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  • Tools for Automated Source Code Editing

    - by Steve
    I'm working on a research project to automatically modify code to include advanced mathematical concepts (like adding random effects into a loop or encapsulating an existing function with a new function that adds in a more advanced physical model). My question to the community is: are there are any good tools for manipulating source code directly? I want to do things like Swap out functions Add variable declarations wherever they are required Determine if a function is multiplied by anything Determine what functions are called on a line of code See what parameters are passed to a function and replace them with alternatives Introduce new function calls on certain lines of code Wherever possible just leaving the rest of the code untouched and write out the results I never want to actually compile the code I only want to understand what symbols are used, replace and add in a syntactically correct way, and be able to declare variables at the right position. I've been using a minimal flex/bison approach with some success but I do not feel the it is robust. I hate to take on writing a full language parser just to add some new info to the end of a line or the top of a function. It seems like this is almost what is going to be required but it also seems like there should be some tools out there to do these types of manipulations already. The code to be changed is in a variety of languages, but I'm particularly interested in FORTRAN. Any thoughts?

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  • How do I code a tree of objects in Haskell with pointers to parent and children?

    - by axilmar
    I've got the following problem: I have a tree of objects of different classes where an action in the child class invalidates the parent. In imperative languages, it is trivial to do. For example, in Java: public class A { private List<B> m_children = new LinkedList<B>(); private boolean m_valid = true; public void invalidate() { m_valid = false; } public void addChild(B child) { m_children.add(child); child.m_parent = this; } } public class B { public A m_parent = null; private int m_data = 0; public void setData(int data) { m_data = 0; m_parent.invalidate(); } } public class Main { public static void main(String[] args) { A a = new A(); B b = new B(); b.setData(0); //invalidates A } } How do I do the above in Haskell? I cannot wrap my mind around this, since once I construct an object in Haskell, it cannot be changed. I would be much obliged if the relevant Haskell code is posted.

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  • Getting rid of function's argument

    - by Max
    It is better to explain my intention with code. So right now I have the following code: class A, IInterfaceUsedByB { } class B { void func(A someObject) { func2(someObject, 1); func3(someObject, "string"); func4(someObject, new MyObject()); } func2(A someObject, int val); func3(A someObject, string val); func4(A someObject, C val); } Where func2, func3, func4 do need references to someObject. I want to change this to void func() { with(someObject, () => { func2(1); func3("string"); func4(new MyObject()); } ); } Or even better to void func(someObject) { func2(1); func3("string"); func4(new MyObject()); } So that I don't have to drag this someObject around, but I should still be able to use it inside func2,3,4. I can use any of the three languages (C#, F# or IronPython) for this. UPDATE In the ideal solution class B would be independent of A. func* functions only depend on a small interface of A consisting of 2 methods.

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  • Patterns to deal with with functions that can have different kinds of results.

    - by KaptajnKold
    Suppose you have an method on an object that given the some input alters the objects state if the input validates according to some complex logic. Now suppose that when the input doesn't validate, it can be due to several different things, each of which we would like to be able to deal with in different ways. I'm sure many of you are thinking: That's what exceptions are for! I've thought of this also. But my reservation against using exceptions is that in some cases there is nothing exceptional about the input not validating and I really would like to avoid using exceptions to control what is really just in the expected flow of the program. If there were only one interpretation possible, I could simply choose to return a boolean value indicating whether or not the operation resulted in a state change or not and the respond appropriately when it did not. There is of course also the option to return a status code which the client can then choose to interpret or not. I don't like this much either because there is nothing semantic about status codes. The solution I have so far is to always check for each possible situation which I am able to handle before I call the method which then returns a boolean to inform the client if the object changed state. This leaves me the flexibility to handle as few or as many as the possible situations as I wish depending on the context I am in. It also has the benefit of making the method I am calling simpler to write. The drawback is that there is quite a lot of duplication in the client code wherever I call the method. Which of these solutions do you prefer and why? What other patterns do people use for providing meaningful feedback from functions? I know that some languages support multiple return values, and I if I had that option I would surely prefer it.

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  • [javascript] Can I overload an object with a function?

    - by user257493
    Lets say I have an object of functions/values. I'm interested in overloading based on calling behavior. For example, this block of code below demonstrates what I wish to do. var main_thing = { initalized: false, something: "Hallo, welt!", something_else: [123,456,789], load: { sub1 : function() { //Some stuff }, sub2 : function() { //Some stuff }, all : function() { this.load.sub1(); this.load.sub2(); } } init: function () { this.initalized=true; this.something="Hello, world!"; this.something_else = [0,0,0]; this.load(); //I want this to call this.load.all() instead. } } The issue to me is that main_thing.load is assigned to an object, and to call main_thing.load.all() would call the function inside of the object (the () operator). What can I do to set up my code so I could use main_thing.load as an access the object, and main_thing.load() to execute some code? Or at least, similar behavior. Basically, this would be similar to a default constructor in other languages where you don't need to call main_thing.constructor(). If this isn't possible, please explain with a bit of detail.

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  • C++ - Creating a god object

    - by Greg Kritzman
    Hypothetical situation that I'm struggling to get my head past. HoldsFooBar.h: #include "foo.h" #include "bar.h" class HoldsFooBar{ foo F; bar B; }; foo.h: //includes? class foo{ HoldsFooBar *H; void Baz(); }; bar.h: //includes? class bar{ HoldsFooBar *H; void Qux(); }; I'm trying to get F to get a hold of B. In all other languages I've worked with, I would be able to H->B.Qux();, but I'm totally lost in C++. At the includes lines in foo.h and bar.h, it seems like my options are to forward-declare class HoldsFooBar; but then I can only access H, and F and B cannot see each other. Likewise, I can #include "HoldsFooBar.h" but because of my include guards, something ends up not getting linked properly, so the program doesn't run. Is what I'm trying to do even possible? Thank you very much! Any help would be appreciated!

