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  • Implements EAN13 and UPC-A barcode in PDF using fpdf in classic ASP

    - by Jeremy N
    /* FPDF library for ASP can be downloaded from: http://www.aspxnet.it/public/default.asp INFORMATIONS: Translated by: Jeremy Author: Olivier License: Freeware DESCRIPTION: This script implements EAN13 and UPC-A barcodes (the second being a particular case of the first one). Bars are drawn directly in the PDF (no image is generated) function EAN13(x,y,barcode,h,w) -x = x coordinate to start drawing the barcode -y = y coordinate to start drawing the barcode -barcode = code to write (must be all numeric) -h = height of the bar -w = the minimum width of individual bar function UPC_A(x,y,barcode,h,w) Same parameters An EAN13 barcode is made up of 13 digits, UPC-A of 12 (leading zeroes are added if necessary). The last digit is a check digit; if it's not supplied or if it is incorrect, it will be automatically computed. USAGE: Copy all of this text and save it in a file called barcode.ext file under fpdf/extends folder EXAMPLE: Set pdf=CreateJsObject("FPDF") pdf.CreatePDF "P","mm","letter" pdf.SetPath("fpdf/") pdf.LoadExtension("barcode") pdf.Open() pdf.AddPage() 'set the fill color to black pdf.setfillcolor 0,0,0 pdf.UPC_A 80,40,"123456789012",16,0.35 pdf.Close() pdf.NewOutput "" , true, "test.pdf" */ this.EAN13=function (x,y,barcode,h,w) { return this.Barcode(x,y,barcode,h,w,13); }; this.UPC_A=function (x,y,barcode,h,w) { return this.Barcode(x,y,barcode,h,w,12); }; function GetCheckDigit(barCode) { bc = barCode.replace(/[^0-9]+/g,''); total = 0; //Get Odd Numbers for (i=bc.length-1; i=0; i=i-2) { total = total + parseInt(bc.substr(i,1)); } //Get Even Numbers for (i=bc.length-2; i=0; i=i-2) { temp = parseInt(bc.substr(i,1)) * 2; if (temp 9) { tens = Math.floor(temp/10); ones = temp - (tens*10); temp = tens + ones; } total = total + temp; } //Determine the checksum modDigit = (10 - total % 10) % 10; return modDigit.toString(); } //Test validity of check digit function TestCheckDigit(barcode) { var cd=GetCheckDigit(barcode.substring(0,barcode.length-1)); return cd==parseInt(barcode.substring(barcode.length-1,1)); } this.Barcode=function Barcode(x,y,barcode,h,w,len) { //Padding while(barcode.length < len-1) { barcode = '0' + barcode; } if(len==12) {barcode='0' + barcode;} //Add or control the check digit if(barcode.length==12) { barcode += GetCheckDigit(barcode); } else { //if the check digit is incorrect, fix the check digit. if(!TestCheckDigit(barcode)) { barcode = barcode.substring(0,barcode.length-1) + GetCheckDigit(barcode.substring(0,barcode.length-1)); } } //Convert digits to bars var codes=[['0001101','0011001','0010011','0111101','0100011','0110001','0101111','0111011','0110111','0001011'], ['0100111','0110011','0011011','0100001','0011101','0111001','0000101','0010001','0001001','0010111'], ['1110010','1100110','1101100','1000010','1011100','1001110','1010000','1000100','1001000','1110100'] ]; var parities=[[0,0,0,0,0,0], [0,0,1,0,1,1], [0,0,1,1,0,1], [0,0,1,1,1,0], [0,1,0,0,1,1], [0,1,1,0,0,1], [0,1,1,1,0,0], [0,1,0,1,0,1], [0,1,0,1,1,0], [0,1,1,0,1,0] ]; var code='101'; var p=parities[parseInt(barcode.substr(0,1))]; var i; for(i=1;i<=6;i++) { code+= codes[p[i-1]][parseInt(barcode.substr(i,1))]; } code+='01010'; for(i=7;i<=12;i++) { code+= codes[2][parseInt(barcode.substr(i,1))]; } code+='101'; //Draw bars for(i=0;i<code.length;i++) { if(code.substr(i,1)=='1') { this.Rect(x+i*w,y,w,h,'F'); } } //Print text uder barcode. this.SetFont('Arial','',12); //Set the x so that the font is centered under the barcode this.Text(x+parseInt(0.5*barcode.length)*w,y+h+11/this.k,barcode.substr(barcode.length-len,len)); }

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  • ViewModel with SelectList binding in ASP.NET MVC2

    - by Junto
    I am trying to implement an Edit ViewModel for my Linq2SQL entity called Product. It has a foreign key linked to a list of brands. Currently I am populating the brand list via ViewData and using DropDownListFor, thus: <div class="editor-field"> <%= Html.DropDownListFor(model => model.BrandId, (SelectList)ViewData["Brands"])%> <%= Html.ValidationMessageFor(model => model.BrandId) %> </div> Now I want to refactor the view to use a strongly typed ViewModel and Html.EditorForModel(): <% using (Html.BeginForm()) {%> <%= Html.ValidationSummary(true) %> <fieldset> <legend>Fields</legend> <%=Html.EditorForModel() %> <p> <input type="submit" value="Save" /> </p> </fieldset> <% } %> In my Edit ViewModel, I have the following: public class EditProductViewModel { [HiddenInput] public int ProductId { get; set; } [Required()] [StringLength(200)] public string Name { get; set; } [Required()] [DataType(DataType.Html)] public string Description { get; set; } public IEnumerable<SelectListItem> Brands { get; set; } public int BrandId { get; set; } public EditProductViewModel(Product product, IEnumerable<SelectListItem> brands) { this.ProductId = product.ProductId; this.Name = product.Name; this.Description = product.Description; this.Brands = brands; this.BrandId = product.BrandId; } } The controller is setup like so: public ActionResult Edit(int id) { BrandRepository br = new BrandRepository(); Product p = _ProductRepository.Get(id); IEnumerable<SelectListItem> brands = br.GetAll().ToList().ToSelectListItems(p.BrandId); EditProductViewModel model = new EditProductViewModel(p, brands); return View("Edit", model); } The ProductId, Name and Description display correctly in the generated view, but the select list does not. The brand list definitely contains data. If I do the following in my view, the SelectList is visible: <% using (Html.BeginForm()) {%> <%= Html.ValidationSummary(true) %> <fieldset> <legend>Fields</legend> <%=Html.EditorForModel() %> <div class="editor-label"> <%= Html.LabelFor(model => model.BrandId) %> </div> <div class="editor-field"> <%= Html.DropDownListFor(model => model.BrandId, Model.Brands)%> <%= Html.ValidationMessageFor(model => model.BrandId) %> </div> <p> <input type="submit" value="Save" /> </p> </fieldset> <% } %> What am I doing wrong? Does EditorForModel() not generically support the SelectList? Am I missing some kind of DataAnnotation? I can't seem to find any examples of SelectList usage in ViewModels that help. I'm truly stumped. This answer seems to be close, but hasn't helped.

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  • boost::asio::async_read_until problem

    - by user368831
    I'm trying to modify the echo server example from boost asio and I'm running into problem when I try to use boost::asio::async_read_until. Here's the code: #include <cstdlib> #include <iostream> #include <boost/bind.hpp> #include <boost/asio.hpp> using boost::asio::ip::tcp; class session { public: session(boost::asio::io_service& io_service) : socket_(io_service) { } tcp::socket& socket() { return socket_; } void start() { std::cout<<"starting"<<std::endl; boost::asio::async_read_until(socket_, boost::asio::buffer(data_, max_length), ' ', boost::bind(&session::handle_read, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } void handle_read(const boost::system::error_code& error, size_t bytes_transferred) { std::cout<<"handling read"<<std::endl; if (!error) { boost::asio::async_write(socket_, boost::asio::buffer(data_, bytes_transferred), boost::bind(&session::handle_write, this, boost::asio::placeholders::error)); } else { delete this; } } void handle_write(const boost::system::error_code& error) { if (!error) { /* socket_.async_read_some(boost::asio::buffer(data_, max_length), boost::bind(&session::handle_read, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); */ } else { delete this; } } private: tcp::socket socket_; enum { max_length = 1024 }; char data_[max_length]; }; class server { public: server(boost::asio::io_service& io_service, short port) : io_service_(io_service), acceptor_(io_service, tcp::endpoint(tcp::v4(), port)) { session* new_session = new session(io_service_); acceptor_.async_accept(new_session->socket(), boost::bind(&server::handle_accept, this, new_session, boost::asio::placeholders::error)); } void handle_accept(session* new_session, const boost::system::error_code& error) { if (!error) { new_session->start(); new_session = new session(io_service_); acceptor_.async_accept(new_session->socket(), boost::bind(&server::handle_accept, this, new_session, boost::asio::placeholders::error)); } else { delete new_session; } } private: boost::asio::io_service& io_service_; tcp::acceptor acceptor_; }; int main(int argc, char* argv[]) { try { if (argc != 2) { std::cerr << "Usage: async_tcp_echo_server <port>\n"; return 1; } boost::asio::io_service io_service; using namespace std; // For atoi. server s(io_service, atoi(argv[1])); io_service.run(); } catch (std::exception& e) { std::cerr << "Exception: " << e.what() << "\n"; } return 0; } The problem is when I try to compile I get this weird error: server.cpp: In member function ‘void session::start()’: server.cpp:27: error: no matching function for call to ‘async_read_until(boost::asio::basic_stream_socket &, boost::asio::mutable_buffers_1, char, boost::_bi::bind_t, boost::_bi::list3, boost::arg<1 ()(), boost::arg<2 ()() )’ Can someone please explain what's going on? From what I can tell the arguments to async_read_until are correct. Thanks!

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  • boost::asio::async_read_until problem

    - by user368831
    Hi again, I'm modify the boost asio echo example to use async_read_until to read the input word by word. Even though I am using async_read_until all the data sent seems to be read from the socket. Could someone please advise: #include <cstdlib> #include <iostream> #include <boost/bind.hpp> #include <boost/asio.hpp> using boost::asio::ip::tcp; class session { public: session(boost::asio::io_service& io_service) : socket_(io_service) { } tcp::socket& socket() { return socket_; } void start() { std::cout<<"starting"<<std::endl; boost::asio::async_read_until(socket_, buffer, ' ', boost::bind(&session::handle_read, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } void handle_read(const boost::system::error_code& error, size_t bytes_transferred) { std::ostringstream ss; ss<<&buffer; std::string s = ss.str(); std::cout<<s<<std::endl; if (!error) { boost::asio::async_write(socket_, boost::asio::buffer(s), boost::bind(&session::handle_write, this, boost::asio::placeholders::error)); } else { delete this; } } void handle_write(const boost::system::error_code& error) { std::cout<<"handling write"<<std::endl; if (!error) { } else { delete this; } } private: tcp::socket socket_; boost::asio::streambuf buffer; }; class server { public: server(boost::asio::io_service& io_service, short port) : io_service_(io_service), acceptor_(io_service, tcp::endpoint(tcp::v4(), port)) { session* new_session = new session(io_service_); acceptor_.async_accept(new_session->socket(), boost::bind(&server::handle_accept, this, new_session, boost::asio::placeholders::error)); } void handle_accept(session* new_session, const boost::system::error_code& error) { if (!error) { new_session->start(); new_session = new session(io_service_); acceptor_.async_accept(new_session->socket(), boost::bind(&server::handle_accept, this, new_session, boost::asio::placeholders::error)); } else { delete new_session; } } private: boost::asio::io_service& io_service_; tcp::acceptor acceptor_; }; int main(int argc, char* argv[]) { try { if (argc != 2) { std::cerr << "Usage: async_tcp_echo_server <port>\n"; return 1; } boost::asio::io_service io_service; using namespace std; // For atoi. server s(io_service, atoi(argv[1])); io_service.run(); } catch (std::exception& e) { std::cerr << "Exception: " << e.what() << "\n"; } return 0; } Thanks!

