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  • Strange Recurrent Excessive I/O Wait

    - by Chris
    I know quite well that I/O wait has been discussed multiple times on this site, but all the other topics seem to cover constant I/O latency, while the I/O problem we need to solve on our server occurs at irregular (short) intervals, but is ever-present with massive spikes of up to 20k ms a-wait and service times of 2 seconds. The disk affected is /dev/sdb (Seagate Barracuda, for details see below). A typical iostat -x output would at times look like this, which is an extreme sample but by no means rare: iostat (Oct 6, 2013) tps rd_sec/s wr_sec/s avgrq-sz avgqu-sz await svctm %util 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16.00 0.00 156.00 9.75 21.89 288.12 36.00 57.60 5.50 0.00 44.00 8.00 48.79 2194.18 181.82 100.00 2.00 0.00 16.00 8.00 46.49 3397.00 500.00 100.00 4.50 0.00 40.00 8.89 43.73 5581.78 222.22 100.00 14.50 0.00 148.00 10.21 13.76 5909.24 68.97 100.00 1.50 0.00 12.00 8.00 8.57 7150.67 666.67 100.00 0.50 0.00 4.00 8.00 6.31 10168.00 2000.00 100.00 2.00 0.00 16.00 8.00 5.27 11001.00 500.00 100.00 0.50 0.00 4.00 8.00 2.96 17080.00 2000.00 100.00 34.00 0.00 1324.00 9.88 1.32 137.84 4.45 59.60 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 22.00 44.00 204.00 11.27 0.01 0.27 0.27 0.60 Let me provide you with some more information regarding the hardware. It's a Dell 1950 III box with Debian as OS where uname -a reports the following: Linux xx 2.6.32-5-amd64 #1 SMP Fri Feb 15 15:39:52 UTC 2013 x86_64 GNU/Linux The machine is a dedicated server that hosts an online game without any databases or I/O heavy applications running. The core application consumes about 0.8 of the 8 GBytes RAM, and the average CPU load is relatively low. The game itself, however, reacts rather sensitive towards I/O latency and thus our players experience massive ingame lag, which we would like to address as soon as possible. iostat: avg-cpu: %user %nice %system %iowait %steal %idle 1.77 0.01 1.05 1.59 0.00 95.58 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn sdb 13.16 25.42 135.12 504701011 2682640656 sda 1.52 0.74 20.63 14644533 409684488 Uptime is: 19:26:26 up 229 days, 17:26, 4 users, load average: 0.36, 0.37, 0.32 Harddisk controller: 01:00.0 RAID bus controller: LSI Logic / Symbios Logic MegaRAID SAS 1078 (rev 04) Harddisks: Array 1, RAID-1, 2x Seagate Cheetah 15K.5 73 GB SAS Array 2, RAID-1, 2x Seagate ST3500620SS Barracuda ES.2 500GB 16MB 7200RPM SAS Partition information from df: Filesystem 1K-blocks Used Available Use% Mounted on /dev/sdb1 480191156 30715200 425083668 7% /home /dev/sda2 7692908 437436 6864692 6% / /dev/sda5 15377820 1398916 13197748 10% /usr /dev/sda6 39159724 19158340 18012140 52% /var Some more data samples generated with iostat -dx sdb 1 (Oct 11, 2013) Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util sdb 0.00 15.00 0.00 70.00 0.00 656.00 9.37 4.50 1.83 4.80 33.60 sdb 0.00 0.00 0.00 2.00 0.00 16.00 8.00 12.00 836.00 500.00 100.00 sdb 0.00 0.00 0.00 3.00 0.00 32.00 10.67 9.96 1990.67 333.33 100.00 sdb 0.00 0.00 0.00 4.00 0.00 40.00 10.00 6.96 3075.00 250.00 100.00 sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.00 0.00 0.00 100.00 sdb 0.00 0.00 0.00 2.00 0.00 16.00 8.00 2.62 4648.00 500.00 100.00 sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2.00 0.00 0.00 100.00 sdb 0.00 0.00 0.00 1.00 0.00 16.00 16.00 1.69 7024.00 1000.00 100.00 sdb 0.00 74.00 0.00 124.00 0.00 1584.00 12.77 1.09 67.94 6.94 86.00 Characteristic charts generated with rrdtool can be found here: iostat plot 1, 24 min interval: http://imageshack.us/photo/my-images/600/yqm3.png/ iostat plot 2, 120 min interval: http://imageshack.us/photo/my-images/407/griw.png/ As we have a rather large cache of 5.5 GBytes, we thought it might be a good idea to test if the I/O wait spikes would perhaps be caused by cache miss events. Therefore, we did a sync and then this to flush the cache and buffers: echo 3 > /proc/sys/vm/drop_caches and directly afterwards the I/O wait and service times virtually went through the roof, and everything on the machine felt like slow motion. During the next few hours the latency recovered and everything was as before - small to medium lags in short, unpredictable intervals. Now my question is: does anybody have any idea what might cause this annoying behaviour? Is it the first indication of the disk array or the raid controller dying, or something that can be easily mended by rebooting? (At the moment we're very reluctant to do this, however, because we're afraid that the disks might not come back up again.) Any help is