Search Results

Search found 22000 results on 880 pages for 'worker process'.

Page 768/880 | < Previous Page | 764 765 766 767 768 769 770 771 772 773 774 775  | Next Page >

  • could not execute a stored procedure(using DAAB) from a client(aspx page) to a wcf service

    - by user1144695
    i am trying to store data to sql database from a asp.net client website through a stored procedure(using DAAB) in a wcf service hosted in a asp.net empty website.When i try to store data to the DB i get the following error: ** - The server was unable to process the request due to an internal error. For more information about the error, either turn on IncludeExceptionDetailInFaults (either from ServiceBehaviorAttribute or from the <serviceDebug> configuration behavior) on the server in order to send the exception information back to the client, or turn on tracing as per the Microsoft .NET Framework SDK documentation and inspect the server trace logs. ** When i try to debug i get the following exception: Activation error occured while trying to get instance of type Database, key "" in the code-- Database db = EnterpriseLibraryContainer.Current.GetInstance<Database>("MyInstance"); where my app.config is <?xml version="1.0"?> <configuration> <configSections> <section name="dataConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Data.Configuration.DatabaseSettings, Microsoft.Practices.EnterpriseLibrary.Data, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="true"/> </configSections> <dataConfiguration defaultDatabase="MyInstance"/> <connectionStrings> <add name="MyInstance" connectionString="Data Source=BLRKDAS307581\KD;Integrated Security=True;User ID=SAPIENT\kdas3;Password=ilove0LINUX" providerName="System.Data.SqlClient" /> </connectionStrings> <startup> <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/> </startup> </configuration> Can anyone help me with it? Thanks in advance...

    Read the article

  • Command or tool to display list of connections to a Windows file share

    - by BizTalkMama
    Is there a Windows command or tool that can tell me what users or computers are connected to a Windows fileshare? Here's why I'm looking for this: I've run into issues in the past where our deployment team has deployed BizTalk applications to one of our environments using the wrong bindings, leaving us with two receive locations pointing to the same file share (i.e. both dev and test servers point to dev receive location uri). When this occurs, the two environments in question tend to take turns processing the files received (meaning if I am attempting to debug something in one environment and the other environment has picked the file up, it looks as if my test file has disappeared into thin air). We have several different environments, plus individual developer machines, and I'd rather not have to check each individually to find the culprit. I'm looking for a quick way to detect what locations are connected to the share once I notice my test files vanishing. If I can determine the connections that are invalid, I can go directly to the person responsible for that environment and avoid the time it takes to randomly ask around. Or if the connections appear to be correct, I can go directly to troubleshooting where in the process the message gets lost. Any suggestions?

    Read the article

  • C# Retrieving Data From XML File

    - by Christopher MacKinnon
    I seem to be having a problem with retrieving XML values with C#, which I know it is due to my very limited knowledge of C# and .XML. I was given the following XML file <PowerBuilderRunTimes> <PowerBuilderRunTime> <Version>12</Version> <Files> <File>EasySoap110.dll</File> <File>exPat110.dll</File> <File>pbacc110.dll</File> </File> </PowerBuilderRunTime> </PowerBuilderRunTimes> I am to process the XML file and make sure that each of the files in the exist in the folder (that's the easy part). It's the processing of the XML file that I have having a hard time with. Here is what I have done thus far: var runtimeXml = File.ReadAllText(string.Format("{0}\\{1}", configPath, Resource.PBRuntimes)); var doc = XDocument.Parse(runtimeXml); var topElement = doc.Element("PowerBuilderRunTimes"); var elements = topElement.Elements("PowerBuilderRunTime"); foreach (XElement section in elements) { //pbVersion is grabbed earlier. It is the version of PowerBuilder if( section.Element("Version").Value.Equals(string.Format("{0}", pbVersion ) ) ) { var files = section.Elements("Files"); var fileList = new List<string>(); foreach (XElement area in files) { fileList.Add(area.Element("File").Value); } } } My issue is that the String List is only ever populated with one value, "EasySoap110.dll", and everything else is ignored. Can someone please help me, as I am at a loss.