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  • MSVC Compiler options with mojo-native in Maven

    - by graham.reeds
    I'm trying to set up a test environment with Maven to build VC++ and I am way behind on this. I have 3 source files that I builds a dll (once I get this fixed it should be a simple matter to add the unit-tests): hook.cpp hook.h hook.def This is compiled, on the command line, with the following: C:\Develop\hook\src\main\msvc>cl -o hook.dll Hook.cpp /D HOOK_DLLEXPORT /link /DLL /DEF:"Hook.def" Which produces the expected obj, dll, lib and exp files. So now to get this working in Maven2 with the Mojo-native plugin. With no options Maven w/Mojo gives me this (truncated) output: [INFO] [native:initialize {execution: default-initialize}] [INFO] [native:unzipinc {execution: default-unzipinc}] [INFO] [native:javah {execution: default-javah}] [INFO] [native:compile {execution: default-compile}] [INFO] cmd.exe /X /C "cl -IC:\Develop\hook\src\main\msvc /FoC:\Develop\hook\targ et\objs\Hook.obj -c C:\Develop\hook\src\main\msvc\Hook.cpp" Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 15.00.30729.01 for 80x86 Copyright (C) Microsoft Corporation. All rights reserved. Hook.cpp [INFO] [native:link {execution: default-link}] [INFO] cmd.exe /X /C "link.exe /out:C:\Develop\hook\target\hook.dll target\objs\ Hook.obj" Microsoft (R) Incremental Linker Version 9.00.30729.01 Copyright (C) Microsoft Corporation. All rights reserved. LINK : fatal error LNK1561: entry point must be defined [INFO] ------------------------------------------------------------------------ [ERROR] BUILD ERROR [INFO] ------------------------------------------------------------------------ [INFO] Error executing command line. Exit code:1561 mojo-native gives options for manipulating the compiler/linker options but gives no example of usage. No matter what I tweak in these settings I get the error of: [ERROR] BUILD ERROR [INFO] ------------------------------------------------------------------------ [INFO] Failed to configure plugin parameters for: org.codehaus.mojo:native-maven -plugin:1.0-alpha-4 (found static expression: '-o hook.dll Hook.cpp /D HOOK_DLLEXPORT /link /DLL /DEF:"Hook.def"' which may act as a default value). Cause: Cannot assign configuration entry 'compilerStartOptions' to 'interface ja va.util.List' from '-o hook.dll Hook.cpp /D HOOK_DLLEXPORT /link /DLL /DEF:"Hook .def"', which is of type class java.lang.String The relevant part of my pom.xml looks like this: <configuration> <sources> <source> <directory>src/main/msvc</directory> <includes> <include>**/*.cpp</include> </includes> </source> </sources> <compilerProvider>msvc</compilerProvider> <compilerExecutable>cl</compilerExecutable> <!-- cl -o hook.dll Hook.cpp /D HOOK_DLLEXPORT /link /DLL /DEF:"Hook.def" --> <compilerStartOptions>-o hook.dll Hook.cpp /D HOOK_DLLEXPORT /link /DLL /DEF:"Hook.def"</compilerStartOptions> <!-- <compilerMiddleOptions></compilerMiddleOptions> <compilerEndOptions></compilerEndOptions> <linkerStartOptions></linkerStartOptions> <linkerMiddleOptions></linkerMiddleOptions> <linkerEndOptions></linkerEndOptions> --> </configuration> How do I manipulate the compiler to produce a DLL like the command line version does? Or should I give up and just use exec?

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  • protobuf-net: Issues deserializing DataMember fields in lieu of read-only property

    - by Paul Smith
    I'm having issues deserializing certain properties of ORM-generated entities using protobuf-net. I suspect something in the way the ORM manages serialization attributes on read-only properties (uses public backing fields with DataMember attributes & [de]serializes) those instead of the corresponding read-only property, which has an IgnoreDataMember attribute). Guid properties might have issues of their own, but the field vs. property thing is my working theory now. Here's a simplified example of the code. Say I have a class, Account with an AccountID read-only guid, and an AccountName read-write string. I serialize & immediately deserialize a clone. In this scenario I get one of two results (depending on the entity, haven't isolated the specific commonality yet). The deserialized clone either: ...has a different AccountID from the original, or ...throws an Incorrect wire-type deserializing Guid exception while deserializing. Here's example usage... Account acct = new Account() { AccountName = "Bob's Checking" }; Debug.WriteLine(acct.AccountID.ToString()); using (MemoryStream ms = new MemoryStream()) { ProtoBuf.Serializer.Serialize<Account>(ms, acct); Debug.WriteLine(Encoding.UTF8.GetString(ms.GetBuffer())); ms.Position = 0; Account clone = ProtoBuf.Serializer.Deserialize<Account>(ms); Debug.WriteLine(clone.AccountID.ToString()); } And here's an example ORM'd class (simplified; hopefully haven't removed the cause of the issue in the process). Uses a shell game to deserialize read-only properties by exposing the backing field ("can't write" essentially becomes "shouldn't write," but we can scan code for instances of assigning to these fields, so the hack works for our purposes): [DataContract()] [Serializable()] public partial class Account { public Account() { _accountID = Guid.NewGuid(); } [XmlAttribute("AccountID")] [DataMember(Name = "AccountID", Order = 0)] public Guid _accountID; /// <summary> /// A read-only property; XML, JSON and DataContract serializers all seem /// to correctly recognize the public backing field when deserializing: /// </summary> [IgnoreDataMember] [XmlIgnore] public Guid AccountID { get { return this._accountID; } } [IgnoreDataMember] protected string _accountName; [DataMember(Name = "AccountName", Order = 1)] [XmlAttribute] public string AccountName { get { return this._accountName; } set { this._accountName = value; } } } XML, JSON and DataContract serializers all seem to serialize / deserialize matching object graphs here, so this attribute arrangement apparently causes those serializers to correctly assign to the public backing field when deserializing. I've tried protobuf-net with lists vs. single instances, different prefix styles, etc., but always either get the 'incorrect wire type ... Guid' exception, or the Guid property (field) not deserializing correctly. So the specific questions are, is there a quick workaround for this, and/or is there an explanation for both of outcomes 1 & 2 above, and/or can protobuf-net somehow be corralled into behaving like WCF in cases like this (i.e. follow the same DataMember/IgnoreDataMember semantics)? We hope not to have to create a protobuf dependency directly in the entity layer; if that's the case, we'll probably create proxy DTO entities with all public properties having protobuf attributes. (This is a subjective issue I have with all declarative serialization models; it's a ubiquitous pattern, but IMO, "normal" should be to have objects and serialization contracts decoupled.) Thanks!

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  • protobuf-net: incorrect wire-type exception deserializing Guid properties

    - by Paul Smith
    I'm having issues deserializing certain Guid properties of ORM-generated entities using protobuf-net. Here's a simplified example of the code (reproduces most elements of the scenario, but doesn't reproduce the behavior; I can't expose our internal entities, so I'm looking for clues to account for the exception). Say I have a class, Account with an AccountID read-only guid, and an AccountName read-write string. I serialize & immediately deserialize a clone. Deserializing throws an Incorrect wire-type deserializing Guid exception while deserializing. Here's example usage... Account acct = new Account() { AccountName = "Bob's Checking" }; Debug.WriteLine(acct.AccountID.ToString()); using (MemoryStream ms = new MemoryStream()) { ProtoBuf.Serializer.Serialize<Account>(ms, acct); Debug.WriteLine(Encoding.UTF8.GetString(ms.GetBuffer())); ms.Position = 0; Account clone = ProtoBuf.Serializer.Deserialize<Account>(ms); Debug.WriteLine(clone.AccountID.ToString()); } And here's an example ORM'd class (simplified, but demonstrates the relevant semantics I can think of). Uses a shell game to deserialize read-only properties by exposing the backing field ("can't write" essentially becomes "shouldn't write," but we can scan code for instances of assigning to these fields, so the hack works for our purposes). Again, this does not reproduce the exception behavior; I'm looking for clues as to what could: [DataContract()] [Serializable()] public partial class Account { public Account() { _accountID = Guid.NewGuid(); } [XmlAttribute("AccountID")] [DataMember(Name = "AccountID", Order = 1)] public Guid _accountID; /// <summary> /// A read-only property; XML, JSON and DataContract serializers all seem /// to correctly recognize the public backing field when deserializing: /// </summary> [IgnoreDataMember] [XmlIgnore] public Guid AccountID { get { return this._accountID; } } [IgnoreDataMember] protected string _accountName; [DataMember(Name = "AccountName", Order = 2)] [XmlAttribute] public string AccountName { get { return this._accountName; } set { this._accountName = value; } } } XML, JSON and DataContract serializers all seem to serialize / deserialize these object graphs just fine, so the attribute arrangement basically works. I've tried protobuf-net with lists vs. single instances, different prefix styles, etc., but still always get the 'incorrect wire-type ... Guid' exception when deserializing. So the specific questions is, is there any known explanation / workaround for this? I'm at a loss trying to trace what circumstances (in the real code but not the example) could be causing it. We hope not to have to create a protobuf dependency directly in the entity layer; if that's the case, we'll probably create proxy DTO entities with all public properties having protobuf attributes. (This is a subjective issue I have with all declarative serialization models; it's a ubiquitous pattern & I understand why it arose, but IMO, if we can put a man on the moon, then "normal" should be to have objects and serialization contracts decoupled. ;-) ) Thanks!

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  • Small performance test on a web service

    - by vtortola
    Hi, I'm trying to develop a small application that test how many requests per second can my service support but I think I'm doing something wrong. The service is in an early development stage, but I'd like to have this test handy in order to check in time to time I'm not doing something that decrease the performance. The problem is that I cannot get the web server or the database server go to the 100% of CPU. I'm using three different computers, in one is the web server (WinSrv Standard 2008 x64 IIS7), in other the database (Win 2K - SQL Server 2005) and the last is my computer (Win7 x64 ultimate), where I'll run the test. The computers are connected through a 100 ethernet switch. The request POST is 9 bytes and the response will be 842 bytes. The test launches several threads, and each thread has a "while" loop, in each loop it creates a WebRequest object, performs a call, increment a common counter and waits between 1 and 5 millisencods, then it do it again: static Int32 counter = 0; static void Main(string[] args) { ServicePointManager.DefaultConnectionLimit = 250; Console.WriteLine("Ready. Press any key..."); Console.ReadKey(); Console.WriteLine("Running..."); String localhost = "localhost"; String linuxmono = "192.168.1.74"; String server= "192.168.1.5:8080"; DateTime start = DateTime.Now; Random r = new Random(DateTime.Now.Millisecond); for (int i = 0; i < 50; i++) { new Thread(new ParameterizedThreadStart(Test)).Start(server); Thread.Sleep(r.Next(1, 3)); } Thread.Sleep(2000); while (true) { Console.WriteLine("Request per second :" + counter/DateTime.Now.Subtract(start).TotalSeconds ); Thread.Sleep(3000); } } public static void Test(Object ip) { Guid guid = Guid.NewGuid(); Random r = new Random(DateTime.Now.Millisecond); while (true) { String test = "<lalala/>"; WebRequest req = WebRequest.Create("http://" + (String)ip + "/WebApp/"+guid.ToString()+"/Data/Tables=whatever"); req.Method = "POST"; req.ContentType = "application/xml"; req.Credentials = new NetworkCredential("aaa", "aaa","domain"); Byte[] array = Encoding.UTF8.GetBytes(test); req.ContentLength = array.Length; using (Stream reqStream = req.GetRequestStream()) { reqStream.Write(array, 0, array.Length); reqStream.Close(); } using (Stream responseStream = req.GetResponse().GetResponseStream()) { String response = new StreamReader(responseStream).ReadToEnd(); if (response.Length != 842) Console.Write(" EEEE "); } Interlocked.Increment(ref counter); Thread.Sleep(r.Next(1,5)); } } If I run the test neither of the computers do an excesive CPU usage. Let's say I get a X requests per second, if I run the console application two times at the same moment, I get X/2 request per second in each one... but still the web server is on 30% of CPU, the database server on 25%... I've tried to remove the thread.sleep in the loop, but it doesn't make a big difference. I'd like to put the machines to the maximun, to check how may requests per second they can provide. I guessed that I could do it in this way... but apparently I'm missing something here... What is the problem? Kind regards.

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  • FreeBSD performance tuning. Sysctls, loader.conf, kernel.

