 5: WCM.ContentWizard.ChooseContentPage.OnSelectionComplete(returnParams, callback); 6: // Load latest DOC_INFO_SIMPLE 7: var cgiPath = DOCLIB.config.httpCgiPath; 8: var jsonBinder = new WCM.Idc.JSONBinder(); 9: jsonBinder.SetLocalDataValue('IdcService', 'DOC_INFO_SIMPLE'); 10: jsonBinder.SetLocalDataValue('dID', returnParams.dID); 11: jsonBinder.Send(cgiPath, $CB(this, function(http) { 12: var ret = http.GetResponseText(); 13: var binder = new WCM.Idc.JSONBinder(ret); 14: var dDocName = binder.GetResultSetValue('DOC_INFO', 'dDocName', 0); 15: if(dDocName.indexOf("_") > 0){ 16: var ssBinder = new WCM.Idc.JSONBinder(); 17: ssBinder.SetLocalDataValue('IdcService', 'SS_CHECKIN_NEW'); 18: //Additional Localization dDocName generated 19: ssBinder.SetLocalDataValue('dDocName', getLocalizedDocName(dDocName, "es")); 20: ssBinder.SetLocalDataValue('primaryFile', 'default.xml'); 21: ssBinder.SetLocalDataValue('ssDefaultDocumentToken', 'SSContributorDataFile'); 22:   23: for(var n = 0 ; n < binder.GetResultSetFields('DOC_INFO').length ; n++) { 24: var field = binder.GetResultSetFields('DOC_INFO')[n]; 25: if(field != 'dID' && 26: field != 'dDocName' && 27: field != 'dID' && 28: field != 'dReleaseState' && 29: field != 'dRevClassID' && 30: field != 'dRevisionID' && 31: field != 'dRevLabel') { 32: ssBinder.SetLocalDataValue(field, binder.GetResultSetValue('DOC_INFO', field, 0)); 33: } 34: } 35: ssBinder.Send(cgiPath, $CB(this, function(http) {})); 36: } 37: })); 38: } 39:   40: //Support function to create localized dDocNames 41: function getLocalizedDocName(dDocName, lang) { 42: var result = dDocName.replace("_EN", ("_" + lang)); 43: return result; 44: } 45: //---------------------------------------A-TEAM--------------------------------------- 3. By applying the enclosed NLSContentProfileRule.zip, the check in screen for DataFile creation will have auto naming enabled with localization suffix (default is English)You can change the default language by updating the GlobalNlsRule and assign preferred prefix.See Rule markup for dDocName field below: <$executeService("GET_WCP_LOCALE_CONTENTID")$><$dprDefaultValue=WCP_LOCALE.LocaleContentId & "_EN"$> Steps to enable above extensions and configurations Install WebCenter Component (WCP-LocalizationSupport.zip), via the AdminServer in WebCenter Content Administration menus Enable the component and restart the content server Apply the configuration bundle to enable the new Global Rule (GlobalNlsRule), via the WebCenter Content Administration/Config Migration Admin New Content Creation Experience Result Content EditingContent editing will by default be enabled for authoring in the current select locale since the content file is selected by (Solution Scenario 1), this means that a user can switch his browser locale and then get the editing experience adaptable to the current selected locale. NotesA-Team are planning to post a solution on how to inline switch the locale of the WebCenter Portal Session, so the Content Presenter, Navigation Model and other Face related features are localized accordingly. Content Presenter examples used in this post is an extension to following post:https://blogs.oracle.com/ATEAM_WEBCENTER/entry/enable_content_editing_of_iterative Downloads CPNLSCustomizations.zip - WebCenter Portal, Content Presenter Customization https://blogs.oracle.com/ATEAM_WEBCENTER/resource/stefan.krantz/CPNLSCustomizations.zip WCP-LocalizationSupport.zip - WebCenter Content, Extension Component to enable localization creation of files with compliant auto naminghttps://blogs.oracle.com/ATEAM_WEBCENTER/resource/stefan.krantz/WCP-LocalizationSupport.zip NLSContentProfileRule.zip - WebCenter Content, Configuration Update Bundle to enable Global rule for new check in naming of data fileshttps://blogs.oracle.com/ATEAM_WEBCENTER/resource/stefan.krantz/NLSContentProfileRule.zip

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  • Oracle Fusion Applications: Changing the Game

    - by kellsey.ruppel(at)oracle.com
    Originally posted in the Oracle Profit Magazine, November 2010 Edition. When the order processing system red-flags a customer's credit status, the IT department doesn't get the customer's call. When a supplier misses a delivery date for a key automotive assembly, it's not the CIO who has to answer for the error. Knowledge workers (known in IT circles as "users") are on the front lines when an exception occurs in an established business process. They're also the ones who study sales trends to decide when to open a new store in an up-and-coming neighborhood, which products are most profitable, how employee skill sets are evolving, and which suppliers are most efficient. In short, knowledge workers are masters of business as unusual. Traditional enterprise resource planning (ERP) systems and other familiar enterprise applications excel at automating, managing, and executing standard business processes. These programs shine when everything goes as planned. Life gets even trickier when a traditional application needs to be extended with a new service or an extra step is added to a business process when new products are brought to market, divisions are merged, or companies are acquired. Monolithic applications often need the IT department to step in and make the necessary adjustments--incurring additional costs and delays. Until now. When Oracle unveiled the much-anticipated family of Oracle Fusion Applications at Oracle OpenWorld in September 2010, knowledge workers in particular had a lot to cheer about. Business users will soon have ready access to analytical information and collaboration tools in the context of what they are working on, so they can make better decisions when problems or opportunities arise. Additionally, the Oracle Fusion Applications platform will make it easy for business users to tweak processes, create new capabilities, and find information, often without the need for IT department assistance and while still following company guidelines. And IT leaders will be happy to hear about new deployment