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  • two scp and ssh processes with single authentication

    - by Tomek Wyderka
    I need to scp and then ssh to the same host. Is it possible to authenticate just one time? Is it possible to input password once, then scp file, then ssh on that host and work interactively? Update I get HOSTNAME and SSH_PASSWORD. I never log in on that machine before. I need to send some files (probably using scp) and then log in using ssh and work on that HOST interactively. I want to save time and input password just once. I have lots of such hosts...

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  • Best way of obfuscating / encrypting form data on the iPhone

    - by cannyboy
    I want to create an app which holds sensitive information (imagine it's bank account details, thought it's not). The user enters this information on a form the first time the app starts up. I want this info to be saved, and available, any time the user uses the app (without having to enter a password). However, if the iPhone has a password lock on it, and is stolen, I don't want the data to be easily accessible from the file system. What is the best way of encrypting or obfuscating the data? There is not a lot of data, just a dozen NSStrings from the UITextFields on the form. I'm aware there are encryption export restrictions on the iPhone for non-US developers (I am in UK), so I would prefer to avoid going jumping through any of Apple's app submission hoops to get it on the store.

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  • Empty files generated from running `mysqldump` using PHP

    - by alex
    I keep getting empty files generated from running $command = 'mysqldump --opt -h localhost -u username -p \'password\' dbname > \'backup 2009-04-15 09-57-13.sql\''; command($command); Anyone know what might be causing this? My password has strange characters in it, but works fine with connecting to the db. I've ran exec($command, $return) and outputted the $return array and it is finding the command. I've also ran it with mysqldump > file.sql and the file contains Usage: mysqldump [OPTIONS] database [tables] OR mysqldump [OPTIONS] --databases [OPTIONS] DB1 [DB2 DB3...] OR mysqldump [OPTIONS] --all-databases [OPTIONS] For more options, use mysqldump --help So it would seem like the command is working.

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  • How to configure IIS7 to Redirect member of An active Directory group to static page

    - by user1759075
    On IIS, we have disabled Anonymous authentication and enabled Windows Authentication What we need is to only allow users who are members of an Active Directory security group to access the Access Point at all. All other users should be directed to a static web page that will give them instructions on how to request access. By adding the security group to the website permissions, and removing the \Users group, we have almost achieved this. Users in the group are allowed through, those not in the group are asked for a (Windows) username and password. Instead of requesting the username and password, we want IIS to redirect them to the static page. Please advise me on how can this be done.

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  • require user to login in at login screen before giving access to iPhone app that accesses secure web

    - by MikeN
    On iPhone, how do I show a login screen to get username and password before giving access to iPhone app? Also, does the iPhone store a cookie to the secure website like a web browser? I was thinking of giving users to my website a long API key to store in the settings of their iPhone instead of asking them to login with a username/password (seems to be the Slicehost iPhone app approach.) Which is the best way to get a user to login securely? I have full control over the design of the iPhone app and website so have a lot of flexibility.

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  • (database) im trying to create a form in access 2007 with 2 drop down boxes to view a report by state or name

    - by jeff orris
    im an intern at a database mngmt company and the boss is training me in access...i took the access tutorials and were definitely not enough info involved to do a what seems a simple task.my problem is this: i have a simple table with contact info with 16 colums (Local_Utility, Requested_User_Type, First_Name, Last_Name, Address 1, Address 2, Country, State, City, Zip, Phone_Number, Username\Email, Password, Confirm Password, and Parcel_Number), with 6 rows of names (keep in mind this is just a test to help me from the boss) I created a form and with 2 drop down boxes (Last Name and State) and im trying to create a view button to view an individual report for a query i made for just simple contact info with 6 colums (Last_Name, First_Name, Address1, City, State, and Phone_Number) Problem1 is that i can view the query with the view by name or state button but cant view a simple individual report from the query using the button Problem2 is that for criteria on the query i put Forms!frmMyparamForm!txtMyStateParamField for the state drop box it works, but when i use Forms!frmMyparamForm!txtMyNameParamField it doesnt and that annoying parameter box pops up Problem3 is that after i close the query, all the states and names in my dropdown box on the form disappear Im a beginner at this please help me

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  • how toaccess the attributes in another form? c#

    - by Chelsea_cole
    I have a problem in a same namespace: public partial class frmForm1 : Form // Form1 { public class Account { public string Username; public string Password; } public class ListAcc { public static int count = 0; private static List<Account> UserList; public static List<Account> Data() { return UserList; } } } public partial class frmForm2 : Form // Form2 { private void button2_Click(object sender, EventArgs e) { frmForm1.Account A; string m = frmForm1.ListAcc<A>.[0].Username; //ERROR } } How could i access the attributes (Username, Password...) in frmForm1? Someone help me? Thanks!

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  • How to specify "PG-USERNAME" in pg_ident.conf so that it'll match any database user ?