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  • Inheritance issue

    - by VenkateshGudipati
    hi Friends i am facing a issue in Inheritance i have a interface called Irewhizz interface irewhzz { void object save(object obj); void object getdata(object obj); } i write definition in different class like public user:irewhzz { public object save(object obj); { ....... } public object getdata(object obj); { ....... } } this is antoher class public client:irewhzz { public object save(object obj); { ....... } public object getdata(object obj); { ....... } } now i have different classes like public partial class RwUser { #region variables IRewhizzDataHelper irewhizz; IRewhizzRelationDataHelper irewhizzrelation; private string _firstName; private string _lastName; private string _middleName; private string _email; private string _website; private int _addressId; private string _city; private string _zipcode; private string _phone; private string _fax; //private string _location; private string _aboutMe; private string _username; private string _password; private string _securityQuestion; private string _securityQAnswer; private Guid _user_Id; private long _rwuserid; private byte[] _image; private bool _changepassword; private string _mobilephone; private int _role; #endregion //IRewhizz is the interface and its functions are implimented by UserDataHelper class //RwUser Class is inheriting the UserDataHelper Properties and functions. //Here UserDataHelper functions are called with Irewhizz Interface Object but not with the //UserDataHelper class Object It will resolves the unit testing conflict. #region Constructors public RwUser() : this(new UserDataHelper(), new RewhizzRelationalDataHelper()) { } public RwUser(IRewhizzDataHelper repositary, IRewhizzRelationDataHelper relationrepositary) { irewhizz = repositary; irewhizzrelation = relationrepositary; } #endregion #region Properties public int Role { get { return _role; } set { _role = value; } } public string MobilePhone { get { return _mobilephone; } set { _mobilephone = value; } } public bool ChangePassword { get { return _changepassword; } set { _changepassword = value; } } public byte[] Image { get { return _image; } set { _image = value; } } public string FirstName { get { return _firstName; } set { _firstName = value; } } public string LastName { get { return _lastName; } set { _lastName = value; } } public string MiddleName { get { return _middleName; } set { _middleName = value; } } public string Email { get { return _email; } set { _email = value; } } public string Website { get { return _website; } set { _website = value; } } public int AddressId { get { return _addressId; } set { _addressId = value; } } public string City { get { return _city; } set { _city = value; } } public string Zipcode { get { return _zipcode; } set { _zipcode = value; } } public string Phone { get { return _phone; } set { _phone = value; } } public string Fax { get { return _fax; } set { _fax = value; } } //public string Location //{ // get // { // return _location; // } // set // { // _location = value; // } //} public string AboutMe { get { return _aboutMe; } set { _aboutMe = value; } } public string username { get { return _username; } set { _username = value; } } public string password { get { return _password; } set { _password = value; } } public string SecurityQuestion { get { return _securityQuestion; } set { _securityQuestion = value; } } public string SecurityQAnswer { get { return _securityQAnswer; } set { _securityQAnswer = value; } } public Guid UserID { get { return _user_Id; } set { _user_Id = value; } } public long RwUserID { get { return _rwuserid; } set { _rwuserid = value; } } #endregion #region MemberFunctions // DataHelperDataContext db = new DataHelperDataContext(); // RewhizzDataHelper rwdh=new RewhizzDataHelper(); //It saves user information entered by user and returns the id of that user public object saveUserInfo(RwUser userObj) { userObj.UserID = irewhizzrelation.GetUserId(username); var res = irewhizz.saveData(userObj); return res; } //It returns the security questions for user registration } public class Agent : RwUser { IRewhizzDataHelper irewhizz; IRewhizzRelationDataHelper irewhizzrelation; private int _roleid; private int _speclisationid; private int[] _language; private string _brokaragecompany; private int _loctionType_lk; private string _rolename; private int[] _specialization; private string _agentID; private string _expDate; private string _regstates; private string _selLangs; private string _selSpels; private string _locations; public string Locations { get { return _locations; } set { _locations = value; } } public string SelectedLanguages { get { return _selLangs; } set { _selLangs = value; } } public string SelectedSpecialization { get { return _selSpels; } set { _selSpels = value; } } public string RegisteredStates { get { return _regstates; } set { _regstates = value; } } //private string _registeredStates; public string AgentID { get { return _agentID; } set { _agentID = value; } } public string ExpDate { get { return _expDate; } set { _expDate = value; } } private int[] _registeredStates; public SelectList RegisterStates { set; get; } public SelectList Languages { set; get; } public SelectList Specializations { set; get; } public int[] RegisterdStates { get { return _registeredStates; } set { _registeredStates = value; } } //public string RegisterdStates //{ // get // { // return _registeredStates; // } // set // { // _registeredStates = value; // } //} public int RoleId { get { return _roleid; } set { _roleid = value; } } public int SpeclisationId { get { return _speclisationid; } set { _speclisationid = value; } } public int[] Language { get { return _language; } set { _language = value; } } public int LocationTypeId { get { return _loctionType_lk; } set { _loctionType_lk = value; } } public string BrokarageCompany { get { return _brokaragecompany; } set { _brokaragecompany = value; } } public string Rolename { get { return _rolename; } set { _rolename = value; } } public int[] Specialization { get { return _specialization; } set { _specialization = value; } } public Agent() : this(new AgentDataHelper(), new RewhizzRelationalDataHelper()) { } public Agent(IRewhizzDataHelper repositary, IRewhizzRelationDataHelper relationrepositary) { irewhizz = repositary; irewhizzrelation = relationrepositary; } public void inviteclient() { //Code related to mailing } //DataHelperDataContext dataObj = new DataHelperDataContext(); //#region IRewhizzFactory Members //public List<object> getAgentInfo(string username) //{ // var res=dataObj.GetCompleteUserDetails(username); // return res.ToList(); // throw new NotImplementedException(); //} //public List<object> GetRegisterAgentData(string username) //{ // var res= dataObj.RegisteredUserdetails(username); // return res.ToList(); //} //public void saveAgentInfo(string username, string password, string firstname, string lastname, string middlename, string securityquestion, string securityQanswer) //{ // User userobj=new User(); // var result = dataObj.rw_Users_InsertUserInfo(firstname, middlename, lastname, dataObj.GetUserId(username), securityquestion, securityquestionanswer); // throw new NotImplementedException(); //} //#endregion public Agent updateData(Agent objectId) { objectId.UserID = irewhizzrelation.GetUserId(objectId.username); objectId = (Agent)irewhizz.updateData(objectId); return objectId; } public Agent GetAgentData(Agent agentodj) { agentodj.UserID = irewhizzrelation.GetUserId(agentodj.username); agentodj = (Agent)irewhizz.getData(agentodj); if (agentodj.RoleId != 0) agentodj.Rolename = (string)(string)irewhizzrelation.getValue(agentodj.RoleId); if (agentodj.RegisterdStates.Count() != 0) { List<SelectListItem> list = new List<SelectListItem>(); string regstates = ""; foreach (int i in agentodj.RegisterdStates) { SelectListItem listitem = new SelectListItem(); listitem.Value = i.ToString(); listitem.Text = (string)irewhizzrelation.getValue(i); list.Add(listitem); regstates += (string)irewhizzrelation.getValue(i) + ","; } SelectList selectlist = new SelectList(list, "Value", "Text"); agentodj.RegisterStates = selectlist; if(regstates!=null) agentodj.RegisteredStates = regstates.Remove(regstates.Length - 1); } if (agentodj.Language.Count() != 0) { List<SelectListItem> list = new List<SelectListItem>(); string selectedlang = ""; foreach (int i in agentodj.Language) { SelectListItem listitem = new SelectListItem(); listitem.Value = i.ToString(); listitem.Text = (string)irewhizzrelation.getValue(i); list.Add(listitem); selectedlang += (string)irewhizzrelation.getValue(i) + ","; } SelectList selectlist = new SelectList(list, "Value", "Text"); agentodj.Languages = selectlist; // agentodj.SelectedLanguages = selectedlang; } if (agentodj.Specialization.Count() != 0) { List<SelectListItem> list = new List<SelectListItem>(); string selectedspel = ""; foreach (int i in agentodj.Specialization) { SelectListItem listitem = new SelectListItem(); listitem.Value = i.ToString(); listitem.Text = (string)irewhizzrelation.getValue(i); list.Add(listitem); selectedspel += (string)irewhizzrelation.getValue(i) + ","; } SelectList selectlist = new SelectList(list, "Value", "Text"); agentodj.Specializations = selectlist; //agentodj.SelectedSpecialization = selectedspel; } return agentodj; } public void SaveImage(byte[] pic, String username) { irewhizzrelation.SaveImage(pic, username); } } now the issue is when ever i am calling agent class it is given error like null reference exception for rwuser class can any body give the solution thanks in advance

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  • Can a pc with a 1.2 ghz dual core run VS 2013? [on hold]

    - by moo2
    Edit: This question is about a tool used for programming, Microsoft Visual Studio 2013. I already read the minimum requirements for VS 2013 before I posted or I wouldn't have asked the question. I searched on the web for an answer for a few hours before posting. Why should I go out and spend $400 on a laptop if I can spend less than $100 and use it to learn how to program? In the context of the question it is clear I was not asking for advice on what laptop to buy and it was also clear I was not asking for someone to walk me through the system requirements of VS 2013. This is a vast community and I was wondering if someone in this vast community would have experience in dealing with my question. In other words has anyone ever tried anything like it? If I had an old computer sitting around I would have tested it. At the moment all I have is a friend's Chromebook I'm borrowing. End Edit. I know the requirements for Microsoft Visual Studio 2013 state 1.6 ghz processor. I'm looking at getting a laptop for school and I found one that is old but cheap and would work for college. The Dell D430 I'm looking at getting has a 1.2ghz Core 2 Duo CPU, 80GB HD, 2GB RAM, and Windows 7 Home Premium. It's refurbished. I can get it for less than most phone's cost and from a Microsoft Authorized Refurbisher. I know it's not a skyrim rig but it's lightweight and can handle being a college laptop and doing word processing. Would Visual Studio 2013 run at all? If it is slower I'm not concerned. I just want to know if it would work and compile my assignments and run them? I'd be using this laptop for doing assignments and learning programming languages not for coding the next social media sensation.

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  • Cannot create Java VM on OpenVZ