    Read the article

  • How to treat Base* pointer as Derived<T>* pointer?

    - by dehmann
    I would like to store pointers to a Base class in a vector, but then use them as function arguments where they act as a specific class, see here: #include <iostream> #include <vector> class Base {}; template<class T> class Derived : public Base {}; void Foo(Derived<int>* d) { std::cerr << "Processing int" << std::endl; } void Foo(Derived<double>* d) { std::cerr << "Processing double" << std::endl; } int main() { std::vector<Base*> vec; vec.push_back(new Derived<int>()); vec.push_back(new Derived<double>()); Foo(vec[0]); Foo(vec[1]); delete vec[0]; delete vec[1]; return 0; } This doesn't compile: error: call of overloaded 'Foo(Base*&)' is ambiguous Is it possible to make it work? I need to process the elements of the vector differently, according to their int, double, etc. types.

    Read the article

  • My python program always brings down my internet connection after several hours running, how do I debug and fix this problem?

    - by Shane
    I'm writing a python script checking/monitoring several server/websites status(response time and similar stuff), it's a GUI program and I use separate thread to check different server/website, and the basic structure of each thread is using an infinite while loop to request that site every random time period(15 to 30 seconds), once there's changes in website/server each thread will start a new thread to do a thorough check(requesting more pages and similar stuff). The problem is, my internet connection always got blocked/jammed/messed up after several hours running of this script, the situation is, from my script side I got urlopen error timed out each time it's requesting a page, and from my FireFox browser side I cannot open any site. But the weird thing is, the moment I close my script my Internet connection got back on immediately which means now I can surf any site through my browser, so it must be the script causing all the problem. I've checked the program carefully and even use del to delete any connection once it's used, still get the same problem. I only use urllib2, urllib, mechanize to do network requests. Anybody knows why such thing happens? How do I debug this problem? Is there a tool or something to check my network status once such situation occurs? It's really bugging me for a while... By the way I'm behind a VPN, does it have something to do with this problem? Although I don't think so because my network always get back on once the script closed, and the VPN connection never drops(as it appears) during the whole process.

    Read the article

  • WSACONNREFUSED when connecting to server

    - by Robert Mason
    I'm currently working on a server. I know that the client side is working (I can connect to www.google.com on port 80, for example), but the server is not functioning correctly. The socket has socket()ed, bind()ed, and listen()ed successfully and is on an accept loop. The only problem is that accept() doesn't seem to work. netstat shows that the server connection is running fine, as it prints the PID of the server process as LISTENING on the correct port. However, accept never returns. Accept just keeps running, and running, and if i try to connect to the port on localhost, i get a 10061 WSACONNREFUSED. I tried looping the connection, and it just keeps refusing connections until i hit ctrl+c. I put a breakpoint directly after the call to accept(), and no matter how many times i try to connect to that port, the breakpoint never fires. Why is accept not accepting connections? Has anyone else had this problem before? Known: [breakpoint0] if ((new_fd = accept(sockint, NULL, NULL)) == -1) { throw netlib::error("Accept Error"); //netlib::error : public std::exception } else { [breakpoint1] code...; } breakpoint0 is reached (and then continued through), no exception is thrown, and breakpoint1 is never reached. The client code is proven to work. Netstat shows that the socket is listening. If it means anything, i'm connecting to 127.0.0.1 on port 5842 (random number). The server is configured to run on 5842, and netstat confirms that the port is correct.

