Search Results

Search found 18464 results on 739 pages for 'virtual functions'.

Page 181/739 | < Previous Page | 177 178 179 180 181 182 183 184 185 186 187 188  | Next Page >

• How can I Include Multiples Tables in my linq to entities eager loading using mvc4 C#

  - by EBENEZER CURVELLO

  I have 6 classes and I try to use linq to Entities to get the SiglaUF information of the last deeper table (in the view - MVC). The problem is I receive the following error: "The ObjectContext instance has been disposed and can no longer be used for operations that require a connection." The view is like that: > @model IEnumerable<DiskPizzaDelivery.Models.EnderecoCliente> > @foreach (var item in Model) { > @Html.DisplayFor(modelItem => item.CEP.Cidade.UF.SiglaUF) > } The query that i use: var cliente = context.Clientes .Include(e => e.Enderecos) .Include(e1 => e1.Enderecos.Select(cep => cep.CEP)) .SingleOrDefault(); The question is: How Can I improve this query to pre loading (eager loading) "Cidade" and "UF"? See below the classes: public partial class Cliente { [Key] [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)] public int IdCliente { get; set; } public string Email { get; set; } public string Senha { get; set; } public virtual ICollection<EnderecoCliente> Enderecos { get; set; } } public partial class EnderecoCliente { public int IdEndereco { get; set; } public int IdCliente { get; set; } public string CEPEndereco { get; set; } public string Numero { get; set; } public string Complemento { get; set; } public string PontoReferencia { get; set; } public virtual Cliente Cliente { get; set; } public virtual CEP CEP { get; set; } } public partial class CEP { public string CodCep { get; set; } public string Tipo_Logradouro { get; set; } public string Logradouro { get; set; } public string Bairro { get; set; } public int CodigoUF { get; set; } public int CodigoCidade { get; set; } public virtual Cidade Cidade { get; set; } } public partial class Cidade { public int CodigoCidade { get; set; } public string NomeCidade { get; set; } public int CodigoUF { get; set; } public virtual ICollection<CEP> CEPs { get; set; } public virtual UF UF { get; set; } public virtual ICollection<UF> UFs { get; set; } } public partial class UF { public int CodigoUF { get; set; } public string SiglaUF { get; set; } public string NomeUF { get; set; } public int CodigoCidadeCapital { get; set; } public virtual ICollection<Cidade> Cidades { get; set; } public virtual Cidade Cidade { get; set; } } var cliente = context.Clientes .Where(c => c.Email == email) .Where(c => c.Senha == senha) .Include(e => e.Enderecos) .Include(e1 => e1.Enderecos.Select(cep => cep.CEP)) .SingleOrDefault(); Thanks!