    - by SaveTheRbtz
    I wanted to share knowledge of tuning FreeBSD via sysctls, so i'm posting them with comments. Based on Igor Sysoev (author of nginx) presentation about FreeBSD tuning up to 100,000-200,000 active connections. Sysctls are for 7.x FreeBSD. Since 7.2 amd64 some of them are tuned well by default. Prior 7.0 some of them are boot only (set via /boot/loader.conf) or does not exist at all. Highload web server sysctls: # Max. backlog size kern.ipc.somaxconn=4096 # Shared memory // 7.2+ can use shared memory > 2Gb kern.ipc.shmmax=2147483648 # Sockets kern.ipc.maxsockets=204800 # Do not use lager sockbufs on 8.0 # ( http://old.nabble.com/Significant-performance-regression-for-increased-maxsockbuf-on-8.0-RELEASE-tt26745981.html#a26745981 ) kern.ipc.maxsockbuf=262144 # Recive clusters (on amd64 7.2+ 65k is default) # For such high value vm.kmem_size must be increased to 3G #kern.ipc.nmbclusters=229376 # Jumbo pagesize(4k/8k) clusters # Used as general packet storage for jumbo frames # can be monitored via `netstat -m` #kern.ipc.nmbjumbop=192000 # Jumbo 9k/16k clusters # If you are using them #kern.ipc.nmbjumbo9=24000 #kern.ipc.nmbjumbo16=10240 # Every socket is a file, so increase them kern.maxfiles=204800 kern.maxfilesperproc=200000 kern.maxvnodes=200000 # Turn off receive autotuning #net.inet.tcp.recvbuf_auto=0 # Small receive space, only usable on http-server, on file server this # should be increased to 65535 or even more #net.inet.tcp.recvspace=8192 # Small send space is useful for http servers that serve small files # Autotuned since 7.x net.inet.tcp.sendspace=16384 # This should be enabled if you going to use big spaces (>64k) #net.inet.tcp.rfc1323=1 # Turn this off on highspeed, lossless connections (LAN 1Gbit+) #net.inet.tcp.delayed_ack=0 # This feature is useful if you are serving data over modems, Gigabit Ethernet, # or even high speed WAN links (or any other link with a high bandwidth delay product), # especially if you are also using window scaling or have configured a large send window. # You can try setting it to 0 on fileserver with 1GBit+ interfaces # Automatically disables on small RTT ( http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/tcp_subr.c?#rev1.237 ) #net.inet.tcp.inflight.enable=0 # Disable randomizing of ports to avoid false RST # Before usage check SA here www.bsdcan.org/2006/papers/ImprovingTCPIP.pdf # (it's also says that port randomization auto-disables at some conn.rates, but I didn't tested it thou) #net.inet.ip.portrange.randomized=0 # Increase portrange # For outgoing connections only. Good for seed-boxes and ftp servers. net.inet.ip.portrange.first=1024 net.inet.ip.portrange.last=65535 # Security net.inet.ip.redirect=0 net.inet.ip.sourceroute=0 net.inet.ip.accept_sourceroute=0 net.inet.icmp.maskrepl=0 net.inet.icmp.log_redirect=0 net.inet.icmp.drop_redirect=1 net.inet.tcp.drop_synfin=1 # Security net.inet.udp.blackhole=1 net.inet.tcp.blackhole=2 # Increases default TTL, sometimes useful # Default is 64 net.inet.ip.ttl=128 # Lessen max segment life to conserve resources # ACK waiting time in miliseconds (default: 30000 from RFC) net.inet.tcp.msl=5000 # Max bumber of timewait sockets net.inet.tcp.maxtcptw=40960 # Don't use tw on local connections # As of 15 Apr 2009. Igor Sysoev says that nolocaltimewait has some buggy realization. # So disable it or now till get fixed #net.inet.tcp.nolocaltimewait=1 # FIN_WAIT_2 state fast recycle net.inet.tcp.fast_finwait2_recycle=1 # Time before tcp keepalive probe is sent # default is 2 hours (7200000) #net.inet.tcp.keepidle=60000 # Should be increased until net.inet.ip.intr_queue_drops is zero net.inet.ip.intr_queue_maxlen=4096 # Interrupt handling via multiple CPU, but with context switch. # You can play with it. Default is 1; #net.isr.direct=0 # This is for routers only #net.inet.ip.forwarding=1 #net.inet.ip.fastforwarding=1 # This speed ups dummynet when channel isn't saturated net.inet.ip.dummynet.io_fast=1 # Increase dummynet(4) hash #net.inet.ip.dummynet.hash_size=2048 #net.inet.ip.dummynet.max_chain_len # Should be increased when you have A LOT of files on server # (Increase until vfs.ufs.dirhash_mem becames lower) vfs.ufs.dirhash_maxmem=67108864 # Explicit Congestion Notification (see http://en.wikipedia.org/wiki/Explicit_Congestion_Notification) net.inet.tcp.ecn.enable=1 # Flowtable - flow caching mechanism # Useful for routers #net.inet.flowtable.enable=1 #net.inet.flowtable.nmbflows=65535 # Extreme polling tuning #kern.polling.burst_max=1000 #kern.polling.each_burst=1000 #kern.polling.reg_frac=100 #kern.polling.user_frac=1 #kern.polling.idle_poll=0 # IPFW dynamic rules and timeouts tuning # Increase dyn_buckets till net.inet.ip.fw.curr_dyn_buckets is lower net.inet.ip.fw.dyn_buckets=65536 net.inet.ip.fw.dyn_max=65536 net.inet.ip.fw.dyn_ack_lifetime=120 net.inet.ip.fw.dyn_syn_lifetime=10 net.inet.ip.fw.dyn_fin_lifetime=2 net.inet.ip.fw.dyn_short_lifetime=10 # Make packets pass firewall only once when using dummynet # i.e. packets going thru pipe are passing out from firewall with accept #net.inet.ip.fw.one_pass=1 # shm_use_phys Wires all shared pages, making them unswappable # Use this to lessen Virtual Memory Manager's work when using Shared Mem. # Useful for databases #kern.ipc.shm_use_phys=1 /boot/loader.conf: # Accept filters for data, http and DNS requests # Usefull when your software uses select() instead of kevent/kqueue or when you under DDoS # DNS accf available on 8.0+ accf_data_load="YES" accf_http_load="YES" accf_dns_load="YES" # Async IO system calls aio_load="YES" # Adds NCQ support in FreeBSD # WARNING! all ad[0-9]+ devices will be renamed to ada[0-9]+ # 8.0+ only #ahci_load= #siis_load= # Increase kernel memory size to 3G. # # Use ONLY if you have KVA_PAGES in kernel configuration, and you have more than 3G RAM # Otherwise panic will happen on next reboot! # # It's required for high buffer sizes: kern.ipc.nmbjumbop, kern.ipc.nmbclusters, etc # Useful on highload stateful firewalls, proxies or ZFS fileservers # (FreeBSD 7.2+ amd64 users: Check that current value is lower!) #vm.kmem_size="3G" # Older versions of FreeBSD can't tune maxfiles on the fly #kern.maxfiles="200000" # Useful for databases # Sets maximum data size to 1G # (FreeBSD 7.2+ amd64 users: Check that current value is lower!) #kern.maxdsiz="1G" # Maximum buffer size(vfs.maxbufspace) # You can check current one via vfs.bufspace # Should be lowered/upped depending on server's load-type # Usually decreased to preserve kmem # (default is 200M) #kern.maxbcache="512M" # Sendfile buffers # For i386 only #kern.ipc.nsfbufs=10240 # syncache Hash table tuning net.inet.tcp.syncache.hashsize=1024 net.inet.tcp.syncache.bucketlimit=100 # Incresed hostcache net.inet.tcp.hostcache.hashsize="16384" net.inet.tcp.hostcache.bucketlimit="100" # TCP control-block Hash table tuning net.inet.tcp.tcbhashsize=4096 # Enable superpages, for 7.2+ only # Also read http://lists.freebsd.org/pipermail/freebsd-hackers/2009-November/030094.html vm.pmap.pg_ps_enabled=1 # Usefull if you are using Intel-Gigabit NIC #hw.em.rxd=4096 #hw.em.txd=4096 #hw.em.rx_process_limit="-1" # Also if you have ALOT interrupts on NIC - play with following parameters # NOTE: You should set them for every NIC #dev.em.0.rx_int_delay: 250 #dev.em.0.tx_int_delay: 250 #dev.em.0.rx_abs_int_delay: 250 #dev.em.0.tx_abs_int_delay: 250 # There is also multithreaded version of em drivers can be found here: # http://people.yandex-team.ru/~wawa/ # # for additional em monitoring and statistics use # `sysctl dev.em.0.stats=1 ; dmesg` # #Same tunings for igb #hw.igb.rxd=4096 #hw.igb.txd=4096 #hw.igb.rx_process_limit=100 # Some useful netisr tunables. See sysctl net.isr #net.isr.defaultqlimit=4096 #net.isr.maxqlimit: 10240 # Bind netisr threads to CPUs #net.isr.bindthreads=1 # Nicer boot logo =) loader_logo="beastie" And finally here is my additions to GENERIC kernel # Just some of them, see also # cat /sys/{i386,amd64,}/conf/NOTES # This one useful only on i386 #options KVA_PAGES=512 # You can play with HZ in environments with high interrupt rate (default is 1000) # 100 is for my notebook to prolong it's battery life #options HZ=100 # Polling is goot on network loads with high packet rates and low-end NICs # NB! Do not enable it if you want more than one netisr thread #options DEVICE_POLLING # Eliminate datacopy on socket read-write # To take advantage with zero copy sockets you should have an MTU of 8K(amd64) # (4k for i386). This req. is only for receiving data. # Read more in man zero_copy_sockets #options ZERO_COPY_SOCKETS # Support TCP sign. Used for IPSec options TCP_SIGNATURE options IPSEC # This ones can be loaded as modules. They described in loader.conf section #options ACCEPT_FILTER_DATA #options ACCEPT_FILTER_HTTP # Adding ipfw, also can be loaded as modules options IPFIREWALL options IPFIREWALL_VERBOSE options IPFIREWALL_VERBOSE_LIMIT=10 options IPFIREWALL_DEFAULT_TO_ACCEPT options IPFIREWALL_FORWARD # Adding kernel NAT options IPFIREWALL_NAT options LIBALIAS # Traffic shaping options DUMMYNET # Divert, i.e. for userspace NAT options IPDIVERT # This is for OpenBSD's pf firewall device pf device pflog # pf's QoS - ALTQ options ALTQ options ALTQ_CBQ # Class Bases Queuing (CBQ) options ALTQ_RED # Random Early Detection (RED) options ALTQ_RIO # RED In/Out options ALTQ_HFSC # Hierarchical Packet Scheduler (HFSC) options ALTQ_PRIQ # Priority Queuing (PRIQ) options ALTQ_NOPCC # Required for SMP build # Pretty console # Manual can be found here http://forums.freebsd.org/showthread.php?t=6134 #options VESA #options SC_PIXEL_MODE # Disable reboot on Ctrl Alt Del #options SC_DISABLE_REBOOT # Change normal|kernel messages color options SC_NORM_ATTR=(FG_GREEN|BG_BLACK) options SC_KERNEL_CONS_ATTR=(FG_YELLOW|BG_BLACK) # More scroll space options SC_HISTORY_SIZE=8192 # Adding hardware crypto device device crypto device cryptodev # Useful network interfaces device vlan device tap #Virtual Ethernet driver device gre #IP over IP tunneling device if_bridge #Bridge interface device pfsync #synchronization interface for PF device carp #Common Address Redundancy Protocol device enc #IPsec interface device lagg #Link aggregation interface device stf #IPv4-IPv6 port # Also for my notebook, but may be used with Opteron #device amdtemp # Support for ECMP. More than one route for destination # Works even with default route so one can use it as LB for two ISP # For now code is unstable and panics (panic: rtfree 2) on route deletions. #options RADIX_MPATH # Multicast routing #options MROUTING #options PIM # DTrace options KDTRACE_HOOKS # all architectures - enable general DTrace hooks options DDB_CTF # all architectures - kernel ELF linker loads CTF data #options KDTRACE_FRAME # amd64-only # Adaptive spining in lockmgr (8.x+) # See http://www.mail-archive.com/[email protected]/msg10782.html options ADAPTIVE_LOCKMGRS # UTF-8 in console (9.x+) #options TEKEN_UTF8 #options TEKEN_XTERM # NCQ support # WARNING! all ad[0-9]+ devices will be renamed to ada[0-9]+ #options ATA_CAM # FreeBSD 9+ # Deadlock resolver thread # For additional information see http://www.mail-archive.com/[email protected]/msg18124.html #options DEADLKRES PS. Also most of FreeBSD's limits can be monitored by # vmstat -z and # limits PPS. variety of network counters can be monitored via # netstat -s In FreeBSD-9 netstat's -Q option appeared, try following command to display netisr stats # netstat -Q PPPS. also see # man 7 tuning PPPPS. I wanted to thank FreeBSD community, especially author of nginx - Igor Sysoev, nginx-ru@ and FreeBSD-performance@ mailing lists for providing useful information about FreeBSD tuning. So here is the question: What tunings are you using on yours FreeBSD servers? You can also post your /etc/sysctl.conf, /boot/loader.conf, kernel options, etc with description of its' meaning (do not copy-paste from sysctl -d). Don't forget to specify server type (web, smb, gateway, etc) Let's share experience!