    Read the article

  • Yii Framework Tutorial - file not found

    - by Heshan Perera
    I am in the process of learning the Yii Framework. I have been following this Tutorial. I have followed all the steps and have by index page loading. In my index.php page I point to two other pages located in protected/views/message The following is the code in my index.php located in the message folder mentioned above. <html> <body> <h1>Welcome</h1> <p> To view our message go to... <?php echo CHtml::link('Here', '/message/show')?> </p> <p> To edit our message go to... <?php echo CHtml::link('Here', '/message/edit')?> </p> </body> </html> "message" is the ID I gave when generating the model and controller through the yii shell application. The problem is, after the above page loads, and I click on any one of the above URLs, it points to "localhost:8080/message/show" and "localhost:8080/message/edit" , whereas the real location of these files is "localhost:8080/test/protected/views/message/..." What could I be doing wrong ?

    Read the article

  • I'm graduating with a Computer Science degree but I don't feel like I know how to program.

    - by Wendy Peters
    I'm graduating with a Computer Science degree but I see websites like Stackoverflow and search engines like Google and don't know where I'd even begin to write something like that. During one summer I worked as a iPhone developer, but I felt like I was mostly gluing together libraries that other people had written with little understanding of what's happening underneath the hood. I'm trying to improve my knowledge by studying algorithms, but it is a long and painful process. I find algorithms difficult and at the rate I am working through my book it will a decade will have passed before I will finish. Given my current situation, I've spent a month looking for work but my skills (C, Python, Objective-C) are not so desirable in the local market, where C#, Java, and web development are much higher in demand. My GPA is ok (3.0) but it's not high enough to apply to the large companies or return for graduate studies and I don't have a good network of friends. Basically I'm graduating with a Computer Science degree but I don't feel like I know how to program. I thought that joining a company and programming full-time would give me a chance to develop my skills and learn from those more experienced than myself, but I'm struggling to find work and am starting to get really frustrated. I am going to cast my net wider and look beyond the city I've grown up in, but what have other people in similar situation tried to do?

    Read the article

  • WPF - Transparency - Stream Desktop Content

    - by Niels Willems
    Greetings I'm in the process of making a Scoreboard for a game (Starcraft II). This scoreboard is being made as a WPF Application with a C# code-behind. I already have a version which works for 90% in WinForms but I lacked the support to easily make it look a lot nicer which are available in WPF. The point of this application will be to form a kind of overlay on top of a running game. This game is in Fulscreen(Windowed Mode) so when in WinForms I coded it so that it should always be on top. It would do so and that was no problem. Since the main look of the app in WPF is based on an image with a transparent background I have set most Background values to Transparent. However when I do this the entire application does not get registered by streaming software. For example it just shows my Desktop or the game I'm playing but not my application even though it IS there. I can see it with my own eyes but the audience on the stream cannot. Does anyone have any experience with this matter because it's really doing my head in. My entire application will be useless if it is not visible on streams. If I have to put the background on a color rather than transparent the UI will be completely demolished as well in terms of looks. I'm basically trying to make a game-overlay in C# & WPF. I have read you can do this on different ways as well but I have little to no knowledge of C++ nor do I know anything about DirectX Thank you for your time reading and your possible insights. Edit: The best solution would be an overlay similar to that one of Steam/Xfire/Dolby Axon. Edit 2: I've had no luck with all the suggestions so I basically made the transparent bits of my image non transparent and let the user decide which one to use depending on what streaming software they would be using.

    Read the article

  • 500 internal server error at form connection

    - by klox
    hi..all..i've a problem i can't connect to database what's wrong with my code?this is my code: $("#mod").change(function() { var barcode; barCode=$("#mod").val(); var data=barCode.split(" "); $("#mod").val(data[0]); $("#seri").val(data[1]); var str=data[0]; var matches=str.match(/(EE|[EJU]).*(D)/i); $.ajax({ type:"post", url:"process1.php", data:"value="+matches+"action=tunermatches", cache:false, async:false, success: function(res){ $('#rslt').replaceWith( "<div id='value'><h6>Tuner range is" + res + " .</h6></div>" ); } }); }); and this is my process file: switch(postVar('action')) { case 'tunermatches' : tunermatches(postVar('tuner')); break; function tunermatches($tuner)){ $Tuner=mysql_real_escape_string($tuner); $sql= "SELECT remark FROM settingdata WHERE itemname="Tuner_range" AND itemdata="$Tunermatches"; $res=mysql_query($sql); $dat=mysql_fetch_array($res,MYSQL_NUM); if($dat[0]>0) { echo $dat[0]; } mysql_close($dbc); }