options, guided implementation and setup tools, and cost-saving management capabilities. Just as important, the underlying technologies in Oracle Fusion Applications will allow organizations to choose among their existing investments and next-generation enterprise applications so they can introduce innovations at a pace that makes the most business and financial sense. "Oracle Fusion Applications are architected so you don't have to do rip and replace," says Jim Hayes, managing director of the consulting firm Accenture. "That's very important for creating a business case that will get through the steering committee and be approved by the board. It shows you can drive value and make a difference in the near term." For these and other reasons, analysts and early adopters are calling Oracle Fusion Applications a game changer for enterprise customers. The differences become apparent in three key areas: the way we innovate, work, and adopt technology. Game Changer #1: New Standard for InnovationChange is a constant challenge for most businesses, whether the catalysts are market dynamics, new competition, or the ever-expanding regulatory environment. And, in an ongoing effort to differentiate, business leaders are constantly looking for new ways to do business, serve constituents, and bring new products and services to market. In addition, companies face significant costs to keep their applications up-to-date. For example, when a company adds new suppliers to a procurement system, the IT shop typically has to invest time, effort, and even consulting fees for custom integrations that allow various ERP systems to communicate with each other. Oracle Fusion Applications were built on Web services and a modular SOA foundation to ease customizations and integration activities among all applications--whether from Oracle or another vendor. Interfaces and updates written in ubiquitous Java, rather than a proprietary coding language, allow organizations to tap into existing in-house technical skills rather than seek expensive outside specialists. And with SOA, organizations can extend a feature set or integrate with other SOA environments by combining Web services such as "look up customer" into a new business process managed by the BPEL orchestration engine. Flexibility like this has long-term implications. "Because users capture these changes at a higher metadata layer, not in the application's code, changes and additions are protected even as new versions of Oracle Fusion Applications are released," says Steve Miranda, senior vice president of applications development at Oracle. "This is a much more sustainable approach because you don't incur costly customizations that prevent upgrades and other innovations." And changes are easier to make: if one change is made in the metadata, that change is automatically reflected throughout the application interface, business intelligence, business process, and business logic. Game Changer #2: New Standard for WorkBoosting productivity comes down to doing the basics right: running business processes more efficiently and managing exceptions more effectively, so users can accomplish more in the course of a day or spend more quality time with the most profitable customers. The fastest way to improve process efficiency is to reduce the number of steps it takes to execute common tasks, such as ordering office equipment from an internal procurement system. Oracle Fusion Applications will deliver a complete role-based user experience with business intelligence and collaboration capabilities provided in the context of the work at hand. "We created every Oracle Fusion Applications screen by asking 'What does the user need to know?' 'What does he or she need to do?' and 'Who do they need to work with to get the job done?'" Miranda explains. So when the sales department heads need new laptops, the self-service procurement screen will not only display a list of approved vendors and configurations, but also a running list of reviews by coworkers who recently purchased the various models. Embedded intelligence may also display prevailing delivery lead times based on actual order histories, not the generic shipping dates vendors may quote. The pervasive business intelligence serves many other business activities across all areas of the enterprise. For example, a manager considering whether to promote a direct report can see the person's employee profile, with a salary history, appraisal summaries, and a rundown of skills and training. This approach to business intelligence also has implications for supply chain management. "One of the challenges at Ingersoll Rand is lack of visibility in our supply chain," says Mike Macrie, global director of enterprise applications for global industrial firm Ingersoll Rand. "Oracle Fusion Applications are going to provide the embedded intelligence to give us that visibility and give us the ability to analyze those orders at any point in our supply chain." Oracle Fusion Applications will also create a "role-based user experience" that displays a work list of events that need attention, based on user job function. Role awareness guides users with daily lists of action items and exceptions. So a credit manager may see seven invoices with discounts that are about to expire or 12 suppliers that have been put on hold because credit memos are awaiting approval. Individualization extends to the search capabilities of Oracle Fusion Applications. The platform uses Web-style search screens powered by an Oracle enterprise search engine, with a security framework that filters search results so individuals will only see the internal information they're authorized to access. A further aid to productivity is Oracle Fusion Applications' integration with Web 2.0 collaboration and social networking resources for business environments. Hover-over text will reveal relevant contact information whenever the name of a person appears in an Oracle Fusion Application. Users can connect via an online chat, phone call, or