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  • Drupal blocks are syncing?

    - by Kevin
    I am trying to enable a new theme on a site running Drupal 6.16. I enable it fine, it has its own namespace in the theme and theme registry. However when you go to the Blocks section, changing a block here will affect that blocks placement in all the other themes, and vice versa. Is this normal behavior? Where should I begin looking to solve this issue?

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  • Upload File to Windows Azure Blob in Chunks through ASP.NET MVC, JavaScript and HTML5

    - by Shaun
    Originally posted on: http://geekswithblogs.net/shaunxu/archive/2013/07/01/upload-file-to-windows-azure-blob-in-chunks-through-asp.net.aspxMany people are using Windows Azure Blob Storage to store their data in the cloud. Blob storage provides 99.9% availability with easy-to-use API through .NET SDK and HTTP REST. For example, we can store JavaScript files, images, documents in blob storage when we are building an ASP.NET web application on a Web Role in Windows Azure. Or we can store our VHD files in blob and mount it as a hard drive in our cloud service. If you are familiar with Windows Azure, you should know that there are two kinds of blob: page blob and block blob. The page blob is optimized for random read and write, which is very useful when you need to store VHD files. The block blob is optimized for sequential/chunk read and write, which has more common usage. Since we can upload block blob in blocks through BlockBlob.PutBlock, and them commit them as a whole blob with invoking the BlockBlob.PutBlockList, it is very powerful to upload large files, as we can upload blocks in parallel, and provide pause-resume feature. There are many documents, articles and blog posts described on how to upload a block blob. Most of them are focus on the server side, which means when you had received a big file, stream or binaries, how to upload them into blob storage in blocks through .NET SDK.  But the problem is, how can we upload these large files from client side, for example, a browser. This questioned to me when I was working with a Chinese customer to help them build a network disk production on top of azure. The end users upload their files from the web portal, and then the files will be stored in blob storage from the Web Role. My goal is to find the best way to transform the file from client (end user’s machine) to the server (Web Role) through browser. In this post I will demonstrate and describe what I had done, to upload large file in chunks with high speed, and save them as blocks into Windows Azure Blob Storage.   Traditional Upload, Works with Limitation The simplest way to implement this requirement is to create a web page with a form that contains a file input element and a submit button. 1: @using (Html.BeginForm("About", "Index", FormMethod.Post, new { enctype = "multipart/form-data" })) 2: { 3: <input type="file" name="file" /> 4: <input type="submit" value="upload" /> 5: } And then in the backend controller, we retrieve the whole content of this file and upload it in to the blob storage through .NET SDK. We can split the file in blocks and upload them in parallel and commit. The code had been well blogged in the community. 1: [HttpPost] 2: public ActionResult About(HttpPostedFileBase file) 3: { 4: var container = _client.GetContainerReference("test"); 5: container.CreateIfNotExists(); 6: var blob = container.GetBlockBlobReference(file.FileName); 7: var blockDataList = new Dictionary<string, byte[]>(); 8: using (var stream = file.InputStream) 9: { 10: var blockSizeInKB = 1024; 11: var offset = 0; 12: var index = 0; 13: while (offset < stream.Length) 14: { 15: var readLength = Math.Min(1024 * blockSizeInKB, (int)stream.Length - offset); 16: var blockData = new byte[readLength]; 17: offset += stream.Read(blockData, 0, readLength); 18: blockDataList.Add(Convert.ToBase64String(BitConverter.GetBytes(index)), blockData); 19:  20: index++; 21: } 22: } 23:  24: Parallel.ForEach(blockDataList, (bi) => 25: { 26: blob.PutBlock(bi.Key, new MemoryStream(bi.Value), null); 27: }); 28: blob.PutBlockList(blockDataList.Select(b => b.Key).ToArray()); 29:  30: return RedirectToAction("About"); 31: } This works perfect if we selected an image, a music or a small video to upload. But if I selected a large file, let’s say a 6GB HD-movie, after upload for about few minutes the page will be shown as below and the upload will be terminated. In ASP.NET there is a limitation of request length and the maximized request length is defined in the web.config file. It’s a number which less than about 4GB. So if we want to upload a really big file, we cannot simply implement in this way. Also, in Windows Azure, a cloud service network load balancer will terminate the connection if exceed the timeout period. From my test the timeout looks like 2 - 3 minutes. Hence, when we need to upload a large file we cannot just use the basic HTML elements. Besides the limitation mentioned above, the simple HTML file upload cannot provide rich upload experience such as chunk upload, pause and pause-resume. So we need to find a better way to upload large file from the client to the server.   Upload in Chunks through HTML5 and JavaScript In order to break those limitation mentioned above we will try to upload the large file in chunks. This takes some benefit to us such as - No request size limitation: Since we upload in chunks, we can define the request size for each chunks regardless how big the entire file is. - No timeout problem: The size of chunks are controlled by us, which means we should be able to make sure request for each chunk upload will not exceed the timeout period of both ASP.NET and Windows Azure load balancer. It was a big challenge to upload big file in chunks until we have HTML5. There are some new features and improvements introduced in HTML5 and we will use them to implement our solution.   In HTML5, the File interface had been improved with a new method called “slice”. It can be used to read part of the file by specifying the start byte index and the end byte index. For example if the entire file was 1024 bytes, file.slice(512, 768) will read the part of this file from the 512nd byte to 768th byte, and return a new object of interface called "Blob”, which you can treat as an array of bytes. In fact,  a Blob object represents a file-like object of immutable, raw data. The File interface is based on Blob, inheriting blob functionality and expanding it to support files on the user's system. For more information about the Blob please refer here. File and Blob is very useful to implement the chunk upload. We will use File interface to represent the file the user selected from the browser and then use File.slice to read the file in chunks in the size we wanted. For example, if we wanted to upload a 10MB file with 512KB chunks, then we can read it in 512KB blobs by using File.slice in a loop.   Assuming we have a web page as below. User can select a file, an input box to specify the block size in KB and a button to start upload. 1: <div> 2: <input type="file" id="upload_files" name="files[]" /><br /> 3: Block Size: <input type="number" id="block_size" value="512" name="block_size" />KB<br /> 4: <input type="button" id="upload_button_blob" name="upload" value="upload (blob)" /> 5: </div> Then we can have the JavaScript function to upload the file in chunks when user clicked the button. 1: <script type="text/javascript"> 1: 2: $(function () { 3: $("#upload_button_blob").click(function () { 4: }); 5: });</script> Firstly we need to ensure the client browser supports the interfaces we are going to use. Just try to invoke the File, Blob and FormData from the “window” object. If any of them is “undefined” the condition result will be “false” which means your browser doesn’t support these premium feature and it’s time for you to get your browser updated. FormData is another new feature we are going to use in the future. It could generate a temporary form for us. We will use this interface to create a form with chunk and associated metadata when invoked the service through ajax. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: if (window.File && window.Blob && window.FormData) { 4: alert("Your brwoser is awesome, let's rock!"); 5: } 6: else { 7: alert("Oh man plz update to a modern browser before try is cool stuff out."); 8: return; 9: } 10: }); Each browser supports these interfaces by their own implementation and currently the Blob, File and File.slice are supported by Chrome 21, FireFox 13, IE 10, Opera 12 and Safari 5.1 or higher. After that we worked on the files the user selected one by one since in HTML5, user can select multiple files in one file input box. 1: var files = $("#upload_files")[0].files; 2: for (var i = 0; i < files.length; i++) { 3: var file = files[i]; 4: var fileSize = file.size; 5: var fileName = file.name; 6: } Next, we calculated the start index and end index for each chunks based on the size the user specified from the browser. We put them into an array with the file name and the index, which will be used when we upload chunks into Windows Azure Blob Storage as blocks since we need to specify the target blob name and the block index. At the same time we will store the list of all indexes into another variant which will be used to commit blocks into blob in Azure Storage once all chunks had been uploaded successfully. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10:  11: // calculate the start and end byte index for each blocks(chunks) 12: // with the index, file name and index list for future using 13: var blockSizeInKB = $("#block_size").val(); 14: var blockSize = blockSizeInKB * 1024; 15: var blocks = []; 16: var offset = 0; 17: var index = 0; 18: var list = ""; 19: while (offset < fileSize) { 20: var start = offset; 21: var end = Math.min(offset + blockSize, fileSize); 22:  23: blocks.push({ 24: name: fileName, 25: index: index, 26: start: start, 27: end: end 28: }); 29: list += index + ","; 30:  31: offset = end; 32: index++; 33: } 34: } 35: }); Now we have all chunks’ information ready. The next step should be upload them one by one to the server side, and at the server side when received a chunk it will upload as a block into Blob Storage, and finally commit them with the index list through BlockBlobClient.PutBlockList. But since all these invokes are ajax calling, which means not synchronized call. So we need to introduce a new JavaScript library to help us coordinate the asynchronize operation, which named “async.js”. You can download this JavaScript library here, and you can find the document here. I will not explain this library too much in this post. We will put all procedures we want to execute as a function array, and pass into the proper function defined in async.js to let it help us to control the execution sequence, in series or in parallel. Hence we will define an array and put the function for chunk upload into this array. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4:  5: // start to upload each files in chunks 6: var files = $("#upload_files")[0].files; 7: for (var i = 0; i < files.length; i++) { 8: var file = files[i]; 9: var fileSize = file.size; 10: var fileName = file.name; 11: // calculate the start and end byte index for each blocks(chunks) 12: // with the index, file name and index list for future using 13: ... ... 14:  15: // define the function array and push all chunk upload operation into this array 16: blocks.forEach(function (block) { 17: putBlocks.push(function (callback) { 18: }); 19: }); 20: } 21: }); 22: }); As you can see, I used File.slice method to read each chunks based on the start and end byte index we calculated previously, and constructed a temporary HTML form with the file name, chunk index and chunk data through another new feature in HTML5 named FormData. Then post this form to the backend server through jQuery.ajax. This is the key part of our solution. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: blocks.forEach(function (block) { 15: putBlocks.push(function (callback) { 16: // load blob based on the start and end index for each chunks 17: var blob = file.slice(block.start, block.end); 18: // put the file name, index and blob into a temporary from 19: var fd = new FormData(); 20: fd.append("name", block.name); 21: fd.append("index", block.index); 22: fd.append("file", blob); 23: // post the form to backend service (asp.net mvc controller action) 24: $.ajax({ 25: url: "/Home/UploadInFormData", 26: data: fd, 27: processData: false, 28: contentType: "multipart/form-data", 29: type: "POST", 30: success: function (result) { 31: if (!result.success) { 32: alert(result.error); 33: } 34: callback(null, block.index); 35: } 36: }); 37: }); 38: }); 39: } 40: }); Then we will invoke these functions one by one by using the async.js. And once all functions had been executed successfully I invoked another ajax call to the backend service to commit all these chunks (blocks) as the blob in Windows Azure Storage. