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• spring-nullpointerexception- cant access autowired annotated service (or dao) in a no-annotations class

  - by user286806

  I have this problem that I cannot fix. From my @Controller, i can easily access my autowired @Service class and play with it no problem. But when I do that from a separate class without annotations, it gives me a NullPointerException. My Controller (works)- @Controller public class UserController { @Autowired UserService userService;... My separate Java class (not working)- public final class UsersManagementUtil { @Autowired UserService userService; or @Autowired UserDao userDao; userService or userDao are always null! Was just trying if any one of them works. My component scan setting has the root level package set for scanning so that should be OK. my servlet context - <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd"> <!-- the application context definition for the springapp DispatcherServlet --> <!-- Enable annotation driven controllers, validation etc... --> <context:property-placeholder location="classpath:jdbc.properties" /> <context:component-scan base-package="x" /> <tx:annotation-driven transaction-manager="hibernateTransactionManager" /> <!-- package shortended --> <bean id="messageSource" class="o.s.c.s.ReloadableResourceBundleMessageSource"> <property name="basename" value="/WEB-INF/messages" /> </bean> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="${database.driver}" /> <property name="url" value="${database.url}" /> <property name="username" value="${database.user}" /> <property name="password" value="${database.password}" /> </bean> <!-- package shortened --> <bean id="viewResolver" class="o.s.w.s.v.InternalResourceViewResolver"> <property name="prefix"> <value>/</value> </property> <property name="suffix"> <value>.jsp</value> </property> <property name="order"> <value>0</value> </property> </bean> <!-- package shortened --> <bean id="sessionFactory" class="o.s.o.h3.a.AnnotationSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="annotatedClasses"> <list> <value>orion.core.models.Question</value> <value>orion.core.models.User</value> <value>orion.core.models.Space</value> <value>orion.core.models.UserSkill</value> <value>orion.core.models.Question</value> <value>orion.core.models.Rating</value> </list> </property> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">${hibernate.dialect}</prop> <prop key="hibernate.show_sql">${hibernate.show_sql}</prop> <prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop> </props> </property> </bean> <bean id="hibernateTransactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"> <property name="sessionFactory" ref="sessionFactory" /> </bean> Any clue?

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• Need help displaying a table dynamically based on a drop down date selection

  - by Gideon

  I am designing a job rota planner for a company and need help displaying a dynamic table containing the staff details. I have the following tables in MySQL database: Staff, Event, and Job. The staff table holds staff details (staffed, name, address...etc), the Event table (eventide, eventName, Fromdate, Todate...etc) and the Job table holds (Jobid, Jobdate, Eventid(fk), Staffid (fk)). I need to dynamically display the available staff list from the staff table when the user selects the event and the date (3 drop downs: date, month, and year) from a PHP form. I need to display staff members that have not been assigned work on the selected date by checking the Jobdate in the Job table. I have been at this for all day and can't get around it. I am still learning PHP and would surely appreciate any help I can get. My current code displays all staff members when an event is selected: //Create the day pull-down menu. $days = range (1, 31); echo "<Select Name=day Value=''><Option>Day</option>"; foreach ($days as $value) { echo '<option value="'.$value.'">'.$value.'</option>\n'; } echo "</Select>"; echo "</td><td>"; //Create the month pull-down menu echo "<Select Name=month Value=''><Option>Month</option>"; echo "<option value='01'>Jan</option>"; echo "<option value='02'>Feb</option>"; echo "<option value='03'>Mar</option>"; echo "<option value='04'>Apr</option>"; echo "<option value='05'>May</option>"; echo "<option value='06'>Jun</option>"; echo "<option value='07'>Jul</option>"; echo "<option value='08'>Aug</option>"; echo "<option value='09'>Sep</option>"; echo "<option value='10'>Oct</option>"; echo "<option value='11'>Nov</option>"; echo "<option value='12'>Dec</option>"; echo "</select>"; echo "</td><td>"; //Create the year pull-down menu $currentYear = date ("Y"); $years = range ($currentYear, 2020); echo "<Select Name=year Value=''><Option>Year</option>"; foreach ($years as $value) { echo '<option value="'.$value.'">'.$value.'</option>\n'; } echo "</Select>"; echo "</td></tr></table>"; echo "</td><td>"; //echo "<img src='../ETMSimages/etms_staff.png'</img></td><td>"; //construct the available staff list $staffsql = "SELECT StaffId, LastName, FirstName FROM Staff order by StaffId"; $staffResult = mysql_query($staffsql); if ($staffResult){ echo "<p><table cellspacing='1' cellpadding='3'>"; echo "<th colspan=6>List of Available Staff</th>"; echo "</tr><tr><th> Select</th><th>Id</th><th></th><th>Last Name </th><th></th><th>First Name </th></tr>"; while ($staffarray = mysql_fetch_array($staffResult)) { echo "<tr onMouseOver= this.bgColor = 'red' onMouseOut =this.bgColor = 'white' bgcolor= '#FFFFFF'> <td align=center><input type='checkbox' name='selectbox[]' id='selectbox[]' value=".$staffarray['StaffId']."> </td><td align=left>".$staffarray['StaffId']." </td><td>&nbsp&nbsp</td><td align=center>".$staffarray['LastName']." </td><td>&nbsp&nbsp</td><td align=center>".$staffarray['FirstName']." </td></tr>"; } echo "</table>"; } else { echo "<br> The Staff list can not be displayed!"; } echo "</td></tr>"; echo "<tr><td></td>"; echo "<td align=center><input type='submit' name='Submit' value='Assign Staff'>&nbsp&nbsp"; echo "<input type='reset' value='Start Over'>"; echo "</td></tr>"; echo "</table>";

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• CRM 2011 - Workflows Vs JavaScripts

  - by Kanini

  In the Contact entity, I have the following attributes Preferred email - A read only field of type Email Personal email 1 - An email field Personal email 2 - An email field Work email 1 - An email field Work email 2 - An email field School email - An email field Other email - An email field Preferred email option - An option set with the following values {Personal email 1, Personal email 2, Work email 1, Work email 2, School email and Other email). None of the above mentioned fields are required. Requirement When user picks a value from Preferred email option, we copy the email address available in that field and apply the same in the Preferred email field. Implementation The Solution Architect suggested that we implement the above requirement as a Workflow. The reason he provided was - most of the times, these values are to be populated by an external website and the data is then fed into CRM 2011 system. So, when they update Preferred email option via a Web Service call to CRM, the WF will run and updated the Preferred email field. My argument / solution What will happen if I do not pick a value from the Preferred email Option Set? Do I set it to any of the email addresses that has a value in it? If so, what if there is more than one of the email address fields are populated, i.e., what if Personal email 1 and Work email 1 is populated but no value is picked in the Option Set? What if a value existed in the Preferred email Option Set and I then change it to NULL? Should the field Preferred email (where the text value of email address is stored) be set to Read Only? If not, what if I have picked Personal email 1 in the Option Set and then edit the Preferred email address text field with a completely new email address If yes, then we are enforcing that the preferred email should be one among Personal email 1, Personal email 2, Work email 1, Work email 2, School email or Other email [My preference would be this] What if I had a value of [email protected] in the personal email 1 field and personal email 2 is empty and choose value of Personal email 1 in the drop down for Preferred email (this will set the Preferred email field to [email protected]) and later, I change the value to Personal email 2 in the Preferred email. It overwrites a valid email address with nothing. I agree that it would be highly unlikely that a user will pick Preferred email as Personal email 2 and not have a value in it but nevertheless it is a possible scenario, isn’t it? What if users typed in a value in Personal email 1 but by mistake picked Personal email 2 in the option set and Personal email 2 field had no value in it. Solution The field Preferred email option should be a required field A JS should run whenever Preferred email option is changed. That JS function should set the relevant email field as required (based on the option chosen) and another JS function should be called (see step 3). A JS function should update the value of Preferred email with the value in the email field (as picked in the option set). The JS function should also be run every time someone updates the actual email field which is chosen in the option set. The guys who are managing the external website should update the Preferred email field - surely, if they can update Preferred email option via a Web Service call, it is easy enough to update the Preferred email right? Question Which is a better method? Should it be written as a JS or a WorkFlow? Also, whose responsibility is it to update the Preferred email field when the data flows from an external website? I am new to CRM 2011 but have around 6 years of experience as a CRM consultant (with other products). I do not come from a development background as I started off as a Application Support Engineer but have picked up development in the last couple of years.

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• Ubuntu 9.10 RSA authentication: ssh fails, filezilla runs fine

  - by MariusPontmercy

  This is quite a mistery for me. I usually use passwordless RSA authentication to login into my remote *nix servers with ssh and sftp. Never had any problem until now. I cannot connect to an Ubuntu 9.10 machine: user@myclient$ ssh -i .ssh/Ganymede_key [email protected] [...] debug1: Host 'ganymede.server.com' is known and matches the RSA host key. debug1: Found key in /home/user/.ssh/known_hosts:14 debug2: bits set: 494/1024 debug1: ssh_rsa_verify: signature correct debug2: kex_derive_keys debug2: set_newkeys: mode 1 debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug2: set_newkeys: mode 0 debug1: SSH2_MSG_NEWKEYS received debug1: SSH2_MSG_SERVICE_REQUEST sent debug2: service_accept: ssh-userauth debug1: SSH2_MSG_SERVICE_ACCEPT received debug2: key: .ssh/Ganymede_key (0xb96a0ef8) debug2: key: .ssh/Ganymede_key ((nil)) debug1: Authentications that can continue: publickey,password,keyboard-interactive debug1: Next authentication method: publickey debug1: Offering public key: .ssh/Ganymede_key debug2: we sent a publickey packet, wait for reply debug1: Authentications that can continue: publickey,password,keyboard-interactive debug1: Trying private key: .ssh/Ganymede_key debug1: read PEM private key done: type RSA debug2: we sent a publickey packet, wait for reply debug1: Authentications that can continue: publickey,password,keyboard-interactive debug2: we did not send a packet, disable method debug1: Next authentication method: keyboard-interactive debug2: userauth_kbdint debug2: we sent a keyboard-interactive packet, wait for reply debug2: input_userauth_info_req debug2: input_userauth_info_req: num_prompts 1 Then it falls back to password authentication. If I disable password authentication on the remote machine my connection attempt just fails with a "Permission denied (publickey)." state. Same thing for sftp from command line. The "funny" thing is that the exact same RSA key works like a charm with a Filezilla sftp session instead: 12:08:00 Trace: Offered public key from "/home/user/.filezilla/keys/Ganymede_key" 12:08:00 Trace: Offer of public key accepted, trying to authenticate using it. 12:08:01 Trace: Access granted 12:08:01 Trace: Opened channel for session 12:08:01 Trace: Started a shell/command 12:08:01 Status: Connected to ganymede.server.com 12:08:02 Trace: CSftpControlSocket::ConnectParseResponse() 12:08:02 Trace: CSftpControlSocket::ResetOperation(0) 12:08:02 Trace: CControlSocket::ResetOperation(0) 12:08:02 Status: Retrieving directory listing... 12:08:02 Trace: CSftpControlSocket::SendNextCommand() 12:08:02 Trace: CSftpControlSocket::ChangeDirSend() 12:08:02 Command: pwd 12:08:02 Response: Current directory is: "/root" 12:08:02 Trace: CSftpControlSocket::ResetOperation(0) 12:08:02 Trace: CControlSocket::ResetOperation(0) 12:08:02 Trace: CSftpControlSocket::ParseSubcommandResult(0) 12:08:02 Trace: CSftpControlSocket::ListSubcommandResult() 12:08:02 Trace: CSftpControlSocket::ResetOperation(0) 12:08:02 Trace: CControlSocket::ResetOperation(0) 12:08:02 Status: Directory listing successful Any thoughts? M