instant message without leaving the main application, reducing the time required for an accounts payable staffer to resolve a mismatch between an invoiced charge and the service record, for example. Addresses of suppliers, customers, or partners will also initiate hover-over text to show contact details and Web-based maps. Finally, Oracle Fusion Applications will promote a new way of working with purpose-driven communities that can bring new efficiencies to everything from cultivating sales leads to managing new projects. As soon as a lead or project materializes, the applications will automatically gather relevant participants into an online community that shares member contact information, schedules, discussion forums, and Wiki pages. "Oracle Fusion Applications will allow us to take it to the next level with embedded Web 2.0 tools and the embedded analytics," says Steve Printz, CIO and vice president, supply chain management, at window-and-door manufacturer Pella. "[This] allows those employees today who are processing transactions to really contribute to the success of the company and become decision-makers." Game Changer #3: New Standard for Technology AdoptionAs IT becomes a dominant component of how businesses run and compete, organizations need to lower the cost of implementing applications and introducing new application features. In the past, rolling out new code often required creating a test bed system, moving beta code to a separate system for user feedback, and--once all the revisions were made--moving version one of the software onto production systems, where business users could finally get the needed new features. Oracle Fusion Applications will use a dedicated setup manager application to streamline this process. First, the setup manager will help scope out the project, querying users about their requirements. "From those questions and answers we determine the steps and the order of those steps that will enable that task," Miranda says. Next, system utilities will assign tasks to owners, track completion status, and monitor the overall status of a programming effort. Oracle Fusion Applications can then recommend Web services that allow users to migrate setup choices and steps across all the various deployments of the application. Those setup capabilities automate the migration from test systems to production systems, as well as between different business units that may be using the same application. "The self-service ability of the setup manager helps business users change setups with very little intervention from the IT team," says Ravi Kumar, vice president at IT services company Infosys. "That to me is a big difference from how we've viewed enterprise applications before." For additional flexibility, organizations will be able to adopt Oracle Fusion Applications modules in either of two modes: a single-instance alternative uses one database for all Oracle Fusion Applications, while a "pillar mode" creates separate databases to underpin each application. This means IT departments running any one of Oracle's applications or even third-party applications can plug Oracle Fusion Applications modules into their environment and see additional business value created on top of their existing systems. And Oracle Fusion Applications offer a hybrid approach to deployment. The applications are all software-as-a-service-ready, so customers can choose on-premises, public or private cloud, or a combination of these to suit their business needs. It's that combination of flexibility and a roadmap for the future that may be the biggest game changer of all. "The Oracle Fusion Applications architecture allows us to migrate our company at a pace that's consistent with our business strategy, whereas before we might have had to do it with a massive upgrade," says Macrie of Ingersoll Rand. "We're looking forward to that architecture to really give us more flexibility in how we migrate over time." For More InformationUser Input Key to the Success of Oracle Fusion ApplicationsTransforming Coexistence into Strategic ValueUnder the HoodOracle Fusion ApplicationsOracle Service-Oriented Architecture  

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  • Toorcon 15 (2013)

    - by danx
    The Toorcon gang (senior staff): h1kari (founder), nfiltr8, and Geo Introduction to Toorcon 15 (2013) A Tale of One Software Bypass of MS Windows 8 Secure Boot Breaching SSL, One Byte at a Time Running at 99%: Surviving an Application DoS Security Response in the Age of Mass Customized Attacks x86 Rewriting: Defeating RoP and other Shinanighans Clowntown Express: interesting bugs and running a bug bounty program Active Fingerprinting of Encrypted VPNs Making Attacks Go Backwards Mask Your Checksums—The Gorry Details Adventures with weird machines thirty years after "Reflections on Trusting Trust" Introduction to Toorcon 15 (2013) Toorcon 15 is the 15th annual security conference held in San Diego. I've attended about a third of them and blogged about previous conferences I attended here starting in 2003. As always, I've only summarized the talks I attended and interested me enough to write about them. Be aware that I may have misrepresented the speaker's remarks and that they are not my remarks or opinion, or those of my employer, so don't quote me or them. Those seeking further details may contact the speakers directly or use The Google. For some talks, I have a URL for further information. A Tale of One Software Bypass of MS Windows 8 Secure Boot Andrew Furtak and Oleksandr Bazhaniuk Yuri Bulygin, Oleksandr ("Alex") Bazhaniuk, and (not present) Andrew Furtak Yuri and Alex talked about UEFI and Bootkits and bypassing MS Windows 8 Secure Boot, with vendor recommendations. They previously gave this talk at the BlackHat 2013 conference. MS Windows 8 Secure Boot Overview UEFI (Unified Extensible Firmware Interface) is interface between hardware and OS. UEFI is processor and architecture independent. Malware can replace bootloader (bootx64.efi, bootmgfw.efi). Once replaced