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• Returning Identity Value in SQL Server: @@IDENTITY Vs SCOPE_IDENTITY Vs IDENT_CURRENT

  - by Arefin Ali

  We have some common misconceptions on returning the last inserted identity value from tables. To return the last inserted identity value we have options to use @@IDENTITY or SCOPE_IDENTITY or IDENT_CURRENT function depending on the requirement but it will be a real mess if anybody uses anyone of these functions without knowing exact purpose. So here I want to share my thoughts on this. @@IDENTITY, SCOPE_IDENTITY and IDENT_CURRENT are almost similar functions in terms of returning identity value. They all return values that are inserted into an identity column. Earlier in SQL Server 7 we used to use @@IDENTITY to return the last inserted identity value because those days we don’t have functions like SCOPE_IDENTITY or IDENT_CURRENT but now we have these three functions. So let’s check out which one responsible for what. IDENT_CURRENT returns the last inserted identity value in a particular table. It never depends on a connection or the scope of the insert statement. IDENT_CURRENT function takes a table name as parameter. Here is the syntax to get the last inserted identity value in a particular table using IDENT_CURRENT function. SELECT IDENT_CURRENT('Employee') Both the @@IDENTITY and SCOPE_IDENTITY return the last inserted identity value created in any table in the current session. But there is little difference between these two i.e. SCOPE_IDENTITY returns value inserted only within the current scope whereas @@IDENTITY is not limited to any particular scope. Here are the syntaxes to get the last inserted identity value using these functions SELECT @@IDENTITY SELECT SCOPE_IDENTITY() Now let’s have a look at the following example. Suppose I have two tables called Employee and EmployeeLog. CREATE TABLE Employee ( EmpId NUMERIC(18, 0) IDENTITY(1,1) NOT NULL, EmpName VARCHAR(100) NOT NULL, EmpSal FLOAT NOT NULL, DateOfJoining DATETIME NOT NULL DEFAULT(GETDATE()) ) CREATE TABLE EmployeeLog ( EmpId NUMERIC(18, 0) IDENTITY(1,1) NOT NULL, EmpName VARCHAR(100) NOT NULL, EmpSal FLOAT NOT NULL, DateOfJoining DATETIME NOT NULL DEFAULT(GETDATE()) ) I have an insert trigger defined on the table Employee which inserts a new record in the EmployeeLog whenever a record insert in the Employee table. So Suppose I insert a new record in the Employee table using following statement: INSERT INTO Employee (EmpName,EmpSal) VALUES ('Arefin','1') The trigger will be fired automatically and insert a record in EmployeeLog. Here the scope of the insert statement and the trigger are different. In this situation if I retrieve last inserted identity value using @@IDENTITY, it will simply return the identity value from the EmployeeLog because it’s not limited to a particular scope. Now if I want to get the Employee table’s identity value then I need to use SCOPE_IDENTITY in this scenario. So the moral is always use SCOPE_IDENTITY to return the identity value of a recently created record in a sql statement or stored procedure. It’s safe and ensures bug free code.

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• Returning Identity Value in SQL Server: @@IDENTITY Vs SCOPE_IDENTITY Vs IDENT_CURRENT

  - by Arefin Ali

  We have some common misconceptions on returning the last inserted identity value from tables. To return the last inserted identity value we have options to use @@IDENTITY or SCOPE_IDENTITY or IDENT_CURRENT function depending on the requirement but it will be a real mess if anybody uses anyone of these functions without knowing exact purpose. So here I want to share my thoughts on this. @@IDENTITY, SCOPE_IDENTITY and IDENT_CURRENT are almost similar functions in terms of returning identity value. They all return values that are inserted into an identity column. Earlier in SQL Server 7 we used to use @@IDENTITY to return the last inserted identity value because those days we don’t have functions like SCOPE_IDENTITY or IDENT_CURRENT but now we have these three functions. So let’s check out which one responsible for what. IDENT_CURRENT returns the last inserted identity value in a particular table. It never depends on a connection or the scope of the insert statement. IDENT_CURRENT function takes a table name as parameter. Here is the syntax to get the last inserted identity value in a particular table using IDENT_CURRENT function. SELECT IDENT_CURRENT('Employee') Both the @@IDENTITY and SCOPE_IDENTITY return the last inserted identity value created in any table in the current session. But there is little difference between these two i.e. SCOPE_IDENTITY returns value inserted only within the current scope whereas @@IDENTITY is not limited to any particular scope. Here are the syntaxes to get the last inserted identity value using these functions SELECT @@IDENTITYSELECT SCOPE_IDENTITY() Now let’s have a look at the following example. Suppose I have two tables called Employee and EmployeeLog. CREATE TABLE Employee( EmpId NUMERIC(18, 0) IDENTITY(1,1) NOT NULL, EmpName VARCHAR(100) NOT NULL, EmpSal FLOAT NOT NULL, DateOfJoining DATETIME NOT NULL DEFAULT(GETDATE()))CREATE TABLE EmployeeLog( EmpId NUMERIC(18, 0) IDENTITY(1,1) NOT NULL, EmpName VARCHAR(100) NOT NULL, EmpSal FLOAT NOT NULL, DateOfJoining DATETIME NOT NULL DEFAULT(GETDATE())) I have an insert trigger defined on the table Employee which inserts a new record in the EmployeeLog whenever a record insert in the Employee table. So Suppose I insert a new record in the Employee table using following statement: INSERT INTO Employee (EmpName,EmpSal) VALUES ('Arefin','1') The trigger will be fired automatically and insert a record in EmployeeLog. Here the scope of the insert statement and the trigger are different. In this situation if I retrieve last inserted identity value using @@IDENTITY, it will simply return the identity value from the EmployeeLog because it’s not limited to a particular scope. Now if I want to get the Employee table’s identity value then I need to use SCOPE_IDENTITY in this scenario. So the moral is always use SCOPE_IDENTITY to return the identity value of a recently created record in a sql statement or stored procedure. It’s safe and ensures bug free code.

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• How to (un)dock IBM Thinkpad X41 from X4 Dock(ing station) successfully?

  - by nutty about natty

  I'd like to start using my docking station again; however, it still doesn't work as it should, see the following bug descriptions (with special focus on Thinkpad X41 & the X4 Dock). Given that it still doesn't work (effective April 2012), my hope is fading that it will start working all of a sudden with Precise Pangolin at the end of the month. This issue is VERY important to me and I would be MOST grateful to anyone being able to sieve through the following links (some of which are actually quite recent) and translate their meaning into reliable and concrete simple (?) steps. I've read briefly about hal and udev, and can imagine that they are somewhat related to this, see links below. I don't want to fire at random. I don't want to tinker around with bash scripts if avoidable... Problem description (more or less ;-) Pressing the undock button on a "ThinkPad X4 Dock" with a ThinkPad X40 does not cause any udev events. And the lights on the dock never change to indicate it is safe to undock. and IBM Thinkpad X41 & docking station no joy :-( ... when pressing the blue undock button on the docking station: - The screen goes blank (with backlight remaining on), - with some SSD/HDD activity; - ctrl alt del causes a shut down after ... seconds, indicating that the system itself hasn't "crashed" but is still (somewhat ?) responsive. and With recent distributions, docking and undocking should function out of the box. You can monitor this by running # udevadm monitor and when you dock or press the undock button you should see a flurry of events. There are some issues though: No event on undock. - In some cases you may not get any events on undock. This is due to the ACPI dock drivers only registering the first logical Dock port they encounter and in some rare cases there may be more then one, such as on a ThinkPad X40 with ThinkPad X4 Dock. Patches are available, and are merged in 2.6.34. Now, if patches are available and merged into 2.6.34 - why isn't (un)docking simply working / fully supported in the latest version of Natty (which to my humble understanding has surpassed kernel version 2.6.34 a while ago)? More relevant links: ThinkPad X41 Docking Station issues and [HOWTO] Run scripts for laptop lid open/close and dock/undock events and finally Symptoms corrected by the latest BIOS Update - ThinkPad X41 - (Fix) USB devices connected to UltraBase X4 or ThinkPad X4 Dock may not be recognized in Boot Menu by pressing F12 during POST. Thanks!!