    Read the article

  • JasperReports reports access image via authenticated URL

    - by user363115
    Hi all, I am hoping that this is a simple issue with a simple solution and that I have missed something obvious. Let me explain the problem; We have an application that generates PDF reports (using Jasper). These reports contain data from our database, as well as imagery (photographs). These photographs are stored in S3. We use signed URLs to access these photographs. We link these photographs into our Jasper reports using these S3 URLs. Because the S3 URLs are signed and time-limited (by design), the process is as follows; User requests a report to be generated, Report is filled, and goes to our database (at which time UUIDs to any required images are retrieved), For each UUID an S3 signed URL must be generated, To do this the URL behind each report image is a call to an authenticated URL in our app (/get_img?uuid=foo), The controller behind this URL generates a signed S3 URL and returns it, Reports loads the image. The problem is with step (4) - the call to the authenticated URL fails because Jasper does not pass any authentication information with the request. Is there a solution here? Thanks all for your time. Ben

    Read the article

  • How to properly recreate BITMAP, that was previously shared by CreateFileMapping()?

    - by zim22
    Dear friends, I need your help. I need to send .bmp file to another process (dialog box) and display it there, using MMF(Memory Mapped File) But the problem is that image displays in reversed colors and upside down. In first application I open picture from HDD and link it to the named MMF "Gigabyte_picture" HANDLE hFile = CreateFile("123.bmp", GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, NULL); CreateFileMapping(hFile, NULL, PAGE_READONLY, 0, 0, "Gigabyte_picture"); In second application I open mapped bmp file and at the end I display m_HBitmap on the static component, using SendMessage function. HANDLE hMappedFile = OpenFileMapping(FILE_MAP_READ, FALSE, "Gigabyte_picture"); PBYTE pbData = (PBYTE) MapViewOfFile(hMappedFile, FILE_MAP_READ, 0, 0, 0); BITMAPINFO bmpInfo = { 0 }; LONG lBmpSize = 60608; // size of the bmp file in bytes bmpInfo.bmiHeader.biBitCount = 32; bmpInfo.bmiHeader.biHeight = 174; bmpInfo.bmiHeader.biWidth = 87; bmpInfo.bmiHeader.biPlanes = 1; bmpInfo.bmiHeader.biSizeImage = lBmpSize; bmpInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER); UINT * pPixels = 0; HDC hDC = CreateCompatibleDC(NULL); HBITMAP m_HBitmap = CreateDIBSection(hDC, &bmpInfo, DIB_RGB_COLORS, (void **)& pPixels, NULL, 0); SetBitmapBits(m_HBitmap, lBmpSize, pbData); SendMessage(gStaticBox, STM_SETIMAGE, (WPARAM)IMAGE_BITMAP,(LPARAM)m_HBitmap); ///////////// HWND gStaticBox = CreateWindowEx(0, "STATIC","", SS_CENTERIMAGE | SS_REALSIZEIMAGE | SS_BITMAP | WS_CHILD | WS_VISIBLE, 10,10,380, 380, myDialog, (HMENU)-1,NULL,NULL);