can modify kernel. Trivial to replace bootloader. Today many legacy bootkits—UEFI replaces them most of them. MS Windows 8 Secure Boot verifies everything you load, either through signatures or hashes. UEFI firmware relies on secure update (with signed update). You would think Secure Boot would rely on ROM (such as used for phones0, but you can't do that for PCs—PCs use writable memory with signatures DXE core verifies the UEFI boat loader(s) OS Loader (winload.efi, winresume.efi) verifies the OS kernel A chain of trust is established with a root key (Platform Key, PK), which is a cert belonging to the platform vendor. Key Exchange Keys (KEKs) verify an "authorized" database (db), and "forbidden" database (dbx). X.509 certs with SHA-1/SHA-256 hashes. Keys are stored in non-volatile (NV) flash-based NVRAM. Boot Services (BS) allow adding/deleting keys (can't be accessed once OS starts—which uses Run-Time (RT)). Root cert uses RSA-2048 public keys and PKCS#7 format signatures. SecureBoot — enable disable image signature checks SetupMode — update keys, self-signed keys, and secure boot variables CustomMode — allows updating keys Secure Boot policy settings are: always execute, never execute, allow execute on security violation, defer execute on security violation, deny execute on security violation, query user on security violation Attacking MS Windows 8 Secure Boot Secure Boot does NOT protect from physical access. Can disable from console. Each BIOS vendor implements Secure Boot differently. There are several platform and BIOS vendors. It becomes a "zoo" of implementations—which can be taken advantage of. Secure Boot is secure only when all vendors implement it correctly. Allow only UEFI firmware signed updates protect UEFI firmware from direct modification in flash memory protect FW update components program SPI controller securely protect secure boot policy settings in nvram protect runtime api disable compatibility support module which allows unsigned legacy Can corrupt the Platform Key (PK) EFI root certificate variable in SPI flash. If PK is not found, FW enters setup mode wich secure boot turned off. Can also exploit TPM in a similar manner. One is not supposed to be able to directly modify the PK in SPI flash from the OS though. But they found a bug that they can exploit from User Mode (undisclosed) and demoed the exploit. It loaded and ran their own bootkit. The exploit requires a reboot. Multiple vendors are vulnerable. They will disclose this exploit to vendors in the future. Recommendations: allow only signed updates protect UEFI fw in ROM protect EFI variable store in ROM Breaching SSL, One Byte at a Time Yoel Gluck and Angelo Prado Angelo Prado and Yoel Gluck, Salesforce.com CRIME is software that performs a "compression oracle attack." This is possible because the SSL protocol doesn't hide length, and because SSL compresses the header. CRIME requests with every possible character and measures the ciphertext length. Look for the plaintext which compresses the most and looks for the cookie one byte-at-a-time. SSL Compression uses LZ77 to reduce redundancy. Huffman coding replaces common byte sequences with shorter codes. US CERT thinks the SSL compression problem is fixed, but it isn't. They convinced CERT that it wasn't fixed and they issued a CVE. BREACH, breachattrack.com BREACH exploits the SSL response body (Accept-Encoding response, Content-Encoding). It takes advantage of the fact that the response is not compressed. BREACH uses gzip and needs fairly "stable" pages that are static for ~30 seconds. It needs attacker-supplied content (say from a web form or added to a URL parameter). BREACH listens to a session's requests and responses, then inserts extra requests and responses. Eventually, BREACH guesses a session's secret key. Can use compression to guess contents one byte at-a-time. For example, "Supersecret SupersecreX" (a wrong guess) compresses 10 bytes, and "Supersecret Supersecret" (a correct guess) compresses 11 bytes, so it can find each character by guessing every character. To start the guess, BREACH needs at least three known initial characters in the response sequence. Compression length then "leaks" information. Some roadblocks include no winners (all guesses wrong) or too many winners (multiple possibilities that compress the same). The solutions include: lookahead (guess 2 or 3 characters at-a-time instead of 1 character). Expensive rollback to last known conflict check compression ratio can brute-force first 3 "bootstrap" characters, if needed (expensive) block ciphers hide exact plain text length. Solution is to align response in advance to block size Mitigations length: use variable padding secrets: dynamic CSRF tokens per request secret: change over time separate secret to input-less servlets Future work eiter understand DEFLATE/GZIP HTTPS extensions Running at 99%: Surviving an Application DoS Ryan Huber Ryan Huber, Risk I/O Ryan first discussed various ways to do a denial of service (DoS) attack against web services. One usual method is to find a slow web page and do several wgets. Or download large files. Apache is not well suited at handling a large number of connections, but one can put something in front of it Can use Apache alternatives, such as nginx How to identify malicious hosts short, sudden web requests user-agent is obvious (curl, python) same url requested repeatedly no web page referer (not normal) hidden links. hide a link and see if a bot gets it restricted access if not your geo IP (unless the website is global) missing common headers in request regular timing first seen IP at beginning of attack count requests per hosts (usually a very large number) Use of captcha can mitigate attacks, but you'll lose a lot of genuine users. Bouncer, goo.gl/c2vyEc and www.github.com/rawdigits/Bouncer Bouncer is software written by Ryan in netflow. Bouncer has a small, unobtrusive footprint and detects DoS attempts. It closes blacklisted sockets immediately (not nice about it, no proper close connection). Aggregator