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• AspNetCompatibility in WCF Services &ndash; easy to trip up

  - by Rick Strahl

  This isn’t the first time I’ve hit this particular wall: I’m creating a WCF REST service for AJAX callbacks and using the WebScriptServiceHostFactory host factory in the service: <%@ ServiceHost Language="C#" Service="WcfAjax.BasicWcfService" CodeBehind="BasicWcfService.cs" Factory="System.ServiceModel.Activation.WebScriptServiceHostFactory" %>   to avoid all configuration. Because of the Factory that creates the ASP.NET Ajax compatible format via the custom factory implementation I can then remove all of the configuration settings that typically get dumped into the web.config file. However, I do want ASP.NET compatibility so I still leave in: <system.serviceModel> <serviceHostingEnvironment aspNetCompatibilityEnabled="true"/> </system.serviceModel> in the web.config file. This option allows you access to the HttpContext.Current object to effectively give you access to most of the standard ASP.NET request and response features. This is not recommended as a primary practice but it can be useful in some scenarios and in backwards compatibility scenerios with ASP.NET AJAX Web Services. Now, here’s where things get funky. Assuming you have the setting in web.config, If you now declare a service like this: [ServiceContract(Namespace = "DevConnections")] #if DEBUG [ServiceBehavior(IncludeExceptionDetailInFaults = true)] #endif public class BasicWcfService (or by using an interface that defines the service contract) you’ll find that the service will not work when an AJAX call is made against it. You’ll get a 500 error and a System.ServiceModel.ServiceActivationException System error. Worse even with the IncludeExceptionDetailInFaults enabled you get absolutely no indication from WCF what the problem is. So what’s the problem?  The issue is that once you specify aspNetCompatibilityEnabled=”true” in the configuration you *have to* specify the AspNetCompatibilityRequirements attribute and one of the modes that enables or at least allows for it. You need either Required or Allow: [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Required)] without it the service will simply fail without further warning. It will also fail if you set the attribute value to NotAllowed. The following also causes the service to fail as above: [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.NotAllowed)] This is not totally unreasonable but it’s a difficult issue to debug especially since the configuration setting is global – if you have more than one service and one requires traditional ASP.NET access and one doesn’t then both must have the attribute specified. This is one reason why you’d want to avoid using this functionality unless absolutely necessary. WCF REST provides some basic access to some of the HTTP features after all, although what’s there is severely limited. I also wish that ServiceActivation errors would provide more error information. Getting an Activation error without further info on what actually is wrong is pretty worthless especially when it is a technicality like a mismatched configuration/attribute setting like this.© Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  WCF  AJAX  

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• Running a simple integration scenario using the Oracle Big Data Connectors on Hadoop/HDFS cluster