    - by felace
    I need to restrict a specific unix user so that it can login with only a few select postgres usernames (with password prompt), but allowing every other user to use whatever pg username they want. Assuming restrUnixUser is the unix user name and restrUser is one of the postgres users it may use, and AllowedDB is the only database they should connect to : pg_hba.conf : local AllowedDB restrUser password local all restrUser reject local all all ident map=exceptrestrUser And pg_ident.conf : exceptrestrUser /^(?!restrUnixUser).*$ user1 exceptrestrUser /^(?!restrUnixUser).*$ user2 exceptrestrUser /^(?!restrUnixUser).*$ postgres does what I exactly want to do right now, however, I'll probably add a lot more users so I wonder if there is something like mapname unixuserpattern allpgusers that'll match with whatever username used to login by any unix user matching the pattern.

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  • jquery ajax sucess - possible to return JSON instead of string?

    - by Haroldo
    To return an error from a $.ajax call, there's gotta be a better way than echoing an error in the ajax.php file and then trimming it! this seems very clumsy and in-robust: success: function(e){ var e = trim(e); if(e == 'SUCCESS') {alert('your password has been changed!');} if(e == 'ERROR1') {alert('please fill in all inputs!');} if(e == 'ERROR2') {alert('password incorrect!');} if(e == 'ERROR3') {alert('change failed!');} } what should i be doing instead?!

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  • cant get ajax response (JSON) to call 'success' function?

    - by Haroldo
    for some reason the success function isnt being called? javscript: $.ajax({ type: 'POST', url: 'http://localhost/hf_latest_desktop/st_pages/user_area/acc_buttons/pass_change/pass_change_ajax.php', data: data, dataType: 'json', success: function(e){ console.log(e); if(e.status == 'success'){ alert('your password has been changed!'); } if(e.status == 'error1'){ alert('please fill in all inputs!'); } if(e.status == 'error2'){ alert('password incorrect!'); } if(e.status == 'error3'){ alert('change failed!'); } } }); php file ajax is calling to: <?php session_start(); session_cache_limiter('nocache'); header('Expires: ' . gmdate('r', 0)); header('Content-type: application/json'); $status = 'error1'; //for sake of example ?> {'status':'<?php echo $status; ?>'}

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  • servlet authentication and further reference to the credentials

    - by user553592
    What I got so far: It all begins with an HTML form which prompts the user for a username and password. From there it post the acquired user/pass to a servlet, GateKeeper. GateKeeper determines if the user/pass combination match any records in the MySQL database. Here is the sql I use: SELECT id FROM Users WHERE username='?' AND password=MD5('?') where the ? indicate information provided the previous HTML form. What I need now: I need some way to store the username and id of the record in the database. GateKeeper redirects the user to a control panel upon success. Therefore, I need a method to reference the username to display simple greetings, etc and also the id so it eliminates unnecessary calls to the database. The control panel may make AJAX calls to Servlets that preform some sort of task to the MySQL database.

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  • Error with connecting ftp through php ...

    - by Holicreature
    Hi, I'm trying to connect to my server using php script to upload some files... But it doesn't connect... I dont know what is the error... I'm sure that ftp is enable, i checked it through php_info() What may be the error... <?php error_reporting(E_ALL); $ftp_server = "server.com"; //address of ftp server (leave out ftp://) $ftp_user_name = "Username"; // Username $ftp_user_pass = "Password"; // Password $conn_id = ftp_connect($ftp_server); // set up basic connection $login_result = ftp_login($conn_id,$ftp_user_name,$ftp_user_pass); if ($login_result = ftp_login($conn_id,$ftp_user_name,$ftp_user_pass)) { echo "Connected as ,$ftp_user_name,$ftp_user_pass \n"; } else { echo "Couldn't connect \n"; } ..... ..... .... .... ftp_close($conn_id); // close the FTP stream ?>

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  • $.ajax + authentication + `@` in username

    - by Koning Baard XIV
    I am creating a web app which uses jQuery to authenticate: $.ajax({ url: "/session/create?format=json", type: "GET", dataType: "json", cache: false, username: $("#signin-email").val(), password: $("#signin-password").val(), success: function(data) { if(data.success) { success = true; } } }); The problem is that the code only makes the AJAX-request when the username does not include things like an @, which is required in my app. Can anyone help me with how I can do this? I do not mind changing the back-end a little bit, but requiring users to have an @-less email is not an option. Oh, my back-end is a Ruby-on-Rails app

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  • Implementing prompts in text-input

    - by AntonAL
    Hi, I have a form with some text-inputs: login, password. If user sees this form the first time, input-texts should "contain" prompts, like "enter login", "enter password". If user clicks text-input, it's prompt should disappear to allow typing. I have seen various examples, that uses background image with prerendered text on it. Those images are appearing with following jQuery: $("form > :text").focus(function(){ // hide image }).blur(function(){ // show image, if text-input is still empty if ( $(this).val() == "" ) // show image with prompt }); This approach has following problems: localization is impossible need to pre-render images for various textual prompts overhead with loading images How do you overcomes such a problems ?