    Read the article

  • Some images fails to load on Windows Server 2008

    - by Guffa
    I have an application running on a Windows Server 2008, that is processing uploaded images. Currently it successfully processes about 8000 images per day, creating 11 different sizes of each image. The problem that I have is that sometimes the application fails to load some images, I get the error "System.Runtime.InteropServices.ExternalException: A generic error occurred in GDI+.". The upload only accepts files with a JPEG extension (jpg/jpeg/jpe) or with a JPEG MIME type, and from what I can tell those images are really JPEG images. If I look at the image file in windows explorer on the server, it can successfully extract the thumbnail from the file, but if I try to open it, I get the error message "This is not a valid bitmap file, or it's format is not currently supported." from Paint. If I copy the image to my own computer, running Windows 7, there is no problem opening the image. It works in Paint, Windows Photo Viewer, Adobe Bridge, and Photoshop. If I try to load the image using Image.FromStream the same way as in the application running on the server, it loads just fine. (I have copied the file back to the server, and it still doesn't work, so there is nothing in the copying process that changes it.) When I look at the image information in Bridge, I see that the images are created using Picasa 3.0, but other than that I can't see anything special about them. I haven't yet found anyone having the same problem, or any known problems like this with the Picasa application. Has anyone had any similar problem, or know if there is something special about images created using Picasa? Is there any image codec that needs installing on the server to handle all kinds of JPEG images?

    Read the article

  • Run arbitrary subprocesses on Windows and still terminate cleanly?

    - by Weeble
    I have an application A that I would like to be able to invoke arbitrary other processes as specified by a user in a configuration file. Batch script B is one such process a user would like to be invoked by A. B sets up some environment variables, shows some messages and invokes a compiler C to do some work. Does Windows provide a standard way for arbitrary processes to be terminated cleanly? Suppose A is run in a console and receives a CTRL+C. Can it pass this on to B and C? Suppose A runs in a window and the user tries to close the window, can it cancel B and C? TerminateProcess is an option, but not a very good one. If A uses TerminateProcess on B, C keeps running. This could cause nasty problems if C is long-running, since we might start another instance of C to operate on the same files while the first instance of C is still secretly at work. In addition, TerminateProcess doesn't result in a clean exit. GenerateConsoleCtrlEvent sounds nice, and might work when everything's running in a console, but the documentation says that you can only send CTRL+C to your own console, and so wouldn't help if A were running in a window. Is there any equivalent to SIGINT on Windows? I would love to find an article like this one: http://www.cons.org/cracauer/sigint.html for Windows.

    Read the article

  • OpenCV. cvFnName() works, but cv::FunName() doesn't work

    - by Innuendo
    I'm using OpenCV to write a plugin for a simulator. I've made an OpenCV project (single - not a plugin) and it works fine. When I added OpenCV libs to the plugin project, I added all libs required. Visual Studio 2010 doesn't highlight any code line with red. All looks fine and compiles fine. But in execution, the program halts with a Runtime Error on any cv::function. For example: cv::imread, or cv::imwrite. But if I replace them with cvLoadImage() and cvSaveImage(), it works fine. Why does this happen? I don't want to rewrite the whole script in old-api-style (cvFnName). It means I should change all Mat objects to IplImages, and so on. UPDATE: // preparing template ifstream ifile(tmplfilename); if ( !FILE_LOADED && ifile ) { // loading template file Mat tmpl = cv::imread(tmplfilename, 1); // << here occurs error FILE_LOADED = true; } Mat src; Bmp2Mat(hDC, hBitmap, src); TargetDetector detector(src, tmpl); detector.detectTarget(); If I change to: if ( !FILE_LOADED && ifile ) { IplImage* tmpl = 0; tmpl = cvLoadImage(tmplfilename, 1); // no error occurs } And then no error occurs. Early it displayed some Runtime Error. Now, I wanted to copy exact message and it just crashes the application (simulator, what I am pluginning). It displays window error - to kill process or no. (I can't show exact message, because I'm using russian windows now)

    Read the article

  • Does Microsoft Access use the PK fields for anything?

    - by chrismay
    Ok this is going to sound strange, but I have inherited an app that is an Access front end with a SQL Server backend. I am in the process of writing a new front end for it, but... we need to continue using the access front end for a while even after we deploy my new front end for reasons I won't go into. So both the existing Access app and my new app will need to be able to access and work with the data. The problem is the database design is a nightmare. For example some simple parent-child table relationships have like 4 and 5 part composite primary keys. I would REALLY like to remove these PKs and replace them with unique constraints or whatever, and add a new column to each of these tables called ID that is just an identity. If I change the PK and FKs on these tables to more managable fields, will the Access app have problems? What I mean is, does access use the meta data from the tables (PK and FK info) in such a way that it would break the app to change these?