greatly appreciated. Thanks in advance, Chris. Edited to add: we do see one or two processes go to 'D' state in top, one of which seems to be kjournald rather frequently. If I'm not mistaken, however, this does not indicate the processes causing the latency, but rather those affected by it - correct me if I'm wrong. Does the information about uninterruptibly sleeping processes help us in any way to address the problem? @Andy Shinn requested smartctl data, here it is: smartctl -a -d megaraid,2 /dev/sdb yields: smartctl 5.40 2010-07-12 r3124 [x86_64-unknown-linux-gnu] (local build) Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net Device: SEAGATE ST3500620SS Version: MS05 Serial number: Device type: disk Transport protocol: SAS Local Time is: Mon Oct 14 20:37:13 2013 CEST Device supports SMART and is Enabled Temperature Warning Disabled or Not Supported SMART Health Status: OK Current Drive Temperature: 20 C Drive Trip Temperature: 68 C Elements in grown defect list: 0 Vendor (Seagate) cache information Blocks sent to initiator = 1236631092 Blocks received from initiator = 1097862364 Blocks read from cache and sent to initiator = 1383620256 Number of read and write commands whose size <= segment size = 531295338 Number of read and write commands whose size > segment size = 51986460 Vendor (Seagate/Hitachi) factory information number of hours powered up = 36556.93 number of minutes until next internal SMART test = 32 Error counter log: Errors Corrected by Total Correction Gigabytes Total ECC rereads/ errors algorithm processed uncorrected fast | delayed rewrites corrected invocations [10^9 bytes] errors read: 509271032 47 0 509271079 509271079 20981.423 0 write: 0 0 0 0 0 5022.039 0 verify: 1870931090 196 0 1870931286 1870931286 100558.708 0 Non-medium error count: 0 SMART Self-test log Num Test Status segment LifeTime LBA_first_err [SK ASC ASQ] Description number (hours) # 1 Background short Completed 16 36538 - [- - -] # 2 Background short Completed 16 36514 - [- - -] # 3 Background short Completed 16 36490 - [- - -] # 4 Background short Completed 16 36466 - [- - -] # 5 Background short Completed 16 36442 - [- - -] # 6 Background long Completed 16 36420 - [- - -] # 7 Background short Completed 16 36394 - [- - -] # 8 Background short Completed 16 36370 - [- - -] # 9 Background long Completed 16 36364 - [- - -] #10 Background short Completed 16 36361 - [- - -] #11 Background long Completed 16 2 - [- - -] #12 Background short Completed 16 0 - [- - -] Long (extended) Self Test duration: 6798 seconds [113.3 minutes] smartctl -a -d megaraid,3 /dev/sdb yields: smartctl 5.40 2010-07-12 r3124 [x86_64-unknown-linux-gnu] (local build) Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net Device: SEAGATE ST3500620SS Version: MS05 Serial number: Device type: disk Transport protocol: SAS Local Time is: Mon Oct 14 20:37:26 2013 CEST Device supports SMART and is Enabled Temperature Warning Disabled or Not Supported SMART Health Status: OK Current Drive Temperature: 19 C Drive Trip Temperature: 68 C Elements in grown defect list: 0 Vendor (Seagate) cache information Blocks sent to initiator = 288745640 Blocks received from initiator = 1097848399 Blocks read from cache and sent to initiator = 1304149705 Number of read and write commands whose size <= segment size = 527414694 Number of read and write commands whose size > segment size = 51986460 Vendor (Seagate/Hitachi) factory information number of hours powered up = 36596.83 number of minutes until next internal SMART test = 28 Error counter log: Errors Corrected by Total Correction Gigabytes Total ECC rereads/ errors algorithm processed uncorrected fast | delayed rewrites corrected invocations [10^9 bytes] errors read: 610862490 44 0 610862534 610862534 20470.133 0 write: 0 0 0 0 0 5022.480 0 verify: 2861227413 203 0 2861227616 2861227616 100872.443 0 Non-medium error count: 1 SMART Self-test log Num Test Status segment LifeTime LBA_first_err [SK ASC ASQ] Description number (hours) # 1 Background short Completed 16 36580 - [- - -] # 2 Background short Completed 16 36556 - [- - -] # 3 Background short Completed 16 36532 - [- - -] # 4 Background short Completed 16 36508 - [- - -] # 5 Background short Completed 16 36484 - [- - -] # 6 Background long Completed 16 36462 - [- - -] # 7 Background short Completed 16 36436 - [- - -] # 8 Background short Completed 16 36412 - [- - -] # 9 Background long Completed 16 36404 - [- - -] #10 Background short Completed 16 36401 - [- - -] #11 Background long Completed 16 2 - [- - -] #12 Background short Completed 16 0 - [- - -] Long (extended) Self Test duration: 6798 seconds [113.3 minutes]