  Read the article

• SPARC T5-4 LDoms for RAC and WebLogic Clusters

  - by Jeff Taylor-Oracle

  I wanted to use two Oracle SPARC T5-4 servers to simultaneously host both Oracle RAC and a WebLogic Server Cluster. I chose to use Oracle VM Server for SPARC to create a cluster like this: There are plenty of trade offs and decisions that need to be made, for example: Rather than configuring the system by hand, you might want to use an Oracle SuperCluster T5-8 My configuration is similar to jsavit's: Availability Best Practices - Example configuring a T5-8 but I chose to ignore some of the advice. Maybe I should have included an  alternate service domain, but I decided that I already had enough redundancy Both Oracle SPARC T5-4 servers were to be configured like this: Cntl 0.25  4  64GB                     App LDom                    2.75 CPU's                                        44 cores                                          704 GB              DB LDom      One CPU         16 cores         256 GB   The systems started with everything in the primary domain: # ldm list NAME             STATE      FLAGS   CONS    VCPU  MEMORY   UTIL  NORM  UPTIME primary          active     -n-c--  UART    512   1023G    0.0%  0.0%  11m # ldm list-spconfig factory-default [current] primary # ldm list -o core,memory,physio NAME              primary           CORE     CID    CPUSET     0      (0, 1, 2, 3, 4, 5, 6, 7)     1      (8, 9, 10, 11, 12, 13, 14, 15)     2      (16, 17, 18, 19, 20, 21, 22, 23) -- SNIP     62     (496, 497, 498, 499, 500, 501, 502, 503)     63     (504, 505, 506, 507, 508, 509, 510, 511) MEMORY     RA               PA               SIZE                 0x30000000       0x30000000       255G     0x80000000000    0x80000000000    256G     0x100000000000   0x100000000000   256G     0x180000000000   0x180000000000   256G # Give this memory block to the DB LDom IO     DEVICE                           PSEUDONYM        OPTIONS     pci@300                          pci_0                pci@340                          pci_1                pci@380                          pci_2                pci@3c0                          pci_3                pci@400                          pci_4                pci@440                          pci_5                pci@480                          pci_6                pci@4c0                          pci_7                pci@300/pci@1/pci@0/pci@6        /SYS/RCSA/PCIE1     pci@300/pci@1/pci@0/pci@c        /SYS/RCSA/PCIE2     pci@300/pci@1/pci@0/pci@4/pci@0/pci@c /SYS/MB/SASHBA0     pci@300/pci@1/pci@0/pci@4/pci@0/pci@8 /SYS/RIO/NET0        pci@340/pci@1/pci@0/pci@6        /SYS/RCSA/PCIE3     pci@340/pci@1/pci@0/pci@c        /SYS/RCSA/PCIE4     pci@380/pci@1/pci@0/pci@a        /SYS/RCSA/PCIE9     pci@380/pci@1/pci@0/pci@4        /SYS/RCSA/PCIE10     pci@3c0/pci@1/pci@0/pci@e        /SYS/RCSA/PCIE11     pci@3c0/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE12     pci@400/pci@1/pci@0/pci@e        /SYS/RCSA/PCIE5     pci@400/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE6     pci@440/pci@1/pci@0/pci@e        /SYS/RCSA/PCIE7     pci@440/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE8     pci@480/pci@1/pci@0/pci@a        /SYS/RCSA/PCIE13     pci@480/pci@1/pci@0/pci@4        /SYS/RCSA/PCIE14     pci@4c0/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE15     pci@4c0/pci@1/pci@0/pci@4        /SYS/RCSA/PCIE16     pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c /SYS/MB/SASHBA1     pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4 /SYS/RIO/NET2    Added an additional service processor configuration: # ldm add-spconfig split # ldm list-spconfig factory-default primary split [current] And removed many of the resources from the primary domain: # ldm start-reconf primary # ldm set-core 4 primary # ldm set-memory 32G primary # ldm rm-io pci@340 primary # ldm rm-io pci@380 primary # ldm rm-io pci@3c0 primary # ldm rm-io pci@400 primary # ldm rm-io pci@440 primary # ldm rm-io pci@480 primary # ldm rm-io pci@4c0 primary # init 6 Needed to add resources to the guest domains: # ldm add-domain db # ldm set-core cid=`seq -s"," 48 63` db # ldm add-memory mblock=0x180000000000:256G db # ldm add-io pci@480 db # ldm add-io pci@4c0 db # ldm add-domain app # ldm set-core 44 app # ldm set-memory 704G  app # ldm add-io pci@340 app # ldm add-io pci@380 app # ldm add-io pci@3c0 app # ldm add-io pci@400 app # ldm add-io pci@440 app Needed to set up services: # ldm add-vds primary-vds0 primary # ldm add-vcc port-range=5000-5100 primary-vcc0 primary Needed to add a virtual network port for the WebLogic application domain: # ipadm NAME              CLASS/TYPE STATE        UNDER      ADDR lo0               loopback   ok           --         --    lo0/v4         static     ok           --         ...    lo0/v6         static     ok           --         ... net0              ip         ok           --         ...    net0/v4        static     ok           --         xxx.xxx.xxx.xxx/24    net0/v6        addrconf   ok           --         ....    net0/v6        addrconf   ok           --         ... net8              ip         ok           --         --    net8/v4        static     ok           --         ... # dladm show-phys LINK              MEDIA                STATE      SPEED  DUPLEX    DEVICE net1              Ethernet             unknown    0      unknown   ixgbe1 net0              Ethernet             up         1000   full      ixgbe0 net8              Ethernet             up         10     full      usbecm2 # ldm add-vsw net-dev=net0 primary-vsw0 primary # ldm add-vnet vnet1 primary-vsw0 app Needed to add a virtual disk to the WebLogic application domain: # format Searching for disks...done AVAILABLE DISK SELECTIONS:        0. c0t5000CCA02505F874d0 <HITACHI-H106060SDSUN600G-A2B0-558.91GB>           /scsi_vhci/disk@g5000cca02505f874           /dev/chassis/SPARC_T5-4.AK00084038/SYS/SASBP0/HDD0/disk        1. c0t5000CCA02506C468d0 <HITACHI-H106060SDSUN600G-A2B0-558.91GB>           /scsi_vhci/disk@g5000cca02506c468           /dev/chassis/SPARC_T5-4.AK00084038/SYS/SASBP0/HDD1/disk        2. c0t5000CCA025067E5Cd0 <HITACHI-H106060SDSUN600G-A2B0-558.91GB>           /scsi_vhci/disk@g5000cca025067e5c           /dev/chassis/SPARC_T5-4.AK00084038/SYS/SASBP0/HDD2/disk        3. c0t5000CCA02506C258d0 <HITACHI-H106060SDSUN600G-A2B0-558.91GB>           /scsi_vhci/disk@g5000cca02506c258           /dev/chassis/SPARC_T5-4.AK00084038/SYS/SASBP0/HDD3/disk Specify disk (enter its number): ^C # ldm add-vdsdev /dev/dsk/c0t5000CCA02506C468d0s2 HDD1@primary-vds0 # ldm add-vdisk HDD1 HDD1@primary-vds0 app Add some additional spice to the pot: # ldm set-variable auto-boot\\?=false db # ldm set-variable auto-boot\\?=false app # ldm set-var boot-device=HDD1 app Bind the logical domains: # ldm bind db # ldm bind app At the end of the process, the system is set up like this: # ldm list -o core,memory,physio NAME             primary          CORE     CID    CPUSET     0      (0, 1, 2, 3, 4, 5, 6, 7)     1      (8, 9, 10, 11, 12, 13, 14, 15)     2      (16, 17, 18, 19, 20, 21, 22, 23)     3      (24, 25, 26, 27, 28, 29, 30, 31) MEMORY     RA               PA               SIZE                0x30000000       0x30000000       32G IO     DEVICE                           PSEUDONYM        OPTIONS     pci@300                          pci_0               pci@300/pci@1/pci@0/pci@6        /SYS/RCSA/PCIE1     pci@300/pci@1/pci@0/pci@c        /SYS/RCSA/PCIE2     pci@300/pci@1/pci@0/pci@4/pci@0/pci@c /SYS/MB/SASHBA0     pci@300/pci@1/pci@0/pci@4/pci@0/pci@8 /SYS/RIO/NET0   ------------------------------------------------------------------------------ NAME             app              CORE     CID    CPUSET     4      (32, 33, 34, 35, 36, 37, 38, 39)     5      (40, 41, 42, 43, 44, 45, 46, 47)     6      (48, 49, 50, 51, 52, 53, 54, 55)     7      (56, 57, 58, 59, 60, 61, 62, 63)     8      (64, 65, 66, 67, 68, 69, 70, 71)     9      (72, 73, 74, 75, 76, 77, 78, 79)     10     (80, 81, 82, 83, 84, 85, 86, 87)     11     (88, 89, 90, 91, 92, 93, 94, 95)     12     (96, 97, 98, 99, 100, 101, 102, 103)     13     (104, 105, 106, 107, 108, 109, 110, 111)     14     (112, 113, 114, 115, 116, 117, 118, 119)     15     (120, 121, 122, 123, 124, 125, 126, 127)     16     (128, 129, 130, 131, 132, 133, 134, 135)     17     (136, 137, 138, 139, 140, 141, 142, 143)     18     (144, 145, 146, 147, 148, 149, 150, 151)     19     (152, 153, 154, 155, 156, 157, 158, 159)     20     (160, 161, 162, 163, 164, 165, 166, 167)     21     (168, 169, 170, 171, 172, 173, 174, 175)     22     (176, 177, 178, 179, 180, 181, 182, 183)     23     (184, 185, 186, 187, 188, 189, 190, 191)     24     (192, 193, 194, 195, 196, 197, 198, 199)     25     (200, 201, 202, 203, 204, 205, 206, 207)     26     (208, 209, 210, 211, 212, 213, 214, 215)     27     (216, 217, 218, 219, 220, 221, 222, 223)     28     (224, 225, 226, 227, 228, 229, 230, 231)     29     (232, 233, 234, 235, 236, 237, 238, 239)     30     (240, 241, 242, 243, 244, 245, 246, 247)     31     (248, 249, 250, 251, 252, 253, 254, 255)     32     (256, 257, 258, 259, 260, 261, 262, 263)     33     (264, 265, 266, 267, 268, 269, 270, 271)     34     (272, 273, 274, 275, 276, 277, 278, 279)     35     (280, 281, 282, 283, 284, 285, 286, 287)     36     (288, 289, 290, 291, 292, 293, 294, 295)     37     (296, 297, 298, 299, 300, 301, 302, 303)     38     (304, 305, 306, 307, 308, 309, 310, 311)     39     (312, 313, 314, 315, 316, 317, 318, 319)     40     (320, 321, 322, 323, 324, 325, 326, 327)     41     (328, 329, 330, 331, 332, 333, 334, 335)     42     (336, 337, 338, 339, 340, 341, 342, 343)     43     (344, 345, 346, 347, 348, 349, 350, 351)     44     (352, 353, 354, 355, 356, 357, 358, 359)     45     (360, 361, 362, 363, 364, 365, 366, 367)     46     (368, 369, 370, 371, 372, 373, 374, 375)     47     (376, 377, 378, 379, 380, 381, 382, 383) MEMORY     RA               PA               SIZE                0x30000000       0x830000000      192G     0x4000000000     0x80000000000    256G     0x8080000000     0x100000000000   256G IO     DEVICE                           PSEUDONYM        OPTIONS     pci@340                          pci_1               pci@380                          pci_2               pci@3c0                          pci_3               pci@400                          pci_4               pci@440                          pci_5               pci@340/pci@1/pci@0/pci@6        /SYS/RCSA/PCIE3     pci@340/pci@1/pci@0/pci@c        /SYS/RCSA/PCIE4     pci@380/pci@1/pci@0/pci@a        /SYS/RCSA/PCIE9     pci@380/pci@1/pci@0/pci@4        /SYS/RCSA/PCIE10     pci@3c0/pci@1/pci@0/pci@e        /SYS/RCSA/PCIE11     pci@3c0/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE12     pci@400/pci@1/pci@0/pci@e        /SYS/RCSA/PCIE5     pci@400/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE6     pci@440/pci@1/pci@0/pci@e        /SYS/RCSA/PCIE7     pci@440/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE8 ------------------------------------------------------------------------------ NAME             db               CORE     CID    CPUSET     48     (384, 385, 386, 387, 388, 389, 390, 391)     49     (392, 393, 394, 395, 396, 397, 398, 399)     50     (400, 401, 402, 403, 404, 405, 406, 407)     51     (408, 409, 410, 411, 412, 413, 414, 415)     52     (416, 417, 418, 419, 420, 421, 422, 423)     53     (424, 425, 426, 427, 428, 429, 430, 431)     54     (432, 433, 434, 435, 436, 437, 438, 439)     55     (440, 441, 442, 443, 444, 445, 446, 447)     56     (448, 449, 450, 451, 452, 453, 454, 455)     57     (456, 457, 458, 459, 460, 461, 462, 463)     58     (464, 465, 466, 467, 468, 469, 470, 471)     59     (472, 473, 474, 475, 476, 477, 478, 479)     60     (480, 481, 482, 483, 484, 485, 486, 487)     61     (488, 489, 490, 491, 492, 493, 494, 495)     62     (496, 497, 498, 499, 500, 501, 502, 503)     63     (504, 505, 506, 507, 508, 509, 510, 511) MEMORY     RA               PA               SIZE                0x80000000       0x180000000000   256G IO     DEVICE                           PSEUDONYM        OPTIONS     pci@480                          pci_6               pci@4c0                          pci_7               pci@480/pci@1/pci@0/pci@a        /SYS/RCSA/PCIE13     pci@480/pci@1/pci@0/pci@4        /SYS/RCSA/PCIE14     pci@4c0/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE15     pci@4c0/pci@1/pci@0/pci@4        /SYS/RCSA/PCIE16     pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c /SYS/MB/SASHBA1     pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4 /SYS/RIO/NET2   Start the domains: # ldm start app LDom app started # ldm start db LDom db started Make sure to start the vntsd service that was created, above. # svcs -a | grep ldo disabled        8:38:38 svc:/ldoms/vntsd:default online          8:38:58 svc:/ldoms/agents:default online          8:39:25 svc:/ldoms/ldmd:default # svcadm enable vntsd Now use the MAC address to configure the Solaris 11 Automated Installation. Database Logical Domain # telnet localhost 5000 {0} ok devalias screen                   /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@7/display@0 disk7                    /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0/disk@p3 disk6                    /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0/disk@p2 disk5                    /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0/disk@p1 disk4                    /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0/disk@p0 scsi1                    /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0 net3                     /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4/network@0,1 net2                     /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4/network@0 virtual-console          /virtual-devices/console@1 name                     aliases {0} ok boot net2 Boot device: /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4/network@0  File and args: 1000 Mbps full duplex Link up Requesting Internet Address for xx:xx:xx:xx:xx:xx Requesting Internet Address for xx:xx:xx:xx:xx:xx WLS Logical Domain # telnet localhost 5001 {0} ok devalias hdd1                     /virtual-devices@100/channel-devices@200/disk@0 vnet1                    /virtual-devices@100/channel-devices@200/network@0 net                      /virtual-devices@100/channel-devices@200/network@0 disk                     /virtual-devices@100/channel-devices@200/disk@0 virtual-console          /virtual-devices/console@1 name                     aliases {0} ok boot net Boot device: /virtual-devices@100/channel-devices@200/network@0  File and args: Requesting Internet Address for xx:xx:xx:xx:xx:xx Requesting Internet Address for xx:xx:xx:xx:xx:xx Repeat the process for the second SPARC T5-4, install Solaris, RAC and WebLogic Cluster, and you are ready to go. Maybe buying a SuperCluster would have been easier.