    Read the article

  • Phonegap Android application exiting - but not really - when home button is pressed

    - by Lucas T
    I have created an Phonegap 1.5/Android application. My client reports that, when he leaves the app using the Home button, and then relaunches it using the app icon, the app relaunches from the start instead of resuming. However, when he holds the home button, the app appears in the running apps, and when he accesses the app through this menu, the app resumes in the expected way. I thought this could be linked to the app being automatically closed by the OS due to a lack of memory, but if that was the case the app shouldn't appear in the running apps. I could not reproduce the bug on my Sony Ericsson XPERIA with Android 2.3.4, the client has experienced this behaviour on a Motorola Defy and on another phone (i'll add the reference of the other phone and the OS versions as soon as I get them). The initialization process of the app is declared this way : window.addEventListener('load', function(){ document.addEventListener('deviceready', _onDeviceReady, false); }, false); Could this be fixed by attaching the processes to other events (although I doubt it, the app really seems to be relaunched from the start) ? Is there a declaration to make in the Android Manifest to prevent this behavior ? Is that a known bug in some Android phones/versions ?

    Read the article

  • Inserting default "admin" user into database during Rails App startup

    - by gbc
    I'm building my first real rails application for a little in-house task. Most of the application tasks require authentication/authorization. The first time the app starts up (or starts with a wiped db), I'd like the process to be: User logs into the admin panel using "admin" & "admin" for authentication info. User navigates to admin credentials editing page and changes name and password to something safer so that "admin" & "admin" is no longer a valid login. To achieve this result, I'd like to stuff a default username & password combination into the database on if the application starts up and detects that there are no user credentials in the 'users' table. For example: if User.count == 0 User.create(:name => "admin", :password => "admin") end However, I'm unsure where to place that code. I tried adding an initializer script in the config/initializers, but the error I received appeared to indicate that the model classes weren't yet loaded into the application. So I'm curious to know at what point I can hook into the application startup cycle and insert data into the database through ActiveRecord before requests are dispatched.

    Read the article

  • The application has stopped unexpectedly: How to Debug?

    - by Android Eve
    Please note, unlike many other questions having the subject title "application has stopped unexpectedly", I am not asking for troubleshooting a particular problem. Rather, I am asking for an outline of the best strategy for an Android/Eclipse/Java rookie to tackle this formidable task of digesting huge amounts of information in order to develop (and debug!) a simple Android application. In my case, I took the sample skeleton app from the SDK, modified it slightly and what did I get the moment I try to run it? The application (process.com.example.android.skeletonapp) has stopped unexpectedly. Please try again. OK, so I know that I have to look LogCat. It's full of timestamped lines staring at me... What do I do now? What do I need to look for? Is there a way to single-step the program, to find the statement that makes the app crash? (I thought Java programs never crash, but apparently I was mistaken) How do I place a breakpoint? Can you recommend an Android debug tutorial online, other than this one?

    Read the article

  • Cleaning up when exiting an OpenGL app

    - by Daniel
    This might be a dumb question but I've spent some time asking Google and haven't been able to find anything. I have an an OSX OpenGL app I'm trying to modify. When I create the app a whole bunch of initialisation functions are called -- including methods where I can specify my own mouse and keyboard handlers etc. For example: glutInit(&argc, argv); glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA); glutInitWindowPosition(100, 100); glutInitWindowSize(700, 700); glutCreateWindow("Map Abstraction"); glutReshapeFunc(resizeWindow); glutDisplayFunc(renderScene); glutIdleFunc(renderScene); glutMouseFunc(mousePressedButton); glutMotionFunc(mouseMovedButton); glutKeyboardFunc(keyPressed); At some point I pass control to glutMainLoop and my application runs. In the process of running I create a whole bunch of objects. I'd like to clean these up. Is there any way I can tell GLUT to call a cleanup method before it quits?