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.series(putBlocks, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: }); That’s all in the client side. The outline of our logic would be - Calculate the start and end byte index for each chunks based on the block size. - Defined the functions of reading the chunk form file and upload the content to the backend service through ajax. - Execute the functions defined in previous step with “async.js”. - Commit the chunks by invoking the backend service in Windows Azure Storage finally.   Save Chunks as Blocks into Blob Storage In above we finished the client size JavaScript code. It uploaded the file in chunks to the backend service which we are going to implement in this step. We will use ASP.NET MVC as our backend service, and it will receive the chunks, upload into Windows Azure Bob Storage in blocks, then finally commit as one blob. As in the client side we uploaded chunks by invoking the ajax call to the URL "/Home/UploadInFormData", I created a new action under the Index controller and it only accepts HTTP POST request. 1: [HttpPost] 2: public JsonResult UploadInFormData() 3: { 4: var error = string.Empty; 5: try 6: { 7: } 8: catch (Exception e) 9: { 10: error = e.ToString(); 11: } 12:  13: return new JsonResult() 14: { 15: Data = new 16: { 17: success = string.IsNullOrWhiteSpace(error), 18: error = error 19: } 20: }; 21: } Then I retrieved the file name, index and the chunk content from the Request.Form object, which was passed from our client side. And then, used the Windows Azure SDK to create a blob container (in this case we will use the container named “test”.) and create a blob reference with the blob name (same as the file name). Then uploaded the chunk as a block of this blob with the index, since in Blob Storage each block must have an index (ID) associated with so that finally we can put all blocks as one blob by specifying their block ID list. 1: [HttpPost] 2: public JsonResult UploadInFormData() 3: { 4: var error = string.Empty; 5: try 6: { 7: var name = Request.Form["name"]; 8: var index = int.Parse(Request.Form["index"]); 9: var file = Request.Files[0]; 10: var id = Convert.ToBase64String(BitConverter.GetBytes(index)); 11:  12: var container = _client.GetContainerReference("test"); 13: container.CreateIfNotExists(); 14: var blob = container.GetBlockBlobReference(name); 15: blob.PutBlock(id, file.InputStream, null); 16: } 17: catch (Exception e) 18: { 19: error = e.ToString(); 20: } 21:  22: return new JsonResult() 23: { 24: Data = new 25: { 26: success = string.IsNullOrWhiteSpace(error), 27: error = error 28: } 29: }; 30: } Next, I created another action to commit the blocks into blob once all chunks had been uploaded. Similarly, I retrieved the blob name from the Request.Form. I also retrieved the chunks ID list, which is the block ID list from the Request.Form in a string format, split them as a list, then invoked the BlockBlob.PutBlockList method. After that our blob will be shown in the container and ready to be download. 1: [HttpPost] 2: public JsonResult Commit() 3: { 4: var error = string.Empty; 5: try 6: { 7: var name = Request.Form["name"]; 8: var list = Request.Form["list"]; 9: var ids = list 10: .Split(',') 11: .Where(id => !string.IsNullOrWhiteSpace(id)) 12: .Select(id => Convert.ToBase64String(BitConverter.GetBytes(int.Parse(id)))) 13: .ToArray(); 14:  15: var container = _client.GetContainerReference("test"); 16: container.CreateIfNotExists(); 17: var blob = container.GetBlockBlobReference(name); 18: blob.PutBlockList(ids); 19: } 20: catch (Exception e) 21: { 22: error = e.ToString(); 23: } 24:  25: return new JsonResult() 26: { 27: Data = new 28: { 29: success = string.IsNullOrWhiteSpace(error), 30: error = error 31: } 32: }; 33: } Now we finished all code we need. The whole process of uploading would be like this below. Below is the full client side JavaScript code. 1: <script type="text/javascript" src="~/Scripts/async.js"></script> 2: <script type="text/javascript"> 3: $(function () { 4: $("#upload_button_blob").click(function () { 5: // assert the browser support html5 6: if (window.File && window.Blob && window.FormData) { 7: alert("Your brwoser is awesome, let's rock!"); 8: } 9: else { 10: alert("Oh man plz update to a modern browser before try is cool stuff out."); 11: return; 12: } 13:  14: // start to upload each files in chunks 15: var files = $("#upload_files")[0].files; 16: for (var i = 0; i < files.length; i++) { 17: var file = files[i]; 18: var fileSize = file.size; 19: var fileName = file.name; 20:  21: // calculate the start and end byte index for each blocks(chunks) 22: // with the index, file name and index list for future using 23: var blockSizeInKB = $("#block_size").val(); 24: var blockSize = blockSizeInKB * 1024; 25: var blocks = []; 26: var offset = 0; 27: var index = 0; 28: var list = ""; 29: while (offset < fileSize) { 30: var start = offset; 31: var end = Math.min(offset + blockSize, fileSize); 32:  33: blocks.push({ 34: name: fileName, 35: index: index, 36: start: start, 37: end: end 38: }); 39: list += index + ","; 40:  41: offset = end; 42: index++; 43: } 44:  45: // define the function array and push all chunk upload operation into this array 46: var putBlocks = []; 47: blocks.forEach(function (block) { 48: putBlocks.push(function (callback) { 49: // load blob based on the start and end index for each chunks 50: var blob = file.slice(block.start, block.end); 51: // put the file name, index and blob into a temporary from 52: var fd = new FormData(); 53: fd.append("name", block.name); 54: fd.append("index", block.index); 55: fd.append("file", blob); 56: // post the form to backend service (asp.net mvc controller action) 57: $.ajax({ 58: url: "/Home/UploadInFormData", 59: data: fd, 60: processData: false, 61: contentType: "multipart/form-data", 62: type: "POST", 63: success: function (result) { 64: if (!result.success) { 65: alert(result.error); 66: } 67: callback(null, block.index); 68: } 69: }); 70: }); 71: }); 72:  73: // invoke the functions one by one 74: // then invoke the commit ajax call to put blocks into blob in azure storage 75: async.series(putBlocks, function (error, result) { 76: var data = { 77: name: fileName, 78: list: list 79: }; 80: $.post("/Home/Commit", data, function (result) { 81: if (!result.success) { 82: alert(result.error); 83: } 84: else { 85: alert("done!"); 86: } 87: }); 88: }); 89: } 90: }); 91: }); 92: </script> And below is the full ASP.NET MVC controller code. 1: public class HomeController : Controller 2: { 3: private CloudStorageAccount _account; 4: private CloudBlobClient _client; 5:  6: public HomeController() 7: : base() 8: { 9: _account = CloudStorageAccount.Parse(CloudConfigurationManager.GetSetting("DataConnectionString")); 10: _client = _account.CreateCloudBlobClient(); 11: } 12:  13: public ActionResult Index() 14: { 15: ViewBag.Message = "Modify this template to jump-start your ASP.NET MVC application."; 16:  17: return View(); 18: } 19:  20: [HttpPost] 21: public JsonResult UploadInFormData() 22: { 23: var error = string.Empty; 24: try 25: { 26: var name = Request.Form["name"]; 27: var index = int.Parse(Request.Form["index"]); 28: var file = Request.Files[0]; 29: var id = Convert.ToBase64String(BitConverter.GetBytes(index)); 30:  31: var container = _client.GetContainerReference("test"); 32: container.CreateIfNotExists(); 33: var blob = container.GetBlockBlobReference(name); 34: blob.PutBlock(id, file.InputStream, null); 35: } 36: catch (Exception e) 37: { 38: error = e.ToString(); 39: } 40:  41: return new JsonResult() 42: { 43: Data = new 44: { 45: success = string.IsNullOrWhiteSpace(error), 46: error = error 47: } 48: }; 49: } 50:  51: [HttpPost] 52: public JsonResult Commit() 53: { 54: var error = string.Empty; 55: try 56: { 57: var name = Request.Form["name"]; 58: var list = Request.Form["list"]; 59: var ids = list 60: .Split(',') 61: .Where(id => !string.IsNullOrWhiteSpace(id)) 62: .Select(id => Convert.ToBase64String(BitConverter.GetBytes(int.Parse(id)))) 63: .ToArray(); 64:  65: var container = _client.GetContainerReference("test"); 66: container.CreateIfNotExists(); 67: var blob = container.GetBlockBlobReference(name); 68: blob.PutBlockList(ids); 69: } 70: catch (Exception e) 71: { 72: error = e.ToString(); 73: } 74:  75: return new JsonResult() 76: { 77: Data = new 78: { 79: success = string.IsNullOrWhiteSpace(error), 80: error = error 81: } 82: }; 83: } 84: } And if we selected a file from the browser we will see our application will upload chunks in the size we specified to the server through ajax call in background, and then commit all chunks in one blob. Then we can find the blob in our Windows Azure Blob Storage.   Optimized by Parallel Upload In previous example we just uploaded our file in chunks. This solved the problem that ASP.NET MVC request content size limitation as well as the Windows Azure load balancer timeout. But it might introduce the performance problem since we uploaded chunks in sequence. In order to improve the upload performance we could modify our client side code a bit to make the upload operation invoked in parallel. The good news is that, “async.js” library provides the parallel execution function. If you remembered the code we invoke the service to upload chunks, it utilized “async.series” which means all functions will be executed in sequence. Now we will change this code to “async.parallel”. This will invoke all functions in parallel. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.parallel(putBlocks, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: }); In this way all chunks will be uploaded to the server side at the same time to maximize the bandwidth usage. This should work if the file was not very large and the chunk size was not very small. But for large file this might introduce another problem that too many ajax calls are sent to the server at the same time. So the best solution should be, upload the chunks in parallel with maximum concurrency limitation. The code below specified the concurrency limitation to 4, which means at the most only 4 ajax calls could be invoked at the same time. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.parallelLimit(putBlocks, 4, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: });   Summary In this post we discussed how to upload files in chunks to the backend service and then upload them into Windows Azure Blob Storage in blocks. We focused on the frontend side and leverage three new feature introduced in HTML 5 which are - File.slice: Read part of the file by specifying the start and end byte index. - Blob: File-like interface which contains the part of the file content. - FormData: Temporary form element that we can pass the chunk alone with some metadata to the backend service. Then we discussed the performance consideration of chunk uploading. Sequence upload cannot provide maximized upload speed, but the unlimited parallel upload might crash the browser and server if too many chunks. So we finally came up with the solution to upload chunks in parallel with the concurrency limitation. We also demonstrated how to utilize “async.js” JavaScript library to help us control the asynchronize call and the parallel limitation.   Regarding the chunk size and the parallel limitation value there is no “best” value. You need to test vary composition and find out the best one for your particular scenario. It depends on the local bandwidth, client machine cores and the server side (Windows Azure Cloud Service Virtual Machine) cores, memory and bandwidth. Below is one of my performance test result. The client machine was Windows 8 IE 10 with 4 cores. I was using Microsoft Cooperation Network. The web site was hosted on Windows Azure China North data center (in Beijing) with one small web role (1.7GB 1 core CPU, 1.75GB memory with 100Mbps bandwidth). The test cases were - Chunk size: 512KB, 1MB, 2MB, 4MB. - Upload Mode: Sequence, parallel (unlimited), parallel with limit (4 threads, 8 threads). - Chunk Format: base64 string, binaries. - Target file: 100MB. - Each case was tested 3 times. Below is the test result chart. Some thoughts, but not guidance or best practice: - Parallel gets better performance than series. - No significant performance improvement between parallel 4 threads and 8 threads. - Transform with binaries provides better performance than base64. - In all cases, chunk size in 1MB - 2MB gets better performance.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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  • blocking bad bots with robots.txt in 2012 [closed]