  Read the article

• What's the best way to expose a Model object in a ViewModel?

  - by Angel

  In a WPF MVVM application, I exposed my model object into my viewModel by creating an instance of Model class (which cause dependency) into ViewModel. Instead of creating separate VM properties, I wrap the Model properties inside my ViewModel Property. My model is just an entity framework generated proxy class: public partial class TblProduct { public TblProduct() { this.TblPurchaseDetails = new HashSet<TblPurchaseDetail>(); this.TblPurchaseOrderDetails = new HashSet<TblPurchaseOrderDetail>(); this.TblSalesInvoiceDetails = new HashSet<TblSalesInvoiceDetail>(); this.TblSalesOrderDetails = new HashSet<TblSalesOrderDetail>(); } public int ProductId { get; set; } public string ProductCode { get; set; } public string ProductName { get; set; } public int CategoryId { get; set; } public string Color { get; set; } public Nullable<decimal> PurchaseRate { get; set; } public Nullable<decimal> SalesRate { get; set; } public string ImagePath { get; set; } public bool IsActive { get; set; } public virtual TblCompany TblCompany { get; set; } public virtual TblProductCategory TblProductCategory { get; set; } public virtual TblUser TblUser { get; set; } public virtual ICollection<TblPurchaseDetail> TblPurchaseDetails { get; set; } public virtual ICollection<TblPurchaseOrderDetail> TblPurchaseOrderDetails { get; set; } public virtual ICollection<TblSalesInvoiceDetail> TblSalesInvoiceDetails { get; set; } public virtual ICollection<TblSalesOrderDetail> TblSalesOrderDetails { get; set; } } Here is my ViewModel: public class ProductViewModel : WorkspaceViewModel { #region Constructor public ProductViewModel() { StartApp(); } #endregion //Constructor #region Properties private IProductDataService _dataService; public IProductDataService DataService { get { if (_dataService == null) { if (IsInDesignMode) { _dataService = new ProductDataServiceMock(); } else { _dataService = new ProductDataService(); } } return _dataService; } } //Get and set Model object private TblProduct _product; public TblProduct Product { get { return _product ?? (_product = new TblProduct()); } set { _product = value; } } #region Public Properties public int ProductId { get { return Product.ProductId; } set { if (Product.ProductId == value) { return; } Product.ProductId = value; RaisePropertyChanged("ProductId"); } } public string ProductName { get { return Product.ProductName; } set { if (Product.ProductName == value) { return; } Product.ProductName = value; RaisePropertyChanged(() => ProductName); } } private ObservableCollection<TblProduct> _productRecords; public ObservableCollection<TblProduct> ProductRecords { get { return _productRecords; } set { _productRecords = value; RaisePropertyChanged("ProductRecords"); } } //Selected Product private TblProduct _selectedProduct; public TblProduct SelectedProduct { get { return _selectedProduct; } set { _selectedProduct = value; if (_selectedProduct != null) { this.ProductId = _selectedProduct.ProductId; this.ProductCode = _selectedProduct.ProductCode; } RaisePropertyChanged("SelectedProduct"); } } #endregion //Public Properties #endregion // Properties #region Commands private ICommand _newCommand; public ICommand NewCommand { get { if (_newCommand == null) { _newCommand = new RelayCommand(() => ResetAll()); } return _newCommand; } } private ICommand _saveCommand; public ICommand SaveCommand { get { if (_saveCommand == null) { _saveCommand = new RelayCommand(() => Save()); } return _saveCommand; } } private ICommand _deleteCommand; public ICommand DeleteCommand { get { if (_deleteCommand == null) { _deleteCommand = new RelayCommand(() => Delete()); } return _deleteCommand; } } #endregion //Commands #region Methods private void StartApp() { LoadProductCollection(); } private void LoadProductCollection() { var q = DataService.GetAllProducts(); this.ProductRecords = new ObservableCollection<TblProduct>(q); } private void Save() { if (SelectedOperateMode == OperateModeEnum.OperateMode.New) { //Pass the Model object into Dataservice for save DataService.SaveProduct(this.Product); } else if (SelectedOperateMode == OperateModeEnum.OperateMode.Edit) { //Pass the Model object into Dataservice for Update DataService.UpdateProduct(this.Product); } ResetAll(); LoadProductCollection(); } #endregion //Methods } Here is my Service class: class ProductDataService:IProductDataService { /// <summary> /// Context object of Entity Framework model /// </summary> private MaizeEntities Context { get; set; } public ProductDataService() { Context = new MaizeEntities(); } public IEnumerable<TblProduct> GetAllProducts() { using(var context=new R_MaizeEntities()) { var q = from p in context.TblProducts where p.IsDel == false select p; return new ObservableCollection<TblProduct>(q); } } public void SaveProduct(TblProduct _product) { using(var context=new R_MaizeEntities()) { _product.LastModUserId = GlobalObjects.LoggedUserID; _product.LastModDttm = DateTime.Now; _product.CompanyId = GlobalObjects.CompanyID; context.TblProducts.Add(_product); context.SaveChanges(); } } public void UpdateProduct(TblProduct _product) { using (var context = new R_MaizeEntities()) { context.TblProducts.Attach(_product); context.Entry(_product).State = EntityState.Modified; _product.LastModUserId = GlobalObjects.LoggedUserID; _product.LastModDttm = DateTime.Now; _product.CompanyId = GlobalObjects.CompanyID; context.SaveChanges(); } } public void DeleteProduct(int _productId) { using (var context = new R_MaizeEntities()) { var product = (from c in context.TblProducts where c.ProductId == _productId select c).First(); product.LastModUserId = GlobalObjects.LoggedUserID; product.LastModDttm = DateTime.Now; product.IsDel = true; context.SaveChanges(); } } } I exposed my model object in my viewModel by creating an instance of it using new keyword, also I instantiated my DataService class in VM. I know this will cause a strong dependency. So: What's the best way to expose a Model object in a ViewModel? What's the best way to use DataService in VM?