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  • email-spec destroys my rake cucumber:all

    - by Leonardo Dario Perna
    This works fine: $ rake cucumber:all Then $ script/plugin install git://github.com/bmabey/email-spec.git remote: Counting objects: 162, done. remote: Compressing objects: 100% (130/130), done. remote: Total 162 (delta 18), reused 79 (delta 13) Receiving objects: 100% (162/162), 127.65 KiB | 15 KiB/s, done. Resolving deltas: 100% (18/18), done. From git://github.com/bmabey/email-spec * branch HEAD - FETCH_HEAD And $ script/generate email_spec exists features/step_definitions create features/step_definitions/email_steps.rb And I add 'require 'email_spec/cucumber' in /feature/support/env.rb so it looks somethinng like: require File.expand_path(File.dirname(__FILE__) + '/../../config/environment') require 'cucumber/rails/world' require 'cucumber/formatter/unicode' # Comment out this line if you don't want Cucumber Unicode support require 'email_spec/cucumber' and now: rake cucumber:all gives me this error: $ rake cucumber:all --trace (in /Users/leonardodarioperna/Projects/frestyl/frestyl) ** Invoke cucumber:all (first_time) ** Invoke cucumber:ok (first_time) ** Invoke db:test:prepare (first_time) ** Invoke db:abort_if_pending_migrations (first_time) ** Invoke environment (first_time) ** Execute environment ** Execute db:abort_if_pending_migrations ** Execute db:test:prepare ** Invoke db:test:load (first_time) ** Invoke db:test:purge (first_time) ** Invoke environment ** Execute db:test:purge ** Execute db:test:load ** Invoke db:schema:load (first_time) ** Invoke environment ** Execute db:schema:load ** Execute cucumber:ok /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby -I "/Library/Ruby/Gems/1.8/gems/cucumber-0.4.4/lib:lib" "/Library/Ruby/Gems/1.8/gems/cucumber-0.4.4/bin/cucumber" --profile default cucumber.yml was not found. Please refer to cucumber's documentation on defining profiles in cucumber.yml. You must define a 'default' profile to use the cucumber command without any arguments. Type 'cucumber --help' for usage. rake aborted! Command failed with status (1): [/System/Library/Frameworks/Ruby.framework/...] /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:995:in `sh' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:1010:in `call' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:1010:in `sh' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:1094:in `sh' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:1029:in `ruby' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:1094:in `ruby' /Library/Ruby/Gems/1.8/gems/cucumber-0.4.4/lib/cucumber/rake/task.rb:68:in `run' /Library/Ruby/Gems/1.8/gems/cucumber-0.4.4/lib/cucumber/rake/task.rb:138:in `define_task' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `call' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `execute' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `each' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `execute' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:597:in `invoke_with_call_chain' /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/monitor.rb:242:in `synchronize' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_call_chain' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:607:in `invoke_prerequisites' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:604:in `each' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:604:in `invoke_prerequisites' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:596:in `invoke_with_call_chain' /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/monitor.rb:242:in `synchronize' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_call_chain' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:583:in `invoke' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2051:in `invoke_task' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `each' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2023:in `top_level' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2001:in `run' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:1998:in `run' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/bin/rake:31 /usr/bin/rake:19:in `load' /usr/bin/rake:19 WHY? but the command: $ cucumber still works Any idea?

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  • PHP/GD - Cropping and Resizing Images

    - by Alix Axel
    I've coded a function that crops an image to a given aspect ratio and finally then resizes it and outputs it as JPG: <?php function Image($image, $crop = null, $size = null) { $image = ImageCreateFromString(file_get_contents($image)); if (is_resource($image) === true) { $x = 0; $y = 0; $width = imagesx($image); $height = imagesy($image); /* CROP (Aspect Ratio) Section */ if (is_null($crop) === true) { $crop = array($width, $height); } else { $crop = array_filter(explode(':', $crop)); if (empty($crop) === true) { $crop = array($width, $height); } else { if ((empty($crop[0]) === true) || (is_numeric($crop[0]) === false)) { $crop[0] = $crop[1]; } else if ((empty($crop[1]) === true) || (is_numeric($crop[1]) === false)) { $crop[1] = $crop[0]; } } $ratio = array ( 0 => $width / $height, 1 => $crop[0] / $crop[1], ); if ($ratio[0] > $ratio[1]) { $width = $height * $ratio[1]; $x = (imagesx($image) - $width) / 2; } else if ($ratio[0] < $ratio[1]) { $height = $width / $ratio[1]; $y = (imagesy($image) - $height) / 2; } /* How can I skip (join) this operation with the one in the Resize Section? */ $result = ImageCreateTrueColor($width, $height); if (is_resource($result) === true) { ImageSaveAlpha($result, true); ImageAlphaBlending($result, false); ImageFill($result, 0, 0, ImageColorAllocateAlpha($result, 255, 255, 255, 127)); ImageCopyResampled($result, $image, 0, 0, $x, $y, $width, $height, $width, $height); $image = $result; } } /* Resize Section */ if (is_null($size) === true) { $size = array(imagesx($image), imagesy($image)); } else { $size = array_filter(explode('x', $size)); if (empty($size) === true) { $size = array(imagesx($image), imagesy($image)); } else { if ((empty($size[0]) === true) || (is_numeric($size[0]) === false)) { $size[0] = round($size[1] * imagesx($image) / imagesy($image)); } else if ((empty($size[1]) === true) || (is_numeric($size[1]) === false)) { $size[1] = round($size[0] * imagesy($image) / imagesx($image)); } } } $result = ImageCreateTrueColor($size[0], $size[1]); if (is_resource($result) === true) { ImageSaveAlpha($result, true); ImageAlphaBlending($result, true); ImageFill($result, 0, 0, ImageColorAllocate($result, 255, 255, 255)); ImageCopyResampled($result, $image, 0, 0, 0, 0, $size[0], $size[1], imagesx($image), imagesy($image)); header('Content-Type: image/jpeg'); ImageInterlace($result, true); ImageJPEG($result, null, 90); } } return false; } ?> The function works as expected but I'm creating a non-required GD image resource, how can I fix it? I've tried joining both calls but I must be doing some miscalculations. <?php /* Usage Examples */ Image('http://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png', '1:1', '600x'); Image('http://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png', '2:1', '600x'); Image('http://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png', '2:', '250x300'); ?> Any help is greatly appreciated, thanks.

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  • boost::asio::async_write problem

    - by user368831
    Hi, I'm trying to figure out how asynchronous reads and writes work in boost asio by manipulating the echo example. Currently, I have a server that should, when sent a sentence, respond with only the first word. However, the boost::asio::async_write never seems to complete even though the write handler is being called. Can someone please explain what's going on? Here's the code: #include <cstdlib> #include <iostream> #include <boost/bind.hpp> #include <boost/asio.hpp> using boost::asio::ip::tcp; class session { public: session(boost::asio::io_service& io_service) : socket_(io_service) { } tcp::socket& socket() { return socket_; } void start() { std::cout<<"starting"<<std::endl; boost::asio::async_read_until(socket_, buffer, ' ', boost::bind(&session::handle_read, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } void handle_read(const boost::system::error_code& error, size_t bytes_transferred) { // std::ostringstream ss; // ss<<&buffer; char* c = new char[bytes_transferred]; //std::string s; buffer.sgetn(c,bytes_transferred); std::cout<<"data: "<< c<<" bytes: "<<bytes_transferred<<std::endl; if (!error) { boost::asio::async_write(socket_, boost::asio::buffer(c,bytes_transferred), boost::bind(&session::handle_write, this, boost::asio::placeholders::error)); } else { delete this; } } void handle_write(const boost::system::error_code& error) { std::cout<<"handling write"<<std::endl; if (!error) { } else { delete this; } } private: tcp::socket socket_; boost::asio::streambuf buffer; }; class server { public: server(boost::asio::io_service& io_service, short port) : io_service_(io_service), acceptor_(io_service, tcp::endpoint(tcp::v4(), port)) { session* new_session = new session(io_service_); acceptor_.async_accept(new_session->socket(), boost::bind(&server::handle_accept, this, new_session, boost::asio::placeholders::error)); } void handle_accept(session* new_session, const boost::system::error_code& error) { if (!error) { new_session->start(); new_session = new session(io_service_); acceptor_.async_accept(new_session->socket(), boost::bind(&server::handle_accept, this, new_session, boost::asio::placeholders::error)); } else { delete new_session; } } private: boost::asio::io_service& io_service_; tcp::acceptor acceptor_; }; int main(int argc, char* argv[]) { try { if (argc != 2) { std::cerr << "Usage: async_tcp_echo_server <port>\n"; return 1; } boost::asio::io_service io_service; using namespace std; // For atoi. server s(io_service, atoi(argv[1])); io_service.run(); } catch (std::exception& e) { std::cerr << "Exception: " << e.what() << "\n"; } return 0; } Thanks!

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  • Filtering in a HierarchicalDataTemplate via MarkupExtension?

    - by Dan Bryant
    I'm trying to create a MarkupExtension to allow filtering of items in an ItemsSource of a HierarchicalDataTemplate. In particular, I'd like to be able to supply a method name that will be executed on the DataContext in order to perform the filtering. The usage syntax I'm after looks like this: <HierarchicalDataTemplate DataType="{x:Type src:DeviceBindingViewModel}" ItemsSource="{Utilities:FilterCollection {Binding Definition.Entries}, MethodName=FilterEntries}"> <StackPanel Orientation="Horizontal"> <Image Source="{StaticResource BindingImage}" Width="24" Height="24" Margin="3"/> <TextBlock Text="{Binding DisplayName}" FontSize="12" VerticalAlignment="Center"/> </StackPanel> </HierarchicalDataTemplate> My code for the custom MarkupExtension looks like this: public sealed class FilterCollectionExtension : MarkupExtension { private readonly MultiBinding _binding; private Predicate<Object> _filterMethod; public string MethodName { get; set; } public FilterCollectionExtension(Binding binding) { _binding = new MultiBinding(); _binding.Bindings.Add(binding); //We package a reference to the DataContext with the binding so that the Converter has access to it var selfBinding = new Binding {RelativeSource = RelativeSource.Self}; _binding.Bindings.Add(selfBinding); _binding.Converter = new InternalConverter(this); } public FilterCollectionExtension(Binding binding, string methodName) : this(binding) { MethodName = methodName; } public override object ProvideValue(IServiceProvider serviceProvider) { return _binding; } private bool FilterInternal(Object dataContext, Object value) { //Filtering is only applicable if a DataContext is defined if (dataContext != null) { if (_filterMethod == null) { var type = dataContext.GetType(); var method = type.GetMethod(MethodName, new[] { typeof(Object) }); if (method == null || method.ReturnType != typeof(bool)) throw new InvalidOperationException("Could not locate a filter predicate named " + MethodName + " on the DataContext"); _filterMethod = (Predicate<Object>)Delegate.CreateDelegate(typeof(Predicate<Object>), dataContext, method); } else { if (_filterMethod.Target != dataContext) { _filterMethod = (Predicate<Object>) Delegate.CreateDelegate(typeof (Predicate<Object>), dataContext, _filterMethod.Method); } } if (_filterMethod != null) return _filterMethod(value); } //If no filtering resolved, just allow all elements return true; } private class InternalConverter : IMultiValueConverter { private readonly FilterCollectionExtension _owner; public InternalConverter(FilterCollectionExtension owner) { _owner = owner; } public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture) { var enumerable = values[0]; var targetElement = (FrameworkElement)values[1]; var view = CollectionViewSource.GetDefaultView(enumerable); view.Filter = item => _owner.FilterInternal(targetElement.DataContext, item); return view; } public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture) { throw new NotSupportedException("Cannot convert back"); } } } I can see that the extension is instantiated and I can see it return the MultiBinding that is used by the Template. I also see the call to the InternalConverter.Convert method, which sees the expected parameters (I see the collection provided by the nested {Binding}) and is successfully able to retrieve the ICollectionView for the incoming collection. The only problem is that FilterInternal never gets called. The template is ultimately being used by a TreeView, if that's relevant. I haven't been able to figure out why the FilterInternal method is not being called and I was hoping somebody might be able to offer some insight.