  - by hamsun

  Between the elephant ( the tradional image of the Hadoop framework) and the Oracle Iron Man (Big Data..) an english setter could be seen as the link to the right data Data, Data, Data, we are living in a world where data technology based on popular applications , search engines, Webservers, rich sms messages, email clients, weather forecasts and so on, have a predominant role in our life. More and more technologies are used to analyze/track our behavior, try to detect patterns, to propose us "the best/right user experience" from the Google Ad services, to Telco companies or large consumer sites (like Amazon:) ). The more we use all these technologies, the more we generate data, and thus there is a need of huge data marts and specific hardware/software servers (as the Exadata servers) in order to treat/analyze/understand the trends and offer new services to the users. Some of these "data feeds" are raw, unstructured data, and cannot be processed effectively by normal SQL queries. Large scale distributed processing was an emerging infrastructure need and the solution seemed to be the "collocation of compute nodes with the data", which in turn leaded to MapReduce parallel patterns and the development of the Hadoop framework, which is based on MapReduce and a distributed file system (HDFS) that runs on larger clusters of rather inexpensive servers. Several Oracle products are using the distributed / aggregation pattern for data calculation ( Coherence, NoSql, times ten ) so once that you are familiar with one of these technologies, lets says with coherence aggregators, you will find the whole Hadoop, MapReduce concept very similar. Oracle Big Data Appliance is based on the Cloudera Distribution (CDH), and the Oracle Big Data Connectors can be plugged on a Hadoop cluster running the CDH distribution or equivalent Hadoop clusters. In this paper, a "lab like" implementation of this concept is done on a single Linux X64 server, running an Oracle Database 11g Enterprise Edition Release 11.2.0.4.0, and a single node Apache hadoop-1.2.1 HDFS cluster, using the SQL connector for HDFS. The whole setup is fairly simple: Install on a Linux x64 server ( or virtual box appliance) an Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 server Get the Apache Hadoop distribution from: http://mir2.ovh.net/ftp.apache.org/dist/hadoop/common/hadoop-1.2.1. Get the Oracle Big Data Connectors from: http://www.oracle.com/technetwork/bdc/big-data-connectors/downloads/index.html?ssSourceSiteId=ocomen. Check the java version of your Linux server with the command: java -version java version "1.7.0_40" Java(TM) SE Runtime Environment (build 1.7.0_40-b43) Java HotSpot(TM) 64-Bit Server VM (build 24.0-b56, mixed mode) Decompress the hadoop hadoop-1.2.1.tar.gz file to /u01/hadoop-1.2.1 Modify your .bash_profile export HADOOP_HOME=/u01/hadoop-1.2.1 export PATH=$PATH:$HADOOP_HOME/bin export HIVE_HOME=/u01/hive-0.11.0 export PATH=$PATH:$HADOOP_HOME/bin:$HIVE_HOME/bin (also see my sample .bash_profile) Set up ssh trust for Hadoop process, this is a mandatory step, in our case we have to establish a "local trust" as will are using a single node configuration copy the new public keys to the list of authorized keys connect and test the ssh setup to your localhost: We will run a "pseudo-Hadoop cluster", in what is called "local standalone mode", all the Hadoop java components are running in one Java process, this is enough for our demo purposes. We need to "fine tune" some Hadoop configuration files, we have to go at our $HADOOP_HOME/conf, and modify the files: core-site.xml hdfs-site.xml mapred-site.xml check that the hadoop binaries are referenced correctly from the command line by executing: hadoop -version As Hadoop is managing our "clustered HDFS" file system we have to create "the mount point" and format it , the mount point will be declared to core-site.xml as: The layout under the /u01/hadoop-1.2.1/data will be created and used by other hadoop components (MapReduce = /mapred/...) HDFS is using the /dfs/... layout structure format the HDFS hadoop file system: Start the java components for the HDFS system As an additional check, you can use the GUI Hadoop browsers to check the content of your HDFS configurations: Once our HDFS Hadoop setup is done you can use the HDFS file system to store data ( big data : )), and plug them back and forth to Oracle Databases by the means of the Big Data Connectors ( which is the next configuration step). You can create / use a Hive db, but in our case we will make a simple integration of "raw data" , through the creation of an External Table to a local Oracle instance ( on the same Linux box, we run the Hadoop HDFS one node cluster and one Oracle DB). Download some public "big data", I use the site: http://france.meteofrance.com/france/observations, from where I can get *.csv files for my big data simulations :). Here is the data layout of my example file: Download the Big Data Connector from the OTN (oraosch-2.2.0.zip), unzip it to your local file system (see picture below) Modify your environment in order to access the connector libraries , and make the following test: [oracle@dg1 bin]$./hdfs_stream Usage: hdfs_stream locationFile [oracle@dg1 bin]$ Load the data to the Hadoop hdfs file system: hadoop fs -mkdir bgtest_data hadoop fs -put obsFrance.txt bgtest_data/obsFrance.txt hadoop fs -ls /user/oracle/bgtest_data/obsFrance.txt [oracle@dg1 bg-data-raw]$ hadoop fs -ls /user/oracle/bgtest_data/obsFrance.txt Found 1 items -rw-r--r-- 1 oracle supergroup 54103 2013-10-22 06:10 /user/oracle/bgtest_data/obsFrance.txt [oracle@dg1 bg-data-raw]$hadoop fs -ls hdfs:///user/oracle/bgtest_data/obsFrance.txt Found 1 items -rw-r--r-- 1 oracle supergroup 54103 2013-10-22 06:10 /user/oracle/bgtest_data/obsFrance.txt Check the content of the HDFS with the browser UI: Start the Oracle database, and run the following script in order to create the Oracle database user, the Oracle directories for the Oracle Big Data Connector (dg1 it’s my own db id replace accordingly yours): #!/bin/bash export ORAENV_ASK=NO export ORACLE_SID=dg1 . oraenv sqlplus /nolog <<EOF CONNECT / AS sysdba; CREATE OR REPLACE DIRECTORY osch_bin_path AS '/u01/orahdfs-2.2.0/bin'; CREATE USER BGUSER IDENTIFIED BY oracle; GRANT CREATE SESSION, CREATE TABLE TO BGUSER; GRANT EXECUTE ON sys.utl_file TO BGUSER; GRANT READ, EXECUTE ON DIRECTORY osch_bin_path TO BGUSER; CREATE OR REPLACE DIRECTORY BGT_LOG_DIR as '/u01/BG_TEST/logs'; GRANT READ, WRITE ON DIRECTORY BGT_LOG_DIR to BGUSER; CREATE OR REPLACE DIRECTORY BGT_DATA_DIR as '/u01/BG_TEST/data'; GRANT READ, WRITE ON DIRECTORY BGT_DATA_DIR to BGUSER; EOF Put the following in a file named t3.sh and make it executable, hadoop jar $OSCH_HOME/jlib/orahdfs.jar \ oracle.hadoop.exttab.ExternalTable \ -D oracle.hadoop.exttab.tableName=BGTEST_DP_XTAB \ -D oracle.hadoop.exttab.defaultDirectory=BGT_DATA_DIR \ -D oracle.hadoop.exttab.dataPaths="hdfs:///user/oracle/bgtest_data/obsFrance.txt" \ -D oracle.hadoop.exttab.columnCount=7 \ -D oracle.hadoop.connection.url=jdbc:oracle:thin:@//localhost:1521/dg1 \ -D oracle.hadoop.connection.user=BGUSER \ -D oracle.hadoop.exttab.printStackTrace=true \ -createTable --noexecute then test the creation fo the external table with it: [oracle@dg1 samples]$ ./t3.sh ./t3.sh: line 2: /u01/orahdfs-2.2.0: Is a directory Oracle SQL Connector for HDFS Release 2.2.0 - Production Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved. Enter Database Password:] The create table command was not executed. The following table would be created. CREATE TABLE "BGUSER"."BGTEST_DP_XTAB" ( "C1" VARCHAR2(4000), "C2" VARCHAR2(4000), "C3" VARCHAR2(4000), "C4" VARCHAR2(4000), "C5" VARCHAR2(4000), "C6" VARCHAR2(4000), "C7" VARCHAR2(4000) ) ORGANIZATION EXTERNAL ( TYPE ORACLE_LOADER DEFAULT DIRECTORY "BGT_DATA_DIR" ACCESS PARAMETERS ( RECORDS DELIMITED BY 0X'0A' CHARACTERSET AL32UTF8 STRING SIZES ARE IN CHARACTERS PREPROCESSOR "OSCH_BIN_PATH":'hdfs_stream' FIELDS TERMINATED BY 0X'2C' MISSING FIELD VALUES ARE NULL ( "C1" CHAR(4000), "C2" CHAR(4000), "C3" CHAR(4000), "C4" CHAR(4000), "C5" CHAR(4000), "C6" CHAR(4000), "C7" CHAR(4000) ) ) LOCATION ( 'osch-20131022081035-74-1' ) ) PARALLEL REJECT LIMIT UNLIMITED; The following location files would be created. osch-20131022081035-74-1 contains 1 URI, 54103 bytes 54103 hdfs://localhost:19000/user/oracle/bgtest_data/obsFrance.txt Then remove the --noexecute flag and create the external Oracle table for the Hadoop data. Check the results: The create table command succeeded. CREATE TABLE "BGUSER"."BGTEST_DP_XTAB" ( "C1" VARCHAR2(4000), "C2" VARCHAR2(4000), "C3" VARCHAR2(4000), "C4" VARCHAR2(4000), "C5" VARCHAR2(4000), "C6" VARCHAR2(4000), "C7" VARCHAR2(4000) ) ORGANIZATION EXTERNAL ( TYPE ORACLE_LOADER DEFAULT DIRECTORY "BGT_DATA_DIR" ACCESS PARAMETERS ( RECORDS DELIMITED BY 0X'0A' CHARACTERSET AL32UTF8 STRING SIZES ARE IN CHARACTERS PREPROCESSOR "OSCH_BIN_PATH":'hdfs_stream' FIELDS TERMINATED BY 0X'2C' MISSING FIELD VALUES ARE NULL ( "C1" CHAR(4000), "C2" CHAR(4000), "C3" CHAR(4000), "C4" CHAR(4000), "C5" CHAR(4000), "C6" CHAR(4000), "C7" CHAR(4000) ) ) LOCATION ( 'osch-20131022081719-3239-1' ) ) PARALLEL REJECT LIMIT UNLIMITED; The following location files were created. osch-20131022081719-3239-1 contains 1 URI, 54103 bytes 54103 hdfs://localhost:19000/user/oracle/bgtest_data/obsFrance.txt This is the view from the SQL Developer: and finally the number of lines in the oracle table, imported from our Hadoop HDFS cluster SQL select count(*) from "BGUSER"."BGTEST_DP_XTAB"; COUNT(*) ---------- 1151 In a next post we will integrate data from a Hive database, and try some ODI integrations with the ODI Big Data connector. Our simplistic approach is just a step to show you how these unstructured data world can be integrated to Oracle infrastructure. Hadoop, BigData, NoSql are great technologies, they are widely used and Oracle is offering a large integration infrastructure based on these services. Oracle University presents a complete curriculum on all the Oracle related technologies: NoSQL: Introduction to Oracle NoSQL Database Using Oracle NoSQL Database Big Data: Introduction to Big Data Oracle Big Data Essentials Oracle Big Data Overview Oracle Data Integrator: Oracle Data Integrator 12c: New Features Oracle Data Integrator 11g: Integration and Administration Oracle Data Integrator: Administration and Development Oracle Data Integrator 11g: Advanced Integration and Development Oracle Coherence 12c: Oracle Coherence 12c: New Features Oracle Coherence 12c: Share and Manage Data in Clusters Oracle Coherence 12c: Oracle GoldenGate 11g: Fundamentals for Oracle Oracle GoldenGate 11g: Fundamentals for SQL Server Oracle GoldenGate 11g Fundamentals for Oracle Oracle GoldenGate 11g Fundamentals for DB2 Oracle GoldenGate 11g Fundamentals for Teradata Oracle GoldenGate 11g Fundamentals for HP NonStop Oracle GoldenGate 11g Management Pack: Overview Oracle GoldenGate 11g Troubleshooting and Tuning Oracle GoldenGate 11g: Advanced Configuration for Oracle Other Resources: Apache Hadoop : http://hadoop.apache.org/ is the homepage for these technologies. "Hadoop Definitive Guide 3rdEdition" by Tom White is a classical lecture for people who want to know more about Hadoop , and some active "googling " will also give you some more references. About the author: Eugene Simos is based in France and joined Oracle through the BEA-Weblogic Acquisition, where he worked for the Professional Service, Support, end Education for major accounts across the EMEA Region. He worked in the banking sector, ATT, Telco companies giving him extensive experience on production environments. Eugen currently specializes in Oracle Fusion Middleware teaching an array of courses on Weblogic/Webcenter, Content,BPM /SOA/Identity-Security/GoldenGate/Virtualisation/Unified Comm Suite) throughout the EMEA region.

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• ASP.NET Asynchronous Pages and when to use them

  - by rajbk

  There have been several articles posted about using  asynchronous pages in ASP.NET but none of them go into detail as to when you should use them. I finally found a great post by Thomas Marquardt that explains the process in depth. He addresses a key misconception also: So, in your ASP.NET application, when should you perform work asynchronously instead of synchronously? Well, only 1 thread per CPU can execute at a time.  Did you catch that?  A lot of people seem to miss this point...only one thread executes at a time on a CPU. When you have more than this, you pay an expensive penalty--a context switch. However, if a thread is blocked waiting on work...then it makes sense to switch to another thread, one that can execute now.  It also makes sense to switch threads if you want work to be done in parallel as opposed to in series, but up until a certain point it actually makes much more sense to execute work in series, again, because of the expensive context switch. Pop quiz: If you have a thread that is doing a lot of computational work and using the CPU heavily, and this takes a while, should you switch to another thread? No! The current thread is efficiently using the CPU, so switching will only incur the cost of a context switch. Ok, well, what if you have a thread that makes an HTTP or SOAP request to another server and takes a long time, should you switch threads? Yes! You can perform the HTTP or SOAP request asynchronously, so that once the "send" has occurred, you can unwind the current thread and not use any threads until there is an I/O completion for the "receive". Between the "send" and the "receive", the remote server is busy, so locally you don't need to be blocking on a thread, but instead make use of the asynchronous APIs provided in .NET Framework so that you can unwind and be notified upon completion. Again, it only makes sense to switch threads if the benefit from doing so out weights the cost of the switch. Read more about it in these posts: Performing Asynchronous Work, or Tasks, in ASP.NET Applications http://blogs.msdn.com/tmarq/archive/2010/04/14/performing-asynchronous-work-or-tasks-in-asp-net-applications.aspx ASP.NET Thread Usage on IIS 7.0 and 6.0 http://blogs.msdn.com/tmarq/archive/2007/07/21/asp-net-thread-usage-on-iis-7-0-and-6-0.aspx   PS: I generally do not write posts that simply link to other posts but think it is warranted in this case.