    - by Stephen Searles
    I'm constantly encountering an error related to Java and certificates on my Ubuntu server running in OpenVZ when installing things from apt-get. I'm pretty sure it has to do with how Java allocates memory. I know the fail counter for privvmpages is very high, so the problem must be that Java is hitting this limit. I have read that the server VM will allocate a lot of memory up front to preempt performance issues, but that the client VM doesn't do this and might be better for what I'm doing. I messed with jvm.cfg to make the system go to the client VM, but get an error that it can't find the client VM. I have tried replacing the Java binary with a script calling Java with -Xms and -Xmx settings, and that solves the issue for when I call basic things from the command line, but not for when doing things like having apt-get configure certificates. I'm at a loss for what to try next. I need to get this working, but simply increasing privvmpages is not an available option. I have the actual error pasted below. Setting up ca-certificates-java (20100412) ... creating /etc/ssl/certs/java/cacerts... Could not create the Java virtual machine. error adding brasil.gov.br/brasil.gov.br.crt error adding cacert.org/cacert.org.crt error adding debconf.org/ca.crt error adding gouv.fr/cert_igca_dsa.crt error adding gouv.fr/cert_igca_rsa.crt error adding mozilla/ABAecom_=sub.__Am._Bankers_Assn.=_Root_CA.crt error adding mozilla/AOL_Time_Warner_Root_Certification_Authority_1.crt error adding mozilla/AOL_Time_Warner_Root_Certification_Authority_2.crt error adding mozilla/AddTrust_External_Root.crt error adding mozilla/AddTrust_Low-Value_Services_Root.crt error adding mozilla/AddTrust_Public_Services_Root.crt error adding mozilla/AddTrust_Qualified_Certificates_Root.crt error adding mozilla/America_Online_Root_Certification_Authority_1.crt error adding mozilla/America_Online_Root_Certification_Authority_2.crt error adding mozilla/Baltimore_CyberTrust_Root.crt error adding mozilla/COMODO_Certification_Authority.crt error adding mozilla/COMODO_ECC_Certification_Authority.crt error adding mozilla/Camerfirma_Chambers_of_Commerce_Root.crt error adding mozilla/Camerfirma_Global_Chambersign_Root.crt error adding mozilla/Certplus_Class_2_Primary_CA.crt error adding mozilla/Certum_Root_CA.crt error adding mozilla/Comodo_AAA_Services_root.crt error adding mozilla/Comodo_Secure_Services_root.crt error adding mozilla/Comodo_Trusted_Services_root.crt error adding mozilla/DST_ACES_CA_X6.crt error adding mozilla/DST_Root_CA_X3.crt error adding mozilla/DigiCert_Assured_ID_Root_CA.crt error adding mozilla/DigiCert_Global_Root_CA.crt error adding mozilla/DigiCert_High_Assurance_EV_Root_CA.crt Could not create the Java virtual machine. error adding mozilla/Digital_Signature_Trust_Co._Global_CA_1.crt error adding mozilla/Digital_Signature_Trust_Co._Global_CA_2.crt error adding mozilla/Digital_Signature_Trust_Co._Global_CA_3.crt error adding mozilla/Digital_Signature_Trust_Co._Global_CA_4.crt error adding mozilla/Entrust.net_Global_Secure_Personal_CA.crt error adding mozilla/Entrust.net_Global_Secure_Server_CA.crt error adding mozilla/Entrust.net_Premium_2048_Secure_Server_CA.crt error adding mozilla/Entrust.net_Secure_Personal_CA.crt error adding mozilla/Entrust.net_Secure_Server_CA.crt error adding mozilla/Entrust_Root_Certification_Authority.crt error adding mozilla/Equifax_Secure_CA.crt error adding mozilla/Equifax_Secure_Global_eBusiness_CA.crt error adding mozilla/Equifax_Secure_eBusiness_CA_1.crt error adding mozilla/Equifax_Secure_eBusiness_CA_2.crt error adding mozilla/Firmaprofesional_Root_CA.crt error adding mozilla/GTE_CyberTrust_Global_Root.crt error adding mozilla/GTE_CyberTrust_Root_CA.crt error adding mozilla/GeoTrust_Global_CA.crt error adding mozilla/GeoTrust_Global_CA_2.crt error adding mozilla/GeoTrust_Primary_Certification_Authority.crt error adding mozilla/GeoTrust_Universal_CA.crt error adding mozilla/GeoTrust_Universal_CA_2.crt error adding mozilla/GlobalSign_Root_CA.crt error adding mozilla/GlobalSign_Root_CA_-_R2.crt error adding mozilla/Go_Daddy_Class_2_CA.crt error adding mozilla/IPS_CLASE1_root.crt error adding mozilla/IPS_CLASE3_root.crt error adding mozilla/IPS_CLASEA1_root.crt error adding mozilla/IPS_CLASEA3_root.crt error adding mozilla/IPS_Chained_CAs_root.crt error adding mozilla/IPS_Servidores_root.crt error adding mozilla/IPS_Timestamping_root.crt error adding mozilla/NetLock_Business_=Class_B=_Root.crt error adding mozilla/NetLock_Express_=Class_C=_Root.crt error adding mozilla/NetLock_Notary_=Class_A=_Root.crt error adding mozilla/NetLock_Qualified_=Class_QA=_Root.crt error adding mozilla/Network_Solutions_Certificate_Authority.crt error adding mozilla/QuoVadis_Root_CA.crt error adding mozilla/QuoVadis_Root_CA_2.crt error adding mozilla/QuoVadis_Root_CA_3.crt error adding mozilla/RSA_Root_Certificate_1.crt error adding mozilla/RSA_Security_1024_v3.crt error adding mozilla/RSA_Security_2048_v3.crt error adding mozilla/SecureTrust_CA.crt error adding mozilla/Secure_Global_CA.crt error adding mozilla/Security_Communication_Root_CA.crt error adding mozilla/Sonera_Class_1_Root_CA.crt error adding mozilla/Sonera_Class_2_Root_CA.crt error adding mozilla/Staat_der_Nederlanden_Root_CA.crt error adding mozilla/Starfield_Class_2_CA.crt error adding mozilla/StartCom_Certification_Authority.crt error adding mozilla/StartCom_Ltd..crt error adding mozilla/SwissSign_Gold_CA_-_G2.crt error adding mozilla/SwissSign_Platinum_CA_-_G2.crt error adding mozilla/SwissSign_Silver_CA_-_G2.crt error adding mozilla/Swisscom_Root_CA_1.crt error adding mozilla/TC_TrustCenter__Germany__Class_2_CA.crt error adding mozilla/TC_TrustCenter__Germany__Class_3_CA.crt error adding mozilla/TDC_Internet_Root_CA.crt error adding mozilla/TDC_OCES_Root_CA.crt error adding mozilla/TURKTRUST_Certificate_Services_Provider_Root_1.crt error adding mozilla/TURKTRUST_Certificate_Services_Provider_Root_2.crt error adding mozilla/Taiwan_GRCA.crt error adding mozilla/Thawte_Personal_Basic_CA.crt error adding mozilla/Thawte_Personal_Freemail_CA.crt error adding mozilla/Thawte_Personal_Premium_CA.crt error adding mozilla/Thawte_Premium_Server_CA.crt error adding mozilla/Thawte_Server_CA.crt error adding mozilla/Thawte_Time_Stamping_CA.crt error adding mozilla/UTN-USER_First-Network_Applications.crt error adding mozilla/UTN_DATACorp_SGC_Root_CA.crt error adding mozilla/UTN_USERFirst_Email_Root_CA.crt error adding mozilla/UTN_USERFirst_Hardware_Root_CA.crt error adding mozilla/ValiCert_Class_1_VA.crt error adding mozilla/ValiCert_Class_2_VA.crt error adding mozilla/VeriSign_Class_3_Public_Primary_Certification_Authority_-_G5.crt error adding mozilla/Verisign_Class_1_Public_Primary_Certification_Authority.crt error adding mozilla/Verisign_Class_1_Public_Primary_Certification_Authority_-_G2.crt error adding mozilla/Verisign_Class_1_Public_Primary_Certification_Authority_-_G3.crt error adding mozilla/Verisign_Class_2_Public_Primary_Certification_Authority.crt error adding mozilla/Verisign_Class_2_Public_Primary_Certification_Authority_-_G2.crt error adding mozilla/Verisign_Class_2_Public_Primary_Certification_Authority_-_G3.crt error adding mozilla/Verisign_Class_3_Public_Primary_Certification_Authority.crt error adding mozilla/Verisign_Class_3_Public_Primary_Certification_Authority_-_G2.crt error adding mozilla/Verisign_Class_3_Public_Primary_Certification_Authority_-_G3.crt error adding mozilla/Verisign_Class_4_Public_Primary_Certification_Authority_-_G2.crt error adding mozilla/Verisign_Class_4_Public_Primary_Certification_Authority_-_G3.crt error adding mozilla/Verisign_RSA_Secure_Server_CA.crt error adding mozilla/Verisign_Time_Stamping_Authority_CA.crt error adding mozilla/Visa_International_Global_Root_2.crt error adding mozilla/Visa_eCommerce_Root.crt error adding mozilla/WellsSecure_Public_Root_Certificate_Authority.crt error adding mozilla/Wells_Fargo_Root_CA.crt error adding mozilla/XRamp_Global_CA_Root.crt error adding mozilla/beTRUSTed_Root_CA-Baltimore_Implementation.crt error adding mozilla/beTRUSTed_Root_CA.crt error adding mozilla/beTRUSTed_Root_CA_-_Entrust_Implementation.crt error adding mozilla/beTRUSTed_Root_CA_-_RSA_Implementation.crt error adding mozilla/thawte_Primary_Root_CA.crt error adding signet.pl/signet_ca1_pem.crt error adding signet.pl/signet_ca2_pem.crt error adding signet.pl/signet_ca3_pem.crt error adding signet.pl/signet_ocspklasa2_pem.crt error adding signet.pl/signet_ocspklasa3_pem.crt error adding signet.pl/signet_pca2_pem.crt error adding signet.pl/signet_pca3_pem.crt error adding signet.pl/signet_rootca_pem.crt error adding signet.pl/signet_tsa1_pem.crt error adding spi-inc.org/spi-ca-2003.crt error adding spi-inc.org/spi-cacert-2008.crt error adding telesec.de/deutsche-telekom-root-ca-2.crt failed (VM used: java-6-openjdk). dpkg: error processing ca-certificates-java (--configure): subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing: ca-certificates-java E: Sub-process /usr/bin/dpkg returned an error code (1)

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  • tproxy squid bridge very slow when cache is full

    - by Roberto
    I have installed a bridge tproxy proxy in a fast server with 8GB ram. The traffic is around 60Mb/s. When I start for first time the proxy (with the cache empty) the proxy works very well but when the cache becomes full (few hours later) the bridge goes very slow, the traffic goes below 10Mb/s and the proxy server becomes unusable. Any hints of what may be happening? I'm using: linux-2.6.30.10 iptables-1.4.3.2 squid-3.1.1 compiled with these options: ./configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share --localstatedir=/var/lib --sysconfdir=/etc/squid --libexecdir=/usr/libexec/squid --localstatedir=/var --datadir=/usr/share/squid --enable-removal-policies=lru,heap --enable-icmp --disable-ident-lookups --enable-cache-digests --enable-delay-pools --enable-arp-acl --with-pthreads --with-large-files --enable-htcp --enable-carp --enable-follow-x-forwarded-for --enable-snmp --enable-ssl --enable-async-io=32 --enable-linux-netfilter --enable-epoll --disable-poll --with-maxfd=16384 --enable-err-languages=Spanish --enable-default-err-language=Spanish My squid.conf: cache_mem 100 MB memory_pools off acl manager proto cache_object acl localhost src 127.0.0.1/32 acl localhost src ::1/128 acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 acl to_localhost dst ::1/128 acl localnet src 10.0.0.0/8 # RFC1918 possible internal network acl localnet src 172.16.0.0/12 # RFC1918 possible internal network acl localnet src 192.168.0.0/16 # RFC1918 possible internal network acl localnet src fc00::/7 # RFC 4193 local private network range acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines acl net-g1 src xxx.xxx.xxx.xxx/24 acl SSL_ports port 443 acl Safe_ports port 80 # http acl Safe_ports port 21 # ftp acl Safe_ports port 443 # https acl Safe_ports port 70 # gopher acl Safe_ports port 210 # wais acl Safe_ports port 1025-65535 # unregistered ports acl Safe_ports port 280 # http-mgmt acl Safe_ports port 488 # gss-http acl Safe_ports port 591 # filemaker acl Safe_ports port 777 # multiling http acl CONNECT method CONNECT http_access allow manager localhost http_access deny manager http_access deny !Safe_ports http_access deny CONNECT !SSL_ports http_access allow net-g1 from where browsing should be allowed http_access allow localnet http_access allow localhost http_access deny all http_port 3128 http_port 3129 tproxy hierarchy_stoplist cgi-bin ? cache_dir ufs /var/spool/squid 8000 16 256 access_log none cache_log /var/log/squid/cache.log coredump_dir /var/spool/squid refresh_pattern ^ftp: 1440 20% 10080 refresh_pattern ^gopher: 1440 0% 1440 refresh_pattern -i (/cgi-bin/|\?) 0 0% 0 refresh_pattern . I have this issue when the cache is full, but do not really know if it is because of that. Thanks in advance and sorry my english. roberto