    - by Rachel Sparks
    does it still work good? I have this: # Generated using http://solidshellsecurity.com services # Begin block Bad-Robots from robots.txt User-agent: asterias Disallow:/ User-agent: BackDoorBot/1.0 Disallow:/ User-agent: Black Hole Disallow:/ User-agent: BlowFish/1.0 Disallow:/ User-agent: BotALot Disallow:/ User-agent: BuiltBotTough Disallow:/ User-agent: Bullseye/1.0 Disallow:/ User-agent: BunnySlippers Disallow:/ User-agent: Cegbfeieh Disallow:/ User-agent: CheeseBot Disallow:/ User-agent: CherryPicker Disallow:/ User-agent: CherryPickerElite/1.0 Disallow:/ User-agent: CherryPickerSE/1.0 Disallow:/ User-agent: CopyRightCheck Disallow:/ User-agent: cosmos Disallow:/ User-agent: Crescent Disallow:/ User-agent: Crescent Internet ToolPak HTTP OLE Control v.1.0 Disallow:/ User-agent: DittoSpyder Disallow:/ User-agent: EmailCollector Disallow:/ User-agent: EmailSiphon Disallow:/ User-agent: EmailWolf Disallow:/ User-agent: EroCrawler Disallow:/ User-agent: ExtractorPro Disallow:/ User-agent: Foobot Disallow:/ User-agent: Harvest/1.5 Disallow:/ User-agent: hloader Disallow:/ User-agent: httplib Disallow:/ User-agent: humanlinks Disallow:/ User-agent: InfoNaviRobot Disallow:/ User-agent: JennyBot Disallow:/ User-agent: Kenjin Spider Disallow:/ User-agent: Keyword Density/0.9 Disallow:/ User-agent: LexiBot Disallow:/ User-agent: libWeb/clsHTTP Disallow:/ User-agent: LinkextractorPro Disallow:/ User-agent: LinkScan/8.1a Unix Disallow:/ User-agent: LinkWalker Disallow:/ User-agent: LNSpiderguy Disallow:/ User-agent: lwp-trivial Disallow:/ User-agent: lwp-trivial/1.34 Disallow:/ User-agent: Mata Hari Disallow:/ User-agent: Microsoft URL Control - 5.01.4511 Disallow:/ User-agent: Microsoft URL Control - 6.00.8169 Disallow:/ User-agent: MIIxpc Disallow:/ User-agent: MIIxpc/4.2 Disallow:/ User-agent: Mister PiX Disallow:/ User-agent: moget Disallow:/ User-agent: moget/2.1 Disallow:/ User-agent: mozilla/4 Disallow:/ User-agent: Mozilla/4.0 (compatible; BullsEye; Windows 95) Disallow:/ User-agent: Mozilla/4.0 (compatible; MSIE 4.0; Windows 95) Disallow:/ User-agent: Mozilla/4.0 (compatible; MSIE 4.0; Windows 98) Disallow:/ User-agent: Mozilla/4.0 (compatible; MSIE 4.0; Windows NT) Disallow:/ User-agent: Mozilla/4.0 (compatible; MSIE 4.0; Windows XP) Disallow:/ User-agent: Mozilla/4.0 (compatible; MSIE 4.0; Windows 2000) Disallow:/ User-agent: Mozilla/4.0 (compatible; MSIE 4.0; Windows ME) Disallow:/ User-agent: mozilla/5 Disallow:/ User-agent: NetAnts Disallow:/ User-agent: NICErsPRO Disallow:/ User-agent: Offline Explorer Disallow:/ User-agent: Openfind Disallow:/ User-agent: Openfind data gathere Disallow:/ User-agent: ProPowerBot/2.14 Disallow:/ User-agent: ProWebWalker Disallow:/ User-agent: QueryN Metasearch Disallow:/ User-agent: RepoMonkey Disallow:/ User-agent: RepoMonkey Bait & Tackle/v1.01 Disallow:/ User-agent: RMA Disallow:/ User-agent: SiteSnagger Disallow:/ User-agent: SpankBot Disallow:/ User-agent: spanner Disallow:/ User-agent: suzuran Disallow:/ User-agent: Szukacz/1.4 Disallow:/ User-agent: Teleport Disallow:/ User-agent: TeleportPro Disallow:/ User-agent: Telesoft Disallow:/ User-agent: The Intraformant Disallow:/ User-agent: TheNomad Disallow:/ User-agent: TightTwatBot Disallow:/ User-agent: Titan Disallow:/ User-agent: toCrawl/UrlDispatcher Disallow:/ User-agent: True_Robot Disallow:/ User-agent: True_Robot/1.0 Disallow:/ User-agent: turingos Disallow:/ User-agent: URLy Warning Disallow:/ User-agent: VCI Disallow:/ User-agent: VCI WebViewer VCI WebViewer Win32 Disallow:/ User-agent: Web Image Collector Disallow:/ User-agent: WebAuto Disallow:/ User-agent: WebBandit Disallow:/ User-agent: WebBandit/3.50 Disallow:/ User-agent: WebCopier Disallow:/ User-agent: WebEnhancer Disallow:/ User-agent: WebmasterWorldForumBot Disallow:/ User-agent: WebSauger Disallow:/ User-agent: Website Quester Disallow:/ User-agent: Webster Pro Disallow:/ User-agent: WebStripper Disallow:/ User-agent: WebZip Disallow:/ User-agent: WebZip/4.0 Disallow:/ User-agent: Wget Disallow:/ User-agent: Wget/1.5.3 Disallow:/ User-agent: Wget/1.6 Disallow:/ User-agent: WWW-Collector-E Disallow:/ User-agent: Xenu's Disallow:/ User-agent: Xenu's Link Sleuth 1.1c Disallow:/ User-agent: Zeus Disallow:/ User-agent: Zeus 32297 Webster Pro V2.9 Win32 Disallow:/