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  • Reading UTF-8 XML and writing it to a file with Python

    - by Harri
    I'm trying to parse UTF-8 XML file and save some parts of it to another file. Problem is, that this is my first Python script ever and I'm totally confused about the character encoding problems I'm finding. My script fails immediately when it tries to write non-ascii character to a file, but it can print it to command prompt (at least in some level) Here's the XML (from the parts that matter at least, it's a *.resx file which contains UI strings) <?xml version="1.0" encoding="utf-8"?> <root> <resheader name="foo"> <value>bar</value> </resheader> <data name="lorem" xml:space="preserve"> <value>ipsum öä</value> </data> </root> And here's my python script from xml.dom.minidom import parse names = [] values = [] def getStrings(path): dom = parse(path) data = dom.getElementsByTagName("data") for i in range(len(data)): name = data[i].getAttribute("name") names.append(name) value = data[i].getElementsByTagName("value") values.append(value[0].firstChild.nodeValue.encode("utf-8")) def writeToFile(): with open("uiStrings-fi.py", "w") as f: for i in range(len(names)): line = names[i] + '="'+ values[i] + '"' #varName='varValue' f.write(line) f.write("\n") getStrings("ResourceFile.fi-FI.resx") writeToFile() And here's the traceback: Traceback (most recent call last): File "GenerateLanguageFiles.py", line 24, in writeToFile() File "GenerateLanguageFiles.py", line 19, in writeToFile line = names[i] + '="'+ values[i] + '"' #varName='varValue' UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 2: ordinal not in ran ge(128) How should I fix my script so it would read and write UTF-8 characters properly? The files I'm trying to generate would be used in test automation with Robots Framework.

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  • Windows Server 2003 Hacked - Files Being Uploaded

    - by jreedinc
    Blank directories are being created on my Windows Server 2003 virtual server with sub directories that are weird (for example: "88ÿ ÿ ÿÿþþ þþ13þ"). It looks like they are uploading bootlegged DVDs and pirated software. All of my bandwidth and file space is being eaten up. Could this be a shared permissions issue? Where should I look to further investigate this? My security permissions for the directory that is being hit are as followed: Administrators - ALL GRANTED IIS_WPG - Read & Execute, List Folder Contents, Read Internet Guest - DENY SYSTEM - ALL GRANTED Users - Read & Execute, List Folder Contents, Read My Event Viewer is showing many Logon/Logoff with NO IP?

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  • May the FileInputStream.available foolish me?

    - by Tom Brito
    This FileInputStream.available() javadoc says: Returns an estimate of the number of remaining bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. The next invocation might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes. In some cases, a non-blocking read (or skip) may appear to be blocked when it is merely slow, for example when reading large files over slow networks. I'm not sure if in this check: if (new FileInputStream(xmlFile).available() == 0) can I rely that empty files will always return zero?

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  • How to pass filename to StandardInput (Process) in C#?

    - by Cosmo
    Hello Guys! I'm using the native windows application spamc.exe (SpamAssassin - sawin32) from command line as follows: C:\SpamAssassin\spamc.exe -R < C:\email.eml Now I'd like to call this process from C#: Process p = new Process(); p.StartInfo.UseShellExecute = false; p.StartInfo.RedirectStandardOutput = true; p.StartInfo.RedirectStandardInput = true; p.StartInfo.FileName = @"C:\SpamAssassin\spamc.exe"; p.StartInfo.Arguments = @"-R"; p.Start(); p.StandardInput.Write(@"C:\email.eml"); p.StandardInput.Close(); Console.Write(p.StandardOutput.ReadToEnd()); p.WaitForExit(); p.Close(); The above code just passes the filename as string to spamc.exe (not the content of the file). However, this one works: Process p = new Process(); p.StartInfo.UseShellExecute = false; p.StartInfo.RedirectStandardOutput = true; p.StartInfo.RedirectStandardInput = true; p.StartInfo.FileName = @"C:\SpamAssassin\spamc.exe"; p.StartInfo.Arguments = @"-R"; p.Start(); StreamReader sr = new StreamReader(@"C:\email.eml"); string msg = sr.ReadToEnd(); sr.Close(); p.StandardInput.Write(msg); p.StandardInput.Close(); Console.Write(p.StandardOutput.ReadToEnd()); p.WaitForExit(); p.Close(); Could someone point me out why it's working if I read the file and pass the content to spamc, but doesn't work if I just pass the filename as I'd do in windows command line?