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• To File Share or to not File Share, that is the Question.

  To file share or to not file share, that is the question. The concept of the internet was developed in the 1960’s as a revolutionary idea to share information and data amongst a group of computers. The original concept was to allow universities and the United States Military share data for research and field operations. This network of computers was designed to provide redundant data storage and communications in case one or more locations were destroyed. Since the inception of the internet, people have attempted to use it for sharing data. As the Internet has evolved so did the users and the information they wanted to share. In today’s modern internet people can share information through various avenues, for example: websites, social networks, email, documents, executable files, data files and much more.  Unfortunately, as the internet and its users have grown, some industries have not paid attention. Currently, there are several industries that have really fallen behind in keeping up with current trends, and are severely paying the price for their lack of action. A current example of this is with the Recording Industry Association of America (RIAA) and file sharing. RIAA contends that customers who purchase music can only listen to the music and cannot share it with others. This can be seen when the RIAA sued Napster for distributing copyrighted music through a technology called file sharing. File sharing as defined by the Media Awareness Network is downloadable software that permits users to share music, video, image or book files directly with peers. Users of file sharing networks simply had to extract the music from a CD into a music compatible format. Typically most music files at that time where saved as MPEG file format. Once the users got music in this format it was very easy share their music with others. The big question now is who actually owns the music, does the music industry still retain the rights of the music regarding who has access to listen to it, or is it up to the owner of the music CD.  According to the First – Sale Doctrine, it is the right of the purchaser of the CD to decide who can access the information on the CD. In addition, the original owner looses all rights to the music once it has been sold.  The importance of defining who actually owns the music has a great impact on the future of the industry. If the industry is determined to be the actual owner of the music then anyone who has shared at least 1 fine with another is guilty of violating the copyright. However, if the owners of the CD are determined to be the owners of the music then the music industry will have to figure out some other way to protect their music so that it is more lucrative for them or they will go out of business. References: http://www.walthowe.com/navnet/history.html http://www.media-awareness.ca/english/resources/special_initiatives/wa_resources/wa_shared/backgrounders/internet_glossary.cfm#F

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• Querying Networking Statistics: dlstat(1M)

  - by user12612042

  Oracle Solaris 11 took another big leap forward in networking technologies providing a reliable, secure and scalable infrastructure to meet the growing needs of today's datacenter implementations. Oracle Solaris 11 introduced a new and powerful network stack architecture, also known as Project Crossbow. From Solaris 11 onwards, we introduced a command line tool viz. dlstat(1M) to query network statistics. dlstat (for datalink statistics) is a statistics querying counterpart for dladm(1M) - the datalink administration tool. The tool is very easy to get started. Just type dlstat on a shell prompt on Solaris 11 (or later). For example,: # dlstat LINK IPKTS RBYTES OPKTS OBYTES net0 834.11K 145.91M 575.19K 104.24M net1 7.87K 2.04M 0 0 In this example, the system has two datalinks net0 and net1. The output columns denote input packets/bytes as well as output packets/bytes. The numbers are abbreviated in xxx.xxUnit format. However, one could get the actual counts by simply running dlstat -u R (R for raw): # dlstat -u R LINK IPKTS RBYTES OPKTS OBYTES net0 834271 145931244 575246 104242934 net1 7869 2036958 0 0 In addition, dlstat also supports various subcommands dlstat help The following subcommands are supported: Stats : show-aggr show-ether show-link show-phys show-bridge For more info, run: dlstat help {default|} I will only describe couple of interesting subcommands/options here. For a comprehensive description of all the dlstat subcommands refer dlstat's official manual . For NICs that support multiple rings (e.g. ixgbe), dlstat show-phys -r allows us to query per Rx ring statistics. For example: dlstat show-phys -r net4 LINK TYPE INDEX IPKTS RBYTES net4 rx 0 0 0 net4 rx 1 0 0 net4 rx 2 0 0 net4 rx 3 0 0 net4 rx 4 0 0 net4 rx 5 0 0 net4 rx 6 0 0 net4 rx 7 0 0 In this case, net4 is just a vanity name for an ixgbe datalink. This view is especially useful if one wants to look at the network traffic spread across all the available rings. Furthermore, any of the dlstat commands could be run with -i option to periodically query and display stats. For example, running dlstat show-phys -r net4 -i 5 will emit per Rx ring stats every 5 seconds. This is especially useful while analyzing a live system. Similarly, dlstat show-phys -t could be used to query per Tx ring stats. -r and -t could also be combined as dlstat show-phys -rt to query both Rx as well as Tx stats at the same time. Finally, there is also a quick way to dump ALL the stats. Just run dlstat -A. You probably want to redirect this output to a file because you are going to get a whole load of stats :-).

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• Adding AjaxOnly Filter in ASP.NET Web API

  - by imran_ku07

          Introduction:                     Currently, ASP.NET MVC 4, ASP.NET Web API and ASP.NET Single Page Application are the hottest topics in ASP.NET community. Specifically, lot of developers loving the inclusion of ASP.NET Web API in ASP.NET MVC. ASP.NET Web API makes it very simple to build HTTP RESTful services, which can be easily consumed from desktop/mobile browsers, silverlight/flash applications and many different types of clients. Client side Ajax may be a very important consumer for various service providers. Sometimes, some HTTP service providers may need some(or all) of thier services can only be accessed from Ajax. In this article, I will show you how to implement AjaxOnly filter in ASP.NET Web API application.         Description:                     First of all you need to create a new ASP.NET MVC 4(Web API) application. Then, create a new AjaxOnly.cs file and add the following lines in this file, public class AjaxOnlyAttribute : System.Web.Http.Filters.ActionFilterAttribute { public override void OnActionExecuting(System.Web.Http.Controllers.HttpActionContext actionContext) { var request = actionContext.Request; var headers = request.Headers; if (!headers.Contains("X-Requested-With") || headers.GetValues("X-Requested-With").FirstOrDefault() != "XMLHttpRequest") actionContext.Response = request.CreateResponse(HttpStatusCode.NotFound); } }                     This is an action filter which simply checks X-Requested-With header in request with value XMLHttpRequest. If X-Requested-With header is not presant in request or this header value is not XMLHttpRequest then the filter will return 404(NotFound) response to the client.                      Now just register this filter, [AjaxOnly] public string GET(string input)                     You can also register this filter globally, if your Web API application is only targeted for Ajax consumer.         Summary:                       ASP.NET WEB API provide a framework for building RESTful services. Sometimes, you may need your certain API services can only be accessed from Ajax. In this article, I showed you how to add AjaxOnly action filter in ASP.NET Web API. Hopefully you will enjoy this article too.

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• Friday Fun: Factory Balls – Christmas Edition

  - by Asian Angel

  Your weekend is almost here, but until the work day is over we have another fun holiday game for you. This week your job is to correctly decorate/paint the ornaments that go on the Christmas tree. Simple you say? Maybe, but maybe not! Factory Balls – Christmas Edition The object of the game is to correctly decorate/paint each Christmas ornament exactly as shown in the “sample image” provided for each level. What starts off as simple will quickly have you working to figure out the correct combination or sequence to complete each ornament. Are you ready? The first level serves as a tutorial to help you become comfortable with how to decorate/paint the ornaments. To move an ornament to a paint bucket or cover part of it with one of the helper items simply drag the ornament towards that area. The ornament will automatically move back to its’ starting position when the action is complete. First, a nice coat of red paint followed by covering the middle area with a horizontal belt. Once the belt is on move the ornament to the bucket of yellow paint. Next, you will need to remove the belt, so move the ornament back to the belt’s original position. One ornament finished! As soon as you complete decorating/painting an ornament, you move on to the next level and will be shown the next “sample Image” in the upper right corner. Starting with a coat of orange paint sounds good… Pop the little serrated edge cap on top… Add some blue paint… Almost have it… Place the large serrated edge cap on top… Another dip in the orange paint… And the second ornament is finished. Level three looks a little bit tougher…just work out your pattern of helper items & colors and you will definitely get it! Have fun decorating/painting those ornaments! Note: Starting with level four you will need to start using a combination of two helper items combined at times to properly complete the ornaments. Play Factory Balls – Christmas Edition Latest Features How-To Geek ETC The Complete List of iPad Tips, Tricks, and Tutorials The 50 Best Registry Hacks that Make Windows Better The How-To Geek Holiday Gift Guide (Geeky Stuff We Like) LCD? LED? Plasma? The How-To Geek Guide to HDTV Technology The How-To Geek Guide to Learning Photoshop, Part 8: Filters Improve Digital Photography by Calibrating Your Monitor Exploring the Jungle Ruins Wallpaper Protect Your Privacy When Browsing with Chrome and Iron Browser Free Shipping Day is Friday, December 17, 2010 – National Free Shipping Day Find an Applicable Quote for Any Programming Situation Winter Theme for Windows 7 from Microsoft Score Free In-Flight Wi-Fi Courtesy of Google Chrome