  Read the article

• MVVM- Expose Model object in ViewModel

  - by Angel

  I have a wpf MVVM application , I exposed my model object into my viewModel by creating an instance of Model class (which cause dependency) into ViewModel , and instead of creating seperate VM properties , I wrap the Model properties inside my ViewModel Property. My model is just an entity framework generated proxy classes. Here is my Model class : public partial class TblProduct { public TblProduct() { this.TblPurchaseDetails = new HashSet<TblPurchaseDetail>(); this.TblPurchaseOrderDetails = new HashSet<TblPurchaseOrderDetail>(); this.TblSalesInvoiceDetails = new HashSet<TblSalesInvoiceDetail>(); this.TblSalesOrderDetails = new HashSet<TblSalesOrderDetail>(); } public int ProductId { get; set; } public string ProductCode { get; set; } public string ProductName { get; set; } public int CategoryId { get; set; } public string Color { get; set; } public Nullable<decimal> PurchaseRate { get; set; } public Nullable<decimal> SalesRate { get; set; } public string ImagePath { get; set; } public bool IsActive { get; set; } public virtual TblCompany TblCompany { get; set; } public virtual TblProductCategory TblProductCategory { get; set; } public virtual TblUser TblUser { get; set; } public virtual ICollection<TblPurchaseDetail> TblPurchaseDetails { get; set; } public virtual ICollection<TblPurchaseOrderDetail> TblPurchaseOrderDetails { get; set; } public virtual ICollection<TblSalesInvoiceDetail> TblSalesInvoiceDetails { get; set; } public virtual ICollection<TblSalesOrderDetail> TblSalesOrderDetails { get; set; } } Here is my ViewModel , public class ProductViewModel : WorkspaceViewModel { #region Constructor public ProductViewModel() { StartApp(); } #endregion //Constructor #region Properties private IProductDataService _dataService; public IProductDataService DataService { get { if (_dataService == null) { if (IsInDesignMode) { _dataService = new ProductDataServiceMock(); } else { _dataService = new ProductDataService(); } } return _dataService; } } //Get and set Model object private TblProduct _product; public TblProduct Product { get { return _product ?? (_product = new TblProduct()); } set { _product = value; } } #region Public Properties public int ProductId { get { return Product.ProductId; } set { if (Product.ProductId == value) { return; } Product.ProductId = value; RaisePropertyChanged("ProductId"); } } public string ProductName { get { return Product.ProductName; } set { if (Product.ProductName == value) { return; } Product.ProductName = value; RaisePropertyChanged(() => ProductName); } } private ObservableCollection<TblProduct> _productRecords; public ObservableCollection<TblProduct> ProductRecords { get { return _productRecords; } set { _productRecords = value; RaisePropertyChanged("ProductRecords"); } } //Selected Product private TblProduct _selectedProduct; public TblProduct SelectedProduct { get { return _selectedProduct; } set { _selectedProduct = value; if (_selectedProduct != null) { this.ProductId = _selectedProduct.ProductId; this.ProductCode = _selectedProduct.ProductCode; } RaisePropertyChanged("SelectedProduct"); } } #endregion //Public Properties #endregion // Properties #region Commands private ICommand _newCommand; public ICommand NewCommand { get { if (_newCommand == null) { _newCommand = new RelayCommand(() => ResetAll()); } return _newCommand; } } private ICommand _saveCommand; public ICommand SaveCommand { get { if (_saveCommand == null) { _saveCommand = new RelayCommand(() => Save()); } return _saveCommand; } } private ICommand _deleteCommand; public ICommand DeleteCommand { get { if (_deleteCommand == null) { _deleteCommand = new RelayCommand(() => Delete()); } return _deleteCommand; } } #endregion //Commands #region Methods private void StartApp() { LoadProductCollection(); } private void LoadProductCollection() { var q = DataService.GetAllProducts(); this.ProductRecords = new ObservableCollection<TblProduct>(q); } private void Save() { if (SelectedOperateMode == OperateModeEnum.OperateMode.New) { //Pass the Model object into Dataservice for save DataService.SaveProduct(this.Product); } else if (SelectedOperateMode == OperateModeEnum.OperateMode.Edit) { //Pass the Model object into Dataservice for Update DataService.UpdateProduct(this.Product); } ResetAll(); LoadProductCollection(); } #endregion //Methods } Here is my Service class: class ProductDataService:IProductDataService { /// <summary> /// Context object of Entity Framework model /// </summary> private MaizeEntities Context { get; set; } public ProductDataService() { Context = new MaizeEntities(); } public IEnumerable<TblProduct> GetAllProducts() { using(var context=new R_MaizeEntities()) { var q = from p in context.TblProducts where p.IsDel == false select p; return new ObservableCollection<TblProduct>(q); } } public void SaveProduct(TblProduct _product) { using(var context=new R_MaizeEntities()) { _product.LastModUserId = GlobalObjects.LoggedUserID; _product.LastModDttm = DateTime.Now; _product.CompanyId = GlobalObjects.CompanyID; context.TblProducts.Add(_product); context.SaveChanges(); } } public void UpdateProduct(TblProduct _product) { using (var context = new R_MaizeEntities()) { context.TblProducts.Attach(_product); context.Entry(_product).State = EntityState.Modified; _product.LastModUserId = GlobalObjects.LoggedUserID; _product.LastModDttm = DateTime.Now; _product.CompanyId = GlobalObjects.CompanyID; context.SaveChanges(); } } public void DeleteProduct(int _productId) { using (var context = new R_MaizeEntities()) { var product = (from c in context.TblProducts where c.ProductId == _productId select c).First(); product.LastModUserId = GlobalObjects.LoggedUserID; product.LastModDttm = DateTime.Now; product.IsDel = true; context.SaveChanges(); } } } I exposed my model object in my viewModel by creating an instance of it using new keyword, also I instantiated my DataService class in VM, I know this will cause a strong dependency. So , 1- Whats the best way to expose Model object in ViewModel ? 2- Whats the best way to use DataService in VM ?