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  • WCF and streaming requests and responses

    - by Cheeso
    Is it correct that in WCF, I cannot have a service write to a stream that is received by the client? My understanding is that streaming is supported in WCF for requests, responses, or both. Is it true that in all cases, the receiver of the stream must invoke Read ? I would like to support a scenario where the receiver of the stream can Write on it. Is this supported? Let me show it this way. The simplest example of Streaming in WCF is the service returning a FileStream to a client. This is a streamed response. The server code is like this: [ServiceContract] public interface IStreamService { [OperationContract] Stream GetData(string fileName); } public class StreamService : IStreamService { public Stream GetData(string filename) { FileStream fs = new FileStream(filename, FileMode.Open) return fs; } } And the client code is like this: StreamDemo.StreamServiceClient client = new WcfStreamDemoClient.StreamDemo.StreamServiceClient(); Stream str = client.GetData(@"c:\path\to\myfile.dat"); do { b = str.ReadByte(); //read next byte from stream ... } while (b != -1); (example taken from http://blog.joachim.at/?p=33) Clear, right? The server returns the Stream to the client, and the client invokes Read on it. Is it possible for the client to provide a Stream, and the server to invoke Write on it? In other words, rather than a pull model - where the client pulls data from the server - it is a push model, where the client provides the "sink" stream and the server writes into it. Is this possible in WCF, and if so, how? What are the config settings required for the binding, interface, etc? The analogy is the Response.OutputStream from an ASP.NET request. In ASPNET, any page can invoke Write on the output stream, and the content is received by the client. Can I do something similar in WCF? Thanks.

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  • Writing XML in different character encodings with Java

    - by Roman Myers
    I am attempting to write an XML library file that can be read again into my program. The file writer code is as follows: XMLBuilder builder = new XMLBuilder(); Document doc = builder.build(bookList); DOMImplementation impl = doc.getImplementation(); DOMImplementationLS implLS = (DOMImplementationLS) impl.getFeature("LS", "3.0"); LSSerializer ser = implLS.createLSSerializer(); String out = ser.writeToString(doc); //System.out.println(out); try{ FileWriter fstream = new FileWriter(location); BufferedWriter outwrite = new BufferedWriter(fstream); outwrite.write(out); outwrite.close(); }catch (Exception e){ } The above code does write an xml document. However, in the XML header, it is an attribute that the file is encoded in UTF-16. when i read in the file, i get the error: "content not allowed in prolog" this error does not occur when the encoding attribute is manually changed to UTF-8. I am trying to get the above code to write an XML document encoded in UTF-8, or successfully parse a UTF-16 file. the code for parsing in is DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder loader = factory.newDocumentBuilder(); Document document = loader.parse(filename); the last line returns the error.

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  • Distributed transactions

    - by javi
    Hello! I've a question regarding distributed transactions. Let's assume I have 3 transaction programs: Transaction A begin a=read(A) b=read(B) c=a+b write(C,c) commit Transaction B begin a=read(A) a=a+1 write(A,a) commit Transaction C begin c=read(C) c=c*2 write(A,c) commit So there are 5 pairs of critical operations: C2-A5, A2-B4, B4-C4, B2-C4, A2-C4. I should ensure integrity and confidentiality, do you have any idea of how to achieve it? Thank you in advance!

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  • Jpeg 2000 and .net

    - by pho3nix
    I working in a activex control using .net for load it in a ie website. I need read a jpeg 2000 file but i don't want use a 3rd party dll because this will cause dependencies or embedding it make my dll very big. Anyone have idea where i can find a class .cs for embedded on my project, i need only read file, no write only read.

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  • Rijndael managed: plaintext length detction

    - by sheepsimulator
    I am spending some time learning how to use the RijndaelManaged library in .NET, and developed the following function to test encrypting text with slight modifications from the MSDN library: Function encryptBytesToBytes_AES(ByVal plainText As Byte(), ByVal Key() As Byte, ByVal IV() As Byte) As Byte() ' Check arguments. If plainText Is Nothing OrElse plainText.Length <= 0 Then Throw New ArgumentNullException("plainText") End If If Key Is Nothing OrElse Key.Length <= 0 Then Throw New ArgumentNullException("Key") End If If IV Is Nothing OrElse IV.Length <= 0 Then Throw New ArgumentNullException("IV") End If ' Declare the RijndaelManaged object ' used to encrypt the data. Dim aesAlg As RijndaelManaged = Nothing ' Declare the stream used to encrypt to an in memory ' array of bytes. Dim msEncrypt As MemoryStream = Nothing Try ' Create a RijndaelManaged object ' with the specified key and IV. aesAlg = New RijndaelManaged() aesAlg.BlockSize = 128 aesAlg.KeySize = 128 aesAlg.Mode = CipherMode.ECB aesAlg.Padding = PaddingMode.None aesAlg.Key = Key aesAlg.IV = IV ' Create a decrytor to perform the stream transform. Dim encryptor As ICryptoTransform = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV) ' Create the streams used for encryption. msEncrypt = New MemoryStream() Using csEncrypt As New CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write) Using swEncrypt As New StreamWriter(csEncrypt) 'Write all data to the stream. swEncrypt.Write(plainText) End Using End Using Finally ' Clear the RijndaelManaged object. If Not (aesAlg Is Nothing) Then aesAlg.Clear() End If End Try ' Return the encrypted bytes from the memory stream. Return msEncrypt.ToArray() End Function Here's the actual code I am calling encryptBytesToBytes_AES() with: Private Sub btnEncrypt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnEncrypt.Click Dim bZeroKey As Byte() = {&H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0} PrintBytesToRTF(encryptBytesToBytes_AES(bZeroKey, bZeroKey, bZeroKey)) End Sub However, I get an exception thrown on swEncrypt.Write(plainText) stating that the 'Length of the data to encrypt is invalid.' However, I know that the size of my key, iv, and plaintext are 16 bytes == 128 bits == aesAlg.BlockSize. Why is it throwing this exception? Is it because the StreamWriter is trying to make a String (ostensibly with some encoding) and it doesn't like &H0 as a value?