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  • DB2 Integrity Checks and Exception Tables

    - by imthefirestartr
    I am working on planning a migration of a DB2 8.1 database from a horrible IBM encoding to UTF-8 to support further languages etc. I am encountering an issue that I am stuck on. A few notes on this migration: We are using db2move to export and load the data and db2look to get the details fo the database (tablespaces, tables, keys etc). We found the loading process worked nicely with db2move import, however, the data takes 7 hours to load and this was unacceptable downtime when we actually complete the conversion on the main database. We are now using db2move load, which is much faster as it seems to simply throw the data in without integrity checks. Which leads to my current issue. After completing the db2move load process, several tables are in a check pending state and require integrity checks. Integrity checks are done via the following: set integrity for . immediate checked This works for most tables, however, some tables give an error: DB21034E The command was processed as an SQL statement because it was not a valid Command Line Processor command. During SQL processing it returned: SQL3603N Check data processing through the SET INTEGRITY statement has found integrity violation involving a constraint with name "blah.SQL120124110232400". SQLSTATE=23514 The internets tell me that the solution to this issue is to create an exception table based on the actual table and tell the SET INTEGRITY command to send any exceptions to that table (as below): db2 create table blah_EXCEPTION like blah db2 SET INTEGRITY FOR blah IMMEDIATE CHECKED FOR EXCEPTION IN blah USE blah_EXCEPTION NOW, here is the specific issue I am having! The above forces all the rows with issues to the specified exception table. Well that's just super, buuuuuut I can not lose data in this conversion, its simply unacceptable. The internets and IBM has a vague description of sending the violations to the exception tables and then "dealing with the data" that is in the exception table. Unfortunately, I am not clear what this means and I was hoping that some wise individual knows and could help me out and let me know how I can retrieve this data from these tables and place the data in the original/proper table rather than these exception tables. Let me know if you have any questions. Thanks!

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  • varnish3, mod_geoip with apache2 using mod_rewrite and mod_rpaf

    - by mursalat
    I am maintaining a website with 3 different versions of the site, with 3 different languages, handles with a single system written in php, which takes in environment variables based on the domain name that is being accessed. These are the three sites: myshop.com : english international version myshop.eu : european version of site myshop.ru : russian version of the site when myshop.com is accessed from russia it is to be redirected to myshop.ru, and any country from europe accesses myshop.com, is redirected to myshop.eu, and international visitors stay at myshop.com, although they can go to the country specific site. All these redirections for the country is done using GeoIP apache2 mod in order to determine the country code, which is used in a RewriteCondition to state a RewriteRule, there are some exceptions of IPs that do not do the rewrite for, basically the IPs of the developer's PCs. The site has been doing just fine, until we decided to setup varnish to give the site a boost, it really did give it a great boost, but the country specific rewrites has become buggy. What started to happen is that a russian visitor can go to myshop.com and won't be redirected, until he clicks a random link (perhaps a link not cached by varnish yet) and the user is redirected to their specific country. For that i setup mod_rpaf, and for exceptions to the rewrite rule (for the developer's ip), i used this RewriteCond %{HTTP:X-FORWARDED-FOR} !^43\.43\.43\.43, and i restarted varnish and apache2, it worked for a while, then it messed up again. And whole day i have been doing changes however i have little no clue as to what's going on, sometimes it works, and sometimes it doesn't, and sometimes it half works, etc... As for geoip, i used a php to check the $_SERVER variable, and here is the general idea of the output [HTTP_X_FORWARDED_FOR] => 43.43.43.44 [HTTP_X_VARNISH] => 1705675599 [SERVER_ADDR] => 127.0.0.1 [SERVER_PORT] => 80 [REMOTE_ADDR] => 43.43.43.44 [GEOIP_ADDR] => 43.43.43.44 [GEOIP_CONTINENT_CODE] => EU [GEOIP_COUNTRY_CODE] => FR [GEOIP_COUNTRY_NAME] => France Now, thanks to the "random" redirects, i hardly have a clue as to what is going on, so can you guys please give me some ideas as to what tools to use to debug this? I have tried to see the redirect logs, but they really dont show much, and varnishlog isn't helping much either - although i must admit i am no professional at varnish. I believe the problem is with varnish trying to cache the url, and thus apache redirects are not being done properly, however visits the site first has a redirect, and based on that other users are served the content, depending on from where the user was when the cache was last updated, is it correct? if so, how can i solve the problem? Also, i have the option of using geoip redirects on varnish3 instead of using apache2 to do the redirects, is that what the best practice is? Any suggestion as to debugging this or to fix this would be helpful! thnx!

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  • What are the pros and cons of AWS Elastic Beanstalk compared with other deployment strategies?

    - by James van Dyke
    I'm pretty new to the whole Netflix OSS stack and deployments in general. As a background for my current level of knowledge ops-wise, my main role is as a front-end application engineer. However, I enjoy the operations side of things, so I'm attempting to setup a new deployment strategy and the tooling for a new project. Our Goals Super easy deploys (we want to push a button to update production) Automated deploys to test environments (using Jenkins) Ease of maintenance (we have an app to write, don't want to spend our time fiddling with production issues) Ability to handle a service oriented architecture (many small apps, various languages and data stores) Enough flexibility to ensure we won't have to change strategies any time soon (we're already trying to get away from RightScale) We're OK with a little more initial setup time if doing so will save us some headaches in the future. So, along these lines, I've been listening to podcasts, watching Ops talks, and reading tons of blog posts and based on our goals and what I've taken to be some forming best practices, we've started forming a plan using Asgard, rolling our package into a jar and rolling that into an AMI. We had this all planned out and like the advantages the process versus using a Chef server and converging instances on the fly (we felt this was error prone given our limited timeline and lack of understanding around a Chef server workflow). However, a coworker did a little looking around on his own and felt like Elastic Beanstalk met our needs. I've looked into it and spun up a test environment with a WAR file and an attached RDS database. Things seem to work and I believe that we can automate deploys to a testing environment using Jenkins via the AWS API. Seems simple enough... perhaps too simple. What I'm wondering is, what's the catch? If Elastic Beanstalk is so simple and effective, why isn't it talked about more? I'm having a hard time finding enough objective opinions and facts about the two different deployment strategies, so I thought I'd ask around. Do you use Elastic Beanstalk? If so, why and what factors lead to that decision? What do you like and dislike? If you don't use Elastic Beanstalk but considered it, what do you use and why didn't you use Elastic Beanstalk? What are the advantages and disadvantages to a Elastic Beanstalk based deployment strategy for an SOA? That is, will Elastic Beanstalk work well with many small applications that rely on each other to work?

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  • apache tomcat loadbalancing clustering on ubuntu

    - by user740010
    i am facing a problem in clustering the tomcat with apache as a loadbalancer using mod_jk on ubuntu. i have install apache2 on my ubuntu 11.04 and i have downloaded tomcat7 created two copies and kept them at two different location. 1st one is at /home/net4u/vishal/test/tomcatA 2nd one is at /home/net4u/vishal/test1/tomcatB i have made following changes to server.xml file in /conf folder 1. <Server port="8205" shutdown="SHUTDOWN"> 2. <Connector port="8280" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" /> 3.<Connector port="8209" protocol="AJP/1.3" redirectPort="8443" /> <Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcatB"> 4. <Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/> similarly i have modified other tomcat i.e tomcatA server.xml content of the server.xml is as follow: -- <!--The connectors can use a shared executor, you can define one or more named thread pools--> <!-- <Executor name="tomcatThreadPool" namePrefix="catalina-exec-" maxThreads="150" minSpareThreads="4"/> --> <!-- A "Connector" represents an endpoint by which requests are received and responses are returned. Documentation at : Java HTTP Connector: /docs/config/http.html (blocking & non-blocking) Java AJP Connector: /docs/config/ajp.html APR (HTTP/AJP) Connector: /docs/apr.html Define a non-SSL HTTP/1.1 Connector on port 8080 --> <Connector port="8280" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" /> <!-- A "Connector" using the shared thread pool--> <!-- <Connector executor="tomcatThreadPool" port="8080" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" /> --> <!-- Define a SSL HTTP/1.1 Connector on port 8443 This connector uses the JSSE configuration, when using APR, the connector should be using the OpenSSL style configuration described in the APR documentation --> <!-- <Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true" maxThreads="150" scheme="https" secure="true" clientAuth="false" sslProtocol="TLS" /> --> <!-- Define an AJP 1.3 Connector on port 8009 --> <Connector port="8109" protocol="AJP/1.3" redirectPort="8443" /> <!-- An Engine represents the entry point (within Catalina) that processes every request. The Engine implementation for Tomcat stand alone analyzes the HTTP headers included with the request, and passes them on to the appropriate Host (virtual host). Documentation at /docs/config/engine.html --> <!-- You should set jvmRoute to support load-balancing via AJP ie : <Engine name="Catalina" defaultHost="localhost" jvmRoute="jvm1"> --> <Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcatB"> <!--For clustering, please take a look at documentation at: /docs/cluster-howto.html (simple how to) /docs/config/cluster.html (reference documentation) --> <!-- uncomment for clustering--> <Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/> <!-- Use the LockOutRealm to prevent attempts to guess user passwords via a brute-force attack --> <Realm className="org.apache.catalina.realm.LockOutRealm"> <!-- This Realm uses the UserDatabase configured in the global JNDI resources under the key "UserDatabase". Any edits that are performed against this UserDatabase are immediately available for use by the Realm. --> <Realm className="org.apache.catalina.realm.UserDatabaseRealm" resourceName="UserDatabase"/> </Realm> <Host name="localhost" appBase="webapps" unpackWARs="true" autoDeploy="true"> <!-- SingleSignOn valve, share authentication between web applications Documentation at: /docs/config/valve.html --> <!-- <Valve className="org.apache.catalina.authenticator.SingleSignOn" /> --> <!-- Access log processes all example. Documentation at: /docs/config/valve.html Note: The pattern used is equivalent to using pattern="common" --> <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs" prefix="localhost_access_log." suffix=".txt" pattern="%h %l %u %t &quot;%r&quot; %s %b" resolveHosts="false"/> </Host> </Engine> i have install libapache2-mod-jk step 1. i have Created jk.load file in /etc/apache2/mods-enabled/jk.load content is as follows: LoadModule jk_module /usr/lib/apache2/modules/mod_jk.so Create /etc/apache2/mods-enabled/jk.conf: JkWorkersFile /etc/apache2/workers.properties JkLogFile /var/log/apache2/jk.log JkMount /ecommerce/* worker1 JkMount /images/* worker1 JkMount /content/* worker1 step 2. Created workers.properties file in /etc/apache2/workers.properties content is as follows: workers.tomcat_home=/home/vishal/Desktop/test/tomcatA workers.java_home=/usr/lib/jvm/default-java ps=/ worker.list=tomcatA,tomcatB,loadbalancer   worker.tomcatA.port=8109 worker.tomcatA.host=localhost worker.tomcatA.type=ajp13 worker.tomcatA.lbfactor=1   worker.tomcatB.port=8209 worker.tomcatB.host=localhost worker.tomcatB.type=ajp13 worker.tomcatB.lbfactor=1 worker.loadbalancer.type=lb worker.loadbalancer.balanced_workers=tomcatA,tomcatB worker.loadbalancer.sticky_session=1 i tried the same thing on the windows machine it is working.