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• Large File Upload in SharePoint 2010

  - by Sahil Malik

  Ad:: SharePoint 2007 Training in .NET 3.5 technologies (more information). Okay this is a big BIG B-I-G problem. And with SP2010 it’s going to be more prominent, because atleast at the server side, SharePoint can support large files much much better than SharePoint 2007 ever did. The issue with very large files being uploaded through any browser based API are - Reliably transferring gigabyte or bigger files without breakages over a protocol like HTTP, which is better suited for tiny transfers like images and text. Not killing your browser because it has to load all that in memory Not killing your web server because All that you upload through HTTP post, first gets streamed into IIS Memory, w3wp.exe memory before the ENTIRE FILE finishes uploading .. before it is stored. Which means, You cannot show an accurate and live progress bar of the upload, IIS gives you no such accurate metric of an upload. All the counters it gives you are approximate. Your w3wp.exe eats up all server memory – 4GB of it, for a 4GB upload. A thread is kept busy for the entire duration of the upload, thereby greatly limiting your web server’s capability to serve newer requests. Kills effective load balancing. Not killing your content database because, As you are uploading a very large file, that large file gets written sequentially into the DB, and therefore for a very large file very severely impacts the database performance. I had put together another video showing RBS usage in SharePoint 2010. I talked about many practical ramifications of using RBS in SharePoint in that video. Note that enabling large file support will never ever be a point and click job, simply because there are too many questions one needs to ask, and too many things one needs to plan for. However, one part that will remain common across all large file upload scenarios, in SharePoint or outside of SharePoint is to do it efficiently while not killing the web server. In this video, I describe using the Telerik Silverlight Upload control with SharePoint 2010 to enable efficient large file uploads in SharePoint. Presenting .. The video Comment on the article ....

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• Using Rich Text Editor (WYSIWYG) in ASP.NET MVC

  - by imran_ku07

     Introduction:          In ASP.NET MVC forum I found some question regarding a sample HTML Rich Text Box Editor(also known as wysiwyg).So i decided to create a sample ASP.NET MVC web application which will use a Rich Text Box Editor. There are are lot of Html Editors are available, but for creating a sample application, i decided to use cross-browser WYSIWYG editor from openwebware. In this article I will discuss what changes needed to work this editor with ASP.NET MVC. Also I had attached the sample application for download at http://www.speedfile.org/155076. Also note that I will only show the important features, not discuss every feature in detail.   Description:          So Let's start create a sample ASP.NET MVC application. You need to add the following script files,         jquery-1.3.2.min.js        jquery_form.js        wysiwyg.js        wysiwyg-settings.js        wysiwyg-popup.js          Just put these files inside Scripts folder. Also put wysiwyg.css in your Content Folder and add the following folders in your project        addons        popups          Also create a empty folder Uploads to store the uploaded images. Next open wysiwyg.js and set your configuration                  // Images Directory        this.ImagesDir = "/addons/imagelibrary/images/";                // Popups Directory        this.PopupsDir = "/popups/";                // CSS Directory File        this.CSSFile = "/Content/wysiwyg.css";              Next create a simple View TextEditor.aspx inside View / Home Folder and add the folllowing HTML.        <%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage" %>            <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">        <html >            <head runat="server">                <title>TextEditor</title>                <script src="../../Scripts/wysiwyg.js" type="text/javascript"></script>                <script src="../../Scripts/wysiwyg-settings.js" type="text/javascript"></script>                <script type="text/javascript">                            WYSIWYG.attach('text', full);                            </script>            </head>            <body>                <% using (Html.BeginForm()){ %>                    <textarea id="text" name="test2" style="width:850px;height:200px;">                    </textarea>                    <input type="submit" value="submit" />                <%} %>            </body>        </html>                  Here i have just added a text area control and a submit button inside a form. Note the id of text area and WYSIWYG.attach function's first parameter is same and next to watch is the HomeController.cs        using System;        using System.Collections.Generic;        using System.Linq;        using System.Web;        using System.Web.Mvc;        using System.IO;        namespace HtmlTextEditor.Controllers        {            [HandleError]            public class HomeController : Controller            {                public ActionResult Index()                {                    ViewData["Message"] = "Welcome to ASP.NET MVC!";                    return View();                }                    public ActionResult About()                {                                return View();                }                        public ActionResult TextEditor()                {                    return View();                }                [AcceptVerbs(HttpVerbs.Post)]                [ValidateInput(false)]                public ActionResult TextEditor(string test2)                {                    Session["html"] = test2;                            return RedirectToAction("Index");                }                        public ActionResult UploadImage()                {                    if (Request.Files[0].FileName != "")                    {                        Request.Files[0].SaveAs(Server.MapPath("~/Uploads/" + Path.GetFileName(Request.Files[0].FileName)));                        return Content(Url.Content("~/Uploads/" + Path.GetFileName(Request.Files[0].FileName)));                    }                    return Content("a");                }            }        }          So simple code, just save the posted Html into Session. Here the parameter of TextArea action is test2 which is same as textarea control name of TextArea.aspx View. Also note ValidateInputAttribute is false, so it's up to you to defends against XSS. Also there is an Action method which simply saves the file inside Upload Folder.          I am uploading the file using Jquery Form Plugin. Here is the code which is found in insert_image.html inside addons folder,        function ChangeImage() {            var myform=document.getElementById("formUpload");                    $(myform).ajaxSubmit({success: function(responseText){                insertImage(responseText);                        window.close();                }            });        }          and here is the Index View which simply renders the html of Editor which was saved in Session        <%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage" %>        <asp:Content ID="indexTitle" ContentPlaceHolderID="TitleContent" runat="server">            Home Page        </asp:Content>        <asp:Content ID="indexContent" ContentPlaceHolderID="MainContent" runat="server">            <h2><%= Html.Encode(ViewData["Message"]) %></h2>            <p>                To learn more about ASP.NET MVC visit <a href="http://asp.net/mvc" title="ASP.NET MVC Website">http://asp.net/mvc</a>.            </p>            <%if (Session["html"] != null){                  Response.Write(Session["html"].ToString());            } %>                    </asp:Content>   Summary:          Hopefully you will enjoy this article. Just download the code and see the effect. From security point, you must handle the XSS attack your self. I had uploaded the sample application in http://www.speedfile.org/155076

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• A Small Utility to Delete Files recursively by Date

  - by Rick Strahl

  It's funny, but for me the following seems to be a recurring theme: Every few months or years I end up with a host of files on my server that need pruning selectively and often under program control. Today I realized that my SQL Server logs on my server were really piling up and nearly ran my backup drive out of drive space. So occasionally I need to check on that server drive and clean out files. Now with a bit of work this can be done with PowerShell or even a complicated DOS batch file, but heck, to me it's always easier to just create a small Console application that handles this sort of thing with a full command line parser and a few extra options, plus in the end I end up with code that I can actually modify and add features to as is invariably the case. No more searching for a script each time :-) So for my typical copy needs the requirements are: Need to recursively delete files Need to be able to specify a filespec (ie. *.bak) Be able to specify a cut off date before which to delete files And it'd be nice to have an option to send files to the Recycle bin just in case for operator error :-)(and yes that came in handy as I blew away my entire database backup folder by accident - oops!) The end result is a small Console file copy utility that I popped up on Github: https://github.com/RickStrahl/DeleteFiles The source code is up there along with the binary file you can just run. Creating DeleteFiles It's pretty easy to create a simple utility like DeleteFiles of course, so I'm not going to spend any talking about how it works. You can check it out in the repository or download and compile it. The nice thing about using a full programming language like C over something like PowerShell or batch file is that you can make short work of the recursive tree walking that's required to make this work. There's very little code, but there's also a very small, self-contained command line parser in there that might be useful that can be plugged into any project - I've been using it quite a bit for just about any Console application I've been building. If you're like me and don't have the patience or the persistence (that funky syntax requires some 'sticking with it' that I simply can't get over) to get into Powershell coding, having an executable file that I can just copy around or keep in my Utility directory is the only way I'll ever get to reuse this functionality without going on a wild search each time :-) Anyway, hope some of you might find this useful. © Rick Strahl, West Wind Technologies, 2005-2012Posted in Windows  CSharp   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Asp.net session on browser close