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• Metro: Understanding Observables

  - by Stephen.Walther

  The goal of this blog entry is to describe how the Observer Pattern is implemented in the WinJS library. You learn how to create observable objects which trigger notifications automatically when their properties are changed. Observables enable you to keep your user interface and your application data in sync. For example, by taking advantage of observables, you can update your user interface automatically whenever the properties of a product change. Observables are the foundation of declarative binding in the WinJS library. The WinJS library is not the first JavaScript library to include support for observables. For example, both the KnockoutJS library and the Microsoft Ajax Library (now part of the Ajax Control Toolkit) support observables. Creating an Observable Imagine that I have created a product object like this: var product = { name: "Milk", description: "Something to drink", price: 12.33 }; Nothing very exciting about this product. It has three properties named name, description, and price. Now, imagine that I want to be notified automatically whenever any of these properties are changed. In that case, I can create an observable product from my product object like this: var observableProduct = WinJS.Binding.as(product); This line of code creates a new JavaScript object named observableProduct from the existing JavaScript object named product. This new object also has a name, description, and price property. However, unlike the properties of the original product object, the properties of the observable product object trigger notifications when the properties are changed. Each of the properties of the new observable product object has been changed into accessor properties which have both a getter and a setter. For example, the observable product price property looks something like this: price: { get: function () { return this.getProperty(“price”); } set: function (value) { this.setProperty(“price”, value); } } When you read the price property then the getProperty() method is called and when you set the price property then the setProperty() method is called. The getProperty() and setProperty() methods are methods of the observable product object. The observable product object supports the following methods and properties: · addProperty(name, value) – Adds a new property to an observable and notifies any listeners. · backingData – An object which represents the value of each property. · bind(name, action) – Enables you to execute a function when a property changes. · getProperty(name) – Returns the value of a property using the string name of the property. · notify(name, newValue, oldValue) – A private method which executes each function in the _listeners array. · removeProperty(name) – Removes a property and notifies any listeners. · setProperty(name, value) – Updates a property and notifies any listeners. · unbind(name, action) – Enables you to stop executing a function in response to a property change. · updateProperty(name, value) – Updates a property and notifies any listeners. So when you create an observable, you get a new object with the same properties as an existing object. However, when you modify the properties of an observable object, then you can notify any listeners of the observable that the value of a particular property has changed automatically. Imagine that you change the value of the price property like this: observableProduct.price = 2.99; In that case, the following sequence of events is triggered: 1. The price setter calls the setProperty(“price”, 2.99) method 2. The setProperty() method updates the value of the backingData.price property and calls the notify() method 3. The notify() method executes each function in the collection of listeners associated with the price property Creating Observable Listeners If you want to be notified when a property of an observable object is changed, then you need to register a listener. You register a listener by using the bind() method like this: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { // Simple product object var product = { name: "Milk", description: "Something to drink", price: 12.33 }; // Create observable product var observableProduct = WinJS.Binding.as(product); // Execute a function when price is changed observableProduct.bind("price", function (newValue) { console.log(newValue); }); // Change the price observableProduct.price = 2.99; } }; app.start(); })(); In the code above, the bind() method is used to associate the price property with a function. When the price property is changed, the function logs the new value of the price property to the Visual Studio JavaScript console. The price property is associated with the function using the following line of code: // Execute a function when price is changed observableProduct.bind("price", function (newValue) { console.log(newValue); }); Coalescing Notifications If you make multiple changes to a property – one change immediately following another – then separate notifications won’t be sent. Instead, any listeners are notified only once. The notifications are coalesced into a single notification. For example, in the following code, the product price property is updated three times. However, only one message is written to the JavaScript console. Only the last value assigned to the price property is written to the JavaScript Console window: // Simple product object var product = { name: "Milk", description: "Something to drink", price: 12.33 }; // Create observable product var observableProduct = WinJS.Binding.as(product); // Execute a function when price is changed observableProduct.bind("price", function (newValue) { console.log(newValue); }); // Change the price observableProduct.price = 3.99; observableProduct.price = 2.99; observableProduct.price = 1.99; Only the last value assigned to price, the value 1.99, appears in the console: If there is a time delay between changes to a property then changes result in different notifications. For example, the following code updates the price property every second: // Simple product object var product = { name: "Milk", description: "Something to drink", price: 12.33 }; // Create observable product var observableProduct = WinJS.Binding.as(product); // Execute a function when price is changed observableProduct.bind("price", function (newValue) { console.log(newValue); }); // Add 1 to price every second window.setInterval(function () { observableProduct.price += 1; }, 1000); In this case, separate notification messages are logged to the JavaScript Console window: If you need to prevent multiple notifications from being coalesced into one then you can take advantage of promises. I discussed WinJS promises in a previous blog entry: http://stephenwalther.com/blog/archive/2012/02/22/windows-web-applications-promises.aspx Because the updateProperty() method returns a promise, you can create different notifications for each change in a property by using the following code: // Change the price observableProduct.updateProperty("price", 3.99) .then(function () { observableProduct.updateProperty("price", 2.99) .then(function () { observableProduct.updateProperty("price", 1.99); }); }); In this case, even though the price is immediately changed from 3.99 to 2.99 to 1.99, separate notifications for each new value of the price property are sent. Bypassing Notifications Normally, if a property of an observable object has listeners and you change the property then the listeners are notified. However, there are certain situations in which you might want to bypass notification. In other words, you might need to change a property value silently without triggering any functions registered for notification. If you want to change a property without triggering notifications then you should change the property by using the backingData property. The following code illustrates how you can change the price property silently: // Simple product object var product = { name: "Milk", description: "Something to drink", price: 12.33 }; // Create observable product var observableProduct = WinJS.Binding.as(product); // Execute a function when price is changed observableProduct.bind("price", function (newValue) { console.log(newValue); }); // Change the price silently observableProduct.backingData.price = 5.99; console.log(observableProduct.price); // Writes 5.99 The price is changed to the value 5.99 by changing the value of backingData.price. Because the observableProduct.price property is not set directly, any listeners associated with the price property are not notified. When you change the value of a property by using the backingData property, the change in the property happens synchronously. However, when you change the value of an observable property directly, the change is always made asynchronously. Summary The goal of this blog entry was to describe observables. In particular, we discussed how to create observables from existing JavaScript objects and bind functions to observable properties. You also learned how notifications are coalesced (and ways to prevent this coalescing). Finally, we discussed how you can use the backingData property to update an observable property without triggering notifications. In the next blog entry, we’ll see how observables are used with declarative binding to display the values of properties in an HTML document.

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• Quartz.Net Windows Service Configure Logging

  - by Tarun Arora

  In this blog post I’ll be covering, Logging for Quartz.Net Windows Service 01 – Why doesn’t Quartz.Net Windows Service log by default 02 – Configuring Quartz.Net windows service for logging to eventlog, file, console, etc 03 – Results: Logging in action If you are new to Quartz.Net I would recommend going through, A brief Introduction to Quartz.net Walkthrough of Installing & Testing Quartz.Net as a Windows Service Writing & Scheduling your First HelloWorld job with Quartz.Net   01 – Why doesn’t Quartz.Net Windows Service log by default If you are trying to figure out why… The Quartz.Net windows service isn’t logging The Quartz.Net windows service isn’t writing anything to the event log The Quartz.Net windows service isn’t writing anything to a file How do I configure Quartz.Net windows service to use log4Net How do I change the level of logging for Quartz.Net Look no further, This blog post should help you answer these questions. Quartz.NET uses the Common.Logging framework for all of its logging needs. If you navigate to the directory where Quartz.Net Windows Service is installed (I have the service installed in C:\Program Files (x86)\Quartz.net, you can find out the location by looking at the properties of the service) and open ‘Quartz.Server.exe.config’ you’ll see that the Quartz.Net is already set up for logging to ConsoleAppender and EventLogAppender, but only ‘ConsoleAppender’ is set up as active. So, unless you have the console associated to the Quartz.Net service you won’t be able to see any logging. <log4net> <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender"> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%d [%t] %-5p %l - %m%n" /> </layout> </appender> <appender name="EventLogAppender" type="log4net.Appender.EventLogAppender"> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%d [%t] %-5p %l - %m%n" /> </layout> </appender> <root> <level value="INFO" /> <appender-ref ref="ConsoleAppender" /> <!-- uncomment to enable event log appending --> <!-- <appender-ref ref="EventLogAppender" /> --> </root> </log4net> Problem: In the configuration above Quartz.Net Windows Service only has ConsoleAppender active. So, no logging will be done to EventLog. More over the RollingFileAppender isn’t setup at all. So, Quartz.Net will not log to an application trace log file. 02 – Configuring Quartz.Net windows service for logging to eventlog, file, console, etc Let’s change this behaviour by changing the config file… In the below config file, I have added the RollingFileAppender. This will configure Quartz.Net service to write to a log file. (<appender name="GeneralLog" type="log4net.Appender.RollingFileAppender">) I have specified the location for the log file (<arg key="configFile" value="Trace/application.log.txt"/>) I have enabled the EventLogAppender and RollingFileAppender to be written to by Quartz. Net windows service Changed the default level of logging from ‘Info’ to ‘All’. This means all activity performed by Quartz.Net Windows service will be logged. You might want to tune this back to ‘Debug’ or ‘Info’ later as logging ‘All’ will produce too much data to the logs. (<level value="ALL"/>) Since I have changed the logging level to ‘All’, I have added applicationSetting to remove logging log4Net internal debugging. (<add key="log4net.Internal.Debug" value="false"/>) <?xml version="1.0" encoding="utf-8" ?> <configuration> <configSections> <section name="quartz" type="System.Configuration.NameValueSectionHandler, System, Version=1.0.5000.0,Culture=neutral, PublicKeyToken=b77a5c561934e089" /> <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" /> <sectionGroup name="common"> <section name="logging" type="Common.Logging.ConfigurationSectionHandler, Common.Logging" /> </sectionGroup> </configSections> <common> <logging> <factoryAdapter type="Common.Logging.Log4Net.Log4NetLoggerFactoryAdapter, Common.Logging.Log4net"> <arg key="configType" value="INLINE" /> <arg key="configFile" value="Trace/application.log.txt"/> <arg key="level" value="ALL" /> </factoryAdapter> </logging> </common> <appSettings> <add key="log4net.Internal.Debug" value="false"/> </appSettings> <log4net> <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender"> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%d [%t] %-5p %l - %m%n" /> </layout> </appender> <appender name="EventLogAppender" type="log4net.Appender.EventLogAppender"> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%d [%t] %-5p %l - %m%n" /> </layout> </appender> <appender name="GeneralLog" type="log4net.Appender.RollingFileAppender"> <file value="Trace/application.log.txt"/> <appendToFile value="true"/> <maximumFileSize value="1024KB"/> <rollingStyle value="Size"/> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%d{HH:mm:ss} [%t] %-5p %c - %m%n"/> </layout> </appender> <root> <level value="ALL" /> <appender-ref ref="ConsoleAppender" /> <appender-ref ref="EventLogAppender" /> <appender-ref ref="GeneralLog"/> </root> </log4net> </configuration>   Note – Please ensure you restart the Quartz.Net Windows service for the config changes to be picked up by the service   03 – Results: Logging in action Once you start the Quartz.Net Windows Service up, the logging should be initiated to write all activities in the Console, EventLog and File… See screen shots below… Figure – Quartz.Net Windows Service logging all activity to the event log Figure – Quartz.Net Windows Service logging all activity to the application log file Where is the output from log4Net ConsoleAppender? As a default behaviour, the console isn't available in windows services, web services, windows forms. The output will simply be dismissed. Unless you are running the process interactively. Which you can do by firing up Quartz.Server.exe –i to see the output   This was fourth in the series of posts on enterprise scheduling using Quartz.net, in the next post I’ll be covering troubleshooting why a scheduled task hasn’t fired on Quartz.net windows service. All Quartz.Net specific blog posts can listed here. Thank you for taking the time out and reading this blog post. If you enjoyed the post, remember to subscribe to http://feeds.feedburner.com/TarunArora. Stay tuned!