  Read the article

• 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.

  Read the article

• DNS protocol message example

  - by virtual-lab

  hello there, I am trying to figure out how to send out DNS messages from an application socket adapter to a DNSBL. I spent the last two days understanding the basics, including experimenting with WireShark to catch an example of message exchanged. Now I would like to query the DNS without using dig or host command (I'm using Ubuntu); how can I perform this action at low level, without the help of these tools in wrapping the request in a proper DNS message format? How the message should be post it? Hex or String? Thanks in advance for any help. Regards Alessandro Ilardo Comment added I am investigating on JDev and Oracle SOA. The platform provides a Socket Adapter which simply apply a transformation (XSLT) and send the message straight to the socket. How the payload parameters (ex. the host I'm looking up) are wrapped within the message is left to the developer. So basically I have an idea on how the all DNS message is structured, but rather than put everything on JDev stright away I'd like to make some tests on my own just to make sure I got a valid message format. So, I am not using any specific language (I don't even understand why they moved my question from serverfault) and I don't want to use any tools which would hide part of the message, such as the header. I know they work well btw. I guess this stuff has something to do with packet injection. Someone suggested me to use telnet, but I've only used for SMTP or HTTP, I haven't got a clue on how it works for DNS request. Does it make more sense now?

  Read the article

• Windows Azure: Announcing Support for Windows Server 2012 R2 + Some Nice Price Cuts

  - by ScottGu

  Today we released some great updates to Windows Azure: Virtual Machines: Support for Windows Server 2012 R2 Cloud Services: Support for Windows Server 2012 R2 and .NET 4.5.1 Windows Azure Pack: Use Windows Azure features on-premises using Windows Server 2012 R2 Price Cuts: Up to 22% Price Reduction on Memory-Intensive Instances Below are more details about each of the improvements: Virtual Machines: Support for Windows Server 2012 R2 This morning we announced the release of Windows Server 2012 R2 – which is a fantastic update to Windows Server and includes a ton of great enhancements. This morning we are also excited to announce that the general availability image of Windows Server 2012 RC is now supported on Windows Azure.  Windows Azure is the first cloud provider to offer the final release of Windows Server 2012 R2, and it is incredibly easy to launch your own Windows Server 2012 R2 instance with it. To create a new Windows Server 2012 R2 instance simply choose New->Compute->Virtual Machine within the Windows Azure Management Portal.  You can select the “Windows Server 2012 R2” image and create a new Virtual Machine using the “Quick Create” option: Or alternatively click the “From Gallery” option if you want to customize even more configuration options (endpoints, remote powershell, availability set, etc): Creating and instantiating a new Virtual Machine on Windows Azure is very fast.  In fact, the Windows Server 2012 R2 image now deploys and runs 30% faster than previous versions of Windows Server. Once the VM is deployed you can drill into it to track its health and manage its settings: Clicking the “Connect” button allows you to remote desktop into the VM – at which point you can customize and manage it as a full administrator however you want: If you haven’t tried Windows Server 2012 R2 yet – give it a try with Windows Azure.  There is no easier way to get an instance of it up and running! Cloud Services: Support for using Windows Server 2012 R2 with Web and Worker Roles Today’s Windows Azure release also allows you to now use Windows Server 2012 R2 and .NET 4.5.1 within Web and Worker Roles within Cloud Service based applications.  Enabling this is easy.  You can configure existing existing Cloud Service application to use Windows Server 2012 R2 by updating your Cloud Service Configuration File (.cscfg) to use the new “OS Family 4” setting: Or alternatively you can use the Windows Azure Management Portal to update cloud services that are already deployed on Windows Azure.  Simply choose the configure tab on them and select Windows Server 2012 R2 in the Operating System Family dropdown: The approaches above enable you to immediately take advantage of Windows Server 2012 R2 and .NET 4.5.1 and all the great features they provide. Windows Azure Pack: Use Windows Azure features on Windows Server 2012 R2 Today we also made generally available the Windows Azure Pack, which is a free download that enables you to run Windows Azure Technology within your own datacenter, an on-premises private cloud environment, or with one of our service provider/hosting partners who run Windows Server. Windows Azure Pack enables you to use a management portal that has the exact same UI as the Windows Azure Management Portal, and within which you can create and manage Virtual Machines, Web Sites, and Service Bus – all of which can run on Windows Server and System Center.  The services provided with the Windows Azure Pack are consistent with the services offered within our Windows Azure public cloud offering.  This consistency enables organizations and developers to build applications and solutions that can run in any hosting environment – and which use the same development and management approach.  The end result is an offering with incredible flexibility. You can learn more about Windows Azure Pack and download/deploy it today here. Price Cuts: Up to 22% Reduction on Memory Intensive Instances Today we are also reducing prices by up to 22% on our memory-intensive VM instances (specifically our A5, A6, and A7 instances).  These price reductions apply to both Windows and Linux VM instances, as well as for Cloud Service based applications: These price reductions will take effect in November, and will enable you to run applications that demand larger memory (such as SharePoint, Databases, in-memory analytics, etc) even more cost effectively. Summary Today’s release enables you to start using Windows Server 2012 R2 within Windows Azure immediately, and take advantage of our Cloud OS vision both within our datacenters – and using the Windows Azure Pack within both your existing datacenters and those of our partners. If you don’t already have a Windows Azure account, you can sign-up for a free trial and start using all of the above features today.  Then visit the Windows Azure Developer Center to learn more about how to build apps with it. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