collects requests and controls your web proxies. Need NTP on the front end web servers for clean data for use by bouncer. Bouncer is also useful for a popularity storm ("Slashdotting") and scraper storms. Future features: gzip collection data, documentation, consumer library, multitask, logging destroyed connections. Takeaways: DoS mitigation is easier with a complete picture Bouncer designed to make it easier to detect and defend DoS—not a complete cure Security Response in the Age of Mass Customized Attacks Peleus Uhley and Karthik Raman Peleus Uhley and Karthik Raman, Adobe ASSET, blogs.adobe.com/asset/ Peleus and Karthik talked about response to mass-customized exploits. Attackers behave much like a business. "Mass customization" refers to concept discussed in the book Future Perfect by Stan Davis of Harvard Business School. Mass customization is differentiating a product for an individual customer, but at a mass production price. For example, the same individual with a debit card receives basically the same customized ATM experience around the world. Or designing your own PC from commodity parts. Exploit kits are another example of mass customization. The kits support multiple browsers and plugins, allows new modules. Exploit kits are cheap and customizable. Organized gangs use exploit kits. A group at Berkeley looked at 77,000 malicious websites (Grier et al., "Manufacturing Compromise: The Emergence of Exploit-as-a-Service", 2012). They found 10,000 distinct binaries among them, but derived from only a dozen or so exploit kits. Characteristics of Mass Malware: potent, resilient, relatively low cost Technical characteristics: multiple OS, multipe payloads, multiple scenarios, multiple languages, obfuscation Response time for 0-day exploits has gone down from ~40 days 5 years ago to about ~10 days now. So the drive with malware is towards mass customized exploits, to avoid detection There's plenty of evicence that exploit development has Project Manager bureaucracy. They infer from the malware edicts to: support all versions of reader support all versions of windows support all versions of flash support all browsers write large complex, difficult to main code (8750 lines of JavaScript for example Exploits have "loose coupling" of multipe versions of software (adobe), OS, and browser. This allows specific attacks against specific versions of multiple pieces of software. Also allows exploits of more obscure software/OS/browsers and obscure versions. Gave examples of exploits that exploited 2, 3, 6, or 14 separate bugs. However, these complete exploits are more likely to be buggy or fragile in themselves and easier to defeat. Future research includes normalizing malware and Javascript. Conclusion: The coming trend is that mass-malware with mass zero-day attacks will result in mass customization of attacks. x86 Rewriting: Defeating RoP and other Shinanighans Richard Wartell Richard Wartell The attack vector we are addressing here is: First some malware causes a buffer overflow. The malware has no program access, but input access and buffer overflow code onto stack Later the stack became non-executable. The workaround malware used was to write a bogus return address to the stack jumping to malware Later came ASLR (Address Space Layout Randomization) to randomize memory layout and make addresses non-deterministic. The workaround malware used was to jump t existing code segments in the program that can be used in bad ways "RoP" is Return-oriented Programming attacks. RoP attacks use your own code and write return address on stack to (existing) expoitable code found in program ("gadgets"). Pinkie Pie was paid $60K last year for a RoP attack. One solution is using anti-RoP compilers that compile source code with NO return instructions. ASLR does not randomize address space, just "gadgets". IPR/ILR ("Instruction Location Randomization") randomizes each instruction with a virtual machine. Richard's goal was to randomize a binary with no source code access. He created "STIR" (Self-Transofrming Instruction Relocation). STIR disassembles binary and operates on "basic blocks" of code. The STIR disassembler is conservative in what to disassemble. Each basic block is moved to a random location in memory. Next, STIR writes new code sections with copies of "basic blocks" of code in randomized locations. The old code is copied and rewritten with jumps to new code. the original code sections in the file is marked non-executible. STIR has better entropy than ASLR in location of code. Makes brute force attacks much harder. STIR runs on MS Windows (PEM) and Linux (ELF). It eliminated 99.96% or more "gadgets" (i.e., moved the address). Overhead usually 5-10% on MS Windows, about 1.5-4% on Linux (but some code actually runs faster!). The unique thing about STIR is it requires no source access and the modified binary fully works! Current work is to rewrite code to enforce security policies. For example, don't create a *.{exe,msi,bat} file. Or don't connect to the network after reading from the disk. Clowntown Express: interesting bugs and running a bug bounty program Collin Greene Collin Greene, Facebook Collin talked about Facebook's bug bounty program. Background at FB: FB has good security frameworks, such as security teams, external audits, and cc'ing on diffs. But there's lots of "deep, dark, forgotten" parts of legacy FB code. Collin gave several examples of bountied bugs. Some bounty submissions were on software purchased from a third-party (but bounty claimers don't know and don't care). We use security questions, as does everyone else, but they are basically insecure (often easily discoverable). Collin didn't expect many bugs from the bounty program, but they ended getting 20+ good bugs in first 24 hours and good submissions continue to come in. Bug bounties bring people in with different perspectives, and are paid only for success. Bug bounty is a better use of a fixed amount of time and money versus just code review or static code analysis. The Bounty