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  • Configuring jdbc-pool (tomcat 7)

    - by john
    i'm having some problems with tomcat 7 for configuring jdbc-pool : i`ve tried to follow this example: http://www.tomcatexpert.com/blog/2010/04/01/configuring-jdbc-pool-high-concurrency so i have: conf/server.xml <GlobalNamingResources> <Resource type="javax.sql.DataSource" name="jdbc/DB" factory="org.apache.tomcat.jdbc.pool.DataSourceFactory" driverClassName="com.mysql.jdbc.Driver" url="jdbc:mysql://localhost:3306/mydb" username="user" password="password" /> </GlobalNamingResources> conf/context.xml <Context> <ResourceLink type="javax.sql.DataSource" name="jdbc/LocalDB" global="jdbc/DB" /> <Context> and when i try to do this: Context initContext = new InitialContext(); Context envContext = (Context)initContext.lookup("java:/comp/env"); DataSource datasource = (DataSource)envContext.lookup("jdbc/LocalDB"); Connection con = datasource.getConnection(); i keep getting this error: javax.naming.NameNotFoundException: Name jdbc is not bound in this Context at org.apache.naming.NamingContext.lookup(NamingContext.java:803) at org.apache.naming.NamingContext.lookup(NamingContext.java:159) pls help tnx

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  • phpMySql connection

    - by Eiriko Pedroza
    PL = VB.net Issue: format of the initialization string does not conform to specification starting at index 17 connection string: objconn.ConnectionString = ("server=" & txtServer.Text & ";" _ & "user id=" & "'" & txtUserId.Text & ";" _ & "password=" & txtPassword.Text & ";" _ & "database=try") Try objconn.Open() MsgBox("Connected") objconn.Close() Catch ex As Exception MsgBox(ex.ToString) End Try -objconn is declared as new mysqlconnection every time I run the application and try to login, i keep on receiving this error message, I already double checked my line of connection string. im using 'localhost' as server and 'root' as username, password is blank. thank you in advance for your response

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  • Use variables entered in login page usable in multiple pages?

    - by deception1
    I have a Login page that captures User input like this. MD5calc ss = new DBCon.MD5calc(); string gs = ss.CalculateMD5Hash(password.Password); int unitID = Convert.ToInt32(Unit_ID.Text); logBO.UnitID = unitID; logBO.UserID = User_name.Text; logBO.UserPass = gs; How would i make them assignable to any other page i created.My Common sense says that creating a static class would be enough,but will it?If i do create a static class where would i put it and how would i call it?I actually need those variable to use in my Sql Stored procedures.

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  • Accessing current class through $this-> from a function called statically. [PHP]

    - by MQA
    This feels a bit messy, but I'd like to be able to call a member function statically, yet have the rest of the class behave normally... Example: <?php class Email { private $username = 'user'; private $password = 'password'; private $from = '[email protected]'; public $to; public function SendMsg($to, $body) { if (isset($this)) $email &= $this; else $email = new Email(); $email->to = $to; // Rest of function... } } Email::SendMsg('[email protected]'); How best do I allow the static function call in this example? Thanks!

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  • Is it easier to create a chat client using java or PHP?

    - by Mendy
    first off, my goal: Create a chat client that requires the user to log in with a password. Would it be easier to create it with just HTML an PHP or java? EDIT: Sorry, I didn't mention. I have some experience in javascript. I'm afraid that is all. I could and would learn another language. So I want to know which language would be better to learn for this project? also, for the username and password login I'm guessing I would need some mySQL knowledge? Thanks.

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  • Select value from database and store into a temporary variable

    - by user1616230
    I want to select a stored value from database and then put it into a temporary variable. For example, I have a column called category, one value under it is m, so I want to select this m value from the database, let's say from a table of a database called user_info. Then I want to put it into a variable, let's name it $res. After that, I want to do some condition stuff, such as if $res=="m", Can anyone help me write a simple structure here? Here is the code: <?php $sql = "Select category FROM user_info WHERE user_name = '" .$_SESSION['username']."' and password = '".$_SESSION['password']."'"; $res = mysql_query($sql); if($res == "a"){ include('MPIncomeStrategy.php'); } if($res == "b"){ include('MPIncomeStrategy.php'); } But it seems that the code is not able to detect $res =="category value in database". Did I just use the wrong way to store the category value?

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  • Looking for another regex explanation

    - by Sam
    In my regex expression, I was trying to match a password between 8 and 16 character, with at least 2 of each of the following: lowercase letters, capital letters, and digits. In my expression I have: ^((?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{8,16})$ But I don't understand why it wouldn't work like this: ^((?=\d)(?=[a-z])(?=[A-Z])(?=\d)(?=[a-z])(?=[A-Z]){8,16})$ Doesnt ".*" just meant "zero or more of any character"? So why would I need that if I'm just checking for specific conditions? And why did I need the period before the curly braces defining the limit of the password? And one more thing, I don't understand what it means to "not consume any of the string" in reference to "?=".

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  • ASP.NET GZip Encoding Caveats