    Read the article

  • Updating target workbook - extracting data from source workbook

    - by Allan
    My question is as follows: I have given a workbook to multiple people. They have this workbook in a folder of their choice. The workbook name is the same for all people, but folder locations vary. Let's assume the common file name is MyData-1.xls. Now I have updated the workbook and want to give it to these people. However when they receive the new one (let's call it MyData-2.xls) I want specific parts of their data pulled from their file (MyData-1) and automatically put into the new one provided (MyData-2). The columns and cells to be copied/imported are identical for both workbooks. Let's assume I want to import cell data (values only) from MyData-1.xls, Sheet 1, cells B8 through C25 ... to ... the same location in the MyData-2.xls workbook. How can I specify in code (possibly attached to a macro driven import data now button) that I want this data brought into this new workbook. I have tried it at my own location by opening the two workbooks and using the copy/paste-special with links process. It works really well, but It seems to create a hard link between the two physical workbooks. I changed the name of the source workbook and it still worked. This makes me believe that there is a "hard link" between the tow and that this will not allow me to give the target (MyData-2.xls) workbook to others and have it find their source workbook.

    Read the article

  • Best way to run multiple queries per second on database, performance wise?

    - by Michael Joell
    I am currently using Java to insert and update data multiple times per second. Never having used databases with Java, I am not sure what is required, and how to get the best performance. I currently have a method for each type of query I need to do (for example, update a row in a database). I also have a method to create the database connection. Below is my simplified code. public static void addOneForUserInChannel(String channel, String username) throws SQLException { Connection dbConnection = null; PreparedStatement ps = null; String updateSQL = "UPDATE " + channel + "_count SET messages = messages + 1 WHERE username = ?"; try { dbConnection = getDBConnection(); ps = dbConnection.prepareStatement(updateSQL); ps.setString(1, username); ps.executeUpdate(); } catch(SQLException e) { System.out.println(e.getMessage()); } finally { if(ps != null) { ps.close(); } if(dbConnection != null) { dbConnection.close(); } } } And my DB connection private static Connection getDBConnection() { Connection dbConnection = null; try { Class.forName(DB_DRIVER); } catch (ClassNotFoundException e) { System.out.println(e.getMessage()); } try { dbConnection = DriverManager.getConnection(DB_CONNECTION, DB_USER,DB_PASSWORD); return dbConnection; } catch (SQLException e) { System.out.println(e.getMessage()); } return dbConnection; } This seems to be working fine for now, with about 1-2 queries per second, but I am worried that once I expand and it is running many more, I might have some issues. My questions: Is there a way to have a persistent database connection throughout the entire run time of the process? If so, should I do this? Are there any other optimizations that I should do to help with performance? Thanks

    Read the article

  • Treating differential operator as algebraic entity

    - by chappar
    I know that this question is offtopic and don't belong here. But i didn't know somewhere else to ask. So here is the question. I was reading e:the story of a number by Eli Maor, where he treats differential operator as just like any algebraic entity. For example if we have a differential equation like y’’ + 5y’ - 6y = 0. This can be treaed as (D^2 + 5D – 6)y = 0. So, either y = 0 (trivial solution) or (D^2 + 5D – 6) = 0. Factoring out above equation we get (D-1)(D+6)= 0 with solutions as D = 1 and D = -6. Since D does not have any meaning on its own, multiplying by y on both the sides we get Dy = y and Dy = -6y for which the solutions are Ae^x and Be^-6x. Combining these 2 solutions we get Ae^x + Be^-6x. Now my doubt is this approach break when we have an equation like D^2y = 0. Which means y = 0 (again trivial) or D^2 = 0 which means D = 0. Now Dy = y*0 = 0. That means y = C ( a constant). The actual answer should be Cx. I know that it is stupidity to treat D^2 = 0 as D = 0, it led me to doubt the entire process of treating differential equation as algebraic equation. Can someone throw light on this? Or any other site where i might get answer?