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  • Algorithm for determining grid based on variably sized "blocks"?

    - by Lite Byte
    I'm trying to convert a set of "blocks" in to a grid-like layout. The blocks have a width of either 25%, 33%, 50%, 66%, or 75% of their container and each row of the grid should try to fit as many blocks as possible, up to a total width of 100%. I've discovered that trying to do this while leaving no remaining blocks in the original set is very hard. Eventually, I think my solution will be to upgrade/downgrade various block sizes (based on their priority or something) so they all fit in to a row. Either case, before I do that, I thought I'd check if someone has some code (or a paper) demonstrating a solution to this problem already? And bonus points if the solution incorporates varying block heights in to its calculations :) Thanks!

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  • A good machine learning technique to weed out good URLs from bad

    - by git-noob
    Hi, I have an application that needs to discriminate between good HTTP GET requests and bad. For example: http://somesite.com?passes=dodgy+parameter # BAD http://anothersite.com?passes=a+good+parameter # GOOD My system can make a binary decision about whether or not a URL is good or bad - but ideally I would like it to predict whether or not a previously unseen URL is good or bad. http://some-new-site.com?passes=a+really+dodgy+parameter # BAD I feel the need for a support vector machine (SVM) ... but I need to learn machine learning. Some questions: 1) Is an SVM appropriate for this task? 2) Can I train it with the raw URLs? - without explicitly specifying 'features' 3) How many URLs will I need for it to be good at predictions? 4) What kind of SVM kernel should I use? 5) After I train it, how do I keep it up to date? 6) How do I test unseen URLs again the SVM to decide whether it's good or bad? I

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  • Is it a bad practice to pass "this" as an argument?

    - by Anna Lear
    I'm currently tempted to write the following: public class Class1() { public Class1() { MyProperty = new Class2(this); } public Class2 MyProperty { get; private set; } } public class Class2() { public Class2(Class1 class1) { ParentClass1 = class1; } public Class1 ParentClass1 { get; set; } } Is passing "this" as an argument a sign of a design problem? What would be a better approach?

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  • Is instanceof considered bad practice? If so, under what circumstances is instanceof still preferabl

    - by aioobe
    Over the years, I've tried to avoid instanceof whenever possible. Using polymorphism or the visitor pattern where applicable. I suppose it simply eases maintenance in some situations... Are there any other drawbacks that one should be aware of? I do however see it here and there in the Java libraries so I suppose it has its place? Under what circumstances is it preferable? Is it ever unavoidable?

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  • Why do i get exc bad access in cases when object is not nil?