  Read the article

• OBIEE 11.1.1 - OBIEE 11g Full Sample App on VMware Player 4

  - by user809526

  The Full Sample App is designed to run on Virtual Box. Let's describe how to run it on VMware Player 4. Open Virtualization Format Tool http://communities.vmware.com/community/vmtn/server/vsphere/automationtools/ovf VMware Player Documentation https://www.vmware.com/support/pubs/player_pubs.html Full Sample App Deployment Guide sampleapp107-vbimage-deployguide-453583.pdf INSTALL VMplayer 4.0.0 as root LINUX # sh VMware-Player-4.0.0-471780.x86_64.bundle (A new VM is not needed and can be deleted later after that installation is completed. "I will install OS later" - blank hard disk Guest: linux, Red Hat Enterprise Linux 5-64bits => rename to RHEL target: eg /a/root/vmware/ Max disk size: 5 GB (will be deleted) Disk: Single file Dummy RHEL.vmk, RHEL.vmdk is generated. "Delete VM from Disk" in VM Player.) Copy Full Sample App files to target /a/root/vmware/ WARNING: Select a target eg /a/root/vmware/ with lots of free space, 95 GB. Check checksums (md5sum). Please do it! ff85c7eacf7fb8c382e98da875e879e1  Sampleapp_v107_GA-disk1.vmdk 973258cb3c7d64ab03ae853278cf2233  Sampleapp_v107_GA-disk2.vmdk e576be16e36d810479736bfb15d050f5  Sampleapp_v107_GA-disk3.vmdk 3455df77279e53e07d5fee6712f1597d  Sampleapp_v107_GA-disk4.vmdk OVF FILE   Sampleapp_v107_GA.ovf CONVERSION $ cd /a/root/vmware/ LINUX $ /usr/bin/ovftool -tt=ovf --compress=1 -dm=monolithicSparse Sampleapp_v107_GA.ovf .  [dot] Opening OVF source: Sampleapp_v107_GA.ovf Warning: No manifest file Opening OVF target: . Writing OVF package: Sampleapp_v107_GA/Sampleapp_v107_GA.ovf Disk Transfer Completed                   Completed successfully WINDOWS CYGWIN $ /cygdrive/c/VMwarePlayer/OVFTool/ovftool.exe -tt=ovf --compress=1 -dm=monolithicSparse Sampleapp_v107_GA.ovf .  [dot] Opening OVF source: Sampleapp_v107_GA.ovf Warning: No manifest file Opening OVF target: . Writing OVF package: Sampleapp_v107_GA\Sampleapp_v107_GA.ovf Disk Transfer Completed Completed successfully /a/root/vmware$ du -sk 49095328    .   [50 GB already occupied] IMPORT - First start of VM Player 4: /usr/bin/vmplayer "Open a Virtual Machine" Browse to /a/root/vmware/Sampleapp_v107_GA/Sampleapp_v107_GA.ovf [the new generated .ovf] "Import Virtual Machine" dialog Name: Sampleapp_v107_GA Location: /a/root/vmware/Sampleapp_v107_GA/storage [was /home/tdubois/vmware/Sampleapp_v107_GA] "Import" "The import failed because /a/root/vmware/Sampleapp_v107_GA/Sampleapp_v107_GA.ovf did not pass OVF specification conformance or virtual hardware compliance checks. Click Retry to relax OVF specification..." "Retry" ; Long import /a/root/vmware/Sampleapp_v107_GA/storage/Sampleapp_v107_GA.vmx and new .vmdk files are created. /a/root/vmware$ du -sk 95551384    .   [95 GB occupied] Full Sample App GUEST SETUP "Edit VM settings" min 3GB, 2+ processors, network bridged. For OBIEE + Essbase testing use 8 GB RAM hardware. At first time lauch of Full Sample App, leave OEL booting for several minutes undisturbed. Problem with X display server may occur [/usr/bin/Xorg ; man Xorg]. "Failed to start the X server.... Would you like to view the X server output to diagnose the problem?" "No" [tab key] "Would you like to try to configure the X server? Note that you will need the root password for this." "Yes" [oracle] X Display Settings 800x600 saved in /etc/X11/xorg.conf "Trying to restart the X server" Login as root/oracle in guest OEL. In guest OEL, Virtual Machine > Install VMware Tools... Extract archive VMwareTools-8.8.0-471268.tar.gz all files in writable local directory eg /root In Terminal run Perl script # cd /root/vmware-tools-distrib ; ./vmware-install.pl [keep all default answers] Set keyboard layout System > Preferences > Keyboard > Layouts Restart X server eg System > Log Out root... , relogin Modify X resolution System > Preferences > Screen Resolution Full Sample App OEL login: oracle/oracle ; root/oracle [default US keyboard layout] Credentials are described in the 'sampleapp107-vbimage-deployguide-453583.pdf' The large files in /a/root/vmware/ /a/root/vmware/Sampleapp_v107_GA/ may be removed. FAILURE REMARK: Adding the 4 original Sampleapp_v107_GA-disks[1234].vmdk to VM Player does NOT work as described below. "Edit VM settings" "Remove" "Hard Disk" "Edit VM settings" "Add" "Hard Disk" "Next" "Use an existing virtual disk" "Browse" "Finish" "Keep existing format" "Ok" for each 4 disks settings one by one. Start VM Player 4. "You do not have write access to a partition" Allow all Sampleapp_v107 OEL linux launches. OEL stalls silently after 'Checking filesystems'.

  Read the article

• A Taxonomy of Numerical Methods v1

  - by JoshReuben

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

  Read the article

• Training on Demand Certification Packages for DBAs

  - by Antoinette O'Sullivan

  The demand for Database Administrators continues to grow.*Almost two-thirds of IT hiring managers indicate that they highly value certifications in validatingIT skills and expertise.** * Job satisfaction and DBA work growth rate: CNN Money's 2011 Best Jobs in America survey.** Survey among nearly 1,700 respondents by CompTIA, the nonprofit trade association for the IT industry, cited in Certification Magazine, Feb. 14 th., 2012. Get Certified with Training on DemandAre you an experienced Database professional eager to achieve certification?Is time your most precious resource?Then try our new Training On Demand Certification Value Package with 20% discount. These all-in-one packages give you everything you need to get certified with success: Why Training On Demand:  Expert training from Oracle’s top instructors Sophisticated streaming video recording Available for 90 days, 24 hours a day, 7 days a week White boarding and training labs for hands-on experience Start, stop, pause, jump or rewind sections of the course as needed  Oracle University instructor Q&A  A full-text search leads to the right video fragment in a matter of seconds. Watch this demo to see how it works. Additional Certification resources: Benefits of Oracle Certification Database Certification Paths Available Database Certification Exams Getting certified has never been easier!For assistance contact your local Oracle University Service Desk. Many organizations deploy both Oracle Database and MySQL side by side to serve different needs, and as a database professional you can find training courses on both topics at Oracle University! Check out the upcoming Oracle Database 11g training courses and MySQL training courses. Even if you're only managing Oracle Databases at this point of time, getting familiar with MySQL Database will broaden your career path with growing job demand. These Value Packages are also available with the following training formats: In-Class, Live Virtual Class and Self Study: MySQL Database Administration Value Packages Your Savings plus get a FREE Retake  save 5% save 20% save 20% save 20%   In Class Edition Live Virtual Class Edition Self-Study Edition Training On Demand MySQL Database Administrator Certification Value Package View Package View Package View Package View Package MySQL Developer Value Packages Your Savings plus get a FREE Retake  save 5% save 20% save 20% save 20%   In Class Edition Live Virtual Class Edition Self-Study Edition Training On Demand       MySQL Developer Certification Value Package View Package View Package     Oracle Database 10g Value Packages Your Savings plus get a FREE Retake  save 5% save 20% save 20% save 20%   In Class Edition Live Virtual Class Edition Self-Study Edition Training On Demand Oracle Database 10g Administrator Certified Associate Certification Value Package View Package View Package View Package   Oracle Database 10g Administrator Certified Professional Certification Value Package View Package View Package View Package   Oracle Database 11g Value Packages Your Savings plus get a FREE Retake  save 5% save 20% save 20% save 20%   In Class Edition Live Virtual Class Edition Self-Study Edition Training On Demand Oracle Database 11g Administrator Certified Associate Certification Value Package View Package View Package View Package View Package Oracle Database 11g Administrator Certified Professional Certification Value Package View Package View Package View Package View Package Exam Prep Seminar Value Package: Oracle Database Admin 1       View Package Oracle Database 11g Administrator Certified Professional UPGRADE Certification Value Package       View Package Oracle Real Application Clusters 11g and Grid Infrastructure Administraton Certified Expert Certification Value Package       View Package Exam Prep Seminar Value Package: Oracle Database Admin 2        View Package Exam Prep Seminar Value Package: Oracle RAC 11g and Grid Infrastructure Administration       View Package Exam Prep Seminar Value Package: Upgrade Oracle Certified Professional (OCP) to Oracle Database 11g       View Package SQL and PL/SQL Value Packages Your Savings plus get a FREE Retake  save 5% save 20% save 20% save 20%   In Class Edition Live Virtual Class Edition Self-Study Edition Training On Demand Oracle Database Sql Expert Certification Value Package View Package View Package View Package View Package Exam Prep Seminar Value Package: Oracle Database SQL       View Package View our Certification Value Packages Mention this code at the time of booking: E1245 Connect For a full list of MySQL Training courses and events, go to http://oracle.com/education/mysql.