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  • Is it possible to configure a CDN so that it will step out of the way for a subset of regional IPs?

    - by rwired
    We have a website which targets customers in China, both expat and local Chinese. We have an ICP license which allows us to host in a datacenter inside China. Internet in China is actually as fast as anywhere else (faster than most places actually), so long as the content is served-up within the boundaries of the Great-Firewall. Anything that crosses the wall is horribly slow. The problem is that most expats have some sort of VPN installed so that they can access all the blocked stuff. What this means is that when they access our site, the traffic first has to go out of China through the firewall to their VPN, and then back in. The performance is terrible, worse than if we were just hosting outside of China directly (which we used to do before the ICP was issued). So I want to use a global CDN to mirror the site automatically, but I only want to deliver the content via the CDN if the user's request IP address is outside of China. Inside China I would like the content to be served by our own server. I also want to be careful with the domain names. We currently use www.xxx.com and www.xxx.cn for language selection purposes, as these perform well in SEO on Google (which the expats use), and Baidu (which the locals use). If possible I would like to avoid having one domain on the outside, and the other on the inside since not all expats use a VPN, and some Chinese speakers also use VPNs. Also some of our legitimate customers in both languages are from outside of China. I also don't want to resort to using something like www2.xxx.com/cn for the outside connection if at all possible, since I have worries about duplicate content and canonical URLs ruining our SEO (unless you know of a quick fix for that). CDNs I'm considering are: Google PageSpeed, CloudFlare, Amazon CloudFront. None of which have datacenters inside China. I have complete control of the .com DNS zone records, but the .cn zones are under the control of the domain issuing body in China. I'm not sure at this time if they would allow even a CNAME to point to an IP outside of China (although I don't see why not). They no longer allow outside registrars like they used to.

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  • PHP `virtual()` with Apache MultiViews not working after upgrade to Ubuntu 12.04

    - by Izzy
    I use PHP's virtual() directive quite a lot on one of my sites, including central elements. This worked fine for the last ~10 years -- but after upgrading (or rather moving, as it is on a new machine) to Ubuntu 12.04 it somehow got broken. Example setup (simplified) To make it easier to understand, I simplify some things (contents). So say I need a HTML fragment like <P>For further instructions, please look <A HREF='foobar'>here</P> in multiple pages. 10 years ago, I used SSI for that, so it is put into a file in a central place -- so if e.g. the targeted URL changes, I only need to update it in one place. To serve multiple languages, I have Apache's MultiViews enabled -- and at $DOCUMENT_ROOT/central/ there are the files: foobar.html (English variant, and the default) foobar.html.de (German variant). Now in the PHP code, I simply placed: <? virtual("/central/foobar"); ?> and let Apache take care to deliver the correct language variant. The problem As said, this worked fine for about 10 years: German visitors got the German variant, all others the English (depending on their preferred language). But after upgrading to Ubuntu 12.04, it no longer worked: Either nothing was delivered from the virtual() command, or (in connection with framesets) it even ended up in binary gibberish. Trying to figure out what happens, I played with a lot of things. I first thought MultiViews was (somehow) not available anymore -- but calling http://<server>/central/foobar showed the right variant, depending on the configured language preferences. This also proved there was nothing wrong with file permissions. The error.log gave no clues either (no error message thrown). Finally, just as a "last ressort", I changed the PHP command to <? virtual("central/foobar.html"); ?> -- and that very same file was in fact included. So PHP's virtual() function basically worked -- but the language dependend stuff obviously did no longer work together with it as it did before. Of course I tried to find some change (most likely in PHP's virtual() command), using Google a lot, and also searching the questions here -- unfortunately to no avail. Finally: The question Putting "design questions" aside (surely today I would design things differently -- but at least currently I miss the time to change that for a quite huge amount of pages): What can be done to make it work again? I surely missed something -- but I cannot figure out what...

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  • C#: System.Lazy&lt;T&gt; and the Singleton Design Pattern

    - by James Michael Hare
    So we've all coded a Singleton at one time or another.  It's a really simple pattern and can be a slightly more elegant alternative to global variables.  Make no mistake, Singletons can be abused and are often over-used -- but occasionally you find a Singleton is the most elegant solution. For those of you not familiar with a Singleton, the basic Design Pattern is that a Singleton class is one where there is only ever one instance of the class created.  This means that constructors must be private to avoid users creating their own instances, and a static property (or method in languages without properties) is defined that returns a single static instance. 1: public class Singleton 2: { 3: // the single instance is defined in a static field 4: private static readonly Singleton _instance = new Singleton(); 5:  6: // constructor private so users can't instantiate on their own 7: private Singleton() 8: { 9: } 10:  11: // read-only property that returns the static field 12: public static Singleton Instance 13: { 14: get 15: { 16: return _instance; 17: } 18: } 19: } This is the most basic singleton, notice the key features: Static readonly field that contains the one and only instance. Constructor is private so it can only be called by the class itself. Static property that returns the single instance. Looks like it satisfies, right?  There's just one (potential) problem.  C# gives you no guarantee of when the static field _instance will be created.  This is because the C# standard simply states that classes (which are marked in the IL as BeforeFieldInit) can have their static fields initialized any time before the field is accessed.  This means that they may be initialized on first use, they may be initialized at some other time before, you can't be sure when. So what if you want to guarantee your instance is truly lazy.  That is, that it is only created on first call to Instance?  Well, there's a few ways to do this.  First we'll show the old ways, and then talk about how .Net 4.0's new System.Lazy<T> type can help make the lazy-Singleton cleaner. Obviously, we could take on the lazy construction ourselves, but being that our Singleton may be accessed by many different threads, we'd need to lock it down. 1: public class LazySingleton1 2: { 3: // lock for thread-safety laziness 4: private static readonly object _mutex = new object(); 5:  6: // static field to hold single instance 7: private static LazySingleton1 _instance = null; 8:  9: // property that does some locking and then creates on first call 10: public static LazySingleton1 Instance 11: { 12: get 13: { 14: if (_instance == null) 15: { 16: lock (_mutex) 17: { 18: if (_instance == null) 19: { 20: _instance = new LazySingleton1(); 21: } 22: } 23: } 24:  25: return _instance; 26: } 27: } 28:  29: private LazySingleton1() 30: { 31: } 32: } This is a standard double-check algorithm so that you don't lock if the instance has already been created.  However, because it's possible two threads can go through the first if at the same time the first time back in, you need to check again after the lock is acquired to avoid creating two instances. Pretty straightforward, but ugly as all heck.  Well, you could also take advantage of the C# standard's BeforeFieldInit and define your class with a static constructor.  It need not have a body, just the presence of the static constructor will remove the BeforeFieldInit attribute on the class and guarantee that no fields are initialized until the first static field, property, or method is called.   1: public class LazySingleton2 2: { 3: // because of the static constructor, this won't get created until first use 4: private static readonly LazySingleton2 _instance = new LazySingleton2(); 5:  6: // Returns the singleton instance using lazy-instantiation 7: public static LazySingleton2 Instance 8: { 9: get { return _instance; } 10: } 11:  12: // private to prevent direct instantiation 13: private LazySingleton2() 14: { 15: } 16:  17: // removes BeforeFieldInit on class so static fields not 18: // initialized before they are used 19: static LazySingleton2() 20: { 21: } 22: } Now, while this works perfectly, I hate it.  Why?  Because it's relying on a non-obvious trick of the IL to guarantee laziness.  Just looking at this code, you'd have no idea that it's doing what it's doing.  Worse yet, you may decide that the empty static constructor serves no purpose and delete it (which removes your lazy guarantee).  Worse-worse yet, they may alter the rules around BeforeFieldInit in the future which could change this. So, what do I propose instead?  .Net 4.0 adds the System.Lazy type which guarantees thread-safe lazy-construction.  Using System.Lazy<T>, we get: 1: public class LazySingleton3 2: { 3: // static holder for instance, need to use lambda to construct since constructor private 4: private static readonly Lazy<LazySingleton3> _instance 5: = new Lazy<LazySingleton3>(() => new LazySingleton3()); 6:  7: // private to prevent direct instantiation. 8: private LazySingleton3() 9: { 10: } 11:  12: // accessor for instance 13: public static LazySingleton3 Instance 14: { 15: get 16: { 17: return _instance.Value; 18: } 19: } 20: } Note, you need your lambda to call the private constructor as Lazy's default constructor can only call public constructors of the type passed in (which we can't have by definition of a Singleton).  But, because the lambda is defined inside our type, it has access to the private members so it's perfect. Note how the Lazy<T> makes it obvious what you're doing (lazy construction), instead of relying on an IL generation side-effect.  This way, it's more maintainable.  Lazy<T> has many other uses as well, obviously, but I really love how elegant and readable it makes the lazy Singleton.