program started July 2011 and paid out $1.5 million to date. 14% of the submissions have been high priority problems that needed to be fixed immediately. The best bugs come from a small % of submitters (as with everything else)—the top paid submitters are paid 6 figures a year. Spammers like to backstab competitors. The youngest sumitter was 13. Some submitters have been hired. Bug bounties also allows to see bugs that were missed by tools or reviews, allowing improvement in the process. Bug bounties might not work for traditional software companies where the product has release cycle or is not on Internet. Active Fingerprinting of Encrypted VPNs Anna Shubina Anna Shubina, Dartmouth Institute for Security, Technology, and Society (I missed the start of her talk because another track went overtime. But I have the DVD of the talk, so I'll expand later) IPsec leaves fingerprints. Using netcat, one can easily visually distinguish various crypto chaining modes just from packet timing on a chart (example, DES-CBC versus AES-CBC) One can tell a lot about VPNs just from ping roundtrips (such as what router is used) Delayed packets are not informative about a network, especially if far away from the network More needed to explore about how TCP works in real life with respect to timing Making Attacks Go Backwards Fuzzynop FuzzyNop, Mandiant This talk is not about threat attribution (finding who), product solutions, politics, or sales pitches. But who are making these malware threats? It's not a single person or group—they have diverse skill levels. There's a lot of fat-fingered fumblers out there. Always look for low-hanging fruit first: "hiding" malware in the temp, recycle, or root directories creation of unnamed scheduled tasks obvious names of files and syscalls ("ClearEventLog") uncleared event logs. Clearing event log in itself, and time of clearing, is a red flag and good first clue to look for on a suspect system Reverse engineering is hard. Disassembler use takes practice and skill. A popular tool is IDA Pro, but it takes multiple interactive iterations to get a clean disassembly. Key loggers are used a lot in targeted attacks. They are typically custom code or built in a backdoor. A big tip-off is that non-printable characters need to be printed out (such as "[Ctrl]" "[RightShift]") or time stamp printf strings. Look for these in files. Presence is not proof they are used. Absence is not proof they are not used. Java exploits. Can parse jar file with idxparser.py and decomile Java file. Java typially used to target tech companies. Backdoors are the main persistence mechanism (provided externally) for malware. Also malware typically needs command and control. Application of Artificial Intelligence in Ad-Hoc Static Code Analysis John Ashaman John Ashaman, Security Innovation Initially John tried to analyze open source files with open source static analysis tools, but these showed thousands of false positives. Also tried using grep, but tis fails to find anything even mildly complex. So next John decided to write his own tool. His approach was to first generate a call graph then analyze the graph. However, the problem is that making a call graph is really hard. For example, one problem is "evil" coding techniques, such as passing function pointer. First the tool generated an Abstract Syntax Tree (AST) with the nodes created from method declarations and edges created from method use. Then the tool generated a control flow graph with the goal to find a path through the AST (a maze) from source to sink. The algorithm is to look at adjacent nodes to see if any are "scary" (a vulnerability), using heuristics for search order. The tool, called "Scat" (Static Code Analysis Tool), currently looks for C# vulnerabilities and some simple PHP. Later, he plans to add more PHP, then JSP and Java. For more information see his posts in Security Innovation blog and NRefactory on GitHub. Mask Your Checksums—The Gorry Details Eric (XlogicX) Davisson Eric (XlogicX) Davisson Sometimes in emailing or posting TCP/IP packets to analyze problems, you may want to mask the IP address. But to do this correctly, you need to mask the checksum too, or you'll leak information about the IP. Problem reports found in stackoverflow.com, sans.org, and pastebin.org are usually not masked, but a few companies do care. If only the IP is masked, the IP may be guessed from checksum (that is, it leaks data). Other parts of packet may leak more data about the IP. TCP and IP checksums both refer to the same data, so can get more bits of information out of using both checksums than just using one checksum. Also, one can usually determine the OS from the TTL field and ports in a packet header. If we get hundreds of possible results (16x each masked nibble that is unknown), one can do other things to narrow the results, such as look at packet contents for domain or geo information. With hundreds of results, can import as CSV format into a spreadsheet. Can corelate with geo data and see where each possibility is located. Eric then demoed a real email report with a masked IP packet attached. Was able to find the exact IP address, given the geo and university of the sender. Point is if you're going to mask a packet, do it right. Eric wouldn't usually bother, but do it correctly if at all, to not create a false impression of security. Adventures with weird machines thirty years after "Reflections on Trusting Trust" Sergey Bratus Sergey Bratus, Dartmouth College (and Julian Bangert and Rebecca Shapiro, not present) "Reflections on Trusting Trust" refers to Ken Thompson's classic 1984 paper. "You can't trust code that you did not totally create yourself." There's invisible links in the chain-of-trust, such as "well-installed microcode bugs" or in the compiler, and other planted bugs. Thompson showed how a compiler can introduce and propagate bugs in unmodified source. But suppose if there's no bugs and you trust the author, can you trust the code? Hell No! There's too many factors—it's Babylonian in