    - by DixieFlatline
    I have an app that receives remote notifications. My view controller that is shown after push has a tableview. App crashes very randomly (1 in 20 tries) at line setting frame: if (!myTableView) { NSLog(@"self.myTableView is nil"); } myTableView.frame=CGRectMake(0, 70, 320, 376); This only happens when i open the app, then open some other apps and then receive the push notification. I guess it has something to do with memory. I use ARC (ios 5). The strange thing is that nslog is not displayed, so tableview is not nil. Crash log: Exception Type: EXC_BAD_ACCESS (SIGSEGV) Exception Codes: KERN_INVALID_ADDRESS at 0x522d580c Crashed Thread: 0 Thread 0 name: Dispatch queue: com.apple.main-thread Thread 0 Crashed: 0 libobjc.A.dylib 0x352b1f7e objc_msgSend + 22 1 Foundation 0x37dc174c NSKVOPendingNotificationCreate + 216 2 Foundation 0x37dc1652 NSKeyValuePushPendingNotificationPerThread + 62 3 Foundation 0x37db3744 NSKeyValueWillChange + 408 4 Foundation 0x37d8a848 -[NSObject(NSKeyValueObserverNotification) willChangeValueForKey:] + 176 5 Foundation 0x37e0ca14 _NSSetPointValueAndNotify + 76 6 UIKit 0x312af25a -[UIScrollView(Static) _adjustContentOffsetIfNecessary] + 1890 7 UIKit 0x312cca54 -[UIScrollView setFrame:] + 548 8 UIKit 0x312cc802 -[UITableView setFrame:] + 182 9 POViO 0x000913cc -[FeedVC viewWillAppear:] (FeedVC.m:303) Dealloc is not called because it is not logged: - (void)dealloc { NSLog(@"dealloc"); }

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  • Measuring Programmers' Productivity. Bad, good or invasive?

    - by Fraga
    A client needs my company to develop an app that will be able to measure the programmer productivity, by getting information from VS, IE, SSMS, profiler and VMware. For example: Lines, Methods, Classes (Added, Deleted, Modified) How many time spent in certain file, class, method, specific task, etc. How many time in different stages of the development cycle (Design, Coding, Debugging, Compiling, Testing) Real lines of code. Etc They told me they want to implement PSP. Would you resign if a company wants to measure this way? OR Would you install this kind of software for self improvement?

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  • IIS 7.0 - responses throttled to 500ms blocks?

    - by Julia Hayward
    Scenario: ASP.NET MVC wep app sitting on my local machine (Vista Ultimate, IIS 7.0), nothing going on except one user (me) logged in and viewing an index page. The page includes 9 dynamic images drawn from the underlying DB and returned from a controller action. I have got the actual processing time for these images down to 15ms each. Turn on Firebug and watch the page load. What I see is 9 requests for images firing off together – no surprise – but four come back to me almost immediately; two more after 0.5s; another after 1s; then at 1.5s and 2s. Logging on the server side suggests the individual responses are still only taking 15ms. So it appears IIS is queueing things up into 500ms chunks. (Repeating the experiment produces different results, but each time the images return in similar blocks – you might get three in the first group, then three at 0.5s, two at 1s etc, for example – and it’s always at 500ms intervals, not anything else.) It’s also repeatable cross-browser, and it’s not repeatable with other forms of content. I haven't found any particular mention of this problem out there, so I'm sort of assuming it's not an IIS bug, so is it: i) IIS on desktop OSs deliberately does it, to make you use server OSs in production? ii) There is some magical setting that has eluded me for as long as I’ve known IIS? iii) Something peculiar to MVC or SQL Server 2008? or something else?

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  • Bad Spot to Be In: Playing Catch-up with Mobile Advertising

    - by Mike Stiles
    You probably noticed, there’s a mass migration going on from online desktop/laptop usage to smartphone/tablet usage.  It’s an indicator of how we live our lives in the modern world: always on the go, with no intention of being disconnected while out there. Consequently, paid as it relates to mobile advertising is taking the social spotlight. eMarketer estimated that in 2013, US adults would spend about 2 hours, 21 minutes a day on mobile, not counting talking time. More people in the world own smartphones than own toothbrushes (bad news I suppose if you’re marketing toothpaste). They’re using those mobile devices to access social networks, consuming at least 17% of their mobile time on them. Frankly, you don’t need a deep dive into mobile usage stats to know what’s going on. Just look around you in any store, venue or coffee shop. It’s really obvious…our mobile devices are now where we “are,” so that’s where marketers can increasingly reach us. And it’s a smart place for them to do just that. Mobile devices can be viewed more and more as shopping facilitators. Usually when someone is on mobile, they are not in passive research mode. They are likely standing near a store or in front of a product, using their mobile to seek reassurance that buying that product is the right move. They are the hottest of hot prospects. Consider that 4 out of 5 consumers use smartphones to shop, 52% of Americans use mobile devices for in-store for research, 70% of mobile searches lead to online action inside of an hour, and people that find you on mobile convert at almost 3x the rate as those that find you on desktop or laptop. But what are marketers doing? Enter statistics from Mary Meeker’s latest State of the Internet report. Common sense says you buy advertising where people are spending their eyeball time, right? But while mobile is 20% of media use and rising, the ad spend there is 4%. Conversely, while print usage is at 5% and falling, ad spend there is 19%. We all love nostalgia, but come on. There are reasons marketing dollar migration to mobile has not matched user migration, including the availability of mobile ad products and the ability to measure user response to mobile ads. But interesting things are happening now. First came Facebook’s mobile ad, which let app developers pay to get potential downloads. Then their mobile ad network was announced at F8, allowing marketers to target users across non-Facebook apps while leveraging the wealth of diverse data Facebook has on those users, a big deal since Nielsen has pointed out mobile apps make up 89% of the media time spent on mobile. Twitter has a similar play in motion with their MoPub acquisition. And now mobile deeplinks have arrived, which can take users straight to sub-pages of mobile apps for a faster, more direct shopper/researcher user experience. The sooner the gratification, the smoother and faster the conversion. To be clear, growth in mobile ad spending is well underway. After posting $13.1 billion in 2013, Gartner expects global mobile ad spending to reach $18 billion this year, then go to $41.9 billion by 2017. Cheap smartphones and data plans are spreading worldwide, further fueling the shift to mobile. Mobile usage in India alone should grow 400% by 2018. And, of course, there’s the famous statistic that mobile should overtake desktop Internet usage this year. How can we as marketers mess up this opportunity? Two ways. We could position ourselves in perpetual “catch-up” mode and keep spending ad dollars where the public used to be. And we could annoy mobile users with horrid old-school marketing practices. Two-thirds of users told Forrester they think interruptive in-app ads are more annoying than TV ads. Make sure your brand’s social marketing technology platform is delivering a crystal clear picture of your social connections so the mobile touch point is highly relevant, mobile optimized, and delivering real value and satisfying experiences. Otherwise, all we’ve done is find a new way to be unwanted. @mikestiles @oraclesocialPhoto: Kate Mallatratt, freeimages.com

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  • Firewall blocks FTP PASV response

    - by harper
    0 down vote favorite I have an FTP server that supports passive server mode (using PASV command). This works fine with Windows XP. When I want to access this server from Windows Vista or Windows 7 with firewall enabled I experience a immediate connection shutdown. A reset packet is sent to the server, the socket is signaled that the server had reset the connection (what is not true). The problem disappears when the firewall is disabled. Connections to other FTP servers work correctly. The difference is that the servers response to PASV does not enclose the address field with parentheses. This is legal as documented in RFC-959 and RFC-1132. How can I configure the firewall to stop this bad behavior?

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  • Firewall blocks FTP PASV response

    - by harper
    I have an FTP server that supports passive server mode (using PASV command). This works fine with Windows XP. When I want to access this server from Windows Vista or Windows 7 with firewall enabled I experience an immediate connection shutdown. A reset packet is sent to the server, and the socket is signaled that the server has reset the connection (which is not true). The problem disappears when the firewall is disabled. Connections to other FTP servers work correctly. The difference is that the server's response to PASV does not enclose the address field with parentheses. This is legal as documented in RFC-959 and RFC-1132. How can I configure the firewall to stop this bad behavior?