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• Plan Caching and Query Memory Part II (Hash Match) – When not to use stored procedure - Most common performance mistake SQL Server developers make.

  - by sqlworkshops

  SQL Server estimates Memory requirement at compile time, when stored procedure or other plan caching mechanisms like sp_executesql or prepared statement are used, the memory requirement is estimated based on first set of execution parameters. This is a common reason for spill over tempdb and hence poor performance. Common memory allocating queries are that perform Sort and do Hash Match operations like Hash Join or Hash Aggregation or Hash Union. This article covers Hash Match operations with examples. It is recommended to read Plan Caching and Query Memory Part I before this article which covers an introduction and Query memory for Sort. In most cases it is cheaper to pay for the compilation cost of dynamic queries than huge cost for spill over tempdb, unless memory requirement for a query does not change significantly based on predicates.   This article covers underestimation / overestimation of memory for Hash Match operation. Plan Caching and Query Memory Part I covers underestimation / overestimation for Sort. It is important to note that underestimation of memory for Sort and Hash Match operations lead to spill over tempdb and hence negatively impact performance. Overestimation of memory affects the memory needs of other concurrently executing queries. In addition, it is important to note, with Hash Match operations, overestimation of memory can actually lead to poor performance.   To read additional articles I wrote click here.   The best way to learn is to practice. To create the below tables and reproduce the behavior, join the mailing list by using this link: www.sqlworkshops.com/ml and I will send you the table creation script. Most of these concepts are also covered in our webcasts: www.sqlworkshops.com/webcasts  Let’s create a Customer’s State table that has 99% of customers in NY and the rest 1% in WA.Customers table used in Part I of this article is also used here.To observe Hash Warning, enable 'Hash Warning' in SQL Profiler under Events 'Errors and Warnings'. --Example provided by www.sqlworkshops.com drop table CustomersState go create table CustomersState (CustomerID int primary key, Address char(200), State char(2)) go insert into CustomersState (CustomerID, Address) select CustomerID, 'Address' from Customers update CustomersState set State = 'NY' where CustomerID % 100 != 1 update CustomersState set State = 'WA' where CustomerID % 100 = 1 go update statistics CustomersState with fullscan go   Let’s create a stored procedure that joins customers with CustomersState table with a predicate on State. --Example provided by www.sqlworkshops.com create proc CustomersByState @State char(2) as begin declare @CustomerID int select @CustomerID = e.CustomerID from Customers e inner join CustomersState es on (e.CustomerID = es.CustomerID) where es.State = @State option (maxdop 1) end go  Let’s execute the stored procedure first with parameter value ‘WA’ – which will select 1% of data. set statistics time on go --Example provided by www.sqlworkshops.com exec CustomersByState 'WA' goThe stored procedure took 294 ms to complete.  The stored procedure was granted 6704 KB based on 8000 rows being estimated.  The estimated number of rows, 8000 is similar to actual number of rows 8000 and hence the memory estimation should be ok.  There was no Hash Warning in SQL Profiler. To observe Hash Warning, enable 'Hash Warning' in SQL Profiler under Events 'Errors and Warnings'.   Now let’s execute the stored procedure with parameter value ‘NY’ – which will select 99% of data. -Example provided by www.sqlworkshops.com exec CustomersByState 'NY' go  The stored procedure took 2922 ms to complete.   The stored procedure was granted 6704 KB based on 8000 rows being estimated.    The estimated number of rows, 8000 is way different from the actual number of rows 792000 because the estimation is based on the first set of parameter value supplied to the stored procedure which is ‘WA’ in our case. This underestimation will lead to spill over tempdb, resulting in poor performance.   There was Hash Warning (Recursion) in SQL Profiler. To observe Hash Warning, enable 'Hash Warning' in SQL Profiler under Events 'Errors and Warnings'.   Let’s recompile the stored procedure and then let’s first execute the stored procedure with parameter value ‘NY’.  In a production instance it is not advisable to use sp_recompile instead one should use DBCC FREEPROCCACHE (plan_handle). This is due to locking issues involved with sp_recompile, refer to our webcasts, www.sqlworkshops.com/webcasts for further details.   exec sp_recompile CustomersByState go --Example provided by www.sqlworkshops.com exec CustomersByState 'NY' go  Now the stored procedure took only 1046 ms instead of 2922 ms.   The stored procedure was granted 146752 KB of memory. The estimated number of rows, 792000 is similar to actual number of rows of 792000. Better performance of this stored procedure execution is due to better estimation of memory and avoiding spill over tempdb.   There was no Hash Warning in SQL Profiler.   Now let’s execute the stored procedure with parameter value ‘WA’. --Example provided by www.sqlworkshops.com exec CustomersByState 'WA' go  The stored procedure took 351 ms to complete, higher than the previous execution time of 294 ms.    This stored procedure was granted more memory (146752 KB) than necessary (6704 KB) based on parameter value ‘NY’ for estimation (792000 rows) instead of parameter value ‘WA’ for estimation (8000 rows). This is because the estimation is based on the first set of parameter value supplied to the stored procedure which is ‘NY’ in this case. This overestimation leads to poor performance of this Hash Match operation, it might also affect the performance of other concurrently executing queries requiring memory and hence overestimation is not recommended.     The estimated number of rows, 792000 is much more than the actual number of rows of 8000.  Intermediate Summary: This issue can be avoided by not caching the plan for memory allocating queries. Other possibility is to use recompile hint or optimize for hint to allocate memory for predefined data range.Let’s recreate the stored procedure with recompile hint. --Example provided by www.sqlworkshops.com drop proc CustomersByState go create proc CustomersByState @State char(2) as begin declare @CustomerID int select @CustomerID = e.CustomerID from Customers e inner join CustomersState es on (e.CustomerID = es.CustomerID) where es.State = @State option (maxdop 1, recompile) end go  Let’s execute the stored procedure initially with parameter value ‘WA’ and then with parameter value ‘NY’. --Example provided by www.sqlworkshops.com exec CustomersByState 'WA' go exec CustomersByState 'NY' go  The stored procedure took 297 ms and 1102 ms in line with previous optimal execution times.   The stored procedure with parameter value ‘WA’ has good estimation like before.   Estimated number of rows of 8000 is similar to actual number of rows of 8000.   The stored procedure with parameter value ‘NY’ also has good estimation and memory grant like before because the stored procedure was recompiled with current set of parameter values.  Estimated number of rows of 792000 is similar to actual number of rows of 792000.    The compilation time and compilation CPU of 1 ms is not expensive in this case compared to the performance benefit.   There was no Hash Warning in SQL Profiler.   Let’s recreate the stored procedure with optimize for hint of ‘NY’. --Example provided by www.sqlworkshops.com drop proc CustomersByState go create proc CustomersByState @State char(2) as begin declare @CustomerID int select @CustomerID = e.CustomerID from Customers e inner join CustomersState es on (e.CustomerID = es.CustomerID) where es.State = @State option (maxdop 1, optimize for (@State = 'NY')) end go  Let’s execute the stored procedure initially with parameter value ‘WA’ and then with parameter value ‘NY’. --Example provided by www.sqlworkshops.com exec CustomersByState 'WA' go exec CustomersByState 'NY' go  The stored procedure took 353 ms with parameter value ‘WA’, this is much slower than the optimal execution time of 294 ms we observed previously. This is because of overestimation of memory. The stored procedure with parameter value ‘NY’ has optimal execution time like before.   The stored procedure with parameter value ‘WA’ has overestimation of rows because of optimize for hint value of ‘NY’.   Unlike before, more memory was estimated to this stored procedure based on optimize for hint value ‘NY’.    The stored procedure with parameter value ‘NY’ has good estimation because of optimize for hint value of ‘NY’. Estimated number of rows of 792000 is similar to actual number of rows of 792000.   Optimal amount memory was estimated to this stored procedure based on optimize for hint value ‘NY’.   There was no Hash Warning in SQL Profiler.   This article covers underestimation / overestimation of memory for Hash Match operation. Plan Caching and Query Memory Part I covers underestimation / overestimation for Sort. It is important to note that underestimation of memory for Sort and Hash Match operations lead to spill over tempdb and hence negatively impact performance. Overestimation of memory affects the memory needs of other concurrently executing queries. In addition, it is important to note, with Hash Match operations, overestimation of memory can actually lead to poor performance.   Summary: Cached plan might lead to underestimation or overestimation of memory because the memory is estimated based on first set of execution parameters. It is recommended not to cache the plan if the amount of memory required to execute the stored procedure has a wide range of possibilities. One can mitigate this by using recompile hint, but that will lead to compilation overhead. However, in most cases it might be ok to pay for compilation rather than spilling sort over tempdb which could be very expensive compared to compilation cost. The other possibility is to use optimize for hint, but in case one sorts more data than hinted by optimize for hint, this will still lead to spill. On the other side there is also the possibility of overestimation leading to unnecessary memory issues for other concurrently executing queries. In case of Hash Match operations, this overestimation of memory might lead to poor performance. When the values used in optimize for hint are archived from the database, the estimation will be wrong leading to worst performance, so one has to exercise caution before using optimize for hint, recompile hint is better in this case.   I explain these concepts with detailed examples in my webcasts (www.sqlworkshops.com/webcasts), I recommend you to watch them. The best way to learn is to practice. To create the above tables and reproduce the behavior, join the mailing list at www.sqlworkshops.com/ml and I will send you the relevant SQL Scripts.  Register for the upcoming 3 Day Level 400 Microsoft SQL Server 2008 and SQL Server 2005 Performance Monitoring & Tuning Hands-on Workshop in London, United Kingdom during March 15-17, 2011, click here to register / Microsoft UK TechNet.These are hands-on workshops with a maximum of 12 participants and not lectures. For consulting engagements click here.   Disclaimer and copyright information:This article refers to organizations and products that may be the trademarks or registered trademarks of their various owners. Copyright of this article belongs to R Meyyappan / www.sqlworkshops.com. You may freely use the ideas and concepts discussed in this article with acknowledgement (www.sqlworkshops.com), but you may not claim any of it as your own work. This article is for informational purposes only; you use any of the suggestions given here entirely at your own risk.   R Meyyappan [email protected] LinkedIn: http://at.linkedin.com/in/rmeyyappan

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• How can I disable the CTRL-ALT-DEL key combination completely on XP/Vista/7?