    - by Rick Strahl
    GZip encoding in ASP.NET is pretty easy to accomplish using the built-in GZipStream and DeflateStream classes and applying them to the Response.Filter property.  While applying GZip and Deflate behavior is pretty easy there are a few caveats that you have watch out for as I found out today for myself with an application that was throwing up some garbage data. But before looking at caveats let’s review GZip implementation for ASP.NET. ASP.NET GZip/Deflate Basics Response filters basically are applied to the Response.OutputStream and transform it as data is written to it through the ASP.NET Response object. So a Response.Write eventually gets written into the output stream which if a filter is also written through the filter stream’s interface. To perform the actual GZip (and Deflate) encoding typically used by Web pages .NET includes the GZipStream and DeflateStream stream classes which can be readily assigned to the Repsonse.OutputStream. With these two stream classes in place it’s almost trivially easy to create a couple of reusable methods that allow you to compress your HTTP output. In my standard WebUtils utility class (from the West Wind West Wind Web Toolkit) created two static utility methods – IsGZipSupported and GZipEncodePage – that check whether the client supports GZip encoding and then actually encodes the current output (note that although the method includes ‘Page’ in its name this code will work with any ASP.NET output). /// <summary> /// Determines if GZip is supported /// </summary> /// <returns></returns> public static bool IsGZipSupported() { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (!string.IsNullOrEmpty(AcceptEncoding) && (AcceptEncoding.Contains("gzip") || AcceptEncoding.Contains("deflate"))) return true; return false; } /// <summary> /// Sets up the current page or handler to use GZip through a Response.Filter /// IMPORTANT: /// You have to call this method before any output is generated! /// </summary> public static void GZipEncodePage() { HttpResponse Response = HttpContext.Current.Response; if (IsGZipSupported()) { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (AcceptEncoding.Contains("deflate")) { Response.Filter = new System.IO.Compression.DeflateStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); Response.Headers.Remove("Content-Encoding"); Response.AppendHeader("Content-Encoding", "deflate"); } else { Response.Filter = new System.IO.Compression.GZipStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); Response.Headers.Remove("Content-Encoding"); Response.AppendHeader("Content-Encoding", "gzip"); } } } As you can see the actual assignment of the Filter is as simple as: Response.Filter = new DeflateStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); which applies the filter to the OutputStream. You also need to ensure that your response reflects the new GZip or Deflate encoding and ensure that any pages that are cached in Proxy servers can differentiate between pages that were encoded with the various different encodings (or no encoding). To use this utility function now is trivially easy: In any ASP.NET code that wants to compress its Response output you simply use: protected void Page_Load(object sender, EventArgs e) { WebUtils.GZipEncodePage(); Entry = WebLogFactory.GetEntry(); var entries = Entry.GetLastEntries(App.Configuration.ShowEntryCount, "pk,Title,SafeTitle,Body,Entered,Feedback,Location,ShowTopAd", "TEntries"); if (entries == null) throw new ApplicationException("Couldn't load WebLog Entries: " + Entry.ErrorMessage); this.repEntries.DataSource = entries; this.repEntries.DataBind(); } Here I use an ASP.NET page, but the above WebUtils.GZipEncode() method call will work in any ASP.NET application type including HTTP Handlers. The only requirement is that the filter needs to be applied before any other output is sent to the OutputStream. For example, in my CallbackHandler service implementation by default output over a certain size is GZip encoded. The output that is generated is JSON or XML and if the output is over 5k in size I apply WebUtils.GZipEncode(): if (sbOutput.Length > GZIP_ENCODE_TRESHOLD) WebUtils.GZipEncodePage(); Response.ContentType = ControlResources.STR_JsonContentType; HttpContext.Current.Response.Write(sbOutput.ToString()); Ok, so you probably get the idea: Encoding GZip/Deflate content is pretty easy. Hold on there Hoss –Watch your Caching Or is it? There are a few caveats that you need to watch out for when dealing with GZip content. The fist issue is that you need to deal with the fact that some clients don’t support GZip or Deflate content. Most modern browsers support it, but if you have a programmatic Http client accessing your content GZip/Deflate support is by no means guaranteed. For example, WinInet Http clients don’t support GZip out of the box – it has to be explicitly implemented. Other low level HTTP clients on other platforms too don’t support GZip out of the box. The problem is that your application, your Web Server and Proxy Servers on the Internet might be caching your generated content. If you return content with GZip once and then again without, either caching is not applied or worse the wrong type of content is returned back to the client from a cache or proxy. The result is an unreadable response for *some clients* which is also very hard to debug and fix once in production. You already saw the issue of Proxy servers addressed in the GZipEncodePage() function: // Allow proxy servers to cache encoded and unencoded versions separately Response.AppendHeader("Vary", "Content-Encoding"); This