  - by budugu

  Note: Cross posted from Vijay Kodali's Blog. Permalink How to capture logoff time when user closes browser? Or How to end user session when browser closed? These are some of the frequently asked questions in asp.net forums. In this post I'll show you how to do this when you're building an ASP.NET web application. Before we start, one fact: There is no full-proof technique to catch the browser close event for 100% of time. The trouble lies in the stateless nature of HTTP. The Web server is out of the picture as soon as it finishes sending the page content to the client. After that, all you can rely on is a client side script. Unfortunately, there is no reliable client side event for browser close. Solution: The first thing you need to do is create the web service. I've added web service and named it AsynchronousSave.asmx.    Make this web service accessible from Script, by setting class qualified with the ScriptServiceAttribute attribute...  Add a method (SaveLogOffTime) marked with [WebMethod] attribute. This method simply accepts UserId as a string variable and writes that value and logoff time to text file. But you can pass as many variables as required. You can then use this information for many purposes. To end user session, you can just call Session.Abandon() in the above web method. To enable web service to be called from page’s client side code, add script manager to page. Here i am adding to SessionTest.aspx page When the user closes the browser, onbeforeunload event fires on the client side. Our final step is adding a java script function to that event, which makes web service calls. The code is simple but effective My Code HTML:( SessionTest.aspx ) C#:( SessionTest.aspx.cs ) That’s’ it. Run the application and after browser close, open the text file to see the log off time. The above code works well in IE 7/8. If you have any questions, leave a comment.

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• Asp.net session on browser close

  - by budugu

  Note: Cross posted from Vijay Kodali's Blog. Permalink How to capture logoff time when user closes browser? Or How to end user session when browser closed? These are some of the frequently asked questions in asp.net forums. In this post I'll show you how to do this when you're building an ASP.NET web application. Before we start, one fact: There is no full-proof technique to catch the browser close event for 100% of time. The trouble lies in the stateless nature of HTTP. The Web server is out of the picture as soon as it finishes sending the page content to the client. After that, all you can rely on is a client side script. Unfortunately, there is no reliable client side event for browser close. Solution: The first thing you need to do is create the web service. I've added web service and named it AsynchronousSave.asmx.    Make this web service accessible from Script, by setting class qualified with the ScriptServiceAttribute attribute...  Add a method (SaveLogOffTime) marked with [WebMethod] attribute. This method simply accepts UserId as a string variable and writes that value and logoff time to text file. But you can pass as many variables as required. You can then use this information for many purposes. To end user session, you can just call Session.Abandon() in the above web method. To enable web service to be called from page’s client side code, add script manager to page. Here i am adding to SessionTest.aspx page When the user closes the browser, onbeforeunload event fires on the client side. Our final step is adding a java script function to that event, which makes web service calls. The code is simple but effective My Code HTML:( SessionTest.aspx ) C#:( SessionTest.aspx.cs ) That’s’ it. Run the application and after browser close, open the text file to see the log off time. The above code works well in IE 7/8. If you have any questions, leave a comment.

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• Oracle VM Deep Dives

  - by rickramsey

  "With IT staff now tasked to deliver on-demand services, datacenter virtualization requirements have gone beyond simple consolidation and cost reduction. Simply provisioning and delivering an operating environment falls short. IT organizations must rapidly deliver services, such as infrastructure-as-a-service (IaaS), platform-as-a-service (PaaS), and software-as-a-service (SaaS). Virtualization solutions need to be application-driven and enable:" "Easier deployment and management of business critical applications" "Rapid and automated provisioning of the entire application stack inside the virtual machine" "Integrated management of the complete stack including the VM and the applications running inside the VM." Application Driven Virtualization, an Oracle white paper That was published in August of 2011. The new release of Oracle VM Server delivers significant virtual networking performance improvements, among other things. If you're not sure how virtual networks work or how to use them, these two articles by Greg King and friends might help. Looking Under the Hood at Virtual Networking by Greg King Oracle VM Server for x86 lets you create logical networks out of physical Ethernet ports, bonded ports, VLAN segments, virtual MAC addresses (VNICs), and network channels. You can then assign channels (or "roles") to each logical network so that it handles the type of traffic you want it to. Greg King explains how you go about doing this, and how Oracle VM Server for x86 implements the network infrastructure you configured. He also describes how the VM interacts with paravirtualized guest operating systems, hardware virtualized operating systems, and VLANs. Finally, he provides an example that shows you how it all looks from the VM Manager view, the logical view, and the command line view of Oracle VM Server for x86. Fundamental Concepts of VLAN Networks by Greg King and Don Smerker Oracle VM Server for x86 supports a wide range of options in network design, varying in complexity from a single network to configurations that include network bonds, VLANS, bridges, and multiple networks connecting the Oracle VM servers and guests. You can create separate networks to isolate traffic, or you can configure a single network for multiple roles. Network design depends on many factors, including the number and type of network interfaces, reliability and performance goals, the number of Oracle VM servers and guests, and the anticipated workload. The Oracle VM Manager GUI presents four different ways to create an Oracle VM network: Bonds and ports VLANs Both bond/ports and VLANS A local network This article focuses the second option, designing a complex Oracle VM network infrastructure using only VLANs, and it steps through the concepts needed to create a robust network infrastructure for your Oracle VM servers and guests. More Resources Virtual Networking for Dummies Download Oracle VM Server for x86 Find technical resources for Oracle VM Server for x86 -Rick Follow me on: Blog | Facebook | Twitter | Personal Twitter | YouTube | The Great Peruvian Novel

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• SQL SERVER – PREEMPTIVE and Non-PREEMPTIVE – Wait Type – Day 19 of 28

  - by pinaldave

  In this blog post, we are going to talk about a very interesting subject. I often get questions related to SQL Server 2008 Book-Online about various Preemptive wait types. I got a few questions asking what these wait types are and how they could be interpreted. To get current wait types of the system, you can read this article and run the script: SQL SERVER – DMV – sys.dm_os_waiting_tasks and sys.dm_exec_requests – Wait Type – Day 4 of 28. Before we continue understanding them, let us study first what PREEMPTIVE and Non-PREEMPTIVE waits in SQL Server mean. PREEMPTIVE: Simply put, this wait means non-cooperative. While SQL Server is executing a task, the Operating System (OS) interrupts it. This leads to SQL Server to involuntarily give up the execution for other higher priority tasks. This is not good for SQL Server as it is a particular external process which makes SQL Server to yield. This kind of wait can reduce the performance drastically and needs to be investigated properly. Non-PREEMPTIVE: In simple terms, this wait means cooperative. SQL Server manages the scheduling of the threads. When SQL Server manages the scheduling instead of the OS, it makes sure its own priority. In this case, SQL Server decides the priority and one thread yields to another thread voluntarily. In the earlier version of SQL Server, there was no preemptive wait types mentioned and the associated task status with them was marked as suspended. In SQL Server 2005, preemptive wait types were not listed as well, but their associated task status was marked as running. In SQL Server 2008, preemptive wait types are properly listed and their associated task status is also marked as running. Now, SQL Server is in Non-Preemptive mode by default and it works fine. When CLR, extended Stored Procedures and other external components run, they run in Preemptive mode, leading to the creation of these wait types. There are a wide variety of preemptive wait types. If you see consistent high value in the Preemptive wait types, I strongly suggest that you look into the wait type and try to know the root cause. If you are still not sure, you can send me an email or leave a comment about it and I will do my best to help you reduce this wait type. Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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• Programming doesn&rsquo;t have to be Magic

  - by Wes McClure

  In the show LOST, the Swan Station had a button that “had to be pushed” every 100 minutes to avoid disaster.  Several characters in the show took it upon themselves to have faith and religiously push the button, resetting the clock and averting the unknown “disaster”.  There are striking similarities in this story to the code we write every day.  Here are some common ones that I encounter: “I don’t know what it does but the application doesn’t work without it” “I added that code because I saw it in other similar places, I didn’t understand it, but thought it was necessary.” (for consistency, or to make things “work”) “An error message recommended it” “I copied that code” (and didn’t look at what it was doing) “It was suggested in a forum online and it fixed my problem so I left it” In all of these cases we haven’t done our due diligence to understand what the code we are writing is actually doing.  In the rush to get things done it seems like we’re willing to push any button (add any line of code) just to get our desired result and move on.  All of the above explanations are common things we encounter, and are valid ways to work through a problem we have, but when we find a solution to a task we are working on (whether a bug or a feature), we should take a moment to reflect on what we don’t understand.  Remove what isn’t necessary, comprehend and simplify what is.  Why is it detrimental to commit code we don’t understand? Perpetuates unnecessary code If you copy code that isn’t necessary, someone else is more likely to do so, especially peers Perpetuates tech debt Adding unnecessary code leads to extra code that must be understood, maintained and eventually cleaned up in longer lived projects Tech debt begets tech debt as other developers copy or use this code as guidelines in similar situations Increases maintenance How do we know the code is simplified if we don’t understand it? Perpetuates a lack of ownership Makes it seem ok to commit anything so long as it “gets the job done” Perpetuates the notion that programming is magic If we don’t take the time to understand every line of code we add, then we are contributing to the notion that it is simply enough to make the code work, regardless of how. TLDR Don’t commit code that you don’t understand, take the time to understand it, simplify it and then commit it!