  - by Travesty3

  I have been googling extensively to figure this out, and nobody seems to be able to give a direct answer. Let me start by saying that I'm NOT talking about requiring CTRL-ALT-DEL to enter logon information. I'm working on a golf simulator program which is used at golf centers. I need the ability to completely disable the CTRL-ALT-DEL key sequence so that the golf center customers can't get out of the program and access the computer at all. I realize there are other key combinations that need to be handled as well, we already have this entire feature working in XP, but we're going to be switching to Windows 7 soon, and CTRL-ALT-DEL is the only one that doesn't seem to work in Win7. I'd really like an all-around solution if at all possible. This same program may also be installed on a client's personal computer for an in-home golf simulator, but the computers that really need this feature (golf center computers) are provided to the golf center by us, so would the best option be to write a new shell? I don't know anything about that at all, other than others that suggest writing a new shell for kiosk mode. I'd really like a simpler option, like modifying the registry in some way. I have heard that you can remove some buttons from the menu screen that pops up, but unless I can remove pretty much all of them (including the shutdown/restart button in the bottom-right corner), this won't be enough of a solution for me. Thanks for taking the time to read this and thanks again for any help you could provide! -Travis

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• SSH login very slow on OS X Leopard

  - by acjohnson55

  My SSH sessions take a very long time to initiate. This applies for logins with and without passwords, interactive and non-interactive. I have tried setting 'GSSAPIAuthentication no' and 'IPQoS 0x00' on the client side, and 'UseDNS no' on the server side, but no dice. I'm really stumped and frustrated. The worst part is that it SFTP takes forever to establish connections too, making file transfer much longer than it would be otherwise. I thought the problem might be something with PAM, because of where the hang is in the sshd log below, so I tried commenting out each line one-by-one in the /etc/pam.d/sshd file. Some caused login to be impossible, some had no apparent effect. I can't really tell if PAM is stalling for other services, but I can say that su'ing into my account from another account with 'su -l' has no apparent delay. I tried creating a new user account, just to see if there was something wrong with my existing account, and the same problem persisted. Any ideas of what's going on? On the client side, the most verbose mode outputs (redacted where reasonable): OpenSSH_5.9p1, OpenSSL 0.9.8r 8 Feb 2011 debug1: Reading configuration data ... debug1: ... line 1: Applying options for ... debug1: Reading configuration data /etc/ssh_config debug1: /etc/ssh_config line 20: Applying options for * debug1: /etc/ssh_config line 53: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to ... [x.x.x.x] port 22. debug1: Connection established. debug1: identity file /.../.ssh/id_rsa type -1 debug1: identity file /.../.ssh/id_rsa-cert type -1 debug3: Incorrect RSA1 identifier debug3: Could not load "/.../.ssh/id_dsa" as a RSA1 public key debug1: identity file /.../.ssh/id_dsa type 2 debug1: identity file /.../.ssh/id_dsa-cert type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.2 debug1: match: OpenSSH_5.2 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.9 debug2: fd 3 setting O_NONBLOCK debug3: load_hostkeys: loading entries for host "..." from file "/.../.ssh/known_hosts" debug3: load_hostkeys: found key type RSA in file /.../.ssh/known_hosts:9 debug3: load_hostkeys: loaded 1 keys debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],ssh-rsa debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: [email protected],[email protected],ssh-rsa,[email protected],[email protected],ssh-dss debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected] debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected] debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,[email protected],zlib debug2: kex_parse_kexinit: none,[email protected],zlib debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: first_kex_follows 0 debug2: kex_parse_kexinit: reserved 0 debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: ssh-rsa,ssh-dss debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected] debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected] debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,[email protected] debug2: kex_parse_kexinit: none,[email protected] debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: first_kex_follows 0 debug2: kex_parse_kexinit: reserved 0 debug2: mac_setup: found hmac-md5 debug1: kex: server->client aes128-ctr hmac-md5 none debug2: mac_setup: found hmac-md5 debug1: kex: client->server aes128-ctr hmac-md5 none debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP debug2: dh_gen_key: priv key bits set: 136/256 debug2: bits set: 523/1024 debug1: SSH2_MSG_KEX_DH_GEX_INIT sent debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY debug1: Server host key: RSA ... debug3: load_hostkeys: loading entries for host "..." from file "/.../.ssh/known_hosts" debug3: load_hostkeys: found key type RSA in file /.../.ssh/known_hosts:9 debug3: load_hostkeys: loaded 1 keys debug3: load_hostkeys: loading entries for host "x.x.x.x" from file "/.../.ssh/known_hosts" debug3: load_hostkeys: found key type RSA in file /.../.ssh/known_hosts:9 debug3: load_hostkeys: loaded 1 keys debug1: Host '...' is known and matches the RSA host key. debug1: Found key in /.../.ssh/known_hosts:9 debug2: bits set: 492/1024 debug1: ssh_rsa_verify: signature correct debug2: kex_derive_keys debug2: set_newkeys: mode 1 debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug2: set_newkeys: mode 0 debug1: SSH2_MSG_NEWKEYS received debug1: Roaming not allowed by server debug1: SSH2_MSG_SERVICE_REQUEST sent debug2: service_accept: ssh-userauth debug1: SSH2_MSG_SERVICE_ACCEPT received debug2: key: /.../.ssh/id_dsa (0x7f8b7b41d6c0) debug2: key: /.../.ssh/id_rsa (0x0) debug1: Authentications that can continue: publickey,password,keyboard-interactive debug3: start over, passed a different list publickey,password,keyboard-interactive debug3: preferred publickey,keyboard-interactive,password debug3: authmethod_lookup publickey debug3: remaining preferred: keyboard-interactive,password debug3: authmethod_is_enabled publickey debug1: Next authentication method: publickey debug1: Offering DSA public key: /.../.ssh/id_dsa debug3: send_pubkey_test debug2: we sent a publickey packet, wait for reply debug1: Server accepts key: pkalg ssh-dss blen 434 debug2: input_userauth_pk_ok: fp ... debug3: sign_and_send_pubkey: DSA ... debug1: Authentication succeeded (publickey). Authenticated to ... ([x.x.x.x]:22). debug1: channel 0: new [client-session] debug3: ssh_session2_open: channel_new: 0 debug2: channel 0: send open debug1: Requesting [email protected] debug1: Entering interactive session. ****** Hangs here ****** debug2: callback start debug2: client_session2_setup: id 0 debug2: fd 3 setting TCP_NODELAY debug2: channel 0: request pty-req confirm 1 debug1: Sending environment. debug3: Ignored env TERM_PROGRAM debug3: Ignored env SHELL debug3: Ignored env TERM debug3: Ignored env TMPDIR debug3: Ignored env Apple_PubSub_Socket_Render debug3: Ignored env TERM_PROGRAM_VERSION debug3: Ignored env TERM_SESSION_ID debug3: Ignored env USER debug3: Ignored env COMMAND_MODE debug3: Ignored env SSH_AUTH_SOCK debug3: Ignored env Apple_Ubiquity_Message debug3: Ignored env __CF_USER_TEXT_ENCODING debug3: Ignored env PATH debug3: Ignored env MKL_NUM_THREADS debug3: Ignored env PWD debug1: Sending env LANG = en_US.UTF-8 debug2: channel 0: request env confirm 0 debug3: Ignored env HOME debug3: Ignored env SHLVL debug3: Ignored env DYLD_LIBRARY_PATH debug3: Ignored env PYTHONPATH debug3: Ignored env LOGNAME debug3: Ignored env DISPLAY debug3: Ignored env SECURITYSESSIONID debug3: Ignored env _ debug2: channel 0: request shell confirm 1 debug2: callback done debug2: channel 0: open confirm rwindow 0 rmax 32768 debug2: channel_input_status_confirm: type 99 id 0 debug2: PTY allocation request accepted on channel 0 debug2: channel 0: rcvd adjust 2097152 debug2: channel_input_status_confirm: type 99 id 0 debug2: shell request accepted on channel 0 On the server side, the debug output looks like: Sep 16 18:46:40 ... sshd[31435]: debug1: inetd sockets after dupping: 3, 4 Sep 16 18:46:40 ... sshd[31435]: Connection from x.x.x.x port 52758 Sep 16 18:46:40 ... sshd[31435]: debug1: Current Session ID is 56AC0FB0 / Session Attributes are 00008000 Sep 16 18:46:40 ... sshd[31435]: debug1: Running in inetd mode in a non-root session... assuming inetd created the session for us. Sep 16 18:46:40 ... sshd[31435]: debug1: Client protocol version 2.0; client software version OpenSSH_5.9 Sep 16 18:46:40 ... sshd[31435]: debug1: match: OpenSSH_5.9 pat OpenSSH* Sep 16 18:46:40 ... sshd[31435]: debug1: Enabling compatibility mode for protocol 2.0 Sep 16 18:46:40 ... sshd[31435]: debug1: Local version string SSH-2.0-OpenSSH_5.2 Sep 16 18:46:40 ... sshd[31435]: debug1: Checking with Service ACLs for ssh login restrictions Sep 16 18:46:40 ... sshd[31435]: debug1: call to mbr_user_name_to_uuid with <...> suceeded to retrieve user_uuid Sep 16 18:46:40 ... sshd[31435]: debug1: Call to mbr_check_service_membership failed with status <0> Sep 16 18:46:40 ... sshd[31435]: debug1: PAM: initializing for "..." Sep 16 18:46:40 ... sshd[31435]: debug1: PAM: setting PAM_RHOST to "x.x.x.x" Sep 16 18:46:40 ... sshd[31435]: Failed none for ... from x.x.x.x port 52758 ssh2 Sep 16 18:46:40 ... sshd[31435]: debug1: temporarily_use_uid: 509/20 (e=0/0) Sep 16 18:46:40 ... sshd[31435]: debug1: trying public key file /.../.ssh/authorized_keys Sep 16 18:46:40 ... sshd[31435]: debug1: restore_uid: 0/0 Sep 16 18:46:40 ... sshd[31435]: debug1: temporarily_use_uid: 509/20 (e=0/0) Sep 16 18:46:40 ... sshd[31435]: debug1: trying public key file /.../.ssh/authorized_keys2 Sep 16 18:46:40 ... sshd[31435]: debug1: fd 5 clearing O_NONBLOCK Sep 16 18:46:40 ... sshd[31435]: debug1: matching key found: file /.../.ssh/authorized_keys2, line 1 Sep 16 18:46:40 ... sshd[31435]: Found matching DSA key: ... Sep 16 18:46:40 ... sshd[31435]: debug1: restore_uid: 0/0 Sep 16 18:46:40 ... sshd[31435]: debug1: temporarily_use_uid: 509/20 (e=0/0) Sep 16 18:46:40 ... sshd[31435]: debug1: trying public key file /.../.ssh/authorized_keys Sep 16 18:46:40 ... sshd[31435]: debug1: restore_uid: 0/0 Sep 16 18:46:40 ... sshd[31435]: debug1: temporarily_use_uid: 509/20 (e=0/0) Sep 16 18:46:40 ... sshd[31435]: debug1: trying public key file /.../.ssh/authorized_keys2 Sep 16 18:46:40 ... sshd[31435]: debug1: fd 5 clearing O_NONBLOCK Sep 16 18:46:40 ... sshd[31435]: debug1: matching key found: file /.../.ssh/authorized_keys2, line 1 Sep 16 18:46:40 ... sshd[31435]: Found matching DSA key: ... Sep 16 18:46:40 ... sshd[31435]: debug1: restore_uid: 0/0 Sep 16 18:46:40 ... sshd[31435]: debug1: ssh_dss_verify: signature correct Sep 16 18:46:40 ... sshd[31435]: debug1: do_pam_account: called Sep 16 18:46:40 ... sshd[31435]: Accepted publickey for ... from x.x.x.x port 52758 ssh2 Sep 16 18:46:40 ... sshd[31435]: debug1: monitor_child_preauth: ... has been authenticated by privileged process Sep 16 18:46:40 ... sshd[31435]: debug1: PAM: establishing credentials ***** Hangs here ***** Sep 16 18:46:54 ... sshd[31435]: User child is on pid 31654 Sep 16 18:46:54 ... sshd[31654]: debug1: PAM: establishing credentials Sep 16 18:46:54 ... sshd[31654]: debug1: permanently_set_uid: 509/20 Sep 16 18:46:54 ... sshd[31654]: debug1: Entering interactive session for SSH2. Sep 16 18:46:54 ... sshd[31654]: debug1: server_init_dispatch_20 Sep 16 18:46:54 ... sshd[31654]: debug1: server_input_channel_open: ctype session rchan 0 win 1048576 max 16384 Sep 16 18:46:54 ... sshd[31654]: debug1: input_session_request Sep 16 18:46:54 ... sshd[31654]: debug1: channel 0: new [server-session] Sep 16 18:46:54 ... sshd[31654]: debug1: session_new: session 0 Sep 16 18:46:54 ... sshd[31654]: debug1: session_open: channel 0 Sep 16 18:46:54 ... sshd[31654]: debug1: session_open: session 0: link with channel 0 Sep 16 18:46:54 ... sshd[31654]: debug1: server_input_channel_open: confirm session Sep 16 18:46:54 ... sshd[31654]: debug1: server_input_global_request: rtype [email protected] want_reply 0 Sep 16 18:46:54 ... sshd[31654]: debug1: server_input_channel_req: channel 0 request pty-req reply 1 Sep 16 18:46:54 ... sshd[31654]: debug1: session_by_channel: session 0 channel 0 Sep 16 18:46:54 ... sshd[31654]: debug1: session_input_channel_req: session 0 req pty-req Sep 16 18:46:54 ... sshd[31654]: debug1: Allocating pty. Sep 16 18:46:54 ... sshd[31435]: debug1: session_new: session 0 Sep 16 18:46:54 ... sshd[31654]: debug1: session_pty_req: session 0 alloc /dev/ttys008 Sep 16 18:46:54 ... sshd[31654]: debug1: server_input_channel_req: channel 0 request env reply 0 Sep 16 18:46:54 ... sshd[31654]: debug1: session_by_channel: session 0 channel 0 Sep 16 18:46:54 ... sshd[31654]: debug1: session_input_channel_req: session 0 req env Sep 16 18:46:54 ... sshd[31654]: debug1: server_input_channel_req: channel 0 request shell reply 1 Sep 16 18:46:54 ... sshd[31654]: debug1: session_by_channel: session 0 channel 0 Sep 16 18:46:54 ... sshd[31654]: debug1: session_input_channel_req: session 0 req shell Sep 16 18:46:54 ... sshd[31655]: debug1: Setting controlling tty using TIOCSCTTY.