ensures that any Proxy servers also check for the Content-Encoding HTTP Header to cache their content – not just the URL. The same thing applies if you do OutputCaching in your own ASP.NET code. If you generate output for GZip on an OutputCached page the GZipped content will be cached (either by ASP.NET’s cache or in some cases by the IIS Kernel Cache). But what if the next client doesn’t support GZip? She’ll get served a cached GZip page that won’t decode and she’ll get a page full of garbage. Wholly undesirable. To fix this you need to add some custom OutputCache rules by way of the GetVaryByCustom() HttpApplication method in your global_ASAX file: public override string GetVaryByCustomString(HttpContext context, string custom) { // Override Caching for compression if (custom == "GZIP") { string acceptEncoding = HttpContext.Current.Response.Headers["Content-Encoding"]; if (string.IsNullOrEmpty(acceptEncoding)) return ""; else if (acceptEncoding.Contains("gzip")) return "GZIP"; else if (acceptEncoding.Contains("deflate")) return "DEFLATE"; return ""; } return base.GetVaryByCustomString(context, custom); } In a page that use Output caching you then specify: <%@ OutputCache Duration="180" VaryByParam="none" VaryByCustom="GZIP" %> To use that custom rule. It’s all Fun and Games until ASP.NET throws an Error Ok, so you’re up and running with GZip, you have your caching squared away and your pages that you are applying it to are jamming along. Then BOOM, something strange happens and you get a lovely garbled page that look like this: Lovely isn’t it? What’s happened here is that I have WebUtils.GZipEncode() applied to my page, but there’s an error in the page. The error falls back to the ASP.NET error handler and the error handler removes all existing output (good) and removes all the custom HTTP headers I’ve set manually (usually good, but very bad here). Since I applied the Response.Filter (via GZipEncode) the output is now GZip encoded, but ASP.NET has removed my Content-Encoding header, so the browser receives the GZip encoded content without a notification that it is encoded as GZip. The result is binary output. Here’s what Fiddler says about the raw HTTP header output when an error occurs when GZip encoding was applied: HTTP/1.1 500 Internal Server Error Cache-Control: private Content-Type: text/html; charset=utf-8 Date: Sat, 30 Apr 2011 22:21:08 GMT Content-Length: 2138 Connection: close ?`I?%&/m?{J?J??t??` … binary output striped here Notice: no Content-Encoding header and that’s why we’re seeing this garbage. ASP.NET has stripped the Content-Encoding header but left our filter intact. So how do we fix this? In my applications I typically have a global Application_Error handler set up and in this case I’ve been using that. One thing that you can do in the Application_Error handler is explicitly clear out the Response.Filter and set it to null at the top: protected void Application_Error(object sender, EventArgs e) { // Remove any special filtering especially GZip filtering Response.Filter = null; … } And voila I get my Yellow Screen of Death or my custom generated error output back via uncompressed content. BTW, the same is true for Page level errors handled in Page_Error or ASP.NET MVC Error handling methods in a controller. Another and possibly even better solution is to check whether a filter is attached just before the headers are sent to the client as pointed out by Adam Schroeder in the comments: protected void Application_PreSendRequestHeaders() { // ensure that if GZip/Deflate Encoding is applied that headers are set // also works when error occurs if filters are still active HttpResponse response = HttpContext.Current.Response; if (response.Filter is GZipStream && response.Headers["Content-encoding"] != "gzip") response.AppendHeader("Content-encoding", "gzip"); else if (response.Filter is DeflateStream && response.Headers["Content-encoding"] != "deflate") response.AppendHeader("Content-encoding", "deflate"); } This uses the Application_PreSendRequestHeaders() pipeline event to check for compression encoding in a filter and adjusts the content accordingly. This is actually a better solution since this is generic – it’ll work regardless of how the content is cleaned up. For example, an error Response.Redirect() or short error display might get changed and the filter not cleared and this code actually handles that. Sweet, thanks Adam. It’s unfortunate that ASP.NET doesn’t natively clear out Response.Filters when an error occurs just as it clears the Response and Headers. I can’t see where leaving a Filter in place in an error situation would make any sense, but hey - this is what it is and it’s easy enough to fix as long as you know where to look. Riiiight! IIS and GZip I should also mention that IIS 7 includes good support for compression natively. If you can defer encoding to let IIS perform it for you rather than doing it in your code by all means you should do it! Especially any static or semi-dynamic content that can be made static should be using IIS built-in compression. Dynamic caching is also supported but is a bit more tricky to judge in terms of performance and footprint. John Forsyth has a great article on the benefits and drawbacks of IIS 7 compression which gives some detailed performance comparisons and impact reviews. I’ll post another entry next with some more info on IIS compression since information on it seems to be a bit hard to come by. Related Content Built-in GZip/Deflate Compression in IIS 7.x HttpWebRequest and GZip Responses © Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET   IIS7  