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  • HOWTO: disable jmx in activemq network of brokers (spring, xbean)

    - by subes
    Since I've struggled a lot with this problem, I am posting my solution. Disabling jmx in an activemq network of brokers removes race conditions about the registration of the jmx connector. When starting multiple activemq servers on the same machine: Failed to start jmx connector: Cannot bind to URL [rmi://localhost:1099/jmxrmi]: javax.naming.NameAlreadyBoundException: jmxrmi [Root exception is java.rmi.AlreadyBoundException: jmxrmi] Another problem with this is, that even if you don't cause a race condition, this exception can still occur. Even when starting one broker after another while waiting for them to initialize properly in between. If one process is run by root as the first instance and the other as a normal user, somehow the user process tries to register its own jmx connector, though there already is one. Or another exception which happens when the broker that successfully registered the jmx connector goes down: Failed to start jmx connector: Cannot bind to URL [rmi://localhost:1099/jmxrmi]: javax.naming.ServiceUnavailableException [Root exception is java.rmi.ConnectException: Connection refused to host: localhost; nested exception is: java.net.ConnectException: Connection refused] Those exceptions cause the network of brokers to stop working, or to not work at all. The trick to disable jmx was, that jmx had to be disabled in the connectionfactory aswell. The documentation http://activemq.apache.org/jmx.html does not say that this is needed explicitly. So I had to struggle for 2 days until I found the solution: <beans xmlns="http://www.springframework.org/schema/beans" xmlns:amq="http://activemq.apache.org/schema/core" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://activemq.apache.org/schema/core http://activemq.apache.org/schema/core/activemq-core-5.3.1.xsd"> <!-- Spring JMS Template --> <bean id="jmsTemplate" class="org.springframework.jms.core.JmsTemplate"> <constructor-arg ref="connectionFactory" /> </bean> <!-- Caching, sodass das jms template überhaupt nutzbar ist in sachen performance --> <bean id="connectionFactory" class="org.springframework.jms.connection.CachingConnectionFactory"> <constructor-arg ref="amqConnectionFactory" /> <property name="exceptionListener" ref="jmsExceptionListener" /> <property name="sessionCacheSize" value="1" /> </bean> <!-- Jeder Client verbindet sich mit seinem eigenen broker, broker sind untereinander vernetzt. Nur wenn hier nochmals jmx deaktiviert wird, bleibt es auch deaktiviert... --> <amq:connectionFactory id="amqConnectionFactory" brokerURL="vm://broker:default?useJmx=false" /> <!-- Broker suchen sich einen eigenen Port und sind gegenseitig verbunden, ergeben dadurch ein Grid. Dies zwar etwas langsamer, aber dafür ausfallsicherer. Siehe http://activemq.apache.org/networks-of-brokers.html --> <amq:broker useJmx="false" persistent="false"> <!-- Wird benötigt um JMX endgültig zu deaktivieren --> <amq:managementContext> <amq:managementContext connectorHost="localhost" createConnector="false" /> </amq:managementContext> <!-- Nun die normale Konfiguration für Network of Brokers --> <amq:networkConnectors> <amq:networkConnector networkTTL="1" duplex="true" dynamicOnly="true" uri="multicast://default" /> </amq:networkConnectors> <amq:persistenceAdapter> <amq:memoryPersistenceAdapter /> </amq:persistenceAdapter> <amq:transportConnectors> <amq:transportConnector uri="tcp://localhost:0" discoveryUri="multicast://default" /> </amq:transportConnectors> </amq:broker> With this, there is no need to specify -Dcom.sun.management.jmxremote=false for the jvm. Which somehow also didn't work for me, because the connectionfactory started the jmx connector.

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  • no namenode error in pseudo-mode

    - by Anshu Basia
    I'm new to hadoop and is in learning phase. As per Hadoop Definitve guide, i have set up my hadoop in pseudo distributed mode and everything was working fine. I was even able to execute all the examples from chapter 3 yesterday. Today, when i rebooted my unix and tried to run start-dfs.sh and then tried http://localhost/50070....it is showing error and when i try to stop dfs (stop-dfs.sh) it says no namenode to stop. I have been googling the issue but no result. Also, when i format my namenode again...everything starts working fine and i'm able to connect to the localhost/50070 and even replicate files and directories in hdfs but as soon as i restart my linux and try to connect to hdfs the same problem comes up. Below is the error log: ************************************************************/ 2011-06-22 15:45:55,249 INFO org.apache.hadoop.hdfs.server.namenode.NameNode: STARTUP_MSG: /************************************************************ STARTUP_MSG: Starting NameNode STARTUP_MSG: host = ubuntu/127.0.1.1 STARTUP_MSG: args = [] STARTUP_MSG: version = 0.20.203.0 STARTUP_MSG: build = http://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.20-security-203 -r 1099333; compiled by 'oom' on Wed May 4 07:57:50 PDT 2011 ************************************************************/ 2011-06-22 15:45:56,383 INFO org.apache.hadoop.metrics2.impl.MetricsConfig: loaded properties from hadoop-metrics2.properties 2011-06-22 15:45:56,455 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source MetricsSystem,sub=Stats registered. 2011-06-22 15:45:56,494 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Scheduled snapshot period at 10 second(s). 2011-06-22 15:45:56,494 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: NameNode metrics system started 2011-06-22 15:45:57,007 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source ugi registered. 2011-06-22 15:45:57,031 WARN org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Source name ugi already exists! 2011-06-22 15:45:57,059 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source jvm registered. 2011-06-22 15:45:57,070 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source NameNode registered. 2011-06-22 15:45:57,374 INFO org.apache.hadoop.hdfs.util.GSet: VM type = 32-bit 2011-06-22 15:45:57,374 INFO org.apache.hadoop.hdfs.util.GSet: 2% max memory = 19.33375 MB 2011-06-22 15:45:57,374 INFO org.apache.hadoop.hdfs.util.GSet: capacity = 2^22 = 4194304 entries 2011-06-22 15:45:57,374 INFO org.apache.hadoop.hdfs.util.GSet: recommended=4194304, actual=4194304 2011-06-22 15:45:57,854 INFO org.apache.hadoop.hdfs.server.namenode.FSNamesystem: fsOwner=anshu 2011-06-22 15:45:57,854 INFO org.apache.hadoop.hdfs.server.namenode.FSNamesystem: supergroup=supergroup 2011-06-22 15:45:57,854 INFO org.apache.hadoop.hdfs.server.namenode.FSNamesystem: isPermissionEnabled=true 2011-06-22 15:45:57,868 INFO org.apache.hadoop.hdfs.server.namenode.FSNamesystem: dfs.block.invalidate.limit=100 2011-06-22 15:45:57,869 INFO org.apache.hadoop.hdfs.server.namenode.FSNamesystem: isAccessTokenEnabled=false accessKeyUpdateInterval=0 min(s), accessTokenLifetime=0 min(s) 2011-06-22 15:45:58,769 INFO org.apache.hadoop.hdfs.server.namenode.FSNamesystem: Registered FSNamesystemStateMBean and NameNodeMXBean 2011-06-22 15:45:58,809 INFO org.apache.hadoop.hdfs.server.namenode.NameNode: Caching file names occuring more than 10 times **2011-06-22 15:45:58,825 INFO org.apache.hadoop.hdfs.server.common.Storage: Storage directory /tmp/hadoop-anshu/dfs/name does not exist. 2011-06-22 15:45:58,827 ERROR org.apache.hadoop.hdfs.server.namenode.FSNamesystem: FSNamesystem initialization failed. org.apache.hadoop.hdfs.server.common.InconsistentFSStateException: Directory /tmp/hadoop-anshu/dfs/name is in an inconsistent state: storage directory does not exist or is not accessible. at org.apache.h**adoop.hdfs.server.namenode.FSImage.recoverTransitionRead(FSImage.java:291) at org.apache.hadoop.hdfs.server.namenode.FSDirectory.loadFSImage(FSDirectory.java:97) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.initialize(FSNamesystem.java:379) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.<init>(FSNamesystem.java:353) at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:254) at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:434) at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1153) at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1162) 2011-06-22 15:45:58,828 ERROR org.apache.hadoop.hdfs.server.namenode.NameNode: org.apache.hadoop.hdfs.server.common.InconsistentFSStateException: Directory /tmp/hadoop-anshu/dfs/name is in an inconsistent state: storage directory does not exist or is not accessible. at org.apache.hadoop.hdfs.server.namenode.FSImage.recoverTransitionRead(FSImage.java:291) at org.apache.hadoop.hdfs.server.namenode.FSDirectory.loadFSImage(FSDirectory.java:97) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.initialize(FSNamesystem.java:379) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.<init>(FSNamesystem.java:353) at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:254) at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:434) at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1153) at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1162) 2011-06-22 15:45:58,829 INFO org.apache.hadoop.hdfs.server.namenode.NameNode: SHUTDOWN_MSG: /************************************************************ SHUTDOWN_MSG: Shutting down NameNode at ubuntu/127.0.1.1 ************************************************************/ Any help is appreciated Thank-you

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  • Management and Monitoring Tools for Windows Azure