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  • Need help diagnosing network performance issues

    - by tokes
    I am currently working in a developing country as a system analyst for a government department. My area of expertise is software projects, but I've come across a few issues with the network setup in my office. (Unfortunately, being a developing country, there's not a lot of professional help available for this sort of thing.) Most recently, I am trying to diagnose a problem with slowness on the network. Our office is connected to the internet via an ADSL wireless modem/router (called Router). The modem is connected via ethernet to a switch (called Switch). The modem also acts as a wireless access point (called Wireless1), though because it is in a room at the end of the floor, it's range is limited. There are ethernet ports installed around the office. The cables of these all lead back to the same switch. In closer vicinity to the bulk of the client computers, there is another wireless router that acts as an access point for those clients (called Wireless2). That router is connected via ethernet to a wall port, and therefore to Switch. There is also a Windows server which acts as a DNS server (called DNSBox) which is located in the same room and is connected directly to Switch. ---Internet----------| Router/Wireless1 192.168.10.1 ---------------| |----|=========| DNSBox | |-------------------- 192.168.10.4 --------------------| Switch |---Other clients---- | |-------------------- |----|=========| Wireless2 ------------------| 192.168.10.198 One final thing to mention about the network setup. All clients are configured with manual IP addresses. Their router/gateway is set to the IP address of Router, and their DNS server is set to the IP address of DNSBox (with a secondary IP set to an external IP - that of our ISP's DNS server). Here are the symptoms we are experiencing: Clients connected to Wireless2 AP experience slow and unstable connections to the internet. (Slow here is defined as speeds of ~1KB/s, though ping response times seem to be as normal.) Clients connected via ethernet to Switch also experience the same slowness. Clients connected to Wireless1 AP (i.e. connecting via wireless directly to the ADSL modem) experience normal connections to the internet. Clients connected via ethernet to Router (i.e. connecting via ethernet directly to the ADSL modem) also experience normal connections to the internet. I also tried to gauge the connection performance between two machines on the network via ethernet: A file transfer between two clients who were both directly connected to Switch was the fastest; A file transfer between one client directly connected to Switch, and one client directly connected to Router (which is directly connected to Switch) performed much slower; A file transfer between two clients directly connected to Router also performed slowly. Things I have attempted to diagnose the problem: Restarted Switch -- no change. We tried unplugging ethernet jacks from Switch 4 at a time and testing the internet connection. The thought here was that perhaps a client on the network has contracted a virus, and is possibly spamming the network with traffic? (Not very technical, I know.) Unfortunately we couldn't get any significant increases in performance using this method. There were a couple of times when it seemed to be better, but then the connection speed quickly dropped back to slow/dead pace. I didn't want to unplug all jacks from Switch because I was concerned that users might be affected or that I would re-plug in the jacks incorrectly (should I even be worried about that? a port is a port on a switch, right?) I tried swapping the ethernet cable used to connect Router to Switch -- no change in performance. I tried swapping the port used on Switch for Router -- no change in performance. Anyone got any ideas on what this could be? Should I be mentioning specific brand names/models of the hardware used? Virii outbreaks are common in this country/office -- what could I be doing to figure out if a virus is at fault? If it is a virus, it doesn't seem to be generating a lot of traffic to/from the internet, because a) I can still get a good speed if I am directly connected to Router / Wireless1 and b) our ISP data usage has not risen suspiciously. Thanks for your help! Update #1 Here are the specs of some of the hardware: Switch is an Edimax ES3132RL 32-Port 10/100 Rackmount Switch Router is a D-Link DSL-G604T Update #2 I just tried unplugging everything except a laptop and Router from Switch. Speeds are still slow. I guess that means that Router / Switch are not being flooded? It seems more and more likely that the cause is something to do with the interaction between Router and Switch. However, I still can't find any useful resources on setting the LAN speed for either (and I'm not well-versed in these advanced networking configurations).

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  • If record exists in database, UPDATE a single column

    - by Doug
    I have a bulk uploading object in place that is being used to bulk upload roughly 25-40 image files at a time. Each image is about 100-150 kb in size. During the upload, I've created a for each loop that takes the file name of the image (minus the file extension) to write it into a column named "sku". Also, for each file being uploaded, the date is recorded to a column named DateUpdated, as well as some image path data. Here is my c# code: protected void graphicMultiFileButton_Click(object sender, EventArgs e) { //graphicMultiFile is the ID of the bulk uploading object ( provided by Dean Brettle: http://www.brettle.com/neatupload ) if (graphicMultiFile.Files.Length > 0) { foreach (UploadedFile file in graphicMultiFile.Files) { //strip ".jpg" from file name (will be assigned as SKU) string sku = file.FileName.Substring(0, file.FileName.Length - 4); //assign the directory where the images will be stored on the server string directoryPath = Server.MapPath("~/images/graphicsLib/" + file.FileName); //ensure that if image existes on server that it will get overwritten next time it's uploaded: file.MoveTo(directoryPath, MoveToOptions.Overwrite); //current sql that inserts a record to the db SqlCommand comm; SqlConnection conn; string connectionString = ConfigurationManager.ConnectionStrings["DataConnect"].ConnectionString; conn = new SqlConnection(connectionString); comm = new SqlCommand("INSERT INTO GraphicsLibrary (sku, imagePath, DateUpdated) VALUES (@sku, @imagePath, @DateUpdated)", conn); comm.Parameters.Add("@sku", System.Data.SqlDbType.VarChar, 50); comm.Parameters["@sku"].Value = sku; comm.Parameters.Add("@imagePath", System.Data.SqlDbType.VarChar, 300); comm.Parameters["@imagePath"].Value = "images/graphicsLib/" + file.FileName; comm.Parameters.Add("@DateUpdated", System.Data.SqlDbType.DateTime); comm.Parameters["@DateUpdated"].Value = DateTime.Now; conn.Open(); comm.ExecuteNonQuery(); conn.Close(); } } } After images are uploaded, managers will go back and re-upload images that have previously been uploaded. This is because these product images are always being revised and improved. For each new/improved image, the file name and extension will remain the same - so that when image 321-54321.jpg was first uploaded to the server, the new/improved version of that image will still have the image file name as 321-54321.jpg. I can't say for sure if the file sizes will remain in the 100-150KB range. I'll assume that the image file size will grow eventually. When images get uploaded (again), there of course will be an existing record in the database for that image. What is the best way to: Check the database for the existing record (stored procedure or SqlDataReader or create a DataSet ...?) Then if record exists, simply UPDATE that record so that the DateUpdated column gets today's date. If no record exists, do the INSERT of the record as normal. Things to consider: If the record exists, we'll let the actual image be uploaded. It will simply overwrite the existing image so that the new version gets displayed on the web. We're using SQL Server 2000 on hosted environment (DiscountAsp). I'm programming in C#. The uploading process will be used by about 2 managers a few times a month (each) - which to me is not a allot of usage. Although I'm a jr. developer, I'm guessing that a stored procedure would be the way to go. Just seems more efficient - to do this record check away from the for each loop... but not sure. I'd need extra help writing a sproc, since I don't have too much experience with them. Thank everyone...

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  • Linker error when compiling boost.asio example

    - by Alon
    Hi, I'm trying to learn a little bit C++ and Boost.Asio. I'm trying to compile the following code example: #include <iostream> #include <boost/array.hpp> #include <boost/asio.hpp> using boost::asio::ip::tcp; int main(int argc, char* argv[]) { try { if (argc != 2) { std::cerr << "Usage: client <host>" << std::endl; return 1; } boost::asio::io_service io_service; tcp::resolver resolver(io_service); tcp::resolver::query query(argv[1], "daytime"); tcp::resolver::iterator endpoint_iterator = resolver.resolve(query); tcp::resolver::iterator end; tcp::socket socket(io_service); boost::system::error_code error = boost::asio::error::host_not_found; while (error && endpoint_iterator != end) { socket.close(); socket.connect(*endpoint_iterator++, error); } if (error) throw boost::system::system_error(error); for (;;) { boost::array<char, 128> buf; boost::system::error_code error; size_t len = socket.read_some(boost::asio::buffer(buf), error); if (error == boost::asio::error::eof) break; // Connection closed cleanly by peer. else if (error) throw boost::system::system_error(error); // Some other error. std::cout.write(buf.data(), len); } } catch (std::exception& e) { std::cerr << e.what() << std::endl; } return 0; } With the following command line: g++ -I /usr/local/boost_1_42_0 a.cpp and it throws an unclear error: /tmp/ccCv9ZJA.o: In function `__static_initialization_and_destruction_0(int, int)': a.cpp:(.text+0x654): undefined reference to `boost::system::get_system_category()' a.cpp:(.text+0x65e): undefined reference to `boost::system::get_generic_category()' a.cpp:(.text+0x668): undefined reference to `boost::system::get_generic_category()' a.cpp:(.text+0x672): undefined reference to `boost::system::get_generic_category()' a.cpp:(.text+0x67c): undefined reference to `boost::system::get_system_category()' /tmp/ccCv9ZJA.o: In function `boost::system::error_code::error_code()': a.cpp:(.text._ZN5boost6system10error_codeC2Ev[_ZN5boost6system10error_codeC5Ev]+0x10): undefined reference to `boost::system::get_system_category()' /tmp/ccCv9ZJA.o: In function `boost::asio::error::get_system_category()': a.cpp:(.text._ZN5boost4asio5error19get_system_categoryEv[boost::asio::error::get_system_category()]+0x7): undefined reference to `boost::system::get_system_category()' /tmp/ccCv9ZJA.o: In function `boost::asio::detail::posix_thread::~posix_thread()': a.cpp:(.text._ZN5boost4asio6detail12posix_threadD2Ev[_ZN5boost4asio6detail12posix_threadD5Ev]+0x1d): undefined reference to `pthread_detach' /tmp/ccCv9ZJA.o: In function `boost::asio::detail::posix_thread::join()': a.cpp:(.text._ZN5boost4asio6detail12posix_thread4joinEv[boost::asio::detail::posix_thread::join()]+0x25): undefined reference to `pthread_join' /tmp/ccCv9ZJA.o: In function `boost::asio::detail::posix_tss_ptr<boost::asio::detail::call_stack<boost::asio::detail::task_io_service<boost::asio::detail::epoll_reactor<false> > >::context>::~posix_tss_ptr()': a.cpp:(.text._ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceINS1_13epoll_reactorILb0EEEEEE7contextEED2Ev[_ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceINS1_13epoll_reactorILb0EEEEEE7contextEED5Ev]+0xf): undefined reference to `pthread_key_delete' /tmp/ccCv9ZJA.o: In function `boost::asio::detail::posix_tss_ptr<boost::asio::detail::call_stack<boost::asio::detail::task_io_service<boost::asio::detail::epoll_reactor<false> > >::context>::posix_tss_ptr()': a.cpp:(.text._ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceINS1_13epoll_reactorILb0EEEEEE7contextEEC2Ev[_ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceINS1_13epoll_reactorILb0EEEEEE7contextEEC5Ev]+0x22): undefined reference to `pthread_key_create' collect2: ld returned 1 exit status How can I fix it? Thank you.