    Read the article

  • Threads are blocked in malloc and free, virtual size

    - by Albert Wang
    Hi, I'm running a 64-bit multi-threaded program on the windows server 2003 server (X64), It run into a case that some of the threads seem to be blocked in the malloc or free function forever. The stack trace is like follows: ntdll.dll!NtWaitForSingleObject() + 0xa bytes ntdll.dll!RtlpWaitOnCriticalSection() - 0x1aa bytes ntdll.dll!RtlEnterCriticalSection() + 0xb040 bytes ntdll.dll!RtlpDebugPageHeapAllocate() + 0x2f6 bytes ntdll.dll!RtlDebugAllocateHeap() + 0x40 bytes ntdll.dll!RtlAllocateHeapSlowly() + 0x5e898 bytes ntdll.dll!RtlAllocateHeap() - 0x1711a bytes MyProg.exe!malloc(unsigned __int64 size=0) Line 168 C MyProg.exe!operator new(unsigned __int64 size=1) Line 59 + 0x5 bytes C++ ntdll.dll!NtWaitForSingleObject() ntdll.dll!RtlpWaitOnCriticalSection() ntdll.dll!RtlEnterCriticalSection() ntdll.dll!RtlpDebugPageHeapFree() ntdll.dll!RtlDebugFreeHeap() ntdll.dll!RtlFreeHeapSlowly() ntdll.dll!RtlFreeHeap() MyProg.exe!free(void * pBlock=0x000000007e8e4fe0) C BTW, the param values passed to the new operator is not correct here maybe due to optimization. Also, at the same time, I found in the process Explorer, the virtual size of this program is 10GB, but the private bytes and working set is very small (<2GB). We did have some threads using virtualalloc but in a way that commit the memory in the call, and these threads are not blocked. m_pBuf = VirtualAlloc(NULL, m_size, MEM_COMMIT, PAGE_READWRITE); ...... VirtualFree(m_pBuf, 0, MEM_RELEASE); This looks strange to me, seems a lot of virtual space is reserved but not committed, and malloc/free is blocked by lock. I'm guessing if there's any corruptions in the memory/object, so plan to turn on gflag with pageheap to troubleshoot this. Does anyone has similar experience on this before? Could you share with me so I may get more hints? Thanks a lot!

    Read the article

  • Why is calling close() after fopen() not closing?

    - by Richard Morgan
    I ran across the following code in one of our in-house dlls and I am trying to understand the behavior it was showing: long GetFD(long* fd, const char* fileName, const char* mode) { string fileMode; if (strlen(mode) == 0 || tolower(mode[0]) == 'w' || tolower(mode[0]) == 'o') fileMode = string("w"); else if (tolower(mode[0]) == 'a') fileMode = string("a"); else if (tolower(mode[0]) == 'r') fileMode = string("r"); else return -1; FILE* ofp; ofp = fopen(fileName, fileMode.c_str()); if (! ofp) return -1; *fd = (long)_fileno(ofp); if (*fd < 0) return -1; return 0; } long CloseFD(long fd) { close((int)fd); return 0; } After repeated calling of GetFD with the appropriate CloseFD, the whole dll would no longer be able to do any file IO. I wrote a tester program and found that I could GetFD 509 times, but the 510th time would error. Using Process Explorer, the number of Handles did not increase. So it seems that the dll is reaching the limit for the number of open files; setting _setmaxstdio(2048) does increase the amount of times we can call GetFD. Obviously, the close() is working quite right. After a bit of searching, I replaced the fopen() call with: long GetFD(long* fd, const char* fileName, const char* mode) { *fd = (long)open(fileName, 2); if (*fd < 0) return -1; return 0; } Now, repeatedly calling GetFD/CloseFD works. What is going on here?

    Read the article

< Previous Page | 764 765 766 767 768 769 770 771 772 773 774 775  | Next Page >