    - by BuckWoody
    With such a large platform, Windows Azure has a lot of moving parts. We’ve done our best to keep the interface as simple as possible, while giving you the most control and visibility we can. However, as with most Microsoft products, there are multiple ways to do something – and I’ve always found that to be a good strength. Depending on the situation, I might want a graphical interface, a command-line interface, or just an API so I can incorporate the management into my own tools, or have third-party companies write other tools. While by no means exhaustive, I thought I might put together a quick list of a few tools you can use to manage and monitor Windows Azure components, from our IaaS, SaaS and PaaS offerings. Some of the products focus on one area more than another, but all are available today. I’ll try and maintain this list to keep it current, but make sure you check the date of this post’s update – if it’s more than six months old, it’s most likely out of date. Things move fast in the cloud. The Windows Azure Management Portal The primary tool for managing Windows Azure is our portal – most everything you need is there, from creating new services to querying a database. There are two versions as of this writing – a Silverlight client version, and a newer HTML5 version. The latter is being updated constantly to be in parity with the Silverlight client. There’s a balance in this portal between simplicity and power – we’re following the “less is more” approach, with increasing levels of detail as you work through the portal rather than overwhelming you with a single, long “more is more” page. You can find the Portal here: http://windowsazure.com (then click “Log In” and then “Portal”) Windows Azure Management API You can also use programming tools to either write your own interface, or simply provide management functions directly within your solution. You have two options – you can use the more universal REST API’s, which area bit more complex but work with any system that can write to them, or the more approachable .NET API calls in code. You can find the reference for the API’s here: http://msdn.microsoft.com/en-us/library/windowsazure/ee460799.aspx  All Class Libraries, for each part of Windows Azure: http://msdn.microsoft.com/en-us/library/ee393295.aspx  PowerShell Command-lets PowerShell is one of the most powerful scripting languages I’ve used with Windows – and it’s baked into all of our products. When you need to work with multiple servers, scripting is really the only way to go, and the Windows Azure PowerShell Command-Lets allow you to work across most any part of the platform – and can even be used within the services themselves. You can do everything with them from creating a new IaaS, PaaS or SaaS service, to controlling them and even working with security and more. You can find more about the Command-Lets here: http://wappowershell.codeplex.com/documentation (older link, still works, will point you to the new ones as well) We have command-line utilities for other operating systems as well: https://www.windowsazure.com/en-us/manage/downloads/  Video walkthrough of using the Command-Lets: http://channel9.msdn.com/Events/BUILD/BUILD2011/SAC-859T  System Center System Center is actually a suite of graphical tools you can use to manage, deploy, control, monitor and tune software from Microsoft and even other platforms. This will be the primary tool we’ll recommend for managing a hybrid or contiguous management process – and as time goes on you’ll see more and more features put into System Center for the entire Windows Azure suite of products. You can find the Management Pack and README for it here: http://www.microsoft.com/en-us/download/details.aspx?id=11324  SQL Server Management Studio / Data Tools / Visual Studio SQL Server has two built-in management and development, and since Version 2008 R2, you can use them to manage Windows Azure Databases. Visual Studio also lets you connect to and manage portions of Windows Azure as well as Windows Azure Databases. You can read more about Visual Studio here: http://msdn.microsoft.com/en-us/library/windowsazure/ee405484  You can read more about the SQL tools here: http://msdn.microsoft.com/en-us/library/windowsazure/ee621784.aspx  Vendor-Provided Tools Microsoft does not suggest or endorse a specific third-party product. We do, however, use them, and see lots of other customers use them. You can browse to these sites to learn more, and chat with their folks directly on how they support Windows Azure. Cerebrata: Tools for managing from the command-line, graphical diagnostics, graphical storage management - http://www.cerebrata.com/  Quest Cloud Tools: Monitoring, Storage Management, and costing tools - http://communities.quest.com/community/cloud-tools  Paraleap: Monitoring tool - http://www.paraleap.com/AzureWatch  Cloudgraphs: Monitoring too -  http://www.cloudgraphs.com/  Opstera: Monitoring for Windows Azure and a Scale-out pattern manager - http://www.opstera.com/products/Azureops/  Compuware: SaaS performance monitoring, load testing -  http://www.compuware.com/application-performance-management/gomez-apm-products.html  SOASTA: Penetration and Security Testing - http://www.soasta.com/cloudtest/enterprise/  LoadStorm: Load-testing tool - http://loadstorm.com/windows-azure  Open-Source Tools This is probably the most specific set of tools, and the list I’ll have to maintain most often. Smaller projects have a way of coming and going, so I’ll try and make sure this list is current. Windows Azure MMC: (I actually use this one a lot) http://wapmmc.codeplex.com/  Windows Azure Diagnostics Monitor: http://archive.msdn.microsoft.com/wazdmon  Azure Application Monitor: http://azuremonitor.codeplex.com/  Azure Web Log: http://www.xentrik.net/software/azure_web_log.html  Cloud Ninja:Multi-Tennant billing and performance monitor -  http://cnmb.codeplex.com/  Cloud Samurai: Multi-Tennant Management- http://cloudsamurai.codeplex.com/    If you have additions to this list, please post them as a comment and I’ll research and then add them. Thanks!

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  • To ORM or Not to ORM. That is the question&hellip;

    - by Patrick Liekhus
    UPDATE:  Thanks for the feedback and comments.  I have adjusted my table below with your recommendations.  I had missed a point or two. I wanted to do a series on creating an entire project using the EDMX XAF code generation and the SpecFlow BDD Easy Test tools discussed in my earlier posts, but I thought it would be appropriate to start with a simple comparison and reasoning on why I choose to use these tools. Let’s start by defining the term ORM, or Object-Relational Mapping.  According to Wikipedia it is defined as the following: Object-relational mapping (ORM, O/RM, and O/R mapping) in computer software is a programming technique for converting data between incompatible type systems in object-oriented programming languages. This creates, in effect, a "virtual object database" that can be used from within the programming language. Why should you care?  Basically it allows you to map your business objects in code to their persistence layer behind them. And better yet, why would you want to do this?  Let me outline it in the following points: Development speed.  No more need to map repetitive tasks query results to object members.  Once the map is created the code is rendered for you. Persistence portability.  The ORM knows how to map SQL specific syntax for the persistence engine you choose.  It does not matter if it is SQL Server, Oracle and another database of your choosing. Standard/Boilerplate code is simplified.  The basic CRUD operations are consistent and case use database metadata for basic operations. So how does this help?  Well, let’s compare some of the ORM tools that I have used and/or researched.  I have been interested in ORM for some time now.  My ORM of choice for a long time was NHibernate and I still believe it has a strong case in some business situations.  However, you have to take business considerations into account and the law of diminishing returns.  Because of these two factors, my recent activity and experience has been around DevExpress eXpress Persistence Objects (XPO).  The primary reason for this is because they have the DevExpress eXpress Application Framework (XAF) that sits on top of XPO.  With this added value, the data model can be created (either database first of code first) and the Web and Windows client can be created from these maps.  While out of the box they provide some simple list and detail screens, you can verify easily extend and modify these to your liking.  DevExpress has done a tremendous job of providing enough framework while also staying out of the way when you need to extend it.  This sounds worse than it really is.  What I mean by this is that if you choose to follow DevExpress coding style and recommendations, the hooks and extension points provided allow you to do some pretty heavy lifting while also not worrying about the basics. I have put together a list of the top features that I have used to compare the limited list of ORM’s that I have exposure with.  Again, the biggest selling point in my opinion is that XPO is just a solid as any of the other ORM’s but with the added layer of XAF they become unstoppable.  And then couple that with the EDMX modeling tools and code generation, it becomes a no brainer. Designer Features Entity Framework NHibernate Fluent w/ Nhibernate Telerik OpenAccess DevExpress XPO DevExpress XPO/XAF plus Liekhus Tools Uses XML to map relationships - Yes - - -   Visual class designer interface Yes - - - - Yes Management integrated w/ Visual Studio Yes - - Yes - Yes Supports schema first approach Yes - - Yes - Yes Supports model first approach Yes - - Yes Yes Yes Supports code first approach Yes Yes Yes Yes Yes Yes Attribute driven coding style Yes - Yes - Yes Yes                 I have a very small team and limited resources with a lot of responsibilities.  In order to keep up with our customers, we must rely on tools like these.  We use the EDMX tool so that we can create a visual representation of the applications with our customers.  Second, we rely on the code generation so that we can focus on the business problems at hand and not whether a field is mapped correctly.  This keeps us from requiring as many junior level developers on our team.  I have also worked on multiple teams where they believed in writing their own “framework”.  In my experiences and opinion this is not the route to take unless you have a team dedicated to supporting just the framework.  Each time that I have worked on custom frameworks, the framework eventually becomes old, out dated and full of “performance” enhancements specific to one or two requirements.  With an ORM, there are a lot smarter people than me working on the bigger issue of persistence and performance.  Again, my recommendation would be to use an available framework and get to working on your business domain problems.  If your coding is not making money for you, why are you working on it?  Do you really need to be writing query to object member code again and again? Thanks

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  • Integrate BING API for Search inside ASP.Net web application