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  • How to install PyQt on Mac OS X 10.6.

    - by Jebagnanadas
    Hello all, I'm quite new to Mac OS X. when i tried to install PyQt on Mac Os X after installing python 3.1, Qt 4.6.2 and SIP 4.10.1 i encounter the following error when i execute $python3 configure.py command. Determining the layout of your Qt installation... This is the GPL version of PyQt 4.7 (licensed under the GNU General Public License) for Python 3.1 on darwin. Type '2' to view the GPL v2 license. Type '3' to view the GPL v3 license. Type 'yes' to accept the terms of the license. Type 'no' to decline the terms of the license. Do you accept the terms of the license? yes Checking to see if the QtGui module should be built... Checking to see if the QtHelp module should be built... Checking to see if the QtMultimedia module should be built... Checking to see if the QtNetwork module should be built... Checking to see if the QtOpenGL module should be built... Checking to see if the QtScript module should be built... Checking to see if the QtScriptTools module should be built... Checking to see if the QtSql module should be built... Checking to see if the QtSvg module should be built... Checking to see if the QtTest module should be built... Checking to see if the QtWebKit module should be built... Checking to see if the QtXml module should be built... Checking to see if the QtXmlPatterns module should be built... Checking to see if the phonon module should be built... Checking to see if the QtAssistant module should be built... Checking to see if the QtDesigner module should be built... Qt v4.6.2 free edition is being used. Qt is built as a framework. SIP 4.10.1 is being used. The Qt header files are in /usr/include. The shared Qt libraries are in /Library/Frameworks. The Qt binaries are in /Developer/Tools/Qt. The Qt mkspecs directory is in /usr/local/Qt4.6. These PyQt modules will be built: QtCore. The PyQt Python package will be installed in /Library/Frameworks/Python.framework/Versions/3.1/lib/python3.1/site-packages. PyQt is being built with generated docstrings. PyQt is being built with 'protected' redefined as 'public'. The Designer plugin will be installed in /Developer/Applications/Qt/plugins/designer. The PyQt .sip files will be installed in /Library/Frameworks/Python.framework/Versions/3.1/share/sip/PyQt4. pyuic4, pyrcc4 and pylupdate4 will be installed in /Library/Frameworks/Python.framework/Versions/3.1/bin. Generating the C++ source for the QtCore module... sip: Usage: sip [-h] [-V] [-a file] [-b file] [-c dir] [-d file] [-e] [-g] [-I dir] [-j #] [-k] [-m file] [-o] [-p module] [-r] [-s suffix] [-t tag] [-w] [-x feature] [-z file] [file] Error: Unable to create the C++ code. Anybody here installed PyQt on Mac OS X 10.6.2 successfully.. Any help would be much appreciated.. Thanks in advance..

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  • Linux IPTables / routing issue

    - by Jon
    Hi all, EDIT 1/3/10 22:00 GMT - rewrote some of it after further investigation It has been a while since I looked at IPtables and I seem to be worse than before as I can not seem to get my webserver online. Below is my firewall rules on the gateway server that is running the dhcp server accessing the net. The webserver is inside my network on a static IP (192.168.0.98, default port). When I use Nmap or GRC.com I see that port 80 is open on the gateway server but when I browse to it, (via public URL. http://www.houseofhawkins.com) it always fails with a connection error, (nmap cannot connect and figure out what the web server is either). I can nmap the webserver and browse to it just fine via same IP inside my network. I believe it is my IPTable rules that are not letting it through. Internally I can route all my requests. Each machine can browse to the website and traffic works just fine. I can MSTSC / ssh to all the webservers internally and they inturn can connect to the web. IPTABLE: *EDIT - Added new firewall rules 2/3/10 * #!/bin/sh iptables="/sbin/iptables" modprobe="/sbin/modprobe" depmod="/sbin/depmod" EXTIF="eth2" INTIF="eth1" load () { $depmod -a $modprobe ip_tables $modprobe ip_conntrack $modprobe ip_conntrack_ftp $modprobe ip_conntrack_irc $modprobe iptable_nat $modprobe ip_nat_ftp echo "enable forwarding.." echo "1" > /proc/sys/net/ipv4/ip_forward echo "enable dynamic addr" echo "1" > /proc/sys/net/ipv4/ip_dynaddr # start firewall # default policies $iptables -P INPUT DROP $iptables -F INPUT $iptables -P OUTPUT DROP $iptables -F OUTPUT $iptables -P FORWARD DROP $iptables -F FORWARD $iptables -t nat -F #echo " Opening loopback interface for socket based services." $iptables -A INPUT -i lo -j ACCEPT $iptables -A OUTPUT -o lo -j ACCEPT #echo " Allow all connections OUT and only existing and related ones IN" $iptables -A INPUT -i $INTIF -j ACCEPT $iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT $iptables -A OUTPUT -o $EXTIF -j ACCEPT $iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT $iptables -A FORWARD -i $EXTIF -o $INTIF -m state --state ESTABLISHED,RELATED -j ACCEPT $iptables -A FORWARD -i $INTIF -o $EXTIF -j ACCEPT $iptables -A FORWARD -j LOG --log-level 7 --log-prefix "Dropped by firewall: " $iptables -A INPUT -j LOG --log-level 7 --log-prefix "Dropped by firewall: " $iptables -A OUTPUT -j LOG --log-level 7 --log-prefix "Dropped by firewall: " #echo " Enabling SNAT (MASQUERADE) functionality on $EXTIF" $iptables -t nat -A POSTROUTING -o $EXTIF -j MASQUERADE $iptables -A INPUT -i $INTIF -j ACCEPT $iptables -A OUTPUT -o $INTIF -j ACCEPT #echo " Allowing packets with ICMP data (i.e. ping)." $iptables -A INPUT -p icmp -j ACCEPT $iptables -A OUTPUT -p icmp -j ACCEPT $iptables -A INPUT -p udp -i $INTIF --dport 67 -m state --state NEW -j ACCEPT #echo " Port 137 is for NetBIOS." $iptables -A INPUT -i $INTIF -p udp --dport 137 -j ACCEPT $iptables -A OUTPUT -o $INTIF -p udp --dport 137 -j ACCEPT #echo " Opening port 53 for DNS queries." $iptables -A INPUT -p udp -i $EXTIF --sport 53 -j ACCEPT #echo " opening Apache webserver" $iptables -A PREROUTING -t nat -i $EXTIF -p tcp --dport 80 -j DNAT --to 192.168.0.96:80 $iptables -A FORWARD -p tcp -m state --state NEW -d 192.168.0.96 --dport 80 -j ACCEPT } flush () { echo "flushing rules..." $iptables -P FORWARD ACCEPT $iptables -F INPUT $iptables -P INPUT ACCEPT echo "rules flushed" } case "$1" in start|restart) flush load ;; stop) flush ;; *) echo "usage: start|stop|restart." ;; esac exit 0 route info: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 5e0412a6.bb.sky * 255.255.255.255 UH 0 0 0 eth2 192.168.0.0 * 255.255.255.0 U 0 0 0 eth1 default 5e0412a6.bb.sky 0.0.0.0 UG 100 0 0 eth2 ifconfig: eth1 Link encap:Ethernet HWaddr 00:22:b0:cf:4a:1c inet addr:192.168.0.1 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::222:b0ff:fecf:4a1c/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:79023 errors:0 dropped:0 overruns:0 frame:0 TX packets:57786 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:11580918 (11.5 MB) TX bytes:22872030 (22.8 MB) Interrupt:17 Base address:0x2b00 eth2 Link encap:Ethernet HWaddr 00:0c:f1:7c:45:5b inet addr:94.4.18.166 Bcast:94.4.18.166 Mask:255.255.255.255 inet6 addr: fe80::20c:f1ff:fe7c:455b/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:57038 errors:0 dropped:0 overruns:0 frame:0 TX packets:34532 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:21631721 (21.6 MB) TX bytes:7685444 (7.6 MB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:16 errors:0 dropped:0 overruns:0 frame:0 TX packets:16 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:1517 (1.5 KB) TX bytes:1517 (1.5 KB) EDIT OK so as requested I will try and expand on my infrastructure: I previously had it setup with a Sky broadband modem router that did the DHCP and I used its web interface to port forward the web across to the web server. The network looked something like this: I have now replaced the sky modem with a dlink modem which gives the IP to the gateway server that now does the DHCP. It looks like: The internet connection is a standard broadband connection with a dynamic IP, (use zoneedit.com to keep it updated). I have tried it on each of the webservers(one Ubuntu Apache server and one WS2008 IIS7). I think there must also be an issue with my IPTable rules as it can route to my win7 box which has the default IIS7 page and that would not display when I forwarded all port 80 to it. I would be really grateful for any and all help with this. Thanks Jon

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  • Understanding Node.js and concept of non-blocking I/O

    - by Saif Bechan
    Recently I became interested in using Node.js to tackle some of the parts of my web-application. I love the part that its full JavaScript and its very light weight so no use anymore to call an JavaScript-PHP call but a lighter JavaScript-JavaScript call. I however do not understand all the concepts explained. Basic concepts Now in the presentation for Node.js Ryan Dahl talks about non-blocking IO and why this is the way we need to create our programs. I can understand the theoretical concept. You just don't wait for a response, you go ahead and do other things. You make a callback for the response, and when the response arrives millions of clock-cycles later, you can fire that. If you have not already I recommend to watch this presentation. It is very easy to follow and pretty detailed. There are some nice concepts explained on how to write your code in a good manner. There are also some examples given and I am going to work with the basic example given. Examples The way we do thing now: puts("Enter your name: "); var name = gets(); puts("Name: " + name); Now the problem with this is that the code is halted at line 1. It blocks your code. The way we need to do things according to node puts("Enter your name: "); gets(function (name) { puts("Name: " + name); }); Now with this your program does not halt, because the input is a function within the output. So the programs continues to work without halting. Questions Now the basic question I have is how does this work in real-life situations. I am talking here for the use in web-applications. The application I am writing does I/O, bit is still does it in am blocking matter. I think that most of the time, if not all, you need to block, because you have to wait on what the response is you have to work with. When you need to get some information from the database, most of the time this data needs to be verified before you can further with the code. Example 1 If you take a login for example. You have to wait for the database to response to return, because you can not do anything else. I can't see a way around this without blocking. Example 2 Going back to the basic example. The use just request something from a database which does not need any verification. You still have to block because you don't have anything to do more. I can not come up with a single example where you want to do other things while you wait for the response to return. Possible answers I have read that this frees up recourses. When you program like this it takes less CPU or memory usage. So this non-blocking IO is ONLY meant to free up recourses and does not have any other practical use. Not that this is not a huge plus, freeing up recourses is always good. Yet I fail to see this as a good solution. because in both of the above examples, the program has to wait for the response of the user. Whether this is inside a function, or just inline, in my opinion there is a program that wait for input. Resources I looked at I have looked at some recourses before I posted this question. They talk a lot about the theoretical concept, which is quite clear. Yet i fail to see some real-life examples where this is makes a huge difference. Stackoverflow: What is in simple words blocking IO and non-blocking IO? Blocking IO vs non-blocking IO; looking for good articles tidy code for asynchronous IO Other recources: Wikipedia: Asynchronous I/O Introduction to non-blocking I/O The C10K problem

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  • All downloads being interrupted