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  • Calling Web Service Functions Asynchronously from a Web Page

    - by SGWellens
    Over on the Asp.Net forums where I moderate, a user had a problem calling a Web Service from a web page asynchronously. I tried his code on my machine and was able to reproduce the problem. I was able to solve his problem, but only after taking the long scenic route through some of the more perplexing nuances of Web Services and Proxies. Here is the fascinating story of that journey. Start with a simple Web Service     public class Service1 : System.Web.Services.WebService    {        [WebMethod]        public string HelloWorld()        {            // sleep 10 seconds            System.Threading.Thread.Sleep(10 * 1000);            return "Hello World";        }    } The 10 second delay is added to make calling an asynchronous function more apparent. If you don't call the function asynchronously, it takes about 10 seconds for the page to be rendered back to the client. If the call is made from a Windows Forms application, the application freezes for about 10 seconds. Add the web service to a web site. Right-click the project and select "Add Web Reference…" Next, create a web page to call the Web Service. Note: An asp.net web page that calls an 'Async' method must have the Async property set to true in the page's header: <%@ Page Language="C#"          AutoEventWireup="true"          CodeFile="Default.aspx.cs"          Inherits="_Default"           Async='true'  %> Here is the code to create the Web Service proxy and connect the event handler. Shrewdly, we make the proxy object a member of the Page class so it remains instantiated between the various events. public partial class _Default : System.Web.UI.Page {    localhost.Service1 MyService;  // web service proxy     // ---- Page_Load ---------------------------------     protected void Page_Load(object sender, EventArgs e)    {        MyService = new localhost.Service1();        MyService.HelloWorldCompleted += EventHandler;          } Here is the code to invoke the web service and handle the event:     // ---- Async and EventHandler (delayed render) --------------------------     protected void ButtonHelloWorldAsync_Click(object sender, EventArgs e)    {        // blocks        ODS("Pre HelloWorldAsync...");        MyService.HelloWorldAsync();        ODS("Post HelloWorldAsync");    }    public void EventHandler(object sender, localhost.HelloWorldCompletedEventArgs e)    {        ODS("EventHandler");        ODS("    " + e.Result);    }     // ---- ODS ------------------------------------------------    //    // Helper function: Output Debug String     public static void ODS(string Msg)    {        String Out = String.Format("{0}  {1}", DateTime.Now.ToString("hh:mm:ss.ff"), Msg);        System.Diagnostics.Debug.WriteLine(Out);    } I added a utility function I use a lot: ODS (Output Debug String). Rather than include the library it is part of, I included it in the source file to keep this example simple. Fire up the project, open up a debug output window, press the button and we get this in the debug output window: 11:29:37.94 Pre HelloWorldAsync... 11:29:37.94 Post HelloWorldAsync 11:29:48.94 EventHandler 11:29:48.94 Hello World   Sweet. The asynchronous call was made and returned immediately. About 10 seconds later, the event handler fires and we get the result. Perfect….right? Not so fast cowboy. Watch the browser during the call: What the heck? The page is waiting for 10 seconds. Even though the asynchronous call returned immediately, Asp.Net is waiting for the event to fire before it renders the page. This is NOT what we wanted. I experimented with several techniques to work around this issue. Some may erroneously describe my behavior as 'hacking' but, since no ingesting of Twinkies was involved, I do not believe hacking is the appropriate term. If you examine the proxy that was automatically created, you will find a synchronous call to HelloWorld along with an additional set of methods to make asynchronous calls. I tried the other asynchronous method supplied in the proxy:     // ---- Begin and CallBack ----------------------------------     protected void ButtonBeginHelloWorld_Click(object sender, EventArgs e)    {        ODS("Pre BeginHelloWorld...");        MyService.BeginHelloWorld(AsyncCallback, null);        ODS("Post BeginHelloWorld");    }    public void AsyncCallback(IAsyncResult ar)    {        String Result = MyService.EndHelloWorld(ar);         ODS("AsyncCallback");        ODS("    " + Result);    } The BeginHelloWorld function in the proxy requires a callback function as a parameter. I tested it and the debug output window looked like this: 04:40:58.57 Pre BeginHelloWorld... 04:40:58.57 Post BeginHelloWorld 04:41:08.58 AsyncCallback 04:41:08.58 Hello World It works the same as before except for one critical difference: The page rendered immediately after the function call. I was worried the page object would be disposed after rendering the page but the system was smart enough to keep the page object in memory to handle the callback. Both techniques have a use: Delayed Render: Say you want to verify a credit card, look up shipping costs and confirm if an item is in stock. You could have three web service calls running in parallel and not render the page until all were finished. Nice. You can send information back to the client as part of the rendered page when all the services are finished. Immediate Render: Say you just want to start a service running and return to the client. You can do that too. However, the page gets sent to the client before the service has finished running so you will not be able to update parts of the page when the service finishes running. Summary: YourFunctionAsync() and an EventHandler will not render the page until the handler fires. BeginYourFunction() and a CallBack function will render the page as soon as possible. I found all this to be quite interesting and did a lot of searching and researching for documentation on this subject….but there isn't a lot out there. The biggest clues are the parameters that can be sent to the WSDL.exe program: http://msdn.microsoft.com/en-us/library/7h3ystb6(VS.100).aspx Two parameters are oldAsync and newAsync. OldAsync will create the Begin/End functions; newAsync will create the Async/Event functions. Caveat: I haven't tried this but it was stated in this article. I'll leave confirming this as an exercise for the student J. Included Code: I'm including the complete test project I created to verify the findings. The project was created with VS 2008 SP1. There is a solution file with 3 projects, the 3 projects are: Web Service Asp.Net Application Windows Forms Application To decide which program runs, you right-click a project and select "Set as Startup Project". I created and played with the Windows Forms application to see if it would reveal any secrets. I found that in the Windows Forms application, the generated proxy did NOT include the Begin/Callback functions. Those functions are only generated for Asp.Net pages. Probably for the reasons discussed earlier. Maybe those Microsoft boys and girls know what they are doing. I hope someone finds this useful. Steve Wellens

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  • Clusterware 11gR2 &ndash; Setting up an Active/Passive failover configuration