nature. Why not? Well, Input is not well-defined/recognized (code's assumptions about "checked" input will be violated (bug/vunerabiliy). For example, HTML is recursive, but Regex checking is not recursive. Input well-formed but so complex there's no telling what it does For example, ELF file parsing is complex and has multiple ways of parsing. Input is seen differently by different pieces of program or toolchain Any Input is a program input executes on input handlers (drives state changes & transitions) only a well-defined execution model can be trusted (regex/DFA, PDA, CFG) Input handler either is a "recognizer" for the inputs as a well-defined language (see langsec.org) or it's a "virtual machine" for inputs to drive into pwn-age ELF ABI (UNIX/Linux executible file format) case study. Problems can arise from these steps (without planting bugs): compiler linker loader ld.so/rtld relocator DWARF (debugger info) exceptions The problem is you can't really automatically analyze code (it's the "halting problem" and undecidable). Only solution is to freeze code and sign it. But you can't freeze everything! Can't freeze ASLR or loading—must have tables and metadata. Any sufficiently complex input data is the same as VM byte code Example, ELF relocation entries + dynamic symbols == a Turing Complete Machine (TM). @bxsays created a Turing machine in Linux from relocation data (not code) in an ELF file. For more information, see Rebecca "bx" Shapiro's presentation from last year's Toorcon, "Programming Weird Machines with ELF Metadata" @bxsays did same thing with Mach-O bytecode Or a DWARF exception handling data .eh_frame + glibc == Turning Machine X86 MMU (IDT, GDT, TSS): used address translation to create a Turning Machine. Page handler reads and writes (on page fault) memory. Uses a page table, which can be used as Turning Machine byte code. Example on Github using this TM that will fly a glider across the screen Next Sergey talked about "Parser Differentials". That having one input format, but two parsers, will create confusion and opportunity for exploitation. For example, CSRs are parsed during creation by cert requestor and again by another parser at the CA. Another example is ELF—several parsers in OS tool chain, which are all different. Can have two different Program Headers (PHDRs) because ld.so parses multiple PHDRs. The second PHDR can completely transform the executable. This is described in paper in the first issue of International Journal of PoC. Conclusions trusting computers not only about bugs! Bugs are part of a problem, but no by far all of it complex data formats means bugs no "chain of trust" in Babylon! (that is, with parser differentials) we need to squeeze complexity out of data until data stops being "code equivalent" Further information See and langsec.org. USENIX WOOT 2013 (Workshop on Offensive Technologies) for "weird machines" papers and videos.

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  • GuestPost: Unit Testing Entity Framework (v1) Dependent Code using TypeMock Isolator

    - by Eric Nelson
    Time for another guest post (check out others in the series), this time bringing together the world of mocking with the world of Entity Framework. A big thanks to Moses for agreeing to do this. Unit Testing Entity Framework Dependent Code using TypeMock Isolator by Muhammad Mosa Introduction Unit testing data access code in my opinion is a challenging thing. Let us consider unit tests and integration tests. In integration tests you are allowed to have environmental dependencies such as a physical database connection to insert, update, delete or retrieve your data. However when performing unit tests it is often much more efficient and productive to remove environmental dependencies. Instead you will need to fake these dependencies. Faking a database (also known as mocking) can be relatively straight forward but the version of Entity Framework released with .Net 3.5 SP1 has a number of implementation specifics which actually makes faking the existence of a database quite difficult. Faking Entity Framework As mentioned earlier, to effectively unit test you will need to fake/simulate Entity Framework calls to the database. There are many free open source mocking frameworks that can help you achieve this but it will require additional effort to overcome & workaround a number of limitations in those frameworks. Examples of these limitations include: Not able to fake calls to non virtual methods Not able to fake sealed classes Not able to fake LINQ to Entities queries (replace database calls with in-memory collection calls) There is a mocking framework which is flexible enough to handle limitations such as those above. The commercially available TypeMock Isolator can do the job for you with less code and ultimately more readable unit tests. I’m going to demonstrate tackling one of those limitations using MoQ as my mocking framework. Then I will tackle the same issue using TypeMock Isolator. Mocking Entity Framework with MoQ One basic need when faking Entity Framework is to fake the ObjectContext. This cannot be done by passing any connection string. You have to pass a correct Entity Framework connection string that specifies CSDL, SSDL and MSL locations along with a provider connection string. Assuming we are going to do that, we’ll explore another limitation. The limitation we are going to face now is related to not being able to fake calls to non-virtual/overridable members with MoQ. I have the following repository method that adds an EntityObject (instance of a Blog entity) to Blogs entity set in an ObjectContext. public override void Add(Blog blog) { if(BlogContext.Blogs.Any(b=>b.Name == blog.Name)) { throw new InvalidOperationException("Blog with same name already exists!"); } BlogContext.AddToBlogs(blog); } The method does a very simple check that the name of the new Blog entity instance doesn’t exist. This is done through the simple LINQ query above. If the blog doesn’t already exist it simply adds it to the current context