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  • Accessing StackExchange API from Emacs

    - by cschol
    I am trying to access the StackExchange API from Emacs' elisp: (require 'url) (require 'json) (defvar url-http-end-of-headers) (defun read-json () (interactive) (with-current-buffer (url-retrieve-synchronously "http://api.stackoverflow.com/0.8/users/2386") (goto-char url-http-end-of-headers) (json-read))) M-x read-json results in the following error: JSON readtable error. Am I missing anything?

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  • Scheme - Memory System

    - by Eric
    I am trying to make a memory system where you input something in a slot of memory. So what I am doing is making an Alist and the car of the pairs is the memory location and the cdr is the val. I need the program to understand two messages, Read and Write. Read just displaying the memory location selected and the val that is assigned to that location and write changes the val of the location or address. How do I make my code so it reads the location you want it to and write to the location you want it to? Feel free to test this yourself. Any help would be much appreciated. This is what I have: (define make-memory (lambda (n) (letrec ((mem '()) (dump (display mem))) (lambda () (if (= n 0) (cons (cons n 0) mem) mem) (cons (cons (- n 1) 0) mem)) (lambda (msg loc val) (cond ((equal? msg 'read) (display (cons n val))(set! n (- n 1))) ((equal? msg 'write) (set! mem (cons val loc)) (set! n (- n 1)) (display mem))))))) (define mymem (make-memory 100))

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  • method names with fluent interface

    - by deamon
    I have a Permissions class with methods in fluent style like this: somePermissions.setRead(true).setWrite(false).setExecute(true) The question is, whether I should name these methods set{Property} or only {property}. The latter would look like this: somePermissions.read(true).write(false).execute(true) If I look at these methods separately I would expect that read reads something, but on the other hand it is closer to the intention to have something like named paramaters like in Scala: Permission(read=true, write=false, execute=true)

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  • ArgumentOutOfRangeException when reading bytes from stream

    - by user345194
    I'm trying to read the response stream from an HttpWebResponse object. I know the length of the stream (_response.ContentLength) however I keep getting the following exception: Specified argument was out of the range of valid values. Parameter name: size While debugging, I noticed that at the time of the error, the values were as such: length = 15032 //the length of the stream as defined by _response.ContentLength bytesToRead = 7680 //the number of bytes in the stream that still need to be read bytesRead = 7680 //the number of bytes that have been read (offset) body.length = 15032 //the size of the byte[] the stream is being copied to The peculiar thing is that the bytesToRead and bytesRead variables are ALWAYS 7680, regardless of the size of the stream (contained in the length variable). Any ideas? Code: int length = (int)_response.ContentLength; byte[] body = null; if (length 0) { int bytesToRead = length; int bytesRead = 0; try { body = new byte[length]; using (Stream stream = _response.GetResponseStream()) { while (bytesToRead > 0) { // Read may return anything from 0 to length. int n = stream.Read(body, bytesRead, length); // The end of the file is reached. if (n == 0) break; bytesRead += n; bytesToRead -= n; } stream.Close(); } } catch (Exception exception) { throw; } } else { body = new byte[0]; } _responseBody = body;

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  • Producer / Consumer - I/O Disk

    - by Pedro Magalhaes
    Hi, I have a compressed file in the disk, that a partitioned in blocks. I read a block from disk decompress it to memory and the read the data. It is possible to create a producer/consumer, one thread that recovers compacted blocks from disk and put in a queue and another thread that decompress and read the data? Will the performance be better? Thanks!