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  • Why enumerator structs are a really bad idea

    - by Simon Cooper
    If you've ever poked around the .NET class libraries in Reflector, I'm sure you would have noticed that the generic collection classes all have implementations of their IEnumerator as a struct rather than a class. As you will see, this design decision has some rather unfortunate side effects... As is generally known in the .NET world, mutable structs are a Very Bad Idea; and there are several other blogs around explaining this (Eric Lippert's blog post explains the problem quite well). In the BCL, the generic collection enumerators are all mutable structs, as they need to keep track of where they are in the collection. This bit me quite hard when I was coding a wrapper around a LinkedList<int>.Enumerator. It boils down to this code: sealed class EnumeratorWrapper : IEnumerator<int> { private readonly LinkedList<int>.Enumerator m_Enumerator; public EnumeratorWrapper(LinkedList<int> linkedList) { m_Enumerator = linkedList.GetEnumerator(); } public int Current { get { return m_Enumerator.Current; } } object System.Collections.IEnumerator.Current { get { return Current; } } public bool MoveNext() { return m_Enumerator.MoveNext(); } public void Reset() { ((System.Collections.IEnumerator)m_Enumerator).Reset(); } public void Dispose() { m_Enumerator.Dispose(); } } The key line here is the MoveNext method. When I initially coded this, I thought that the call to m_Enumerator.MoveNext() would alter the enumerator state in the m_Enumerator class variable and so the enumeration would proceed in an orderly fashion through the collection. However, when I ran this code it went into an infinite loop - the m_Enumerator.MoveNext() call wasn't actually changing the state in the m_Enumerator variable at all, and my code was looping forever on the first collection element. It was only after disassembling that method that I found out what was going on The MoveNext method above results in the following IL: .method public hidebysig newslot virtual final instance bool MoveNext() cil managed { .maxstack 1 .locals init ( [0] bool CS$1$0000, [1] valuetype [System]System.Collections.Generic.LinkedList`1/Enumerator CS$0$0001) L_0000: nop L_0001: ldarg.0 L_0002: ldfld valuetype [System]System.Collections.Generic.LinkedList`1/Enumerator EnumeratorWrapper::m_Enumerator L_0007: stloc.1 L_0008: ldloca.s CS$0$0001 L_000a: call instance bool [System]System.Collections.Generic.LinkedList`1/Enumerator::MoveNext() L_000f: stloc.0 L_0010: br.s L_0012 L_0012: ldloc.0 L_0013: ret } Here, the important line is 0002 - m_Enumerator is accessed using the ldfld operator, which does the following: Finds the value of a field in the object whose reference is currently on the evaluation stack. So, what the MoveNext method is doing is the following: public bool MoveNext() { LinkedList<int>.Enumerator CS$0$0001 = this.m_Enumerator; bool CS$1$0000 = CS$0$0001.MoveNext(); return CS$1$0000; } The enumerator instance being modified by the call to MoveNext is the one stored in the CS$0$0001 variable on the stack, and not the one in the EnumeratorWrapper class instance. Hence why the state of m_Enumerator wasn't getting updated. Hmm, ok. Well, why is it doing this? If you have a read of Eric Lippert's blog post about this issue, you'll notice he quotes a few sections of the C# spec. In particular, 7.5.4: ...if the field is readonly and the reference occurs outside an instance constructor of the class in which the field is declared, then the result is a value, namely the value of the field I in the object referenced by E. And my m_Enumerator field is readonly! Indeed, if I remove the readonly from the class variable then the problem goes away, and the code works as expected. The IL confirms this: .method public hidebysig newslot virtual final instance bool MoveNext() cil managed { .maxstack 1 .locals init ( [0] bool CS$1$0000) L_0000: nop L_0001: ldarg.0 L_0002: ldflda valuetype [System]System.Collections.Generic.LinkedList`1/Enumerator EnumeratorWrapper::m_Enumerator L_0007: call instance bool [System]System.Collections.Generic.LinkedList`1/Enumerator::MoveNext() L_000c: stloc.0 L_000d: br.s L_000f L_000f: ldloc.0 L_0010: ret } Notice on line 0002, instead of the ldfld we had before, we've got a ldflda, which does this: Finds the address of a field in the object whose reference is currently on the evaluation stack. Instead of loading the value, we're loading the address of the m_Enumerator field. So now the call to MoveNext modifies the enumerator stored in the class rather than on the stack, and everything works as expected. Previously, I had thought enumerator structs were an odd but interesting feature of the BCL that I had used in the past to do linked list slices. However, effects like this only underline how dangerous mutable structs are, and I'm at a loss to explain why the enumerators were implemented as structs in the first place. (interestingly, the SortedList<TKey, TValue> enumerator is a struct but is private, which makes it even more odd - the only way it can be accessed is as a boxed IEnumerator!). I would love to hear people's theories as to why the enumerators are implemented in such a fashion. And bonus points if you can explain why LinkedList<int>.Enumerator.Reset is an explicit implementation but Dispose is implicit... Note to self: never ever ever code a mutable struct.

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  • GNU/Linux swapping blocks system

    - by Ole Tange
    I have used GNU/Linux on systems from 4 MB RAM to 512 GB RAM. When they start swapping, most of the time you can still log in and kill off the offending process - you just have to be 100-1000 times more patient. On my new 32 GB system that has changed: It blocks when it starts swapping. Sometimes with full disk activity but other times with no disk activity. To examine what might be the issue I have written this program. The idea is: 1 grab 3% of the memory free right now 2 if that caused swap to increase: stop 3 keep the chunk used for 30 seconds by forking off 4 goto 1 - #!/usr/bin/perl sub freekb { my $free = `free|grep buffers/cache`; my @a=split / +/,$free; return $a[3]; } sub swapkb { my $swap = `free|grep Swap:`; my @a=split / +/,$swap; return $a[2]; } my $swap = swapkb(); my $lastswap = $swap; my $free; while($lastswap >= $swap) { print "$swap $free"; $lastswap = $swap; $swap = swapkb(); $free = freekb(); my $used_mem = "x"x(1024 * $free * 0.03); if(not fork()) { sleep 30; exit(); } } print "Swap increased $swap $lastswap\n"; Running the program forever ought to keep the system at the limit of swapping, but only grabbing a minimal amount of swap and do that very slowly (i.e. a few MB at a time at most). If I run: forever free | stdbuf -o0 timestamp > freelog I ought to see swap slowly rising every second. (forever and timestamp from https://github.com/ole-tange/tangetools). But that is not the behaviour I see: I see swap increasing in jumps and that the system is completely blocked during these jumps. Here the system is blocked for 30 seconds with the swap usage increases with 1 GB: secs 169.527 Swap: 18440184 154184 18286000 170.531 Swap: 18440184 154184 18286000 200.630 Swap: 18440184 1134240 17305944 210.259 Swap: 18440184 1076228 17363956 Blocked: 21 secs. Swap increase 2400 MB: 307.773 Swap: 18440184 581324 17858860 308.799 Swap: 18440184 597676 17842508 330.103 Swap: 18440184 2503020 15937164 331.106 Swap: 18440184 2502936 15937248 Blocked: 20 secs. Swap increase 2200 MB: 751.283 Swap: 18440184 885288 17554896 752.286 Swap: 18440184 911676 17528508 772.331 Swap: 18440184 3193532 15246652 773.333 Swap: 18440184 1404540 17035644 Blocked: 37 secs. Swap increase 2400 MB: 904.068 Swap: 18440184 613108 17827076 905.072 Swap: 18440184 610368 17829816 942.424 Swap: 18440184 3014668 15425516 942.610 Swap: 18440184 2073580 16366604 This is bad enough, but what is even worse is that the system sometimes stops responding at all - even if I wait for hours. I have the feeling it is related to the swapping issue, but I cannot tell for sure. My first idea was to tweak /proc/sys/vm/swappiness from 60 to 0 or 100, just to see if that had any effect at all. 0 did not have an effect, but 100 did cause the problem to arise less often. How can I prevent the system from blocking for such a long time? Why does it decide to swapout 1-3 GB when less than 10 MB would suffice?