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• Modify MDT wizard to automate computer naming

  - by Jeramy

  I originally posted this question to StackOverflow, but upon further consideration it might be more appropriate here. Situation: I am imaging new systems using MDT Lite-Touch. I am trying to customize the wizard to automate the naming of new systems so that they include a prefix "AG-", a department code which is selected from a drop-down box in the wizard page (eg. "COMM"), and finally the serial number of the computer being imaged, so that my result in this case would be "AG-COMM-1234567890" Status: I have banged away at this for a while but my Google searches have not turned up answers, my trial-and-error is not producing useful error messages and I think I am missing some fundamentals of how to get variables from the wizard page into the variables used by the lite-touch wizard. Progress: I first created the HTML page which I will include below and added a script to the page to concatenate the pieces into a variable called OSDComputername which, for testing, I could output in a msgbox and get to display correctly. The problem with this is I don't know how to trigger the script then assign it to the OSDComputername variable that is used throughout the rest of the Light-Touch process. I changed the script to a function and added it to DeployWiz_Initization.vbs then used the Initialization field in WDS to call it. I'll include the function below. The problem with this is I would get "Undefined Variable" for OSDComputername and I am not sure it is pulling the data from the HTML correctly. I tried adding the scripting into the customsettings.ini file after the "OSDComputername=" This resulted in the wizard just outputting my code in text as the computer name. I am now trying adding variables to "Properties=" (eg.DepartmentName) in the customsettings.ini, pulling thier value from the HTML Form and setting that value to the variable in my function in DeployWiz_Initization.vbs and calling them after "OSDComputername=" in the fashion "OSDComputername="AG-" & %DepartmentName%" in customsettings.ini I am rebuilding right now and will see how this goes Any help would be appreciated. The HTML page: <HTML> <H1>Configure the computer name.</H1> <span style="width: 95%;"> <p>Please answer the following questions. Your answers will be used to formulate the computer's name and description.</p> <FORM NAME="TestForm"> <p>Departmental Prefix: <!-- <label class=ErrMsg id=DepartmentalPrefix_Err>* Required (MISSING)</label> --> <SELECT NAME="DepartmentalPrefix_Edit" class=WideEdit> <option value="AADC">AADC</option> <option value="AEM">AEM</option> <option value="AIP">AIP</option> <option value="COM">COM</option> <option value="DO">DO</option> <option value="DSOC">DSOC</option> <option value="EDU">EDU</option> <option value="EPE">EPE</option> <option value="ITN">ITN</option> <option value="LA">LA</option> <option value="OAP">OAP</option> <option value="SML">SML</option> </SELECT> </p> <p><span class="Larger">Client's Net<u class=larger>I</u>D:</span> <INPUT NAME="ClientNetID" TYPE="TEXT" ID="ClientNetID" SIZE="15"></p> <p>Building: <!-- <label class=ErrMsg id=Building_Err>* Required (MISSING)</label> --> <SELECT NAME="Building_Edit" class=WideEdit> <option value="Academic Surge Facility A">Academic Surge Facility A</option> <option value="Academic Surge Facility B">Academic Surge Facility B</option> <option value="Caldwell">Caldwell</option> <option value="Kennedy">Kennedy</option> <option value="Roberts">Roberts</option> <option value="Warren">Warren</option> </SELECT> </p> <p> <span class="Larger">Room <u class=larger>N</u>umber:</span> <input type=text id="RoomNumber" name=RoomNumber size=15 /> </p> </FORM> </span> </HTML> The Function: Function SetComputerName OSDComputerName = "AG-" & oEnvironment.Item("DepartmentalPrefix_Edit") ComputerDescription = oEnvironment.Item("DepartmentalPrefix_Edit") & ", " & oEnvironment.Item("ClientNetID") & ", " & oEnvironment.Item("RoomNumber") & " " & oEnvironment.Item("Building_Edit") End Function

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• Which design better when use foreign key instead of a string to store a list of id

  - by Kien Thanh

  I'm building online examination system. I have designed to table, Question and GeneralExam. The table GeneralExam contains info about the exam like name, description, duration,... Now I would like to design table GeneralQuestion, it will contain the ids of questions belongs to a general exam. Currently, I have two ideas to design GeneralQuestion table: It will have two columns: general_exam_id, question_id. It will have two columns: general_exam_id, list_question_ids (string/text). I would like to know which designing is better, or pros and cons of each designing. I'm using Postgresql database.

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• SSH onto Ubuntu box using RSA keys

  - by jex

  I recently installed OpenSSH on one of my Ubuntu machines and I've been running into problems getting it to use RSA keys. I've generated the RSA key on the client (ssh-keygen), and appended the public key generated to both the /home/jex/.ssh/authorized_keys and /etc/ssh/authorized_keys files on the server. However, when I try to login (ssh -o PreferredAuthorizations=publickey jex@host -v [which forces the use of public key for login]) I get the following output: debug1: Host 'pentheon.local' is known and matches the RSA host key. debug1: Found key in /home/jex/.ssh/known_hosts:2 debug1: ssh_rsa_verify: signature correct debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: SSH2_MSG_SERVICE_REQUEST sent debug1: SSH2_MSG_SERVICE_ACCEPT received Banner message debug1: Authentications that can continue: publickey,keyboard-interactive debug1: Next authentication method: publickey debug1: Offering public key: /home/jex/.ssh/id_rsa debug1: Authentications that can continue: publickey,keyboard-interactive debug1: Trying private key: /home/jex/.ssh/identity debug1: Trying private key: /home/jex/.ssh/id_dsa debug1: No more authentication methods to try. Permission denied (publickey,keyboard-interactive). I'm not entirely sure where I've gone wrong. I am willing to post my /etc/ssh/sshd_config if needed.

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• Cannot log in to the desktop on ubuntu 11.10?