to be saved when SaveChanges of the ObjectContext instance (e.g. BlogContext) is called. However, if a blog with the same name exits, and exception (InvalideOperationException) will be thrown. Let us now create a unit test for the Add method using MoQ. [TestMethod] [ExpectedException(typeof(InvalidOperationException))] public void Add_Should_Throw_InvalidOperationException_When_Blog_With_Same_Name_Already_Exits() { //(1) We shouldn't depend on configuration when doing unit tests! But, //its a workaround to fake the ObjectContext string connectionString = ConfigurationManager .ConnectionStrings["MyBlogConnString"] .ConnectionString; //(2) Arrange: Fake ObjectContext var fakeContext = new Mock<MyBlogContext>(connectionString); //(3) Next Line will pass, as ObjectContext now can be faked with proper connection string var repo = new BlogRepository(fakeContext.Object); //(4) Create fake ObjectQuery<Blog>. Will be used to substitute MyBlogContext.Blogs property var fakeObjectQuery = new Mock<ObjectQuery<Blog>>("[Blogs]", fakeContext.Object); //(5) Arrange: Set Expectations //Next line will throw an exception by MoQ: //System.ArgumentException: Invalid setup on a non-overridable member fakeContext.SetupGet(c=>c.Blogs).Returns(fakeObjectQuery.Object); fakeObjectQuery.Setup(q => q.Any(b => b.Name == "NewBlog")).Returns(true); //Act repo.Add(new Blog { Name = "NewBlog" }); } This test method is checking to see if the correct exception ([ExpectedException(typeof(InvalidOperationException))]) is thrown when a developer attempts to Add a blog with a name that’s already exists. On (1) a connection string is initialized from configuration file. To retrieve the full connection string. On (2) a fake ObjectContext is being created. The ObjectContext here is MyBlogContext and its being created using this var fakeContext = new Mock<MyBlogContext>(connectionString); This way a fake context is being created using MoQ. On (3) a BlogRepository instance is created. BlogRepository has dependency on generate Entity Framework ObjectContext, MyObjectContext. And so the fake context is passed to the constructor. var repo = new BlogRepository(fakeContext.Object); On (4) a fake instance of ObjectQuery<Blog> is being created to use as a substitute to MyObjectContext.Blogs property as we will see in (5). On (5) setup an expectation for calling Blogs property of MyBlogContext and substitute the return result with the fake ObjectQuery<Blog> instance created on (4). When you run this test it will fail with MoQ throwing an exception because of this line: fakeContext.SetupGet(c=>c.Blogs).Returns(fakeObjectQuery.Object); This happens because the generate property MyBlogContext.Blogs is not virtual/overridable. And assuming it is virtual or you managed to make it virtual it will fail at the following line throwing the same exception: fakeObjectQuery.Setup(q => q.Any(b => b.Name == "NewBlog")).Returns(true); This time the test will fail because the Any extension method is not virtual/overridable. You won’t be able to replace ObjectQuery<Blog> with fake in memory collection to test your LINQ to Entities queries. Now lets see how replacing MoQ with TypeMock Isolator can help. Mocking Entity Framework with TypeMock Isolator The following is the same test method we had above for MoQ but this time implemented using TypeMock Isolator: [TestMethod] [ExpectedException(typeof(InvalidOperationException))] public void Add_New_Blog_That_Already_Exists_Should_Throw_InvalidOperationException() { //(1) Create fake in memory collection of blogs var fakeInMemoryBlogs = new List<Blog> {new Blog {Name = "FakeBlog"}}; //(2) create fake context var fakeContext = Isolate.Fake.Instance<MyBlogContext>(); //(3) Setup expected call to MyBlogContext.Blogs property through the fake context Isolate.WhenCalled(() => fakeContext.Blogs) .WillReturnCollectionValuesOf(fakeInMemoryBlogs.AsQueryable()); //(4) Create new blog with a name that already exits in the fake in memory collection in (1) var blog = new Blog {Name = "FakeBlog"}; //(5) Instantiate instance of BlogRepository (Class under test) var repo = new BlogRepository(fakeContext); //(6) Acting by adding the newly created blog () repo.Add(blog); } When running the above test method it will pass as the Add method of BlogRepository is going to throw an InvalidOperationException which is the expected behaviour. Nothing prevents us from faking out the database interaction! Even faking ObjectContext  at (2) didn’t require a connection string. On (3) Isolator sets up a faking result for MyBlogContext.Blogs when its being called through the fake instance fakeContext created on (2). The faking result is just an in-memory collection declared an initialized on (1). Finally at (6) action we call the Add method of BlogRepository passing a new Blog instance that has a name that’s already exists in the fake in-memory collection which we set up at (1). As expected the test will pass because it will throw the expected exception defined on top of the test method - InvalidOperationException. TypeMock Isolator succeeded in faking Entity Framework with ease. Conclusion We explored how to write a simple unit test using TypeMock Isolator for code which is using Entity Framework. We also explored a few of the limitations of other mocking frameworks which TypeMock is successfully able to handle. There are workarounds that you can use to overcome limitations when using MoQ or Rhino Mock, however the workarounds will require you to write more code and your tests will likely be more complex. For a comparison between different mocking frameworks take a look at this document produced by TypeMock. You might also want to check out this open source project to compare mocking frameworks. I hope you enjoyed this post Muhammad Mosa http://mosesofegypt.net/ http://twitter.com/mosessaur Screencast of unit testing Entity Framework Related Links GuestPost: Introduction to Mocking GuesPost: Typemock Isolator – Much more than an Isolation framework

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