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  • chkdsk, SeaTools, and "does not have enough space to replace bad clusters"

    - by Zian Choy
    When I tried to do a Windows Vista Complete PC Backup, I received an error message that blathered about bad sectors. Then, when I ran chkdsk /r on the destination drive, this is what I got: C:\Windows\system32>chkdsk /R E: The type of the file system is NTFS. Volume label is Desktop Backup. CHKDSK is verifying files (stage 1 of 5)... 822016 file records processed. File verification completed. 1 large file records processed. 0 bad file records processed. 0 EA records processed. 0 reparse records processed. CHKDSK is verifying indexes (stage 2 of 5)... 848938 index entries processed. Index verification completed. 0 unindexed files processed. CHKDSK is verifying security descriptors (stage 3 of 5)... 822016 security descriptors processed. Security descriptor verification completed. 13461 data files processed. CHKDSK is verifying file data (stage 4 of 5)... The disk does not have enough space to replace bad clusters detected in file 239649 of name . The disk does not have enough space to replace bad clusters detected in file 239650 of name . The disk does not have enough space to replace bad clusters detected in file 239651 of name . An unspecified error occurred.f 822000 files processed) Yet, when I ran the SeaTools short & long generic tests on the Seagate disk, I didn't receive any errors. I know that I could reformat the disk and try running chkdsk /r again but I'd prefer to avoid waiting 4 hours in the hope that the problem was magically fixed. On the other hand, if I RmA the drive to Seagate, I have no SeaTools error number to use and they may claim that the drive is just fine. What should I try to do next? Side frustration: There is plenty of free hard drive space. The E: partition has 182 GB free.

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  • Creating static NAT blocks outbound traffic Cisco ASA

    - by natediggs
    Hi Everyone, I have two web servers sitting behind a Cisco ASA 5505, which I don't have much experience with. I'm trying to create two static NATs. One static NAT that goes to xx.xx.xx.150 and another that goes to xx.xx.xx.151. I've created the static NAT for the .150 web server and it works FINE. Incoming and outgoing traffic work great. This is the staging web server. I now need to duplicate the setup for the production web server. So, I connect the webserver to the firewall, change the public IP address on one of the NICs reboot the server and I have outbound internet access. Then I run the command: static (inside,outside) xx.xx.xx.150 192.168.1.x which is successful. I then run the command: access-list acl-outside permit tcp any host xx.xx.xx.150 eq 80 Which is successful. I then try to browse the internet and I get nothing. I try to telnet in through port 80 and I get nothing (though I'm guessing because the response to the telnet request is being blocked). I've tried this with the production web server and then I tried it with another web server that is for internal testing and have the exact same problem. Both work fine until I run the static NAT rule and then no outbound internet access. I have a feeling that it's something simple that I'm missing, but my limited experience with this device is killing me. Below I've pasted the current configuration. I'm currently trying to get this to work on the .153 server which is the internal testing server. Once I can verify that works, I'll try it with production. : Saved : ASA Version 8.2(4) ! hostname QG domain-name XX.com enable password passwd names ! interface Ethernet0/0 switchport access vlan 2 ! interface Ethernet0/1 ! interface Ethernet0/2 ! interface Ethernet0/3 ! interface Ethernet0/4 ! interface Ethernet0/5 ! interface Ethernet0/6 ! interface Ethernet0/7 ! interface Vlan1 nameif inside security-level 100 ip address 192.168.1.1 255.255.255.0 ! interface Vlan2 nameif outside security-level 0 ip address XX.XX.XX.148 255.255.255.0 ! interface Vlan3 shutdown no forward interface Vlan1 nameif dmz security-level 50 ip address dhcp ! boot system disk0:/asa824.bin ftp mode passive clock timezone EST -5 clock summer-time EDT recurring dns server-group DefaultDNS domain-name fw.XXgroup.com same-security-traffic permit inter-interface access-list acl-outside extended permit tcp any host XX.XX.XX.150 eq www access-list acl-outside extended permit tcp any host XX.XX.XX.150 eq https access-list acl-outside extended permit tcp any host XX.XX.XX.151 eq www access-list acl-outside extended permit tcp any host XX.XX.XX.151 eq https access-list acl-outside extended permit tcp any host XX.XX.XX.153 eq www access-list inside_access_in extended permit ip 192.168.1.0 255.255.255.0 any access-list inside_nat0_outbound extended permit ip any 192.168.1.32 255.255.255.240 pager lines 24 logging enable logging asdm informational mtu inside 1500 mtu outside 1500 mtu dmz 1500 ip local pool VPNIPs 192.168.1.35-192.168.1.44 mask 255.255.255.0 icmp unreachable rate-limit 1 burst-size 1 asdm image disk0:/asdm-635.bin no asdm history enable arp timeout 14400 global (outside) 1 interface nat (inside) 0 access-list inside_nat0_outbound nat (inside) 1 0.0.0.0 0.0.0.0 static (inside,outside) XX.XX.XX150 192.168.1.100 netmask 255.255.255.255 static (inside,outside) XX.XX.XX153 192.168.1.102 netmask 255.255.255.255 access-group acl-outside in interface outside route outside 0.0.0.0 0.0.0.0 XX.XX.XX129 1 timeout xlate 3:00:00 timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02 timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00 timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00 timeout sip-provisional-media 0:02:00 uauth 0:05:00 absolute timeout tcp-proxy-reassembly 0:01:00 dynamic-access-policy-record DfltAccessPolicy aaa authorization command LOCAL http server enable http 192.168.1.0 255.255.255.0 inside http 0.0.0.0 0.0.0.0 outside no snmp-server location no snmp-server contact snmp-server enable traps snmp authentication linkup linkdown coldstart crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac crypto ipsec security-association lifetime seconds 28800 crypto ipsec security-association lifetime kilobytes 4608000 crypto dynamic-map outside_dyn_map 20 set pfs group1 crypto dynamic-map outside_dyn_map 20 set transform-set ESP-3DES-SHA crypto map outside_map 65535 ipsec-isakmp dynamic outside_dyn_map crypto map outside_map interface outside crypto isakmp enable outside crypto isakmp policy 10 authentication crack encryption 3des hash sha group 2 lifetime 86400 no crypto isakmp nat-traversal client-update enable telnet timeout 5 ssh timeout 5 console timeout 0 dhcpd auto_config outside ! dhcpd address 192.168.1.2-192.168.1.33 inside dhcpd dns 208.77.88.4 interface inside dhcpd enable inside ! threat-detection basic-threat threat-detection statistics access-list no threat-detection statistics tcp-intercept webvpn enable outside svc image disk0:/sslclient-win-1.1.0.154.pkg 1 svc image disk0:/anyconnect-win-2.5.2019-k9.pkg 2 svc enable group-policy ATSAdmin internal group-policy ATSAdmin attributes dns-server value 208.77.88.4 208.85.174.9 vpn-tunnel-protocol IPSec svc webvpn webvpn url-list none svc keep-installer installed svc rekey method ssl svc ask enable username qgadmin password /oHfeGQ/R.bd3KPR encrypted privilege 15 username benl password 0HNIGQNI0uruJvhW encrypted privilege 0 username benl attributes vpn-group-policy ATSAdmin username kuzma password rH7MM7laoynyvf9U encrypted privilege 0 username kuzma attributes vpn-group-policy ATSAdmin username nate password BXHOURyT37e4O5mt encrypted privilege 0 username nate attributes vpn-group-policy ATSAdmin tunnel-group ATSAdmin type remote-access tunnel-group ATSAdmin general-attributes address-pool VPNIPs default-group-policy ATSAdmin tunnel-group SSLVPN type remote-access tunnel-group SSLVPN general-attributes address-pool VPNIPs default-group-policy ATSAdmin ! class-map inspection_default match default-inspection-traffic ! ! policy-map type inspect dns preset_dns_map parameters message-length maximum 512 policy-map global_policy class inspection_default inspect dns preset_dns_map inspect ftp inspect h323 h225 inspect h323 ras inspect rsh inspect rtsp inspect esmtp inspect sqlnet inspect skinny inspect sunrpc inspect xdmcp inspect sip inspect netbios inspect tftp inspect ip-options ! service-policy global_policy global privilege cmd level 3 mode exec command perfmon privilege cmd level 3 mode exec command ping privilege cmd level 3 mode exec command who privilege cmd level 3 mode exec command logging privilege cmd level 3 mode exec command failover privilege show level 5 mode exec command running-config privilege show level 3 mode exec command reload privilege show level 3 mode exec command mode privilege show level 3 mode exec command firewall privilege show level 3 mode exec command interface privilege show level 3 mode exec command clock privilege show level 3 mode exec command dns-hosts privilege show level 3 mode exec command access-list privilege show level 3 mode exec command logging privilege show level 3 mode exec command ip privilege show level 3 mode exec command failover privilege show level 3 mode exec command asdm privilege show level 3 mode exec command arp privilege show level 3 mode exec command route privilege show level 3 mode exec command ospf privilege show level 3 mode exec command aaa-server privilege show level 3 mode exec command aaa privilege show level 3 mode exec command crypto privilege show level 3 mode exec command vpn-sessiondb privilege show level 3 mode exec command ssh privilege show level 3 mode exec command dhcpd privilege show level 3 mode exec command vpn privilege show level 3 mode exec command blocks privilege show level 3 mode exec command uauth privilege show level 3 mode configure command interface privilege show level 3 mode configure command clock privilege show level 3 mode configure command access-list privilege show level 3 mode configure command logging privilege show level 3 mode configure command ip privilege show level 3 mode configure command failover privilege show level 5 mode configure command asdm privilege show level 3 mode configure command arp privilege show level 3 mode configure command route privilege show level 3 mode configure command aaa-server privilege show level 3 mode configure command aaa privilege show level 3 mode configure command crypto privilege show level 3 mode configure command ssh privilege show level 3 mode configure command dhcpd privilege show level 5 mode configure command privilege privilege clear level 3 mode exec command dns-hosts privilege clear level 3 mode exec command logging privilege clear level 3 mode exec command arp privilege clear level 3 mode exec command aaa-server privilege clear level 3 mode exec command crypto privilege cmd level 3 mode configure command failover privilege clear level 3 mode configure command logging privilege clear level 3 mode configure command arp privilege clear level 3 mode configure command crypto privilege clear level 3 mode configure command aaa-server prompt hostname context call-home profile CiscoTAC-1 no active destination address http https://tools.cisco.com/its/service/oddce/services/DDCEService destination address email [email protected] destination transport-method http subscribe-to-alert-group diagnostic subscribe-to-alert-group environment subscribe-to-alert-group inventory periodic monthly subscribe-to-alert-group configuration periodic monthly subscribe-to-alert-group telemetry periodic daily Cryptochecksum:0ed0580e151af288d865f4f3603d792a : end asdm image disk0:/asdm-635.bin no asdm history enable