    - by Gilles Haro
    Oracle is providing a large range of interesting solutions to ensure High Availability of the database. Dataguard, RAC or even both configurations (as recommended by Oracle for a Maximum Available Architecture - MAA) are the most frequently found and used solutions. But, when it comes to protecting a system with an Active/Passive architecture with failover capabilities, people often thinks to other expensive third party cluster systems. Oracle Clusterware technology, which comes along at no extra-cost with Oracle Database or Oracle Unbreakable Linux, is - in the knowing of most people - often linked to Oracle RAC and therefore, is seldom used to implement failover solutions. Oracle Clusterware 11gR2  (a part of Oracle 11gR2 Grid Infrastructure)  provides a comprehensive framework to setup automatic failover configurations. It is actually possible to make "failover-able'", and then to protect, almost any kind of application (from the simple xclock to the most complex Application Server). Quoting Oracle: “Oracle Clusterware is a portable cluster software that allows clustering of single servers so that they cooperate as a single system. Oracle Clusterware also provides the required infrastructure for Oracle Real Application Clusters (RAC). In addition Oracle Clusterware enables the protection of any Oracle application or any other kind of application within a cluster.” In the next couple of lines, I will try to present the different steps to achieve this goal : Have a fully operational 11gR2 database protected by automatic failover capabilities. I assume you are fluent in installing Oracle Database 11gR2, Oracle Grid Infrastructure 11gR2 on a Linux system and that ASM is not a problem for you (as I am using it as a shared storage). If not, please have a look at Oracle Documentation. As often, I made my tests using an Oracle VirtualBox environment. The scripts are tested and functional on my system. Unfortunately, there can always be a typo or a mistake. This blog entry does not replace a course around the Clusterware Framework. I just hope it will let you see how powerful it is and that it will give you the whilst to go further with it...  Note : This entry has been revised (rev.2) following comments from Philip Newlan. Prerequisite 2 Linux boxes (OELCluster01 and OELCluster02) at the same OS level. I used OEL 5 Update 5 with an Enterprise Kernel. Shared Storage (SAN). On my VirtualBox system, I used Openfiler to simulate the SAN Oracle 11gR2 Database (11.2.0.1) Oracle 11gR2 Grid Infrastructure (11.2.0.1)   Step 1 - Install the software Using asmlib, create 3 ASM disks (ASM_CRS, ASM_DTA and ASM_FRA) Install Grid Infrastructure for a cluster (OELCluster01 and OELCluster02 are the 2 nodes of the cluster) Use ASM_CRS to store Voting Disk and OCR. Use SCAN. Install Oracle Database Standalone binaries on both nodes. Use asmca to check/mount the disk groups on 2 nodes Use dbca to create and configure a database on the primary node Let's name it DB11G. Copy the pfile, password file to the second node. Create adump directoty on the second node.   Step 2 - Setup the resource to be protected After its creation with dbca, the database is automatically protected by the Oracle Restart technology available with Grid Infrastructure. Consequently, it restarts automatically (if possible) after a crash (ex: kill -9 smon). A database resource has been created for that in the Cluster Registry. We can observe this with the command : crsctl status resource that shows and ora.dba11g.db entry. Let's save the definition of this resource, for future use : mkdir -p /crs/11.2.0/HA_scripts chown oracle:oinstall /crs/11.2.0/HA_scripts crsctl status resource ora.db11g.db -p > /crs/11.2.0/HA_scripts/myResource.txt Although very interesting, Oracle Restart is not cluster aware and cannot restart the database on any other node of the cluster. So, let's remove it from the OCR definitions, we don't need it ! srvctl stop database -d DB11G srvctl remove database -d DB11G Instead of it, we need to create a new resource of a more general type : cluster_resource. Here are the steps to achieve this : Create an action script :  /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh #!/bin/bash export ORACLE_HOME=/oracle/product/11.2.0/dbhome_1 export ORACLE_SID=DB11G case $1 in 'start')   $ORACLE_HOME/bin/sqlplus /nolog <<EOF   connect / as sysdba   startup EOF   RET=0   ;; 'stop')   $ORACLE_HOME/bin/sqlplus /nolog <<EOF   connect / as sysdba   shutdown immediate EOF   RET=0   ;; 'clean')   $ORACLE_HOME/bin/sqlplus /nolog <<EOF   connect / as sysdba   shutdown abort    ##for i in `ps -ef | grep -i $ORACLE_SID | awk '{print $2}' ` ;do kill -9 $i; done EOF   RET=0   ;; 'check')    ok=`ps -ef | grep smon | grep $ORACLE_SID | wc -l`    if [ $ok = 0 ]; then      RET=1    else      RET=0    fi    ;; '*')      RET=0   ;; esac if [ $RET -eq 0 ]; then    exit 0 else    exit 1 fi   This script must provide, at least, methods to start, stop, clean and check the database. It is self-explaining and contains nothing special. Just be aware that it must be runnable (+x), it runs as