  Read the article

• aspnet_regiis -lk is not listing the site I need

  - by Luke Duddridge

  I am trying to release a site to run under framework 4 on a server that also hosts framework 2 sites. By default the App has defaulted to framework 2, but when I try to change it's framework to 4 I get a message saying that the following action will cause the iis to reset. The problem I have is there are serveral active sites that I do not want to interupt with a restart. The message goes on to say you can avoid restarting by running the following: aspnet_regiis -norestart -s [IIS Virtual Path] I have been attempting to find the site virtual path but when I run aspnet_regiis -lk the site I am after does not appear to be listed. My first thoughts were that it has something to do with the app pool?, but I'm sure I saw sites that are inactive listed, and after creating a basic site to get it to run under framework 2, the site still did not appear in the -lk list. Can anyone tell me if there is an alternative location to the -lk that I can find the specific information realating to the IIS Virtual Path?

  Read the article

• Bullet physics debug drawing not working

  - by Krishnabhadra

  Background I am following on from this question, which isn't answered yet. Basically I have a cube and a UVSphere in my scene, with UVSphere on the top of the cube without touching the cube. Both exported from blender. When I run the app The UVSphere does circle around the cube for 3 or 4 times and jump out of the scene. What I actually expect was the sphere to fall on top of the cube. What this question about From the comment to the linked question, I got to know about bullet debug drawing, which helps in debugging by drawing outline of physics bodies which are normally invisible. I did some research on that and came up with the code given below. From whatever I have read, below code should work, but it doesn't. My Code My bullet initialization code. -(void) initializeScene { /*Setup physics world*/ _physicsWorld = [[CC3PhysicsWorld alloc] init]; [_physicsWorld setGravity:0 y:-9.8 z:0]; /*Setting up debug draw*/ MyDebugDraw *draw = new MyDebugDraw; draw->setDebugMode(draw->getDebugMode() | btIDebugDraw::DBG_DrawWireframe ); _physicsWorld._discreteDynamicsWorld->setDebugDrawer(draw); /*Setup camera and lamb*/ ………….. //This simpleCube.pod contains the cube [self addContentFromPODFile: @"simpleCube.pod"]; //This file contains sphere [self addContentFromPODFile: @"SimpleSphere.pod"]; [self createGLBuffers]; CC3MeshNode* cubeNode = (CC3MeshNode*)[self getNodeNamed:@"Cube"]; CC3MeshNode* sphereNode = (CC3MeshNode*)[self getNodeNamed:@"Sphere"]; // both cubeNode and sphereNode are not nil from this point float *cVertexData = (float*)((CC3VertexArrayMesh*)cubeNode.mesh) .vertexLocations.vertices; int cVertexCount = ((CC3VertexArrayMesh*)cubeNode.mesh) .vertexLocations.vertexCount; btTriangleMesh* cTriangleMesh = new btTriangleMesh(); int offset = 0; for (int i = 0; i < (cVertexCount / 3); i++) { unsigned int index1 = offset; unsigned int index2 = offset+6; unsigned int index3 = offset+12; cTriangleMesh->addTriangle( btVector3(cVertexData[index1], cVertexData[index1+1], cVertexData[index1+2]), btVector3(cVertexData[index2], cVertexData[index2+1], cVertexData[index2+2]), btVector3(cVertexData[index3], cVertexData[index3+1], cVertexData[index3+2])); offset += 18; } [self releaseRedundantData]; /*Create a triangle mesh from the vertices*/ btBvhTriangleMeshShape* cTriMeshShape = new btBvhTriangleMeshShape(cTriangleMesh,true); btCollisionShape *sphereShape = new btSphereShape(1); gTriMeshObject = [_physicsWorld createPhysicsObjectTrimesh:cubeNode shape:cTriMeshShape mass:0 restitution:1.0 position:cubeNode.location]; sphereObject = [_physicsWorld createPhysicsObject:sphereNode shape:sphereShape mass:1 restitution:0.1 position:sphereNode.location]; sphereObject.rigidBody->setDamping(0.1,0.8); /*Enable debug drawing*/ _physicsWorld._discreteDynamicsWorld->debugDrawWorld(); } And My btIDebugDraw implementation (MyDebugDraw.h) //MyDebugDraw.h class MyDebugDraw: public btIDebugDraw{ int m_debugMode; public: virtual void drawLine(const btVector3& from,const btVector3& to ,const btVector3& color); virtual void drawContactPoint(const btVector3& PointOnB ,const btVector3& normalOnB,btScalar distance ,int lifeTime,const btVector3& color); virtual void reportErrorWarning(const char* warningString); virtual void draw3dText(const btVector3& location ,const char* textString); virtual void setDebugMode(int debugMode); virtual int getDebugMode() const; }; void MyDebugDraw::drawLine(const btVector3& from,const btVector3& to ,const btVector3& color){ LogInfo(@"Works!!"); glPushMatrix(); glColor4f(color.getX(), color.getY(), color.getZ(), 1.0); const GLfloat line[] = { from.getX()*1, from.getY()*1, from.getZ()*1, //point A to.getX()*1, to.getY()*1,to.getZ()*1 //point B }; glVertexPointer( 3, GL_FLOAT, 0, &line ); glPointSize( 5.0f ); glDrawArrays( GL_POINTS, 0, 2 ); glDrawArrays( GL_LINES, 0, 2 ); glPopMatrix(); } void MyDebugDraw::drawContactPoint(const btVector3 &PointOnB ,const btVector3 &normalOnB, btScalar distance ,int lifeTime, const btVector3 &color){ } void MyDebugDraw::reportErrorWarning(const char *warningString){ } void MyDebugDraw::draw3dText(const btVector3 &location , const char *textString){ } void MyDebugDraw::setDebugMode(int debugMode){ } int MyDebugDraw::getDebugMode() const{ return DBG_DrawWireframe; } My Problem The drawLine method is getting called. I can see the cube and sphere in place. Sphere again does some circling around the cube before jumping off. No debug lines are getting drawn.

  Read the article

• Windows 7 Virtualized on Ubuntu Server

  - by garbagecollector

  I have an issue, we are moving to a production build server now. I need a virtual machine up and running on my Ubuntu 10.10 server edition. I have to setup and install various tool and plugins, on this windows 7 virtual machine as well The problem I am facing is how do I install windows 7 on this machine ( ubuntu 10.10 server) also, how am i supposed to gain access to it in order to install tools that are required on it. I would prefer virtual box as my tool of choice. Please and thank you.

  Read the article

• Recent Updates on Oracle Hardware Technical Resource Center

  - by uwes

  Over the last two weeks there have been some updates on the Oracle Hardware Technical Resource Center (HW TRC). The following list summarize the categories which have been added or changed. Feel free to explore. SPARC Netra T4 Servers customer and technical presentation, partner FAQ and more Oracle Solaris added: 4 customer presentations, technical presentation StorageTek Virtual Storage Manager (VSM) and Virtual Library Extension (VLE) added presentations: customer, technical, value virtual tape, role of tape in mainframe, partner FAQ, config guide T10000 Tape Drives added: sales and technical presentation, partner FAQ T9840D Tape Drives added: sales and technical presentation, FAQ LTO Tape Drives added: customer and technical presentation, partner FAQ, ordering guide and more Netra ATCA Blade Servers Netra x86 Servers added: technical presentation, partner FAQ, configuration hints and more Netra 6000 Modular System added: customer and technical presentation, partner FAQ, order menu and more

  Read the article

• How to clone a VirtualBox Disk

  - by [email protected]

   How to clone a VirtualBox DiskCopying the image of Virtual Disk (.vdi file) is a convenient way to duplicate the disk, in cases you want to avoid re-installing an operating system from scratch. However, simply copying the .vdi file into another location will make a verbatim copy of the virtual disk, including the UUID of the disk. If you try to add the copy in the Virtual Media Manager, you will get an error like this:In this case, you have to do is to clone the vdi disk: cd C:\Program Files\Sun\VirtualBox\C:\Program Files\Sun\VirtualBox>vboxmanage clonevdi G:\VMWARES\Database\11GR2onOEL5forVbox\11GR2_OEL5_32GB.vdi G:\VMWARES\Database\11GR2onOEL5forVbox\OEL5_32GB.vdi$ VBoxManage clonevdi Master.vdi Clone.vdiIn case you receive a error like this. It means that the disk is already a copy of other VirtualBox Disk.In that case you chould change the UUID before to clone the Disk.Follow the steps given here in order to do that.