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  • Crash and Centos

    - by Jackob
    Hello guys and girls, I've a big problem it's the second time that my server crashed. I tried to check every thing and seems correct except this /var/log/messages: May 25 20:16:11 srv1 kernel: swap_free: Bad swap offset entry 00300000 May 25 20:16:33 srv1 kernel: swap_free: Unused swap offset entry 00080000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00340000 May 25 20:16:33 srv1 kernel: swap_free: Unused swap offset entry 000c0000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00a00000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00200000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00890000 May 25 20:16:33 srv1 kernel: swap_free: Unused swap offset entry 00080000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00f00000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00f90000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00980000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00980000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00820000 May 25 20:16:33 srv1 kernel: swap_free: Unused swap offset entry 000d0000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00a60000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00a20000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 009a0000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00170000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00f20000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00b60000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00a30000 May 25 20:16:33 srv1 kernel: swap_free: Bad swap offset entry 00320000 May 25 20:16:47 srv1 kernel: swap_free: Bad swap offset entry 002c0000 May 25 20:16:47 srv1 kernel: Eeek! page_mapcount(page) went negative! (-1) What can be my problem? Thanks so much!

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  • c declaring variables in blocks

    - by anon
    I know that in C++, I can declare variables pretty much everywhere. I recall once reading that in C, variables must be declared at the top of a function i.e. the following is invalid: void foo() { int good; if (...) { int bad; } } In the above code, is the declaraing of the bad varaible legal by C standards, or only legal due to a gcc extension? Thanks!

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  • c declaraing varibles in blocks

    - by anon
    I know that in C++, I can declare variables pretty much everywhere. I recall once reading that in C, variables must be declared at the top of a function i.e. the following is invalid: void foo() { int good; if (...) { int bad; } } In the above code, is the declaraing of the bad varaible legal by C standards, or only legal due to a gcc extension? Thanks!

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  • Ways to call Blocks within Magento: createBlock vs Layout xml file

    - by N. B.
    Context: I'm trying to include Adminhtml blocks in the frontend of the site to replace some of the user account blocks. The first thing I'm trying to do is simply display the block on the correct page. I can replace the entire page by setting the Body of the response inside the controller, but I'm having a hard time including the block in the layout xml file and then calling it within the template. Why would I be able to create an adminhtml/sales_order_grid from Mage_Sales_OrderController using createBlock: $this->getResponse()->setBody($this->getLayout()->createBlock('adminhtml/sales_order_grid')->toHtml()); But not from a frontend layout, using a declaration <block type="adminhtml/sales_order_grid" name="orders_widget"/> within app/design/frontend/default/default/layout/sales.xml The latter produces an error without a stack trace: Fatal error: Call to a member function toHtml() on a non-object in app/code/core/Mage/Core/Model/Layout.php on line 526 Thanks for any guidance!

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  • Is using the break statement bad practice?

    - by Lchi
    I've been told by professors and peers at my university that using the break statement is bad practice, but through my coursework haven't come up with a great reason why. Those who claim that it is bad say that it's a "get out of jail free card" and that you can always avoid using it. My guesses for why its considered bad would be that you could possibly skip some cleanup code after the break, or similarly exit some control structure in an inconsistent state. Is there any reason why using break is(n't) bad practice?

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  • Keeping track of dirty blocks on a block device

    - by mikeY
    I'm looking for a way to keep track of what blocks on a block device are modified after a point in time. How I eventually want to use this for is to keep two 2TB disks in sync, one which only comes online (connected through USB) once a month. Without knowing what blocks have been modified, I have to go through the whole 2TB every time. I'm using a recent GNU/Linux OS and have C and Python experience. I'm hoping to avoid writing kernel level code as I don't have any experience in that area whatsoever. My current theory is that there should be some hooks somewhere where my code can get called when a disk flush is performed. Any ideas?

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  • Defend Your Servers from the Bad Guys in ‘Install D’

    - by Akemi Iwaya
    If you love playing tower defense games, then you will definitely want to give today’s offering a try. In ‘Install D’, you must defend your servers from all manner of problems such as glitches, bugs, and viruses that are ready to bring your systems to their knees! Can you succeed, or will the IT department be hanging out the ‘Help Wanted’ sign?Click Here to Continue Reading

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