    - by sreejukg
    As you might already know, Bing is the Microsoft Search engine and is getting popular day by day. Bing offers APIs that can be integrated into your website to increase your website functionality. At this moment, there are two important APIs available. They are Bing Search API Bing Maps The Search API enables you to build applications that utilize Bing’s technology. The API allows you to search multiple source types such as web; images, video etc. and supports various output prototypes such as JSON, XML, and SOAP. Also you will be able to customize the search results as you wish for your public facing website. Bing Maps API allows you to build robust applications that use Bing Maps. In this article I am going to describe, how you can integrate Bing search into your website. In order to start using Bing, First you need to sign in to http://www.bing.com/toolbox/bingdeveloper/ using your windows live credentials. Click on the Sign in button, you will be asked to enter your windows live credentials. Once signed in you will be redirected to the Developer page. Here you can create applications and get AppID for each application. Since I am a first time user, I don’t have any applications added. Click on the Add button to add a new application. You will be asked to enter certain details about your application. The fields are straight forward, only thing you need to note is the website field, here you need to enter the website address from where you are going to use this application, and this field is optional too. Of course you need to agree on the terms and conditions and then click Save. Once you click on save, the application will be created and application ID will be available for your use. Now we got the APP Id. Basically Bing supports three protocols. They are JSON, XML and SOAP. JSON is useful if you want to call the search requests directly from the browser and use JavaScript to parse the results, thus JSON is the favorite choice for AJAX application. XML is the alternative for applications that does not support SOAP, e.g. flash/ Silverlight etc. SOAP is ideal for strongly typed languages and gives a request/response object model. In this article I am going to demonstrate how to search BING API using SOAP protocol from an ASP.Net application. For the purpose of this demonstration, I am going to create an ASP.Net project and implement the search functionality in an aspx page. Open Visual Studio, navigate to File-> New Project, select ASP.Net empty web application, I named the project as “BingSearchSample”. Add a Search.aspx page to the project, once added the solution explorer will looks similar to the following. Now you need to add a web reference to the SOAP service available from Bing. To do this, from the solution explorer, right click your project, select Add Service Reference. Now the new service reference dialog will appear. In the left bottom of the dialog, you can find advanced button, click on it. Now the service reference settings dialog will appear. In the bottom left, you can find Add Web Reference button, click on it. The add web reference dialog will appear now. Enter the URL as http://api.bing.net/search.wsdl?AppID=<YourAppIDHere>&version=2.2 (replace <yourAppIDHere> with the appID you have generated previously) and click on the button next to it. This will find the web service methods available. You can change the namespace suggested by Bing, but for the purpose of this demonstration I have accepted all the default settings. Click on the Add reference button once you are done. Now the web reference to Search service will be added your project. You can find this under solution explorer of your project. Now in the Search.aspx, that you previously created, place one textbox, button and a grid view. For the purpose of this demonstration, I have given the identifiers (ID) as txtSearch, btnSearch, gvSearch respectively. The idea is to search the text entered in the text box using Bing service and show the results in the grid view. In the design view, the search.aspx looks as follows. In the search.aspx.cs page, add a using statement that points to net.bing.api. I have added the following code for button click event handler. The code is very straight forward. It just calls the service with your AppID, a query to search and a source for searching. Let us run this page and see the output when I enter Microsoft in my textbox. If you want to search a specific site, you can include the site name in the query parameter. For e.g. the following query will search the word Microsoft from www.microsoft.com website. searchRequest.Query = “site:www.microsoft.com Microsoft”; The output of this query is as follows. Integrating BING search API to your website is easy and there is no limit on the customization of the interface you can do. There is no Bing branding required so I believe this is a great option for web developers when they plan for site search.

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  • Java: micro-optimizing array manipulation

    - by Martin Wiboe
    Hello all, I am trying to make a Java port of a simple feed-forward neural network. This obviously involves lots of numeric calculations, so I am trying to optimize my central loop as much as possible. The results should be correct within the limits of the float data type. My current code looks as follows (error handling & initialization removed): /** * Simple implementation of a feedforward neural network. The network supports * including a bias neuron with a constant output of 1.0 and weighted synapses * to hidden and output layers. * * @author Martin Wiboe */ public class FeedForwardNetwork { private final int outputNeurons; // No of neurons in output layer private final int inputNeurons; // No of neurons in input layer private int largestLayerNeurons; // No of neurons in largest layer private final int numberLayers; // No of layers private final int[] neuronCounts; // Neuron count in each layer, 0 is input // layer. private final float[][][] fWeights; // Weights between neurons. // fWeight[fromLayer][fromNeuron][toNeuron] // is the weight from fromNeuron in // fromLayer to toNeuron in layer // fromLayer+1. private float[][] neuronOutput; // Temporary storage of output from previous layer public float[] compute(float[] input) { // Copy input values to input layer output for (int i = 0; i < inputNeurons; i++) { neuronOutput[0][i] = input[i]; } // Loop through layers for (int layer = 1; layer < numberLayers; layer++) { // Loop over neurons in the layer and determine weighted input sum for (int neuron = 0; neuron < neuronCounts[layer]; neuron++) { // Bias neuron is the last neuron in the previous layer int biasNeuron = neuronCounts[layer - 1]; // Get weighted input from bias neuron - output is always 1.0 float activation = 1.0F * fWeights[layer - 1][biasNeuron][neuron]; // Get weighted inputs from rest of neurons in previous layer for (int inputNeuron = 0; inputNeuron < biasNeuron; inputNeuron++) { activation += neuronOutput[layer-1][inputNeuron] * fWeights[layer - 1][inputNeuron][neuron]; } // Store neuron output for next round of computation neuronOutput[layer][neuron] = sigmoid(activation); } } // Return output from network = output from last layer float[] result = new float[outputNeurons]; for (int i = 0; i < outputNeurons; i++) result[i] = neuronOutput[numberLayers - 1][i]; return result; } private final static float sigmoid(final float input) { return (float) (1.0F / (1.0F + Math.exp(-1.0F * input))); } } I am running the JVM with the -server option, and as of now my code is between 25% and 50% slower than similar C code. What can I do to improve this situation? Thank you, Martin Wiboe

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  • On Contract Employment

    - by kerry
    I am going to post about something I don’t post about a lot, the business side of development.  Scott at the antipimp does a good job of explaining how contracts work from a business perspective.  I am going to give a view from the ground. First, a little background on myself.  I have recently taken a 6 month contract after about 8 years of fulltime employment.  I have 2 kids, and a stay at home wife.  I took this contract opportunity because I wanted to try it on for size.  I have always wondered whether I would like doing contracts over fulltime employment.  So, in keeping with the theme of this blog I will write this down now so that I may reference it later. ALL jobs are temporary! Right now you may not realize it, most people simply ignore it, but EVERY job is temporary.  Everyone should be planning for life after the money stops coming in.  Sadly, most people do not.  Contracting pushes this issue to the forefront, making you deal with it.  After a month on a contract, I am happy to say that I am saving more than I ever saved in a fulltime position.  Hopefully, I will be ready in case of an extended window of unemployment between contracts. Networking I find it extremely gratifying getting to know people.  It is especially beneficial when moving to a new city.  What better way to go out and meet people in your field than to work a few contracts?  6 months of working beside someone and you get to know them pretty well.  This is one of my favorite aspects. Technical Agility Moving between IS shops takes (or molds you into) a flexible person.  You have to be able to go in and hit the ground running.  This means you need to be able to sit down and start work on a large codebase working in a language that you may or may not have that much experience in.  It is also an excellent way to learn new languages and broaden your technical skill set.  I took my current position to learn Ruby.  A month ago, I had only used it in passing, but now I am using it every day.  It’s a tragedy in this field when people start coding for the joy and love of coding, then become deeply entrenched in their companies methods and technologies that it becomes a just a job. Less Stress I am not talking about the kind of stress you get from a jackass boss.  I am talking about the kind of stress I (or others) experience about planning and future proofing your code.  Not saying I stay up at night worrying whether we have done it right, if that code I wrote today is going to bite me later, but it still creeps around in the dark recesses of my mind.  Careful though, I am not suggesting you write sloppy code; just defer any large architectural or design decisions to the ‘code owners’. Flexible Scheduling It makes me very happy to be able to cut out a few hours early on a Friday (provided the work is done) and start the weekend off early by going to the pool, or taking the kids to the park.  Contracting provides you this opportunity (mileage may vary).  Most of your fulltime brethren will not care, they will be jealous that they’re corporate policy prevents them from doing the same.  However, you must be mindful of situations where this is not appropriate, and don’t over do it.  You are there to work after all. Affirmation of Need Have you ever been stuck in a job where you thought you were underpaid?  Have you ever been in a position where you felt like there was not enough workload for you?  This is not a problem for contractors.  When you start a contract it is understood that you are needed, and the employer knows that you are happy with the terms. Contracting may not be for everyone.  But, if you develop a relationship with a good consulting firm, keep their clients happy, then they will keep you happy.  They want you to work almost as much as you do.  Just be sure and plan financially for any windows of unemployment.

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  • terminating java applet thread on page unload

    - by Hammad Tariq
    Hello, I have got a problem here in terminating the threads. The problem is that I am using applet thread to access JS DOM and manipulate innerHTML of a span to right the Thread Name as the innerHTML. It works fine until I keep refreshing the page but if I dont give it a sleep of like 200ms and go to another page which dont have any applet on it, it will give me an error in firebug console: document.getElementById("userName") is null What I am suspecting is, although I send an interrupt on stop and I have also tried the same by setting a flag variable of running in run while loop, the thread executes much faster than the time JVM takes to unload it and I get my page changed in browser but applet is still trying to find an element with id userName. Is that true? Is there any work around of it? Is there any way to know how many threads are running at the moment? Is there any kill all command to send on destroy()? I have searched a lot, seen all the API of java threads and applets, couldn't get this to work. Below is the code: import java.applet.Applet; import netscape.javascript.*; //No need to extend JApplet, since we don't add any components; //we just paint. public class firstApplet extends Applet { /** * */ private static final long serialVersionUID = 1L; firstThread first; boolean running = false; public class firstThread extends Thread{ JSObject win; JSObject doc; firstThread second; public firstThread(JSObject window){ this.win = window; } public void run() { try{ System.out.println("running... "); while (!isInterrupted()){ doc = (JSObject) win.getMember("document"); String userName = Thread.currentThread().getName(); //String userName = "John Doe"; String S = "document.getElementById(\"userName\").innerHTML = \""+userName+"\";"; doc.eval(S); Thread.sleep(5); } }catch(Exception e){ System.out.println("exception in first thread... "); e.printStackTrace(); } } } public void init() { System.out.println("initializing... "); } public void start() { System.out.println("starting... "); JSObject window = JSObject.getWindow(this); first = new firstThread(window); first.start(); running = true; } public void stop() { first.interrupt(); first = null; System.out.println("stopping... "); } public void destroy() { if(first != null){ first = null; } System.out.println("preparing for unloading..."); } } Thanks

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