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• Using SurfaceFormat.Single and HLSL for GPGPU with XNA

  - by giancarlo todone

  I'm trying to implement a so-called ping-pong technique in XNA; you basically have two RenderTarget2D A and B and at each iteration you use one as texture and the other as target - and vice versa - for a quad rendered through an HLSL pixel shader. step1: A--PS--B step2: B--PS--A step3: A--PS--B ... In my setup, both RenderTargets are SurfaceFormat.Single. In my .fx file, I have a tachnique to do the update, and another to render the "current buffer" to the screen. Before starting the "ping-pong", buffer A is filled with test data with SetData<float>(float[]) function: this seems to work properly, because if I render a quad on the screen through the "Draw" pixel shader, i do see the test data being correctly rendered. However, if i do update buffer B, something does not function proerly and the next rendering to screen will be all black. For debug purposes, i replaced the "Update" HLSL pixel shader with one that should simply copy buffer A into B (or B into A depending on which among "ping" and "pong" phases we are...). From some examples i found on the net, i see that in order to correctly fetch a float value from a texture sampler from HLSL code, i should only need to care for the red channel. So, basically the debug "Update" HLSL function is: float4 ComputePS(float2 inPos : TEXCOORD0) : COLOR0 { float v1 = tex2D(bufSampler, inPos.xy).r; return float4(v1,0,0,1); } which still doesn't work and results in a all-zeroes ouput. Here's the "Draw" function that seems to properly display initial data: float4 DrawPS(float2 inPos : TEXCOORD0) : COLOR0 { float v1 = tex2D(bufSampler, inPos.xy).r; return float4(v1,v1,v1,1); } Now: playing around with HLSL doesn't change anything, so maybe I'm missing something on the c# side of this, so here's the infamous Update() function: _effect.Parameters["bufTexture"].SetValue(buf[_currentBuf]); _graphicsDevice.SetRenderTarget(buf[1 - _currentBuf]); _graphicsDevice.Clear(Color.Black); // probably not needed since RenderTargetUsage is DiscardContents _effect.CurrentTechnique = _computeTechnique; _computeTechnique.Passes[0].Apply(); _quadRender.Render(); _graphicsDevice.SetRenderTarget(null); _currentBuf = 1 - _currentBuf; Any clue?

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• Add a Cache Clearing Button to Firefox

  - by Asian Angel

  While emptying your browser’s cache may not be something that you need to worry with often or at all there are times when clearing it can be helpful. The Empty Cache Button extension lets you have instant on-demand cache clearing in Firefox. Some reasons why you might want or need to clear your browser’s cache: Clear out older (or out of date) versions of images, etc. from your favorite websites Free up disk space Clearing the cache may help fix browser behavior issues Help protect privacy (i.e. images, etc. displayed within a personal account) Before For our example we loaded three webpages in order to add content to our browser’s cache. Using the “CacheViewer” we were able to easily see the contents of our browser’s cache after the webpages finished loading. What if you need to clear your cache immediately without restarting your browser (if the options are set to empty the cache on browser exit)? Note: CacheViewer is available via a separate extension and can be found here. Empty Cache Button in Action Once you install the extension all that you need to do is right click on any of your browser’s toolbars and select “Customise”. Drag the “Toolbar Button” to an appropriate location in your browser’s UI and you are ready to go. To clear your browser’s cache simply click the button…that is all there is to it. When the cache is empty you will see this small message window appear in the lower right corner of your “Desktop”. Opening up the “CacheViewer” again shows that everything has been cleared out. Terrific! Conclusion If you ever find yourself needing to clear your browser’s cache immediately then the Empty Cache Button extension provides an easy way to do so without restarting your browser (if the options are set to empty the cache on browser exit). Links Download the Empty Cache Button extension (Mozilla Add-ons) Similar Articles Productive Geek Tips Change SuperFetch to Only Cache System Boot Files in VistaTroubleshoot Browsing Issues by Reloading the DNS Client Cache in VistaSearch for Install Packages from the Ubuntu Command LineQuick Tip: Empty Internet Explorer 7 Cache when Browser is ClosedRemove the New Tab Button in Firefox TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 PCmover Professional Use Quick Translator to Translate Text in 50 Languages (Firefox) Get Better Windows Search With UltraSearch Scan News With NY Times Article Skimmer SpeedyFox Claims to Speed up your Firefox Beware Hover Kitties Test Drive Mobile Phones Online With TryPhone

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• System crashes/lockups + compiz/cairo/gnome-panel crashing due to cached ram, please help?

  - by Kristian Thomson

  Can someone help me to troubleshoot system crashes and lockups which result in compiz/cairo dock and gnome-panel crashing? I also get no window borders after the crash and a lot of kernel memory errors. Logs are telling me that apps were killed due to not enough memory, but the system is caching like 14GB of my ram so I'm a bit stuck on what/how to stop it. I'm running Ubuntu 12.10 on a 2011 Mac Mini with 16 GB ram. Here's some of the logs that look like they could be causing trouble. I woke up this morning to find chrome/skype/cairo dock and a few others had been killed and here is what the log said. Nov 5 04:00:45 linkandzelda-Macmini kernel: [ 9310.959890] Out of memory: Kill process 12247 (chromium-browse) score 101 or sacrifice child Nov 5 04:00:45 linkandzelda-Macmini kernel: [ 9310.959893] Killed process 12247 (chromium-browse) total-vm:238948kB, anon-rss:17064kB, file-rss:20008kB Nov 5 04:00:45 linkandzelda-Macmini kernel: [ 9310.972283] Out of memory: Kill process 10976 (dropbox) score 3 or sacrifice child Nov 5 04:00:45 linkandzelda-Macmini kernel: [ 9310.972288] Killed process 10976 (dropbox) total-vm:316392kB, anon-rss:115484kB, file-rss:16504kB Nov 5 04:00:45 linkandzelda-Macmini kernel: [ 9310.975890] Out of memory: Kill process 10887 (rhythmbox) score 3 or sacrifice child Nov 5 04:00:45 linkandzelda-Macmini kernel: [ 9310.975895] Killed process 11515 (tray_icon_worke) total-vm:63336kB, anon-rss:15960kB, file-rss:11436kB Nov 5 04:00:45 linkandzelda-Macmini kernel: [ 9311.281535] Out of memory: Kill process 10887 (rhythmbox) score 3 or sacrifice child Nov 5 04:00:45 linkandzelda-Macmini kernel: [ 9311.281539] Killed process 10887 (rhythmbox) total-vm:528980kB, anon-rss:92272kB, file-rss:36520kB Nov 5 04:00:45 linkandzelda-Macmini kernel: [ 9311.283110] Out of memory: Kill process 10889 (skype) score 3 or sacrifice child Nov 5 04:00:45 linkandzelda-Macmini kernel: [ 9311.283113] Killed process 10889 (skype) total-vm:415056kB, anon-rss:84880kB, file-rss:22160kB I went to look deeper into things and saw that the whole time I'm having these kernel errors with out of memory and something mentioning radeon. I have a Radeon HD 6600M graphics card using the open source driver, not the proprietary one. I was wondering if perhaps using the proprietary one would solve the problem. Also, while writing this in Chrome rhythmbox and chrome just got killed while typing this, due to out of memory errors or so it reports, though I have 7 GB of free RAM at the time with 7 GB cached as well. Here is a full copy of my logs that happened in kern.log simply from when I began typing this question. http://pastebin.com/cdxxDktG Thanks in advance, Kris

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• Silverlight Cream for January 14, 2011 -- #1027