  - by Jichao

  The problem is, I could log in under the terminal, i could ifup eth0, i could do anything I want in the terminal, but if I use ctrl+alt+f7 goto the gnome login screen, after I input the correct password, the system just send me back to same login screen again. I have created a new user, but it didn't work. I have change all the files under ~/ to jichao:jichao(which is my username) with chown -hR jichao:jichao /home/jichao, but it didn't work too. I searched the internet, somebody said I should see the logs under /var/log/gdm, but there is not a /var/log/gdm directory in my box. Here are the tail of files under /var/log/ tail X.org.log [ 3263.348] (II) Loading /usr/lib/xorg/modules/input/evdev_drv.so [ 3263.348] (**) Dell Dell USB Keyboard: always reports core events [ 3263.348] (**) Dell Dell USB Keyboard: Device: "/dev/input/event5" [ 3263.348] (--) Dell Dell USB Keyboard: Found keys [ 3263.348] (II) Dell Dell USB Keyboard: Configuring as keyboard [ 3263.348] (**) Option "config_info" "udev:/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4:1.0/input/input29/event5" [ 3263.348] (II) XINPUT: Adding extended input device "Dell Dell USB Keyboard" (type: KEYBOARD) [ 3263.348] (**) Option "xkb_rules" "evdev" [ 3263.348] (**) Option "xkb_model" "pc105" [ 3263.348] (**) Option "xkb_layout" "us" kern.log Mar 20 09:32:58 jichao-MS-730 kernel: [ 3182.701247] input: Dell Dell USB Keyboard as /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4:1.0/input/input27 Mar 20 09:32:58 jichao-MS-730 kernel: [ 3182.701392] generic-usb 0003:413C:2003.0018: input,hidraw1: USB HID v1.10 Keyboard [Dell Dell USB Keyboard] on usb-0000:00:1d.0-1.4/input0 Mar 20 09:33:02 jichao-MS-730 kernel: [ 3186.642572] usb 2-1.3: new low speed USB device number 17 using ehci_hcd Mar 20 09:33:02 jichao-MS-730 kernel: [ 3186.741892] input: Microsoft Microsoft 5-Button Mouse with IntelliEye(TM) as /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.3/2-1.3:1.0/input/input28 Mar 20 09:33:02 jichao-MS-730 kernel: [ 3186.742080] generic-usb 0003:045E:0047.0019: input,hidraw2: USB HID v1.10 Mouse [Microsoft Microsoft 5-Button Mouse with IntelliEye(TM)] on usb-0000:00:1d.0-1.3/input0 Mar 20 09:33:27 jichao-MS-730 kernel: [ 3212.473901] usb 2-1.3: USB disconnect, device number 17 Mar 20 09:33:28 jichao-MS-730 kernel: [ 3212.702031] usb 2-1.4: USB disconnect, device number 16 Mar 20 09:34:08 jichao-MS-730 kernel: [ 3253.022655] usb 2-1.4: new low speed USB device number 18 using ehci_hcd Mar 20 09:34:08 jichao-MS-730 kernel: [ 3253.124278] input: Dell Dell USB Keyboard as /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4:1.0/input/input29 Mar 20 09:34:08 jichao-MS-730 kernel: [ 3253.124423] generic-usb 0003:413C:2003.001A: input,hidraw1: USB HID v1.10 Keyboard [Dell Dell USB Keyboard] on usb-0000:00:1d.0-1.4/input0 Mar 20 09:33:02 jichao-MS-730 kernel: [ 3186.741892] input: Microsoft Microsoft 5-Button Mouse with IntelliEye(TM) as /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.3/2-1.3:1.0/input/input28 Mar 20 09:33:02 jichao-MS-730 kernel: [ 3186.742080] generic-usb 0003:045E:0047.0019: input,hidraw2: USB HID v1.10 Mouse [Microsoft Microsoft 5-Button Mouse with IntelliEye(TM)] on usb-0000:00:1d.0-1.3/input0 syslog Mar 20 09:33:02 jichao-MS-730 mtp-probe: bus: 2, device: 17 was not an MTP device Mar 20 09:33:27 jichao-MS-730 kernel: [ 3212.473901] usb 2-1.3: USB disconnect, device number 17 Mar 20 09:33:28 jichao-MS-730 kernel: [ 3212.702031] usb 2-1.4: USB disconnect, device number 16 Mar 20 09:34:08 jichao-MS-730 kernel: [ 3253.022655] usb 2-1.4: new low speed USB device number 18 using ehci_hcd Mar 20 09:34:08 jichao-MS-730 mtp-probe: checking bus 2, device 18: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4" Mar 20 09:34:08 jichao-MS-730 mtp-probe: bus: 2, device: 18 was not an MTP device Mar 20 09:34:08 jichao-MS-730 kernel: [ 3253.124278] input: Dell Dell USB Keyboard as /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4:1.0/input/input29 Mar 20 09:34:08 jichao-MS-730 kernel: [ 3253.124423] generic-usb 0003:413C:2003.001A: input,hidraw1: USB HID v1.10 Keyboard [Dell Dell USB Keyboard] on usb-0000:00:1d.0-1.4/input0 auth.log Mar 20 09:18:52 jichao-MS-730 lightdm: pam_ck_connector(lightdm-autologin:session): nox11 mode, ignoring PAM_TTY :0 Mar 20 09:18:53 jichao-MS-730 lightdm: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "jichao" Mar 20 09:18:53 jichao-MS-730 dbus[835]: [system] Rejected send message, 2 matched rules; type="method_call", sender=":1.240" (uid=104 pid=6457 comm="/usr/lib/indicator-datetime/indicator-datetime-ser") interface="org.freedesktop.DBus.Properties" member="GetAll" error name="(unset)" requested_reply="0" destination=":1.11" (uid=0 pid=1156 comm="/usr/sbin/console-kit-daemon --no-daemon ") Mar 20 09:19:38 jichao-MS-730 sudo: jichao : TTY=tty6 ; PWD=/home ; USER=root ; COMMAND=/bin/chown -hR jichao:jichao jicha Mar 20 09:19:39 jichao-MS-730 sudo: jichao : TTY=tty6 ; PWD=/home ; USER=root ; COMMAND=/bin/chown -hR jichao:jichao jichao Mar 20 09:20:10 jichao-MS-730 lightdm: pam_unix(lightdm-autologin:session): session closed for user lightdm Mar 20 09:20:11 jichao-MS-730 lightdm: pam_unix(lightdm-autologin:session): session opened for user lightdm by (uid=0) Mar 20 09:20:11 jichao-MS-730 lightdm: pam_ck_connector(lightdm-autologin:session): nox11 mode, ignoring PAM_TTY :0 Mar 20 09:20:12 jichao-MS-730 lightdm: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "jichao" Mar 20 09:20:12 jichao-MS-730 dbus[835]: [system] Rejected send message, 2 matched rules; type="method_call", sender=":1.247" (uid=104 pid=6572 comm="/usr/lib/indicator-datetime/indicator-datetime-ser") interface="org.freedesktop.DBus.Properties" member="GetAll" error name="(unset)" requested_reply="0" destination=":1.11" (uid=0 pid=1156 comm="/usr/sbin/console-kit-daemon --no-daemon ") It seems that my .xsession-errors does not grow since yesterday. Here is my .xsession-error: (gnome-settings-daemon:1550): Gdk-WARNING **: The program 'gnome-settings-daemon' received an X Window System error. This probably reflects a bug in the program. The error was 'BadWindow (invalid Window parameter)'. (Details: serial 26702 error_code 3 request_code 2 minor_code 0) (Note to programmers: normally, X errors are reported asynchronously; that is, you will receive the error a while after causing it. To debug your program, run it with the --sync command line option to change this behavior. You can then get a meaningful backtrace from your debugger if you break on the gdk_x_error() function.) (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed (nautilus:3106): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed WARN 2012-03-17 19:28:46 glib <unknown>:0 Unable to fetch children: Method "Children" with signature "" on interface "org.ayatana.bamf.view" doesn't exist WARN 2012-03-17 19:28:46 glib <unknown>:0 Unable to fetch children: Method "Children" with signature "" on interface "org.ayatana.bamf.view" doesn't exist (yunio:2430): Gtk-WARNING **: ??????????????:“pixmap”, (yunio:2430): Gtk-WARNING **: ??????????????:“pixmap”, (polkit-gnome-authentication-agent-1:1601): Gtk-WARNING **: ??????????????:“pixmap”, (yunio:2430): Gtk-WARNING **: ??????????????:“pixmap”, (yunio:2430): Gtk-WARNING **: ??????????????:“pixmap”, (polkit-gnome-authentication-agent-1:1601): Gtk-WARNING **: ??????????????:“pixmap”, (polkit-gnome-authentication-agent-1:1601): Gtk-WARNING **: ??????????????:“pixmap”, (polkit-gnome-authentication-agent-1:1601): Gtk-WARNING **: ??????????????:“pixmap”, /usr/share/system-config-printer/applet.py:336: GtkWarning: ??????????????:“pixmap”, self.loop.run () (unity-window-decorator:1652): Gtk-WARNING **: ??????????????:“pixmap”, (unity-window-decorator:1652): Gtk-WARNING **: ??????????????:“pixmap”, (unity-window-decorator:1652): Gtk-WARNING **: ??????????????:“pixmap”, (unity-window-decorator:1652): Gtk-WARNING **: ??????????????:“pixmap”, common-plugin-Message: checking whether we have a device for 4: yes common-plugin-Message: checking whether we have a device for 5: yes common-plugin-Message: checking whether we have a device for 6: yes common-plugin-Message: checking whether we have a device for 7: yes common-plugin-Message: checking whether we have a device for 10: yes common-plugin-Message: checking whether we have a device for 8: yes common-plugin-Message: checking whether we have a device for 9: yes (gnome-settings-daemon:13791): GLib-GObject-CRITICAL **: g_object_unref: assertion `G_IS_OBJECT (object)' failed [1331983727,000,xklavier.c:xkl_engine_start_listen/] The backend does not require manual layout management - but it is provided by the application ** (gnome-fallback-mount-helper:1584): DEBUG: ConsoleKit session is active 0 (gnome-fallback-mount-helper:1584): Gdk-WARNING **: gnome-fallback-mount-helper: Fatal IO error 11 (???????) on X server :0. (gdu-notification-daemon:1708): Gdk-WARNING **: gdu-notification-daemon: Fatal IO error 11 (???????) on X server :0. unity-window-decorator: Fatal IO error 11 (???????) on X server :0.0. (bluetooth-applet:1583): Gdk-WARNING **: bluetooth-applet: Fatal IO error 11 (???????) on X server :0. (nm-applet:1596): Gdk-WARNING **: nm-applet: Fatal IO error 11 (???????) on X server :0. (nautilus:3106): IBUS-WARNING **: _connection_closed_cb: Underlying GIOStream returned 0 bytes on an async read (update-notifier:1821): Gdk-WARNING **: update-notifier: Fatal IO error 11 (???????) on X server :0. applet.py: Fatal IO error 11 (???????) on X server :0. (nautilus:3106): Gdk-WARNING **: nautilus: Fatal IO error 11 (???????) on X server :0. Could you help me, Thanks.

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• Logstash agent doesn't run as a daemon on MAC OS X 10.9.1

  - by user329324

  I need to run the logstash agent as a Daemon on an MAC OS X System whenever the system boots up terminal: /usr/local/logstash/bin/logstash agent -f /usr/local/etc/cvlog.conf Per terminal the program is working succesfully but as an daemon it doesn't start. My com.bcd.logstash.plist <plist version="1.0"> <dict> <key>Label</key> <string>com.bcd.logstash</string> <key>KeepAlive</key> <dict> <key>SuccessfulExit</key> </false> </dict> <key>ProgramArguments</key> <array> <string>/usr/local/logstash/bin/logstash</string> <string>agent</string> <string>-f</string> <string>/usr/local/etc/cvlog.conf</string> </array> <key>RunAtLoad</key> </true> </dict> </plist> I start with: launchtl load /Library/LaunchDaemons/com.bcd.logstash.plist Syslog Error Message com.apple.launchd[1] (com.bcd.logstash[pid]): Exited with code:1 com.apple.launchd[1] (com.bcd.logstash[pid]): Exited with code:143 What's wrong with my plist?