    - by Jake
    System: Windows 7 Professional 64bit. 8GB RAM, Intel i5-2400 CPU, +300GB free on the hard drive. AVG Internet Security 2012 (enabled & disabled, with firewall enabled and disabled - no effect for either). This computer is less than a year old. Network: This problem is occurring on a single computer on a network with multiple computers. The router is a Motorola Netopia 3347-02 (DSL Modem/Wireless Router combined). The computer is plugged in directly to the modem, other computers are using the wireless successfully. The router has been reset. The only thing odd about the connection between the router and computer is that it is configured to allow RDP through, so it is assigned a static IP by the router and port forwarding is enabled for port 3389. Also, though I doubt it matters, a second wireless router is active behind this router providing a second network that some computers in the area use without issues. Details: All downloads initiated on this specific computer eventually fail, this includes streaming from youtube, specialized downloads (itunes), downloads from websites, FTP downloads, etc. Failure occurs with all browsers, but in chrome this is the process it takes: 1) Download begins normally, 2) At some point between (observed) 7MBs and 229MBs the download stops progressing (at this point, if watching chrome's task manager, you can see the network activity for the downloading tab drop to 0kps), 3) for some time the download sits there still attempting to complete, but will eventually display "123,049,871/0 B, Interrupted" (where the number is whatever it actually got to). The file I am using to test this is a very large .zip file located on a server I control, but the problem seems to occur on any site. The amount downloaded is completely random, and seems to be more time-based than anything (if I start a download immediately after the last one fails, it tends to get further than the last one). Small files can get through for this reason, though they can fail as well. In a test where I simultaneously downloaded the same file via HTTP (chrome) and FTP (windows explorer), both downloads failed at the same instant, though explorer displayed "Connection timed out" several minutes before chrome finally showed the download as interrupted. Other things I have tried based on advice given to people with similar/identical problems: Setting my MTU to 1492 (as described here: http://blog.thecompwiz.com/2011/08/networking-issues.html) Disabling write caching to the hard drive storing the download on an external device successfully transmitted +1GB file from one computer on the same network to this computer disabling indexing in the folder the download was being stored in disabling all security software checked to make sure all drivers were up to date read about 50 accounts with nearly exact descriptions of what I'm experiencing, none of which had a solution given Running Processes: Image Name PID Session Name Session# Mem Usage ========================= ======== ================ =========== ============ System Idle Process 0 Services 0 24 K System 4 Services 0 104,836 K smss.exe 332 Services 0 1,276 K csrss.exe 764 Services 0 5,060 K wininit.exe 820 Services 0 4,748 K csrss.exe 844 Console 1 23,764 K services.exe 876 Services 0 11,856 K lsass.exe 892 Services 0 14,420 K lsm.exe 900 Services 0 7,820 K winlogon.exe 944 Console 1 7,716 K svchost.exe 428 Services 0 12,744 K svchost.exe 796 Services 0 12,240 K svchost.exe 1036 Services 0 22,372 K svchost.exe 1084 Services 0 174,132 K svchost.exe 1112 Services 0 56,144 K svchost.exe 1288 Services 0 18,640 K svchost.exe 1404 Services 0 29,616 K spoolsv.exe 1576 Services 0 25,924 K svchost.exe 1616 Services 0 12,788 K AppleMobileDeviceService. 1728 Services 0 9,796 K avgwdsvc.exe 1820 Services 0 8,268 K mDNSResponder.exe 1844 Services 0 5,832 K w3dbsmgr.exe 1108 Services 0 43,760 K QBCFMonitorService.exe 1336 Services 0 16,408 K svchost.exe 2404 Services 0 28,240 K taskhost.exe 3020 Console 1 12,372 K dwm.exe 2280 Console 1 5,968 K explorer.exe 2964 Console 1 152,476 K WUDFHost.exe 3316 Services 0 6,740 K svchost.exe 3408 Services 0 5,556 K RAVCpl64.exe 3684 Console 1 13,864 K igfxtray.exe 3700 Console 1 7,804 K hkcmd.exe 3772 Console 1 7,868 K igfxpers.exe 3788 Console 1 10,940 K sidebar.exe 3836 Console 1 84,400 K chrome.exe 3964 Console 1 19,640 K pptd40nt.exe 4068 Console 1 5,156 K acrotray.exe 3908 Console 1 14,676 K avgtray.exe 3872 Console 1 9,508 K jusched.exe 4076 Console 1 4,412 K iTunesHelper.exe 1532 Console 1 87,308 K SearchIndexer.exe 3492 Services 0 36,948 K iPodService.exe 4136 Services 0 7,944 K BrccMCtl.exe 4276 Console 1 18,132 K splwow64.exe 4380 Console 1 32,600 K qbupdate.exe 4836 Console 1 24,236 K svchost.exe 4288 Services 0 20,700 K wmpnetwk.exe 3112 Services 0 9,516 K FNPLicensingService.exe 5248 Services 0 5,852 K QBW32.EXE 5508 Console 1 127,068 K QBDBMgrN.exe 5600 Services 0 42,252 K EXCEL.EXE 2512 Console 1 99,100 K LMS.exe 3188 Services 0 5,616 K UNS.exe 1600 Services 0 7,308 K axlbridge.exe 5260 Console 1 5,132 K chrome.exe 5888 Console 1 200,336 K chrome.exe 3536 Console 1 26,076 K chrome.exe 1952 Console 1 20,168 K chrome.exe 4596 Console 1 24,696 K chrome.exe 4292 Console 1 48,096 K chrome.exe 2796 Console 1 23,520 K Acrobat.exe 1240 Console 1 87,252 K 123w.exe 4892 Console 1 22,728 K calc.exe 1700 Console 1 12,636 K chrome.exe 1328 Console 1 28,888 K chrome.exe 3696 Console 1 47,012 K rundll32.exe 6320 Console 1 7,104 K chrome.exe 4928 Console 1 44,248 K AVGIDSAgent.exe 260 Services 0 12,940 K avgfws.exe 6052 Services 0 26,912 K avgnsa.exe 5064 Services 0 2,496 K avgrsa.exe 3088 Services 0 2,200 K avgcsrva.exe 2596 Services 0 380 K avgcsrva.exe 6948 Services 0 408 K StikyNot.exe 452 Console 1 14,772 K chrome.exe 4580 Console 1 28,200 K chrome.exe 4016 Console 1 57,756 K svchost.exe 7140 Services 0 4,500 K chrome.exe 6264 Console 1 56,824 K chrome.exe 7008 Console 1 56,896 K chrome.exe 2224 Console 1 38,032 K taskhost.exe 612 Console 1 7,228 K chrome.exe 6000 Console 1 10,928 K chrome.exe 2568 Console 1 43,052 K chrome.exe 272 Console 1 75,988 K chrome.exe 7328 Console 1 53,240 K PaprPort.exe 7976 Console 1 137,152 K pplinks.exe 7500 Console 1 14,052 K ppscanmg.exe 5744 Console 1 18,996 K taskeng.exe 7388 Console 1 6,308 K SearchProtocolHost.exe 8024 Services 0 8,804 K SearchFilterHost.exe 7232 Services 0 7,848 K chrome.exe 8016 Console 1 37,440 K cmd.exe 7692 Console 1 3,096 K conhost.exe 7516 Console 1 5,872 K tasklist.exe 8160 Console 1 5,772 K WmiPrvSE.exe 7684 Services 0 6,400 K Any help with this would be greatly appreciated, I've been beating my head against a wall over this all day. This computer serves dual purpose as the main company document server and the Owner's work computer, it's fairly important it be fully functional and I cannot figure this out.

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  • ASP.NET WebControl ITemplate child controls are null

    - by tster
    Here is what I want: I want a control to put on a page, which other developers can place form elements inside of to display the entities that my control is searching. I have the Searching logic all working. The control builds custom search fields and performs searches based on declarative C# classes implementing my SearchSpec interface. Here is what I've been trying: I've tried using ITemplate on a WebControl which implements INamingContainer I've tried implementing a CompositeControl The closest I can get to working is below. OK I have a custom WebControl [ AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal), AspNetHostingPermission(SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal), DefaultProperty("SearchSpecName"), ParseChildren(true), ToolboxData("<{0}:SearchPage runat=\"server\"> </{0}:SearchPage>") ] public class SearchPage : WebControl, INamingContainer { [Browsable(false), PersistenceMode(PersistenceMode.InnerProperty), DefaultValue(typeof(ITemplate), ""), Description("Form template"), TemplateInstance(TemplateInstance.Single), TemplateContainer(typeof(FormContainer))] public ITemplate FormTemplate { get; set; } public class FormContainer : Control, INamingContainer{ } public Control MyTemplateContainer { get; private set; } [Bindable(true), Category("Behavior"), DefaultValue(""), Description("The class name of the SearchSpec to use."), Localizable(false)] public virtual string SearchSpecName { get; set; } [Bindable(true), Category("Behavior"), DefaultValue(true), Description("True if this is query mode."), Localizable(false)] public virtual bool QueryMode { get; set; } private SearchSpec _spec; private SearchSpec Spec { get { if (_spec == null) { Type type = Assembly.GetExecutingAssembly().GetTypes().Where(t => t.Name == SearchSpecName).First(); _spec = (SearchSpec)Assembly.GetExecutingAssembly().CreateInstance(type.Namespace + "." + type.Name); } return _spec; } } protected override void CreateChildControls() { if (FormTemplate != null) { MyTemplateContainer = new FormTemplateContainer(this); FormTemplate.InstantiateIn(MyTemplateContainer); Controls.Add(MyTemplateContainer); } else { Controls.Add(new LiteralControl("blah")); } } protected override void RenderContents(HtmlTextWriter writer) { // <snip> } protected override HtmlTextWriterTag TagKey { get { return HtmlTextWriterTag.Div; } } } public class FormTemplateContainer : Control, INamingContainer { private SearchPage parent; public FormTemplateContainer(SearchPage parent) { this.parent = parent; } } then the usage: <tster:SearchPage ID="sp1" runat="server" SearchSpecName="TestSearchSpec" QueryMode="False"> <FormTemplate> <br /> Test Name: <asp:TextBox ID="testNameBox" runat="server" Width="432px"></asp:TextBox> <br /> Owner: <asp:TextBox ID="ownerBox" runat="server" Width="427px"></asp:TextBox> <br /> Description: <asp:TextBox ID="descriptionBox" runat="server" Height="123px" Width="432px" TextMode="MultiLine" Wrap="true"></asp:TextBox> </FormTemplate> </tster:SearchPage> The problem is that in the CodeBehind, the page has members descriptionBox, ownerBox and testNameBox. However, they are all null. Furthermore, FindControl("ownerBox") returns null as does this.sp1.FindControl("ownerBox"). I have to do this.sp1.MyTemplateContainer.FindControl("ownerBox") to get the control. How can I make it so that the C# Code Behind will have the controls generated and not null in my Page_Load event so that developers can just do this: testNameBox.Text = "foo"; ownerBox.Text = "bar"; descriptionBox.Text = "baz";

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  • Nginx + php-fpm "504 Gateway Time-out" error with almost zero load (on a test-server)