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  • In asp.Net, writing code in the control tag generates compile error

    - by Nour Sabouny
    Hi this is really strange !! But look at the following asp code: <div runat="server" id="MainDiv"> <%foreach (string str in new string[]{"First#", "Second#"}) { %> <div id="<%=str.Replace("#","div") %>"> </div> <%} %> </div> now if you put this code inside any web page (and don't worry about the moral of this code, I made it just to show the idea) you'll get this error : Compiler Error Message: CS1518: Expected class, delegate, enum, interface, or struct Of course the error has nothing to do with the real problem, I searched for the code that was generated by asp.net and figured out the following : private void @__RenderMainDiv(System.Web.UI.HtmlTextWriter @__w, System.Web.UI.Control parameterContainer) { @__w.Write("\r\n "); #line 20 "blabla\blabla\Default.aspx" foreach (string str in new string[] { "First#", "Second#" }) { #line default #line hidden @__w.Write("\r\n <div id=\""); #line 22 "blabla\blabla\Default.aspx" @__w.Write(str.Replace("#", "div")); #line default #line hidden @__w.Write("\">\r\n "); } This is the code that was generated from the asp page and this is the method that is meant to render our div (MainDiv), I found out that there is a missing bracket "}" that closes the method or the (for loop). now the problem has three parts: 1- first you should have a server control (in our situation is the MainDiv) and I'm not sure if it is only the div tag. 2- HTML control inside the server control and a code inside it using the double quotation mark ( for example <div id="<%=str instead of <div id='<%=str. 3-Any keyword which has block brackets e.g.:for{},while{},using{}...etc. now removing any part, will solve the problem !!! how is this happening ?? any ideas ? BTW: please help me to make the question more obvious, because I couldn't find the best words to describe the problem.

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  • "image contains error", trying to create and display images using google app engine

    - by bert
    Hello all the general idea is to create a galaxy-like map. I run into problems when I try to display a generated image. I used Python Image library to create the image and store it in the datastore. when i try to load the image i get no error on the log console and no image on the browser. when i copy/paste the image link (including datastore key) i get a black screen and the following message: The image “view-source:/localhost:8080/img?img_id=ag5kZXZ-c3BhY2VzaW0xMnINCxIHTWFpbk1hcBgeDA” cannot be displayed because it contains errors. the firefox error console: Error: Image corrupt or truncated: /localhost:8080/img?img_id=ag5kZXZ-c3BhY2VzaW0xMnINCxIHTWFpbk1hcBgeDA import cgi import datetime import urllib import webapp2 import jinja2 import os import math import sys from google.appengine.ext import db from google.appengine.api import users from PIL import Image #SNIP #class to define the map entity class MainMap(db.Model): defaultmap = db.BlobProperty(default=None) #SNIP class Generator(webapp2.RequestHandler): def post(self): #SNIP test = Image.new("RGBA",(100, 100)) dMap=MainMap() dMap.defaultmap = db.Blob(str(test)) dMap.put() #SNIP result = db.GqlQuery("SELECT * FROM MainMap LIMIT 1").fetch(1) if result: print"item found<br>" #debug info if result[0].defaultmap: print"defaultmap found<br>" #debug info string = "<div><img src='/img?img_id=" + str(result[0].key()) + "' width='100' height='100'></img>" print string else: print"nothing found<br>" else: self.redirect('/?=error') self.redirect('/') class Image_load(webapp2.RequestHandler): def get(self): self.response.out.write("started Image load") defaultmap = db.get(self.request.get("img_id")) if defaultmap.defaultmap: try: self.response.headers['Content-Type'] = "image/png" self.response.out.write(defaultmap.defaultmap) self.response.out.write("Image found") except: print "Unexpected error:", sys.exc_info()[0] else: self.response.out.write("No image") #SNIP app = webapp2.WSGIApplication([('/', MainPage), ('/generator', Generator), ('/img', Image_load)], debug=True) the browser shows the "item found" and "defaultmap found" strings and a broken imagelink the exception handling does not catch any errors Thanks for your help Regards Bert

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  • CStdioFile Undeclared Identifier

    - by Eric Regnier
    I am unable to compile my code when using a CStdioFile type. I have included the afx.h header file but I am still receiving errors. What I am trying to do is write a cstring that contains an entire xml document to file. This cstring contains comments inside of it, but when I use other objects such as wofstream to write it to file, these comments are striped out for some reason. So that is why I am trying to write this to file using CStdioFile now. If anyone can help me out as to why I cannot compile my code using CStdioFile, or any other way to write a cstring that contains xml comments to file, please let me know! Below is my code using CStdioFile: CStdioFile xmlFile; xmlFile.Open( "c:\\test.txt", CFile::modeCreate | CFile::modeWrite | CFile::typeText ); xmlFile.WriteString( m_sData ); xmlFile.Close(); And my errors: error C2065: 'CStdioFile' : undeclared identifier error C2065: 'modeCreate' : undeclared identifier error C2065: 'modeWrite' : undeclared identifier error C2065: 'typeText' : undeclared identifier error C2065: 'xmlFile' : undeclared identifier error C2146: syntax error : missing ';' before identifier 'xmlFile' error C2228: left of '.Close' must have class/struct/union type type is ''unknown-type'' error C2228: left of '.Open' must have class/struct/union type type is ''unknown-type'' error C2228: left of '.WriteString' must have class/struct/union type type is ''unknown-type'' error C2653: 'CFile' : is not a class or namespace name error C2653: 'CFile' : is not a class or namespace name error C2653: 'CFile' : is not a class or namespace name error C3861: 'xmlFile': identifier not found, even with argument-dependent lookup error C3861: 'xmlFile': identifier not found, even with argument-dependent lookup error C3861: 'xmlFile': identifier not found, even with argument-dependent lookup

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  • Writing file from HttpWebRequest periodically vs. after download finishes?