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• Green (Screen) Computing

  - by onefloridacoder

  I recently was given an assignment to create a UX where a user could use the up and down arrow keys, as well as the tab and enter keys to move through a Silverlight datagrid that is going be used as part of a high throughput data entry UI. And to be honest, I’ve not trapped key codes since I coded JavaScript a few years ago.  Although the frameworks I’m using made it easy, it wasn’t without some trial and error.    The other thing that bothered me was that the customer tossed this into the use case as they were delivering the use case.  Fine.  I’ll take a whack at anything and beat up myself and beg (I’m not beyond begging for help) the community for help to get something done if I have to. It wasn’t as bad as I thought and I thought I would hopefully save someone a few keystrokes if you wanted to build a green screen for your customer.   Here’s the ValueConverter to handle changing the strings to decimals and then back again.  The value is a nullable valuetype so there are few extra steps to take.  Usually the “ConvertBack()” method doesn’t get addressed but in this case we have two-way binding and the converter needs to ensure that if the user doesn’t enter a value it will remain null when the value is reapplied to the model object’s setter.  1: using System; 2: using System.Windows.Data; 3: using System.Globalization; 4:  5: public class NullableDecimalToStringConverter : IValueConverter 6: { 7: public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) 8: { 9: if (!(((decimal?)value).HasValue)) 10: { 11: return (decimal?)null; 12: } 13: if (!(value is decimal)) 14: { 15: throw new ArgumentException("The value must be of type decimal"); 16: } 17:  18: NumberFormatInfo nfi = culture.NumberFormat; 19: nfi.NumberDecimalDigits = 4; 20:  21: return ((decimal)value).ToString("N", nfi); 22: } 23:  24: public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) 25: { 26: decimal nullableDecimal; 27: decimal.TryParse(value.ToString(), out nullableDecimal); 28:  29: return nullableDecimal == 0 ? null : nullableDecimal.ToString(); 30: } 31: }            The ConvertBack() method uses TryParse to create a value from the incoming string so if the parse fails, we get a null value back, which is what we would expect.  But while I was testing I realized that if the user types something like “2..4” instead of “2.4”, TryParse will fail and still return a null.  The user is getting “puuu-lenty” of eye-candy to ensure they know how many values are affected in this particular view. Here’s the XAML code.   This is the simple part, we just have a DataGrid with one column here that’s bound to the the appropriate ViewModel property with the Converter referenced as well. 1: <data:DataGridTextColumn 2: Header="On-Hand" 3: Binding="{Binding Quantity, 4: Mode=TwoWay, 5: Converter={StaticResource DecimalToStringConverter}}" 6: IsReadOnly="False" /> Nothing too magical here.  Just some XAML to hook things up.   Here’s the code behind that’s handling the DataGridKeyup event.  These are wired to a local/private method but could be converted to something the ViewModel could use, but I just need to get this working for now. 1: // Wire up happens in the constructor 2: this.PicDataGrid.KeyUp += (s, e) => this.HandleKeyUp(e);   1: // DataGrid.BeginEdit fires when DataGrid.KeyUp fires. 2: private void HandleKeyUp(KeyEventArgs args) 3: { 4: if (args.Key == Key.Down || 5: args.Key == Key.Up || 6: args.Key == Key.Tab || 7: args.Key == Key.Enter ) 8: { 9: this.PicDataGrid.BeginEdit(); 10: } 11: }   And that’s it.  The ValueConverter was the biggest problem starting out because I was using an existing converter that didn’t take nullable value types into account.   Once the converter was passing back the appropriate value (null, “#.####”) the grid cell(s) and the model objects started working as I needed them to. HTH.

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• What are the Key Requirements for Privacy Control Software?

  Are you concerned about protecting your privacy regarding your computer activities? With today?s personal computers and operating systems insuring your privacy on your personal computer requires much... [Author: Chet Childers - Computers and Internet - August 24, 2009]

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• Discover the Value of Specialization for your Business - Free, Live and Online!

  - by julien.haye

  Pre-qualified leads. New customers. Greater revenues. A higher market profile. And increased profitability. Specialization with Oracle can deliver all of this and more! Join us online at 14:00 CET on Monday January 24th 2011 for: a clear definition of the value of specialization with Oracle; full details on how and why Oracle proactively helps its specialized partners attract and engage with their ideal customers; all you need to know about OPN Specialized tools and resources; sessions tailored to specific regions, business models and Oracle solution areas; first-hand testimony from your peers about how specialization is helping them succeed. The event will also feature a networking lounge, interactive information booths staffed by Oracle experts, and live Q&A sessions! Click here now to register for this essential online event!

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• Problems with bash script, mysql inserts and launchd

  - by Armands

  ========= I am developing a automated system, which consists of 3 parts: mysql, bash and launchd. Bash script takes folders of work related stuff, zips, archives and puts info about them into database that is located on a local MAMP server. Everything works as expected when I run the script from terminal. But when I use Launchd to automatically run this script, it functions without errors and it does not put the values into database. I've tried to make logs of returned messages, but the logs end up being empty as the command has run the way it was supposed to. Any help would be appreciated! .plist contents <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>Label</key> <string>com.adevo.ari.zip</string> <key>ProgramArguments</key> <array> <string>/Volumes/Archive-Plus/B-ARCHIVE-PLUS/ZZ_UTILITY_FOLDER/Compress.sh</string> </array> <key>Nice</key> <integer>1</integer> <key>StartInterval</key> <integer>120</integer> <key>RunAtLoad</key> <true/> </dict> </plist> I made this .plist file just by searching the web.

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• SSL certificate for Oracle Application Server 11g

  - by Easter Sunshine

  I was asked to get an SSL certificate for an "Oracle Application Server 11g" which has a soon-to-expire certificate. Brushing aside the fact that 10g seems to be the newest version, I got a certificate from InCommon, as I usually do without problem (except this is the first time I supplied Oracle Application Server 11g as the software type on the CSR form). On the email containing links to download the certificate, it mentioned: Certificate Details: SSL Type : InCommon SSL Server : OTHER I forwarded the email over to the person responsible for installing it and got a reply that the server type must be Oracle Application Server for the certificate to work (the CN is the same as before). They were unable to install this certificate (no details provided to me) and mentioned they had this issue previously with Thawte when they didn't supply Oracle Application Server as the server type. I don't see any significant difference between the currently installed certificate (working) and the new one I just got signed by InCommon (not working). $ openssl x509 -in sso-current.cer -text shows, with irrelevant information ommitted. Data: Version: 3 (0x2) Signature Algorithm: sha1WithRSAEncryption Issuer: C=ZA, ST=Western Cape, L=Cape Town, O=Thawte Consulting cc, OU=Certification Services Division, CN=Thawte Premium Server CA/[email protected] Validity Not Before: Oct 1 00:00:00 2009 GMT Not After : Nov 28 23:59:59 2012 GMT Subject Public Key Info: Public Key Algorithm: rsaEncryption Public-Key: (2048 bit) Modulus: Exponent: 65537 (0x10001) X509v3 extensions: X509v3 Basic Constraints: critical CA:FALSE X509v3 CRL Distribution Points: Full Name: URI:http://crl.thawte.com/ThawteServerPremiumCA.crl X509v3 Extended Key Usage: TLS Web Server Authentication, TLS Web Client Authentication Authority Information Access: OCSP - URI:http://ocsp.thawte.com Signature Algorithm: sha1WithRSAEncryption and $ openssl x509 -in sso-new.cer -text shows Data: Version: 3 (0x2) Signature Algorithm: sha1WithRSAEncryption Issuer: C=US, O=Internet2, OU=InCommon, CN=InCommon Server CA Validity Not Before: Nov 8 00:00:00 2012 GMT Not After : Nov 8 23:59:59 2014 GMT Subject Public Key Info: Public Key Algorithm: rsaEncryption Public-Key: (2048 bit) Modulus: Exponent: 65537 (0x10001) X509v3 extensions: X509v3 Authority Key Identifier: keyid:48:4F:5A:FA:2F:4A:9A:5E:E0:50:F3:6B:7B:55:A5:DE:F5:BE:34:5D X509v3 Subject Key Identifier: 18:8D:F6:F5:87:4D:C4:08:7B:2B:3F:02:A1:C7:AC:6D:A7:90:93:02 X509v3 Key Usage: critical Digital Signature, Key Encipherment X509v3 Basic Constraints: critical CA:FALSE X509v3 Extended Key Usage: TLS Web Server Authentication, TLS Web Client Authentication X509v3 Certificate Policies: Policy: 1.3.6.1.4.1.5923.1.4.3.1.1 CPS: https://www.incommon.org/cert/repository/cps_ssl.pdf X509v3 CRL Distribution Points: Full Name: URI:http://crl.incommon.org/InCommonServerCA.crl Authority Information Access: CA Issuers - URI:http://cert.incommon.org/InCommonServerCA.crt OCSP - URI:http://ocsp.incommon.org Nothing jumps out at me as the reason one would not work so I don't have a specific request for the signer for what to do differently when re-signing.

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• how to setup .ssh directory inside an encrypted volume on Mac OSX and still have public key logins?

  - by Vitaly Kushner

  I have my .ssh directory inside an encrypted sparse image. i.e. ~/.ssh is a symlink to /Volumes/VolumeName/.ssh The problem is that when I try to ssh into that machine using a public key I see the following error message in /var/log/secure.log: Authentication refused: bad ownership or modes for directory /Volumes Any way to solve this in a clean way? Update: The permissions on ~/.ssh and authorized_keys are right: > ls -ld ~ drwxr-xr-x+ 77 vitaly staff 2618 Mar 16 08:22 /Users/vitaly/ > ls -l ~/.ssh lrwxr-xr-x 1 vitaly staff 22 Mar 15 23:48 /Users/vitaly/.ssh@ -> /Volumes/Astrails/.ssh > ls -ld /Volumes/Astrails/.ssh drwx------ 3 vitaly staff 646 Mar 15 23:46 /Volumes/Astrails/.ssh/ > ls -ld /Volumes/Astrails/ drwx--x--x@ 18 vitaly staff 1360 Jan 12 22:05 /Volumes/Astrails// > ls -ld /Volumes/ drwxrwxrwt@ 5 root admin 170 Mar 15 20:38 /Volumes// error message sats the problem is with /Volumes, but I don't see the problem. Yes it is o+w but it is also +t which should be ok but apparently isn't. The problem is I can't change /Volumes permissions (or rather shouldn't) but I do want public key login to work. First I thought of mounting the image on other place then /Volumes, but it is automaunted on login by standard OSX mounting. I asked about it here: How to change disk image's default mount directory on osx The only answer I got is "you can't" ;) I could hack my way around, by writing some shellscript that will manually mounting volume at a non-standard location but it would be a gross hack, I'm still looking for a cleaner way to do what I need.

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• Why does key-based ssh fail even after setting up the authorized_keys file on the remote host?

  - by Brad Grissom

  These details don't matter but I am on a Ubuntu 12.04 machine and I want to ssh into my RaspberryPi without a password. I followed the standard procedure for setting up ssh without a password: local $ ssh-keygen -t rsa (hit enter for defaults to the questions) local $ scp ~/.ssh/id_rsa.pub matt@raspihost:~/.ssh/authorized_keys I logged onto the raspihost and checked all my permissions on ~/.ssh/ and on the authorized_keys file itself. It was still not working!

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• I want to master ASP.NET - What concepts should I focus on/What concepts do you most value?

  - by Josh

  I start a job this summer doing work in ASP.NET 4 (C#). I plan on working with some legacy code as well as MVC. I want to get a running start. I have good understanding of HTML/CSS/Javascript, and pretty good understanding of C# itself, Design principles, Design Patterns, and understand masterpages, basic MVC2, and code behinds for web forms. In your opinion what aspects of ASP.NET are the most important to master for web applications? What do you value most in your usage of ASP.NET? Do you have a recommendation for understanding the internals of ASP.NET itself?

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• Javascript Date Range Validation

  Here is a Javascript function that will tell you if 2 dates make a valid date range. function isValidDateRange( objstartMonth,objstartDay, objstartYear, objendMonth,objendDay, objendYear) { var startDate = new Date(objstartYear.options[objstartYear.selectedIndex].value, objstartMonth.options[objstartMonth.selectedIndex].value, objstartDay.options[objstartDay.selectedIndex].value); var endDate = new Date(objendYear.options[objendYear.selectedIndex].value, objendMonth.options[objendMonth.selectedIndex].value, objendDay.options[objendDay.selectedIndex].value); if (startDate >= endDate){ alert("Invaild Date Range"); return false; } else{ return true; } }

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• How does one remove an encryption type from a kerberos principal?