Oracle user (because of the ACL property - see later) and needs to know about the environment. Also make sure it exists on every node of the cluster. Moreover, as of 11.2, the clean method is mandatory. It must provide the “last gasp clean up”, for example, a shutdown abort or a kill –9 of all the remaining processes. chmod +x /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh scp  /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh   oracle@OELCluster02:/crs/11.2.0/HA_scripts Create a new resource file, based on the information we got from previous  myResource.txt . Name it myNewResource.txt. myResource.txt  is shown below. As we can see, it defines an ora.database.type resource, named ora.db11g.db. A lot of properties are related to this type of resource and do not need to be used for a cluster_resource. NAME=ora.db11g.db TYPE=ora.database.type ACL=owner:oracle:rwx,pgrp:oinstall:rwx,other::r-- ACTION_FAILURE_TEMPLATE= ACTION_SCRIPT= ACTIVE_PLACEMENT=1 AGENT_FILENAME=%CRS_HOME%/bin/oraagent%CRS_EXE_SUFFIX% AUTO_START=restore CARDINALITY=1 CHECK_INTERVAL=1 CHECK_TIMEOUT=600 CLUSTER_DATABASE=false DB_UNIQUE_NAME=DB11G DEFAULT_TEMPLATE=PROPERTY(RESOURCE_CLASS=database) PROPERTY(DB_UNIQUE_NAME= CONCAT(PARSE(%NAME%, ., 2), %USR_ORA_DOMAIN%, .)) ELEMENT(INSTANCE_NAME= %GEN_USR_ORA_INST_NAME%) DEGREE=1 DESCRIPTION=Oracle Database resource ENABLED=1 FAILOVER_DELAY=0 FAILURE_INTERVAL=60 FAILURE_THRESHOLD=1 GEN_AUDIT_FILE_DEST=/oracle/admin/DB11G/adump GEN_USR_ORA_INST_NAME= GEN_USR_ORA_INST_NAME@SERVERNAME(oelcluster01)=DB11G HOSTING_MEMBERS= INSTANCE_FAILOVER=0 LOAD=1 LOGGING_LEVEL=1 MANAGEMENT_POLICY=AUTOMATIC NLS_LANG= NOT_RESTARTING_TEMPLATE= OFFLINE_CHECK_INTERVAL=0 ORACLE_HOME=/oracle/product/11.2.0/dbhome_1 PLACEMENT=restricted PROFILE_CHANGE_TEMPLATE= RESTART_ATTEMPTS=2 ROLE=PRIMARY SCRIPT_TIMEOUT=60 SERVER_POOLS=ora.DB11G SPFILE=+DTA/DB11G/spfileDB11G.ora START_DEPENDENCIES=hard(ora.DTA.dg,ora.FRA.dg) weak(type:ora.listener.type,uniform:ora.ons,uniform:ora.eons) pullup(ora.DTA.dg,ora.FRA.dg) START_TIMEOUT=600 STATE_CHANGE_TEMPLATE= STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.DTA.dg,shutdown:ora.FRA.dg) STOP_TIMEOUT=600 UPTIME_THRESHOLD=1h USR_ORA_DB_NAME=DB11G USR_ORA_DOMAIN=haroland USR_ORA_ENV= USR_ORA_FLAGS= USR_ORA_INST_NAME=DB11G USR_ORA_OPEN_MODE=open USR_ORA_OPI=false USR_ORA_STOP_MODE=immediate VERSION=11.2.0.1.0 I removed database type related entries from myResource.txt and modified some other to produce the following myNewResource.txt. Notice the NAME property that should not have the ora. prefix Notice the TYPE property that is not ora.database.type but cluster_resource. Notice the definition of ACTION_SCRIPT. Notice the HOSTING_MEMBERS that enumerates the members of the cluster (as returned by the olsnodes command). NAME=DB11G.db TYPE=cluster_resource DESCRIPTION=Oracle Database resource ACL=owner:oracle:rwx,pgrp:oinstall:rwx,other::r-- ACTION_SCRIPT=/crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh PLACEMENT=restricted ACTIVE_PLACEMENT=0 AUTO_START=restore CARDINALITY=1 CHECK_INTERVAL=10 DEGREE=1 ENABLED=1 HOSTING_MEMBERS=oelcluster01 oelcluster02 LOGGING_LEVEL=1 RESTART_ATTEMPTS=1 START_DEPENDENCIES=hard(ora.DTA.dg,ora.FRA.dg) weak(type:ora.listener.type,uniform:ora.ons,uniform:ora.eons) pullup(ora.DTA.dg,ora.FRA.dg) START_TIMEOUT=600 STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.DTA.dg,shutdown:ora.FRA.dg) STOP_TIMEOUT=600 UPTIME_THRESHOLD=1h Register the resource. Take care of the resource type. It needs to be a cluster_resource and not a ora.database.type resource (Oracle recommendation) .   crsctl add resource DB11G.db  -type cluster_resource -file /crs/11.2.0/HA_scripts/myNewResource.txt Step 3 - Start the resource crsctl start resource DB11G.db This command launches the ACTION_SCRIPT with a start and a check parameter on the primary node of the cluster. Step 4 - Test this We will test the setup using 2 methods. crsctl relocate resource DB11G.db This command calls the ACTION_SCRIPT  (on the two nodes)  to stop the database on the active node and start it on the other node. Once done, we can revert back to the original node, but, this time we can use a more "MS$ like" method :Turn off the server on which the database is running. After short delay, you should observe that the database is relocated on node 1. Conclusion Once the software installed and the standalone database created (which is a rather common and usual task), the steps to reach the objective are quite easy : Create an executable action script on every node of the cluster. Create a resource file. Create/Register the resource with OCR using the resource file. Start the resource. This solution is a very interesting alternative to licensable third party solutions. References Clusterware 11gR2 documentation Oracle Clusterware Resource Reference Clusterware for Unbreakable Linux Using Oracle Clusterware to Protect A Single Instance Oracle Database 11gR1 (to have an idea of complexity) Oracle Clusterware on OTN   Gilles Haro Technical Expert - Core Technology, Oracle Consulting   

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