    - by rahul286
    After debugging for 6-hours - I am giving this up :| We have a nginx+php-fpm+mysql in LAN with almost 100 wordpress (created and used by different designers/developers all working on test wordpres setup) We are using nginx without any issues from long. Today, all of a sudden - nginx started returning "504 Gateway Time-out" out of the blue... I checked nginx error log for a virtual host... 2010/09/06 21:24:24 [error] 12909#0: *349 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /favicon.ico HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 21:25:11 [error] 12909#0: *349 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /favicon.ico HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 21:25:11 [error] 12909#0: *443 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /info.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 21:25:12 [error] 12909#0: *443 connect() failed (111: Connection refused) while connecting to upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /favicon.ico HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 22:08:32 [error] 12909#0: *1025 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET / HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 22:09:33 [error] 12909#0: *1025 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /favicon.ico HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 22:09:40 [error] 12909#0: *1064 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /info.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 22:09:40 [error] 12909#0: *1064 connect() failed (111: Connection refused) while connecting to upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /favicon.ico HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 22:24:44 [error] 12909#0: *1313 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET / HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 22:24:53 [error] 12909#0: *1313 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /favicon.ico HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" As I run php-fpm on port 9000 via TCP mode, I ran "netstat | grep 9000" and noticed something unusual... (Pasting partial output here for ease of read) tcp 9 0 localhost:9000 localhost:36094 CLOSE_WAIT 14269/php5-fpm tcp 0 0 localhost:46664 localhost:9000 FIN_WAIT2 - tcp 1257 0 localhost:9000 localhost:36135 CLOSE_WAIT - tcp 1257 0 localhost:9000 localhost:36125 CLOSE_WAIT - tcp 9 0 localhost:9000 localhost:36102 CLOSE_WAIT 14268/php5-fpm tcp 0 0 localhost:46662 localhost:9000 FIN_WAIT2 - tcp 745 0 localhost:9000 localhost:46644 CLOSE_WAIT - tcp 0 0 localhost:46658 localhost:9000 FIN_WAIT2 - tcp 1265 0 localhost:9000 localhost:46607 CLOSE_WAIT - tcp 0 0 localhost:46672 localhost:9000 ESTABLISHED 12909/nginx: worker tcp 1257 0 localhost:9000 localhost:36119 CLOSE_WAIT - tcp 1265 0 localhost:9000 localhost:46613 CLOSE_WAIT - tcp 0 0 localhost:46646 localhost:9000 FIN_WAIT2 - tcp 1257 0 localhost:9000 localhost:36137 CLOSE_WAIT - tcp 0 0 localhost:46670 localhost:9000 ESTABLISHED 12909/nginx: worker tcp 1265 0 localhost:9000 localhost:46619 CLOSE_WAIT - tcp 1336 0 localhost:9000 localhost:46668 ESTABLISHED - tcp 0 0 localhost:46648 localhost:9000 FIN_WAIT2 - tcp 1336 0 localhost:9000 localhost:46670 ESTABLISHED - tcp 9 0 localhost:9000 localhost:36108 CLOSE_WAIT 14274/php5-fpm tcp 1336 0 localhost:9000 localhost:46684 ESTABLISHED - tcp 0 0 localhost:46674 localhost:9000 ESTABLISHED 12909/nginx: worker tcp 1336 0 localhost:9000 localhost:46666 ESTABLISHED - tcp 1257 0 localhost:9000 localhost:46648 CLOSE_WAIT - tcp 1336 0 localhost:9000 localhost:46678 ESTABLISHED - tcp 0 0 localhost:46668 localhost:9000 ESTABLISHED 12909/nginx: wo There are plenty of "CLOSE_WAIT" & "FIN_WAIT2" pairs as highlighted below (in above output): tcp 1337 0 localhost:9000 localhost:46680 CLOSE_WAIT - tcp 0 0 localhost:46680 localhost:9000 FIN_WAIT2 - Please note port 46680 in above. I enabled mysql slow queries error log, but it didn't work. As of now restarting php5-fpm every minute via a cronjob (see command below) keeping everything running "smoothly" but I hate patchwork and want to solve this... 1 * * * * service php5-fpm restart > /dev/null I searched extensively on Google - got no help. As mentioned, this a test-server in LAN, CPU load is never crossed 0.10 and memory usage is also below 25% (System has 2GB RAM and ubuntu-server installed) So if you find its time-confusing to help me out, please atleast drop a hint. Thanks in advance for help. -Rahul (note - this is reposting of - http://forum.nginx.org/read.php?11,127694) Update: I found answer, which is posted below.

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  • Load-balancing between a Procurve switch and a server

    - by vlad
    Hello I've been searching around the web for this problem i've been having. It's similar in a way to this question: How exactly & specifically does layer 3 LACP destination address hashing work? My setup is as follows: I have a central switch, a Procurve 2510G-24, image version Y.11.16. It's the center of a star topology, there are four switches connected to it via a single gigabit link. Those switches service the users. On the central switch, I have a server with two gigabit interfaces that I want to bond together in order to achieve higher throughput, and two other servers that have single gigabit connections to the switch. The topology looks as follows: sw1 sw2 sw3 sw4 | | | | --------------------- | sw0 | --------------------- || | | srv1 srv2 srv3 The servers were running FreeBSD 8.1. On srv1 I set up a lagg interface using the lacp protocol, and on the switch I set up a trunk for the two ports using lacp as well. The switch showed that the server was a lacp partner, I could ping the server from another computer, and the server could ping other computers. If I unplugged one of the cables, the connection would keep working, so everything looked fine. Until I tested throughput. There was only one link used between srv1 and sw0. All testing was conducted with iperf, and load distribution was checked with systat -ifstat. I was looking to test the load balancing for both receive and send operations, as I want this server to be a file server. There were therefore two scenarios: iperf -s on srv1 and iperf -c on the other servers iperf -s on the other servers and iperf -c on srv1 connected to all the other servers. Every time only one link was used. If one cable was unplugged, the connections would keep going. However, once the cable was plugged back in, the load was not distributed. Each and every server is able to fill the gigabit link. In one-to-one test scenarios, iperf was reporting around 940Mbps. The CPU usage was around 20%, which means that the servers could withstand a doubling of the throughput. srv1 is a dell poweredge sc1425 with onboard intel 82541GI nics (em driver on freebsd). After troubleshooting a previous problem with vlan tagging on top of a lagg interface, it turned out that the em could not support this. So I figured that maybe something else is wrong with the em drivers and / or lagg stack, so I started up backtrack 4r2 on this same server. So srv1 now uses linux kernel 2.6.35.8. I set up a bonding interface bond0. The kernel module was loaded with option mode=4 in order to get lacp. The switch was happy with the link, I could ping to and from the server. I could even put vlans on top of the bonding interface. However, only half the problem was solved: if I used srv1 as a client to the other servers, iperf was reporting around 940Mbps for each connection, and bwm-ng showed, of course, a nice distribution of the load between the two nics; if I run the iperf server on srv1 and tried to connect with the other servers, there was no load balancing. I thought that maybe I was out of luck and the hashes for the two mac addresses of the clients were the same, so I brought in two new servers and tested with the four of them at the same time, and still nothing changed. I tried disabling and reenabling one of the links, and all that happened was the traffic switched from one link to the other and back to the first again. I also tried setting the trunk to "plain trunk mode" on the switch, and experimented with other bonding modes (roundrobin, xor, alb, tlb) but I never saw any traffic distribution. One interesting thing, though: one of the four switches is a Cisco 2950, image version 12.1(22)EA7. It has 48 10/100 ports and 2 gigabit uplinks. I have a server (call it srv4) with a 4 channel trunk connected to it (4x100), FreeBSD 8.0 release. The switch is connected to sw0 via gigabit. If I set up an iperf server on one of the servers connected to sw0 and a client on srv4, ALL 4 links are used, and iperf reports around 330Mbps. systat -ifstat shows all four interfaces are used. The cisco port-channel uses src-mac to balance the load. The HP should use both the source and destination according to the manual, so it should work as well. Could this mean there is some bug in the HP firmware? Am I doing something wrong?

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  • Modern Java alternatives

    - by Ralph
    I'm not sure if stackoverflow is the best forum for this discussion. I have been a Java developer for 14 years and have written an enterprise-level (~500,000 line) Swing application that uses most of the standard library APIs. Recently, I have become disappointed with the progress that the language has made to "modernize" itself, and am looking for an alternative for ongoing development. I have considered moving to the .NET platform, but I have issues with using something the only runs well in Windows (I know about Mono, but that is still far behind Microsoft). I also plan on buying a new Macbook Pro as soon as Apple releases their new rumored Arrandale-based machines and want to develop in an environment that will feel "at home" in Unix/Linux. I have considered using Python or Ruby, but the standard Java library is arguably the largest of any modern language. In JVM-based languages, I looked at Groovy, but am disappointed with its performance. Rumor has it that with the soon-to-be released JDK7, with its InvokeDynamic instruction, this will improve, but I don't know how much. Groovy is also not truly a functional language, although it provides closures and some of the "functional" features on collections. It does not embrace immutability. I have narrowed my search down to two JVM-based alternatives: Scala and Clojure. Each has its strengths and weaknesses. I am looking for the stackoverflow readerships' opinions. I am not an expert at either of these languages; I have read 2 1/2 books on Scala and am currently reading Stu Halloway's book on Clojure. Scala is strongly statically typed. I know the dynamic language folks claim that static typing is a crutch for not doing unit testing, but it does provide a mechanism for compile-time location of a whole class of errors. Scala is more concise than Java, but not as much as Clojure. Scala's inter-operation with Java seems to be better than Clojure's, in that most Java operations are easier to do in Scala than in Clojure. For example, I can find no way in Clojure to create a non-static initialization block in a class derived from a Java superclass. For example, I like the Apache commons CLI library for command line argument parsing. In Java and Scala, I can create a new Options object and add Option items to it in an initialization block as follows (Java code): final Options options = new Options() { { addOption(new Option("?", "help", false, "Show this usage information"); // other options } }; I can't figure out how to the same thing in Clojure (except by using (doit...)), although that may reflect my lack of knowledge of the language. Clojure's collections are optimized for immutability. They rarely require copy-on-write semantics. I don't know if Scala's immutable collections are implemented using similar algorithms, but Rich Hickey (Clojure's inventor) goes out of his way to explain how that language's data structures are efficient. Clojure was designed from the beginning for concurrency (as was Scala) and with modern multi-core processors, concurrency takes on more importance, but I occasionally need to write simple non-concurrent utilities, and Scala code probably runs a little faster for these applications since it discourages, but does not prohibit, "simple" mutability. One could argue that one-off utilities do not have to be super-fast, but sometimes they do tasks that take hours or days to complete. I know that there is no right answer to this "question", but I thought I would open it up for discussion. If anyone has a suggestion for another JVM-based language that can be used for enterprise level development, please list it. Also, it is not my intent to start a flame war. Thanks, Ralph

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  • Simple Convention Automapper for two-way Mapping (Entities to/from ViewModels)

    - by Omu
    UPDATE: this stuff has evolved into a nice project, see it at http://valueinjecter.codeplex.com check this out, I just wrote a simple automapper, it takes the value from the property with the same name and type of one object and puts it into another, and you can add exceptions (ifs, switch) for each type you may need so tell me what do you think about it ? I did it so I could do something like this: Product –> ProductDTO ProductDTO –> Product that's how it begun: I use the "object" type in my Inputs/Dto/ViewModels for DropDowns because I send to the html a IEnumerable<SelectListItem> and I receive a string array of selected keys back public void Map(object a, object b) { var pp = a.GetType().GetProperties(); foreach (var pa in pp) { var value = pa.GetValue(a, null); // property with the same name in b var pb = b.GetType().GetProperty(pa.Name); if (pb == null) { //no such property in b continue; } if (pa.PropertyType == pb.PropertyType) { pb.SetValue(b, value, null); } } } UPDATE: the real usage: the Build methods (Input = Dto): public static TI BuildInput<TI, T>(this T entity) where TI: class, new() { var input = new TI(); input = Map(entity, input) as TI; return input; } public static T BuildEntity<T, TI, TR>(this TI input) where T : class, new() where TR : IBaseAdvanceService<T> { var id = (long)input.GetType().GetProperty("Id").GetValue(input, null); var entity = LocatorConfigurator.Resolve<TR>().Get(id) ?? new T(); entity = Map(input, entity) as T; return entity; } public static TI RebuildInput<T, TI, TR>(this TI input) where T: class, new() where TR : IBaseAdvanceService<T> where TI : class, new() { return input.BuildEntity<T, TI, TR>().BuildInput<TI, T>(); } in the controller: public ActionResult Create() { return View(new Organisation().BuildInput<OrganisationInput, Organisation>()); } [AcceptVerbs(HttpVerbs.Post)] public ActionResult Create(OrganisationInput o) { if (!ModelState.IsValid) { return View(o.RebuildInput<Organisation,OrganisationInput, IOrganisationService>()); } organisationService.SaveOrUpdate(o.BuildEntity<Organisation, OrganisationInput, IOrganisationService>()); return RedirectToAction("Index"); } The real Map method public static object Map(object a, object b) { var lookups = GetLookups(); var propertyInfos = a.GetType().GetProperties(); foreach (var pa in propertyInfos) { var value = pa.GetValue(a, null); // property with the same name in b var pb = b.GetType().GetProperty(pa.Name); if (pb == null) { continue; } if (pa.PropertyType == pb.PropertyType) { pb.SetValue(b, value, null); } else if (lookups.Contains(pa.Name) && pa.PropertyType == typeof(LookupItem)) { pb.SetValue(b, (pa.GetValue(a, null) as LookupItem).GetSelectList(pa.Name), null); } else if (lookups.Contains(pa.Name) && pa.PropertyType == typeof(object)) { pb.SetValue(b, pa.GetValue(a, null).ReadSelectItemValue(), null); } else if (pa.PropertyType == typeof(long) && pb.PropertyType == typeof(Organisation)) { pb.SetValue(b, pa.GetValue<long>(a).ReadOrganisationId(), null); } else if (pa.PropertyType == typeof(Organisation) && pb.PropertyType == typeof(long)) { pb.SetValue(b, pa.GetValue<Organisation>(a).Id, null); } } return b; }

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