  - by 84104

  I would like to remove all of the des keys from the principal below, but have no idea how to do so without someone inputting the password. kadmin: getprinc user Principal: [email protected] Expiration date: [never] Last password change: Thu May 26 08:52:51 PDT 2013 Password expiration date: [none] Maximum ticket life: 0 days 12:00:00 Maximum renewable life: 7 days 00:00:00 Last modified: Tue Jul 16 15:17:18 PDT 2013 (administrator/[email protected]) Last successful authentication: Wed Jul 24 14:40:53 PDT 2013 Last failed authentication: [never] Failed password attempts: 0 Number of keys: 8 Key: vno 3, aes256-cts-hmac-sha1-96, no salt Key: vno 3, arcfour-hmac, no salt Key: vno 3, des3-cbc-sha1, no salt Key: vno 3, des-cbc-crc, no salt Key: vno 3, des-cbc-md5, no salt Key: vno 3, des-cbc-md5, Version 5 - No Realm Key: vno 3, des-cbc-md5, Version 5 - Realm Only Key: vno 3, des-cbc-md5, AFS version 3 MKey: vno 2 Attributes: REQUIRES_PRE_AUTH Policy: [none] Also, the the kdc is using an OpenLDAP backend.

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• C#/.NET Little Wonders: Interlocked CompareExchange()

  - by James Michael Hare

  Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. Two posts ago, I discussed the Interlocked Add(), Increment(), and Decrement() methods (here) for adding and subtracting values in a thread-safe, lightweight manner.  Then, last post I talked about the Interlocked Read() and Exchange() methods (here) for safely and efficiently reading and setting 32 or 64 bit values (or references).  This week, we’ll round out the discussion by talking about the Interlocked CompareExchange() method and how it can be put to use to exchange a value if the current value is what you expected it to be. Dirty reads can lead to bad results Many of the uses of Interlocked that we’ve explored so far have centered around either reading, setting, or adding values.  But what happens if you want to do something more complex such as setting a value based on the previous value in some manner? Perhaps you were creating an application that reads a current balance, applies a deposit, and then saves the new modified balance, where of course you’d want that to happen atomically.  If you read the balance, then go to save the new balance and between that time the previous balance has already changed, you’ll have an issue!  Think about it, if we read the current balance as $400, and we are applying a new deposit of $50.75, but meanwhile someone else deposits $200 and sets the total to $600, but then we write a total of $450.75 we’ve lost $200! Now, certainly for int and long values we can use Interlocked.Add() to handles these cases, and it works well for that.  But what if we want to work with doubles, for example?  Let’s say we wanted to add the numbers from 0 to 99,999 in parallel.  We could do this by spawning several parallel tasks to continuously add to a total: 1: double total = 0; 2:  3: Parallel.For(0, 10000, next => 4: { 5: total += next; 6: }); Were this run on one thread using a standard for loop, we’d expect an answer of 4,999,950,000 (the sum of all numbers from 0 to 99,999).  But when we run this in parallel as written above, we’ll likely get something far off.  The result of one of my runs, for example, was 1,281,880,740.  That is way off!  If this were banking software we’d be in big trouble with our clients.  So what happened?  The += operator is not atomic, it will read in the current value, add the result, then store it back into the total.  At any point in all of this another thread could read a “dirty” current total and accidentally “skip” our add.   So, to clean this up, we could use a lock to guarantee concurrency: 1: double total = 0.0; 2: object locker = new object(); 3:  4: Parallel.For(0, count, next => 5: { 6: lock (locker) 7: { 8: total += next; 9: } 10: }); Which will give us the correct result of 4,999,950,000.  One thing to note is that locking can be heavy, especially if the operation being locked over is trivial, or the life of the lock is a high percentage of the work being performed concurrently.  In the case above, the lock consumes pretty much all of the time of each parallel task – and the task being locked on is relatively trivial. Now, let me put in a disclaimer here before we go further: For most uses, lock is more than sufficient for your needs, and is often the simplest solution!    So, if lock is sufficient for most needs, why would we ever consider another solution?  The problem with locking is that it can suspend execution of your thread while it waits for the signal that the lock is free.  Moreover, if the operation being locked over is trivial, the lock can add a very high level of overhead.  This is why things like Interlocked.Increment() perform so well, instead of locking just to perform an increment, we perform the increment with an atomic, lockless method. As with all things performance related, it’s important to profile before jumping to the conclusion that you should optimize everything in your path.  If your profiling shows that locking is causing a high level of waiting in your application, then it’s time to consider lighter alternatives such as Interlocked. CompareExchange() – Exchange existing value if equal some value So let’s look at how we could use CompareExchange() to solve our problem above.  The general syntax of CompareExchange() is: T CompareExchange<T>(ref T location, T newValue, T expectedValue) If the value in location == expectedValue, then newValue is exchanged.  Either way, the value in location (before exchange) is returned. Actually, CompareExchange() is not one method, but a family of overloaded methods that can take int, long, float, double, pointers, or references.  It cannot take other value types (that is, can’t CompareExchange() two DateTime instances directly).  Also keep in mind that the version that takes any reference type (the generic overload) only checks for reference equality, it does not call any overridden Equals(). So how does this help us?  Well, we can grab the current total, and exchange the new value if total hasn’t changed.  This would look like this: 1: // grab the snapshot 2: double current = total; 3:  4: // if the total hasn’t changed since I grabbed the snapshot, then 5: // set it to the new total 6: Interlocked.CompareExchange(ref total, current + next, current); So what the code above says is: if the amount in total (1st arg) is the same as the amount in current (3rd arg), then set total to current + next (2nd arg).  This check and exchange pair is atomic (and thus thread-safe). This works if total is the same as our snapshot in current, but the problem, is what happens if they aren’t the same?  Well, we know that in either case we will get the previous value of total (before the exchange), back as a result.  Thus, we can test this against our snapshot to see if it was the value we expected: 1: // if the value returned is != current, then our snapshot must be out of date 2: // which means we didn't (and shouldn't) apply current + next 3: if (Interlocked.CompareExchange(ref total, current + next, current) != current) 4: { 5: // ooops, total was not equal to our snapshot in current, what should we do??? 6: } So what do we do if we fail?  That’s up to you and the problem you are trying to solve.  It’s possible you would decide to abort the whole transaction, or perhaps do a lightweight spin and try again.  Let’s try that: 1: double current = total; 2:  3: // make first attempt... 4: if (Interlocked.CompareExchange(ref total, current + i, current) != current) 5: { 6: // if we fail, go into a spin wait, spin, and try again until succeed 7: var spinner = new SpinWait(); 8:  9: do 10: { 11: spinner.SpinOnce(); 12: current = total; 13: } 14: while (Interlocked.CompareExchange(ref total, current + i, current) != current); 15: } 16:  This is not trivial code, but it illustrates a possible use of CompareExchange().  What we are doing is first checking to see if we succeed on the first try, and if so great!  If not, we create a SpinWait and then repeat the process of SpinOnce(), grab a fresh snapshot, and repeat until CompareExchnage() succeeds.  You may wonder why not a simple do-while here, and the reason it’s more efficient to only create the SpinWait until we absolutely know we need one, for optimal efficiency. Though not as simple (or maintainable) as a simple lock, this will perform better in many situations.  Comparing an unlocked (and wrong) version, a version using lock, and the Interlocked of the code, we get the following average times for multiple iterations of adding the sum of 100,000 numbers: 1: Unlocked money average time: 2.1 ms 2: Locked money average time: 5.1 ms 3: Interlocked money average time: 3 ms So the Interlocked.CompareExchange(), while heavier to code, came in lighter than the lock, offering a good compromise of safety and performance when we need to reduce contention. CompareExchange() - it’s not just for adding stuff… So that was one simple use of CompareExchange() in the context of adding double values -- which meant we couldn’t have used the simpler Interlocked.Add() -- but it has other uses as well. If you think about it, this really works anytime you want to create something new based on a current value without using a full lock.  For example, you could use it to create a simple lazy instantiation implementation.  In this case, we want to set the lazy instance only if the previous value was null: 1: public static class Lazy<T> where T : class, new() 2: { 3: private static T _instance; 4:  5: public static T Instance 6: { 7: get 8: { 9: // if current is null, we need to create new instance 10: if (_instance == null) 11: { 12: // attempt create, it will only set if previous was null 13: Interlocked.CompareExchange(ref _instance, new T(), (T)null); 14: } 15:  16: return _instance; 17: } 18: } 19: } So, if _instance == null, this will create a new T() and attempt to exchange it with _instance.  If _instance is not null, then it does nothing and we discard the new T() we created. This is a way to create lazy instances of a type where we are more concerned about locking overhead than creating an accidental duplicate which is not used.  In fact, the BCL implementation of Lazy<T> offers a similar thread-safety choice for Publication thread safety, where it will not guarantee only one instance was created, but it will guarantee that all readers get the same instance.  Another possible use would be in concurrent collections.  Let’s say, for example, that you are creating your own brand new super stack that uses a linked list paradigm and is “lock free”.  We could use Interlocked.CompareExchange() to be able to do a lockless Push() which could be more efficient in multi-threaded applications where several threads are pushing and popping on the stack concurrently. Yes, there are already concurrent collections in the BCL (in .NET 4.0 as part of the TPL), but it’s a fun exercise!  So let’s assume we have a node like this: 1: public sealed class Node<T> 2: { 3: // the data for this node 4: public T Data { get; set; } 5:  6: // the link to the next instance 7: internal Node<T> Next { get; set; } 8: } Then, perhaps, our stack’s Push() operation might look something like: 1: public sealed class SuperStack<T> 2: { 3: private volatile T _head; 4:  5: public void Push(T value) 6: { 7: var newNode = new Node<int> { Data = value, Next = _head }; 8:  9: if (Interlocked.CompareExchange(ref _head, newNode, newNode.Next) != newNode.Next) 10: { 11: var spinner = new SpinWait(); 12:  13: do 14: { 15: spinner.SpinOnce(); 16: newNode.Next = _head; 17: } 18: while (Interlocked.CompareExchange(ref _head, newNode, newNode.Next) != newNode.Next); 19: } 20: } 21:  22: // ... 23: } Notice a similar paradigm here as with adding our doubles before.  What we are doing is creating the new Node with the data to push, and with a Next value being the original node referenced by _head.  This will create our stack behavior (LIFO – Last In, First Out).  Now, we have to set _head to now refer to the newNode, but we must first make sure it hasn’t changed! So we check to see if _head has the same value we saved in our snapshot as newNode.Next, and if so, we set _head to newNode.  This is all done atomically, and the result is _head’s original value, as long as the original value was what we assumed it was with newNode.Next, then we are good and we set it without a lock!  If not, we SpinWait and try again. Once again, this is much lighter than locking in highly parallelized code with lots of contention.  If I compare the method above with a similar class using lock, I get the following results for pushing 100,000 items: 1: Locked SuperStack average time: 6 ms 2: Interlocked SuperStack average time: 4.5 ms So, once again, we can get more efficient than a lock, though there is the cost of added code complexity.  Fortunately for you, most of the concurrent collection you’d ever need are already created for you in the System.Collections.Concurrent (here) namespace – for more information, see my Little Wonders – The Concurent Collections Part 1 (here), Part 2 (here), and Part 3 (here). Summary We’ve seen before how the Interlocked class can be used to safely and efficiently add, increment, decrement, read, and exchange values in a multi-threaded environment.  In addition to these, Interlocked CompareExchange() can be used to perform more complex logic without the need of a lock when lock contention is a concern. The added efficiency, though, comes at the cost of more complex code.  As such, the standard lock is often sufficient for most thread-safety needs.  But if profiling indicates you spend a lot of time waiting for locks, or if you just need a lock for something simple such as an increment, decrement, read, exchange, etc., then consider using the Interlocked class’s methods to reduce wait. Technorati Tags: C#,CSharp,.NET,Little Wonders,Interlocked,CompareExchange,threading,concurrency

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