    - by WB3000
    Right now I am using this code to download files (with a Range header). Most of the files are large, and it is running 99% of CPU currently as the file downloads. Is there any way that the file can be written periodically so that it does not remain in RAM constantly? private byte[] GetWebPageContent(string url, long start, long finish) { byte[] result = new byte[finish]; HttpWebRequest request; request = WebRequest.Create(url) as HttpWebRequest; //request.Headers.Add("Range", "bytes=" + start + "-" + finish); request.AddRange((int)start, (int)finish); using (WebResponse response = request.GetResponse()) { return ReadFully(response.GetResponseStream()); } } public static byte[] ReadFully(Stream stream) { byte[] buffer = new byte[32768]; using (MemoryStream ms = new MemoryStream()) { while (true) { int read = stream.Read(buffer, 0, buffer.Length); if (read <= 0) return ms.ToArray(); ms.Write(buffer, 0, read); } } }

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  • WCF and ASP.NET - Server.Execute throwing object reference not set to an instance of an object

    - by user208662
    Hello, I have an ASP.NET page that calls to a WCF service. This WCF service uses a BackgroundWorker to asynchronously create an ASP.NET page on my server. Oddly, when I execute the WCF Service [OperationContract] [WebInvoke(Method = "POST", BodyStyle = WebMessageBodyStyle.WrappedRequest, RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json)] public void PostRequest(string comments) { // Do stuff // If everything went o.k. asynchronously render a page on the server. I do not want to // block the caller while this is occurring. BackgroundWorker myWorker = new BackgroundWorker(); myWorker.DoWork += new DoWorkEventHandler(myWorker_DoWork); myWorker.RunWorkerAsync(HttpContext.Current); } private void myWorker_DoWork(object sender, DoWorkEventArgs e) { // Set the current context so we can render the page via Server.Execute HttpContext context = (HttpContext)(e.Argument); HttpContext.Current = context; // Retrieve the url to the page string applicationPath = context.Request.ApplicationPath; string sourceUrl = applicationPath + "/log.aspx"; string targetDirectory = currentContext.Server.MapPath("/logs/"); // Execute the other page and load its contents using (StringWriter stringWriter = new StringWriter()) { // Write the contents out to the target url // NOTE: THIS IS WHERE MY ERROR OCCURS currentContext.Server.Execute(sourceUrl, stringWriter); // Prepare to write out the result of the log targetPath = targetDirectory + "/" + DateTime.Now.ToShortDateString() + ".aspx"; using (StreamWriter streamWriter = new StreamWriter(targetPath, false)) { // Write out the content to the file sb.Append(stringWriter.ToString()); streamWriter.Write(sb.ToString()); } } } Oddly, when the currentContext.Server.Execute method is executed, it throws an "object reference not set to an instance of an object" error. The reason this is so strange is because I can look at the currentContext properties in the watch window. In addition, Server is not null. Because of this, I have no idea where this error is coming from. Can someone point me in the correct direction of what the cause of this could be? Thank you!

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  • Caching in mmap

    - by myahya
    I am using mmap call to read from a very big file using simple pointer arithmetic in C++. The problem is that when I read small chunks of data (in the order of KBs) multiple times, each read take the same amount of time as the previous one. How can I know if the disk is being accessed to fulfill my request or whether the request is being fulfilled from main memory (page cache) in calls after the first one.

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  • How to MakeTable ReadOnly including contents like images

    - by GustlyWind
    I have a table which has two text boxes and a image beside it to click and open a popup. In read-only mode based on condition I am able to make text boxes read-only but images are not becoming read-only.One solution I had is the anchor tag associated with image calls for JavaScript where I can check for a dummy click when it is in read-only mode. The problem here is the function is common and effects everywhere. So is there a way to make the entire table read-only so that no extra workaround needs to done. Edited for code <table> <tr> <td class="lightbg" colspan='4'>&nbsp; Expires:<input type="TEXT" value="" id="element1" name="expireDate" size="10" maxlength="20" class="" onChange="javascript:validateDateEntry('element1',true);;"> Period:<input type="TEXT" value="" id="element2" name="refershDate" size="10" maxlength="20" class="" onChange="javascript:validateDateEntry('element2',true);;"> &nbsp; <a href="javascript:doCalendar('element1');"> <img src="/PWM/images/images_2006/calendarbtn.gif" border="0" alt="Click to select date from calendar" align="absmiddle"> </a> </td> </tr> <tr> <td colspan='4'><b>*</b>Times are in the WFM Server's Time Zone.</td></tr> </table> Thanks