  - by Dave Campbell

  In this Issue: Sigurd Snørteland, Yochay Kiriaty, WindowsPhoneGeek(-2-), Jesse Liberty(-2-), Kunal Chowdhury, Martin Krüger(-2-), Jonathan Cardy. Above the Fold: Silverlight: "Image Viewer using a GridSplitter control" Martin Krüger WP7: "Implementing WP7 ToggleImageControl from the ground up: Part1" WindowsPhoneGeek VS2010 Templates: "MVVM Project Templates for Visual Studio 2010" Jonathan Cardy From SilverlightCream.com: BabySmash7 - a WP7 children's game (source code included) Sigurd Snørteland not only brings Scott Hanselman's Baby Smash to WP7, but he's delivering the source to us as well as discussion of the app. Windows Push Notification Server Side Helper Library Yochay Kiriaty has a tutorial up on Push Notification... not explaining them, but a discussion of a WP7 Push Recipe that provides an easy way for sending all 3 kinds of push notification messages currently supported. Implementing WP7 ToggleImageControl from the ground up: Part1 WindowsPhoneGeek has a great 2-part series up on building a useful WP7 custom control -- a ToggleImage control... this part 1 is definition, deciding on Visual states, etc... buckle up... this is good stuff Implementing WP7 ToggleImageControl from the ground up: Part2 Part 2 in WindowsPhoneGeek's series is also up and where the real fun lives -- implementing the behavior of the control... and the source is available at the end of this post. The Full Stack #5 – Entity Framework Code First Jesse Liberty has episode 5 of the "Full Stack" series he and Jon Galloway are doing and are discussing Entity Framework Code First. Windows Phone From Scratch #18 – MVVM Light Toolkit Soup To Nuts 3 Jesse Liberty also has part 3 of his MVVMLight and WP7 post up and is digging into messaging in this one... for example view <--> ViewModel communication. Exploring Ribbon Control for Silverlight (Part - 1) Kunal Chowdhury has part 1 of a series up on using the Silverlight Ribbon Control from DevComponents... lots of information and a great intro to a great control. Image Viewer using a GridSplitter control Martin Krüger has a very nice picture viewer up as a demo and code available that simply uses the GridSplitter to implement tha aperture... check it out. How to: Gentle animation of a magnify effect Martin Krüger's latest is a take-off on a prior post he links to called 'just for fun' in which he smoothly animates a magnify effect... just very cool animation... explanation and source. MVVM Project Templates for Visual Studio 2010 Jonathan Cardy has a couple resources you probably wanna grab... two MVVM project templates for VS2010... one WPF and one Silverlight Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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• JavaFX 2.0 at Devoxx 2011

  - by Janice J. Heiss

  JavaFX Sessions Abound JavaFX had a big presence at Devoxx 2011 as witnessed by the number of sessions this year given by leading JavaFX movers and shakers.     “JavaFX 2.0 -- A Java Developer's Guide” by Java Champions Stephen Chin and Peter Pilgrim     “JavaFX 2.0 Hands On” by Jasper Potts and Richard Bair     “Animation Bringing your User Interfaces to Life” by Michael Heinrichs and John Yoong (JavaFX development team)     “Complete Guide to Writing Custom Bindings in JavaFX 2.0” by Michael Heinrichs (JavaFX development team)     “Java Rich Clients with JavaFX 2.0” by Jasper Potts and Richard Bair     “JavaFX Properties & Bindings for Experts” (and those who want to become experts) by Michael Heinrichs (JavaFX development team)     “JavaFX Under the Hood” by Richard Bair     “JavaFX Open Mic” with Jasper Potts and Richard Bair With the release of JavaFX 2.0 and Oracle’s move towards an open development model with an open bug database already created, it’s a great time for developers to take the JavaFX plunge. One Devoxx attendee, Mark Stephens, a developer at IDRsolutions blogged about a problem he was having setting up JavaFX on NetBeans to work on his Mac. He wrote: “I’ve tried desperate measures (I even read and reread the instructions) but it did not help. Luckily, I am at Devoxx at the moment and there seem to be a lot of JavaFX gurus here (and it is running on all their Macs). So I asked them… It turns out that sometimes the software does not automatically pickup the settings like it should do if you give it the JavaFX SDK path. The solution is actually really simple (isn’t it always once you know). Enter these values manually and it will work.” He simply entered certain values and his problem was solved. He thanked Java Champion Stephen Chin, “for a great talk at Devoxx and putting me out of my misery.” JavaFX in Java Magazine Over in the November/December 2011 issue of Java Magazine, Oracle’s Simon Ritter, well known for his creative Java inventions at JavaOne, has an article up titled “JavaFX and Swing Integration” in which he shows developers how to use the power of JavaFX to migrate Swing interfaces to JavaFX. The consensus among JavaFX experts is that JavaFX is the next step in the evolution of Java as a rich client platform. In the same issue Java Champion and JavaFX maven James Weaver has an article, “Using Transitions for Animation in JavaFX 2.0”. In addition, Oracle’s Vice President of Java Client Development, Nandini Ramani, provides the keys to unlock the mysteries of JavaFX 2.0 in her Java Magazine interview. Look for the JavaFX community to grow and flourish in coming years.

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• Customer Experience Online Forum

  - by Christie Flanagan

  Missed Oracle’s Customer Experience Online Forum?  Don’t worry. You can still catch the sessions at your convenience. Watch the Customer Experience Online Forum on demand to hear from Bruce Tempkin, a leading expert in customer experience, as well as other thought leaders and they delve into topics such as the ROI of customer experience and strategies for winning over customers.  Simply register to gain access to these sessions and more: The Customer Experience RevolutionCustomer experience has become the most important and defensible differentiator for your business. The customer experience is a journey that transcends all customer touchpoints and stages of the customer lifecycle. Discover where you are in the journey, identify how to begin optimizing the experience you deliver your customers, and join the Revolution.The ROI of Customer ExperienceBruce Temkin, Customer Experience Transformist & Managing Partner, Temkin GroupResearch of US and UK customers demonstrates a high correlation between a positive customer experience and loyalty. A successful customer interaction increases the willingness to buy more and to recommend your company. US companies can gain $380 million over three years by providing an optimized customer experience. This session will help companies determine the business impact that customer experience has on their specific business. Integrating Marketing and Loyalty to Deliver Great Customer ExperiencesNew devices and channels, such as mobile, social and web, are creating radical shifts in the customer buying process and the ways your company can reach and communicate with existing and potential customers. Learn how leading brands are using Oracle's marketing solutions to harness big data and better understand their customers, extend their marketing reach into social channels, and retain their high value customers through more rewarding customer experience.Where to Start Your Organization's RevolutionThe process of crafting a great customer experience starts with understanding customers and their goals. This session helps you to begin mapping a sound customer experience strategy, describing the intended experience and kinds of processes that create differentiation. The ROI of Customer Experience: A Tempkin Group Insight Report Did you know that customer experience leaders have more than a 16 percentage point advantage over customer experience laggards in consumers’ willingness to buy more, their reluctance to switch business away, and their likelihood to recommend? Did you know that even a modest increase in customer experience can translate into millions of dollars gained? Learn more about the ROI of customer experience in this free report.

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• On Writing Blogs

  - by Tony Davis

  Why are so many blogs about IT so difficult to read? Over at SQLServerCentral.com, we do a special subscription-only newsletter called Database Weekly. Every other week, it is my turn to look through all the blogs, news and events that might be of relevance to people working with databases. We provide the title, with the link, and a short abstract of what you can expect to read. It is a popular service with close to a million subscribers. You might think that this is a happy and fascinating task. Sometimes, yes. If a blog comes to the point quickly, and says something both interesting and original, then it has our immediate attention. If it backs up what it says with supporting material, then it is more-or-less home and dry, featured in DBW's list. If it also takes trouble over the formatting and presentation, maybe with an illustration or two and any code well-formatted, then we are agog with joy and it is marked as a must-visit destination in our blog roll. More often, however, a task that should be fun becomes a routine chore, and the effort of trawling so many badly-written blogs is enough to make any conscientious Health & Safety officer whistle through their teeth at the risk to the editor's spiritual and psychological well-being. And yet, frustratingly, most blogs could be improved very easily. There is, I believe, a simple formula for a successful blog. First, choose a single topic that is reasonably fresh and interesting. Second, get to the point quickly; explain in the first paragraph exactly what the blog is about, and then stay on topic. In writing the first paragraph, you must picture yourself as a pilot, hearing the smooth roar of the engines as your plane gracefully takes air. Too often, however, the accompanying sound is that of the engine stuttering before the plane veers off the runway into a field, and a wheel falls off. The author meanders around the topic without getting to the point, and takes frequent off-radar diversions to talk about themselves, or the weather, or which friends have recently tagged them. This might work if you're J.D Salinger, or James Joyce, but it doesn't help a technical blog. Sometimes, the writing is so convoluted that we are entirely defeated in our quest to shoehorn its meaning into a simple summary sentence. Finally, write simply, in plain English, and in a conversational way such that you can read it out loud, and sound natural. That's it! If you could also avoid any references to The Matrix then this is a bonus but is purely personal preference. Cheers, Tony.

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