  Read the article

• proper way to uninstall ubuntu server

  - by user314187

  I have installed ubuntu server on Widows 8.1 Hyper-V virtual machine. As part of learning I just want to remove the ubuntu server completely sothat I can reinstall the server once again to get a better understanding on the installation process. If I delete the Virtual Machine (By remove option in Hyper - V) I am able to delete the server and the hard disc where the server is installed. But, Using this process my Host OS Windows 8.1 is getting corrupted and had to reinstall the Windows OS (Tried this 3 times already). Can someone please tell me the right way of uninstalling the ubuntu server from the Hyper-V virtual machine. Thanks, Uday

  Read the article

• Developing an ELO like point system for a multiplayer gaming site

  - by Alejandro Piad

  I'm currently working on a gaming site where users will submit virtual players for different games, like Chess, Nash, Backgammon, Go, etc. The idea is that users don't compete themselves, but through their virtual players. There will be leagues, tournaments, and other competition formats. The question is which would be a good rating system for users in this environment. Take into account that every user may have many different virtual players playing in many different games. As a general guideline I would like to guarantee the following properties: Users who have a lot of mediocre players should not score higher than users with a few very good players. A user with a high rating should not be penalized if he adds a new bad player, until he has had enough time to improve his player. Users who don't play often should not score higher than users who play every day. Thanks in advance.

  Read the article

• Incremental file system backups

  - by brunopereira81

  I use Virtual Box a lot for distro / applications testing purposes. One of the features I simply love about it is virtual machines snapshots, its saves a state of a virtual machine and is able to restore it to its former glory if something you did went wrong without any problems and without consuming your all hard disk space. On my live systems I know how to create a 1:1 image of the file system but all the solutions I'v known will create a new image of the complete file system. Are there any programs / file systems that are capable of taking a snapshot of a current file system, save it on another location but instead of making a complete new image it creates incremental backups? To easy describe what I want, it should be as dd images of a file system, but instead of only a full backup it would also create incremental. I am not looking for clonezilla, etc. It should run within the system itself with no (or almost none) intervention from the user, but contain all the data of the file systems.

  Read the article

• Objective-C Lesson in Class Design

  - by Pota Onasys

  I have the following classes: Teacher Student Class (like a school class) They all extend from KObject that has the following code: - initWithKey - send - processKey Teacher, Student Class all use the functions processKey and initWithKey from KObject parent class. They implement their own version of send. The problem I have is that KObject should not be instantiated ever. It is more like an abstract class, but there is no abstract class concept in objective-c. It is only useful for allowing subclasses to have access to one property and two functions. What can I do so that KObject cannot be instantiated but still allow subclasses to have access to the functions and properties of KObject?

  Read the article

• Advanced Control Panel Modules - OliverHine.com for DotNetNuke - Video

  How to install and use 2 Advanced Administrator Control Panels for DotNetNuke. This includes an optimized version for faster page load times and a Ribbon Bar version for improved features. The video contains: Introduction Optimised control panel Page load time test result improvements Ribbon Bar control panel Features of the Ribbon Bar How to download the advanced control panel How to install the advanced control panel How to apply one of the advanced control panels to your DotNetNuke installation How to use the Ribbon Bar control panel Page view modes Page functions Add functions Add module functions Copy an existing module Reference an existing module Common Tasks Demonstration of the various control panel view options available Time Length: 10min 47secsDid you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

  Read the article

• Links for PrDC10 Session Visual Studio 2010 Testing Tools

  - by Aaron Kowall

  Here are the links I promised to post from my session on Visual Studio 2010 Testing Tools. To download and configure the TFS 2010 Virtual Machine the best instructions are here: http://blogs.msdn.com/b/briankel/archive/2010/03/18/now-available-visual-studio-2010-release-candidate-virtual-machines-with-sample-data-and-hands-on-labs.aspx To download and configure the Lab Management Virtual Machine, the best instructions are here: http://blogs.msdn.com/b/lab_management/archive/2010/02/12/one-box-lab-management-walkthrough.aspx Thanks to all that attended my presentation!  Hope you learned a bit. Technorati Tags: PrDC10,TFS 2010,VHD,Lab Management

  Read the article

• Liskov substitution and abstract classes / strategy pattern

  - by Kolyunya

  I'm trying to follow LSP in practical programming. And I wonder if different constructors of subclasses violate it. It would be great to hear an explanation instead of just yes/no. Thanks much! P.S. If the answer is no, how do I make different strategies with different input without violating LSP? class IStrategy { public: virtual void use() = 0; }; class FooStrategy : public IStrategy { public: FooStrategy(A a, B b) { c = /* some operations with a, b */ } virtual void use() { std::cout << c; } private: C c; }; class BarStrategy : public IStrategy { public: BarStrategy(D d, E e) { f = /* some operations with d, e */ } virtual void use() { std::cout << f; } private: F f; };

  Read the article

• API Design Techniques

  - by Dehumanizer

  Is it right or more beautiful to name the functions with an prefix, like in Qt? Or using "many" namespaces, but 'normal' names for functions? For example, slOpenFile(); //"sl" means "some lib" vs some_lib::file_functions::openFile(); UPD: I've read somewhere that the first variant(using some prefix) is better, because the API users can perform 'fast' search among the documentation and in the Internet. E.g. by typing the magic prefix search engine starts to advice the exact functions. Is it enough to use the first variant?

  Read the article

• Windows XP guest in Ubuntu VirtualBox OSE VM does not install driver to use host's HP laptop webcam.

  - by Guillermo Torres

  I recently created a virtual windows xp with Virtual Box OSE. The sound and video seem to be working just fine. However, it does not recognize the webcam which I use to video chat with yahoo messenger. I use Windows to have video chats with my daughters who live in another country. Since I did not want to go back to windows, I decided to try installing windows in a virtual machine. But when I tried using it yesterday, everything worked perfectly except for the webcam. I was not able to make the webcam work. I tried to download the drivers for it, but since my laptop is HP Pavilion g4-1287la, Core i3, none of the drivers I tried worked. I got the same error every time I tried to install them, something like: This driver cannot be installed in this machine

  Read the article

• Why is the Touchpad tab missing?

  - by U47

  So my Dell Vostro 3360 came out of the box with an Alps touchpad which was detected as PS/2. Through these steps, I was able to get as far as it appearing to be recognized as a touchpad. Howevver, I do not get the Touchpad tab in the Mouse/Touchpad settings. Two-finger scrolling appears to work, and the Fn-F3 does disable the touchpad, but the settings are so brutal that it is almost impossible to work with. Very difficult to scroll at all accurately. I'm hoping there's some settings which can be tweaked which will help with this. Any ideas? My xinput listing is as follows: ? Virtual core pointer id=2 [master pointer (3)] ? ? Virtual core XTEST pointer id=4 [slave pointer (2)] ? ? GlidePoint Virtual Touchpad id=12 [slave pointer (2)] Thanks,

  Read the article

< Previous Page | 177 178 179 180 181 182 183 184 185 186 187 188  | Next Page >