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  • Odd performance with C# Asynchronous server socket

    - by The.Anti.9
    I'm working on a web server in C# and I have it running on Asynchronous socket calls. The weird thing is that for some reason, when you start loading pages, the 3rd request is where the browser won't connect. It just keeps saying "Connecting..." and doesn't ever stop. If I hit stop. and then refresh, it will load again, but if I try another time after that it does the thing where it doesn't load again. And it continues in that cycle. I'm not really sure what is making it do that. The code is kind of hacked together from a couple of examples and some old code I had. Any miscellaneous tips would be helpful as well. Heres my little Listener class that handles everything (pastied here. thought it might be easier to read this way) using System; using System.Collections.Generic; using System.Net; using System.Net.Sockets; using System.Text; using System.Threading; namespace irek.Server { public class Listener { private int port; private Socket server; private Byte[] data = new Byte[2048]; static ManualResetEvent allDone = new ManualResetEvent(false); public Listener(int _port) { port = _port; } public void Run() { server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); IPEndPoint iep = new IPEndPoint(IPAddress.Any, port); server.Bind(iep); Console.WriteLine("Server Initialized."); server.Listen(5); Console.WriteLine("Listening..."); while (true) { allDone.Reset(); server.BeginAccept(new AsyncCallback(AcceptCon), server); allDone.WaitOne(); } } private void AcceptCon(IAsyncResult iar) { allDone.Set(); Socket s = (Socket)iar.AsyncState; Socket s2 = s.EndAccept(iar); SocketStateObject state = new SocketStateObject(); state.workSocket = s2; s2.BeginReceive(state.buffer, 0, SocketStateObject.BUFFER_SIZE, 0, new AsyncCallback(Read), state); } private void Read(IAsyncResult iar) { try { SocketStateObject state = (SocketStateObject)iar.AsyncState; Socket s = state.workSocket; int read = s.EndReceive(iar); if (read > 0) { state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, read)); if (s.Available > 0) { s.BeginReceive(state.buffer, 0, SocketStateObject.BUFFER_SIZE, 0, new AsyncCallback(Read), state); return; } } if (state.sb.Length > 1) { string requestString = state.sb.ToString(); // HANDLE REQUEST HERE // Temporary response string resp = "<h1>It Works!</h1>"; string head = "HTTP/1.1 200 OK\r\nContent-Type: text/html;\r\nServer: irek\r\nContent-Length:"+resp.Length+"\r\n\r\n"; byte[] answer = Encoding.ASCII.GetBytes(head+resp); // end temp. state.workSocket.BeginSend(answer, 0, answer.Length, SocketFlags.None, new AsyncCallback(Send), state.workSocket); } } catch (Exception) { return; } } private void Send(IAsyncResult iar) { try { SocketStateObject state = (SocketStateObject)iar.AsyncState; int sent = state.workSocket.EndSend(iar); state.workSocket.Shutdown(SocketShutdown.Both); state.workSocket.Close(); } catch (Exception) { } return; } } } And my SocketStateObject: public class SocketStateObject { public Socket workSocket = null; public const int BUFFER_SIZE = 1024; public byte[] buffer = new byte[BUFFER_SIZE]; public StringBuilder sb = new StringBuilder(); }

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  • How to wrtie a XML License Line(ended with a forward slash '/') in C#?

    - by Nano HE
    I want to write a XML file as below: <?xml version="1.0" encoding="UTF-8"?> <books xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <License licenseId="" licensePath="" /> Some piece of my code attached here // Create a new file in D:\\ and set the encoding to UTF-8 XmlTextWriter textWriter = new XmlTextWriter("D:\\books.xml", System.Text.Encoding.UTF8); // Format automatically textWriter.Formatting = Formatting.Indented; // Opens the document textWriter.WriteStartDocument(); // Write the namespace declaration. textWriter.WriteStartElement("books", null); // Write the genre attribute. textWriter.WriteAttributeString("xmlns", "xsd", null, "http://www.w3.org/2001/XMLSchema"); textWriter.WriteAttributeString("xmlns", "xsi", null, "http://www.w3.org/2001/XMLSchema-instance"); And now I need to write the License Line below in C# <License licenseId="" licensePath="" /> But I don't know how to move on for I found the Line ended with the forward slash / .Thank you.

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  • Javascript - how to replace a sub-string?

    - by Jangwenyi
    This is a simple one. I want to replace a sub-string with another sub-string on client-side using Javascript. Original string is 'original READ ONLY' I want to replace the 'READ ONLY' with 'READ WRITE' Any quick answer please? Possibly with a javascript code snippet...

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