I am attempting to find out what is causing certain.Oracle WebLogic Server Application Server and Application Grid Business Intelligence Technology.Database and SQL Oracle Fusion Middleware Oracle Enterprise Manager.QA for database professionals who wish to improve their database skills and learn from others in the community.For one our applications we encountered deadlock issues when.Day by mssqltips.Tip of the Day SQL Server.SQL Server instance is causing CPU.C Socket.Async. Event.Args High Performance Socket Code.Introduction.Microsoft created the Socket.Async.Event. Args class to help you write scalable, high performance socket server code.Socket.Async. Event.Args uses IO Completion Ports via the asynchronous methods in the.NET Socket class.A proven way to write scalable, high performance socket code for TCPIP in Windows can be seen in this article on IO Completion Ports.And heres another link to a Microsoft page on IO Completion Ports.Socket.Async. Event.Args helps us to access a socket with advantages like working asynchronously, raising the Completed event, setting buffer space, object pooling, having a state object, accessing the socket through a property, etc., while having the performance characteristics of IO completion ports.Very nice.The purpose of this article is to help you understand the fundamentals of using the Socket.Async. How To Install Presets In Adobe After Effects Cs5 For Mac . Event. Args class.Background.You may have started your research into this topic at Microsofts main page for the Socket.Async.Event. Args class, as I did.The example code on that page got me started.But it was also confusing.Some of the problems that I noticed with their example code were It seems that Microsoft removed example code about the User.Tokenlt code property.The User.Token is really important, because if you have to post multiple receive operations to receive a message, then you will need a place to store data between operations.And the same is true for send operations.Some of the method names in the example code were a bit confusing, as were some of the variable names.Sql Query To Find Deadlocks' title='Sql Query To Find Deadlocks' />Deadlock DetectedTheir reason for using a Semaphore was not explained really.The example in the Buffer.Manager code on Microsofts page for the Set.Buffer method shows how to build the buffer.While their code for building the Buffer.Manager was mostly good, the way that they dealt with the Set.Buffer method in their Process.Receive method in the example code for the Socket.Async.Event. Args class will pretty much work in only the narrowest of examples.If you send a 1.Their code sets the buffer to be whatever size you send on the first message from the client.So after the first message, it would just send back the first 1.So, we need a better example of how to get the data from the buffer after a receive operation completes, use the data, put data in the buffer for a send operation, and resize the buffer before and after a send operation.Also, in the Socket.Listener constructor where the Buffer.Database DeadlockManager is created, Microsofts example included the variable ops.To.Pre. Alloc in the calculation for total.Bytes, but not of buffer.Size.Thats a mistake which leaves half of the total buffer space being unused.In the explanation of their example code, they said For example, if a server application needs to have 1.Socket.Async. Event.Args objects for that purpose.But then their example only included reusable Socket.Async.Event. Args objects for receivesend, not for accept.The Socket.Async.Event. Args object for the accept operation would wait until the receivesend finished to do another accept op.Instead, we can use a pool, as they mentioned in their explanation, and post accept operations faster.After Microsoft invested the resources to create the Socket.Async.Event. Args class, it is surprising that they did not invest the resources to give good understandable example code and explanation to help us learn how to use it.This article is designed to fill in that void, because the class really is well done, and very helpful after you understand it.The code in this article was developed on Visual Studio 2.NET 3.This article assumes some knowledge of delegates and event handling in Windows.Regarding the Socket.Async.Event. Args class, Microsofts website says it requires Platforms Windows 7, Windows Vista, Windows XP SP3, Windows Server 2.Windows Server 2.The.NET Framework Supported in 4, 3.SP1, 3.SP1, 2.SP1. The. NET Framework Client Profile Supported in 4, 3.SP1.TCP Socket Basics.If you have experience with socket server code, you can skip this section.A socket is like a reference or handle to a port which allows us to access data sent to that port, which is a reserved space in memory.We will be accessing network data through a socket which listens on a TCP port.For those new to socket programming, there are four main steps in using a socket server with TCP.Its often described as six parts, but I like to put the first three together into one.Listen for connection requests on the server.In order to listen, you need to create a socketbind that socket to a portlisten with that socket.The client must do its part too.A client not a server can initiate a connection request by using the Connect or Connect.Async method.The client machines Windows TCPIP subsystem will automatically assign an outgoing port to the socket on the client machine.It will contact the server by sending a SYN packet which is addressed to the socket servers IP address and port number.The client does not listen for incoming connections.It always initiates connections and the server responds.After a client initiates a connection on the servers listening socket, the Windows TCPIP subsystem of the server will respond with SYN, ACK.Then the client machines Windows TCPIP subsystem responds back with an ACK packet.When the ACK is received by the server, the handshake is complete, and the connection is established.Windows will handle this TCPIP protocol stuff for you.In other words, SYN, ACK, PSH, packets, and similar parts of TCPIP protocol do not have to be coded by you.Smile here.The servers listening socket can maintain a queue of connection requests waiting to be accepted.This queue is called the backlog.The listening socket passes the connection info to another socket via an accept operation, and then gets the next incoming connection in the backlog queue, or if there is none, waits till there is a new connection request from a client.Accept connection requests.In order to have multiple connections on the same port, the servers listening socket must pass off the connection info to another socket, which accepts it.The accepting socket is not bound to the port.You post an accept operation to pass the connection from the listening socket to the accepting socket.The accept operation can be posted before the incoming connection is established, so that the listening socket immediately passes off the new connection info to the accepting socket.The client does not need to perform an accept operation.ReceiveSend via the connection.After the accept operation has completed, you can now receive or send data with that connection.The same Socket.Async.Event. Args object that did the accept operation could also do the receiving or sending, if we post a receive or send on it and have buffer space for it.In the design of the code below, the Socket.Async.Event. Args which did the accept operation passes the connection info over to another Socket.Async.Event. Args object to do receivingsending.Receive is also known as read.Send is also referred to as write.We could also split the receiving and sending into two separate Socket.Async.Event. Args objects, if we wish.But that is more difficult.Close the connection.Either client or server can initiate an operation to close the connection.Usually, the client would initiate that.Again, the lower level TCPIP of the disconnect is handled by the Windows Operating System.The connection can be closed using the Close method, which destroys the Socket and cleans up its managed and unmanaged resources.So, those are the four main steps in using a socket server with TCP.There are a few more things that you must understand about TCP, in order to be able to write code that uses it.With TCP, there is no guarantee that one send operation on the client will be equal to one receive operation on the server.One send operation on the client might be equal to one, two, or more receive operations on the server.And the same is true going back to the client from the server.This peculiarity can be due to buffer size, network lag, and the way that the Operating System handles TCP to improve performance.So you must have some way of determining where a TCP message begins andor ends.Three possible ways to handle TCP messages are Prefix every message with an integer that tells the length of the message.SQL Servers.What is a major difference between SQL Server 6.SQL Server 6.Windows NT Server.SQL Server 7.Windows NT Server, workstation and Windows 9.Is SQL Server implemented as a service or an applicationIt is implemented as a service on Windows NT server and workstation and as an application on Windows 9.What is the difference in Login Security Modes between v.Standard Mode, only Windows NT Integrated mode and Mixed mode that consists of both Windows NT Integrated and SQL Server authentication modes.What is a traditional Network Library for SQL Servers Named Pipes What is a default TCPIP socket assigned for SQL Server If you encounter this kind of an error message, what you need to look into to solve this problem MicrosoftODBC SQL Server DriverNamed PipesSpecified SQL Server not found.Check if MS SQL Server service is running on the computer you are trying to log into 2.Check on Client Configuration utility.Client and Server have to in sync.What are the two options the DBA has to assign a password to saSQL statement Use master Exec sppassword NULL, b to use Query Analyzer utility What is new philosophy for database devises for SQL Server 7.There are no devises anymore in SQL Server 7.It is file system now.When you create a database how is it stored It is stored in two separate files one file contains the data, system tables, other database objects, the other file stores the transaction log.Lets assume you have data that resides on SQL Server 6.You have to move it SQL Server 7.How are you going to do itYou have to use transfer command.Direct.Connect Have you ever tested 3 tier applications Do you know anything about Direct.Connect software Who is a vendor of the software Sybase.What platform does it run onUNIX.How did you use it What kind of tools have you used to test connection SQL Server or Sybase client tools.How to set up a permission for 3 tier applicationContact System Administrator.What UNIX command do you use to connect to UNIX server FTP Server Name Do you know how to configure DB2 side of the application Set up an application ID, create RACF group with tables attached to this group, attach the ID to this RACF group.Web Application What kind of LAN types do you knowEthernet networks and token ring networks.What is the difference between themWith Ethernet, any devices on the network can send data in a packet to any location on the network at any time.With Token Ring, data is transmitted in tokens from computer to computer in a ring or star configuration.Steve Dalton from Exchange.Technology This is such a common mistake that people make about TR I didnt want it to propagated further Token ring is the IEEE 8.Devices on the ring cannot transmit data until permission is received from the network in the form of an electronic token.The token is a short message that can be passed around the network when the owner is finished.At any time, one node owns the token and is free to send messages.As with Ethernet the messages are packetized.The packet startflag address header message checksum stopflag.The message packets circulate around the ring until the addressed recipient receives them.When the sender is finished sending the full message normally many packets,he sends the token.An Ethernet message is sent in packets too.The sending protocol goes like this wait until you see no activity on the network.Token ring speed is 41.Mbitsec, Ethernet 1.Mbitsec For more info see http www.What protocol both networks use What it stands for TCPIP.Transmission Control Protocol Internet Protocol.How many bits IP Address consist of An IP Address is a 3.How many layers of TCPIP protocol combined of Five.Application, Transport, Internet, Data link, Physical How to define testing of network layers Reviewing with your developers to identify the layers of the Network layered architecture, your Web client and Web server application interact with.Determine the hardware and software configuration dependencies for the application under test.How to test proper TCPIP configuration Windows machine To run command on Windows NT IPCONFIGALL Windows 9.WINIPCFG Ping or ping What is a component based Architecture How to approach testing of a component based application Define how many and what kind of components your application has.Identify how server side components are distributed Identify How server side software components interact with each other Identify how Web To Database connectivity is implemented Identify how processing load is distributed between client and server to prepare for load stress and performance testing Prepare for compatibility and reliability testing How to maintain Browser settings Go to Control Panel, Internet Option.What kind of testing considerations you have to have in mind for Security Testing In clientserver system, every component carries its own security weaknesses.The primary components which need to be tested are application software the database servers the client workstations the network How to Hire a QA Person.What criteria do people use to select QA engineers Its natural to think that the right kinds of people to hire are people just like youbut this can be a mistake.In fact, every job requires its own unique set of skills and personality types, and the skills that make you successful in your field may have significant differences from the skills needed for the QA job.If you read many job posting specifications for QA roles, youll find that they commonly describe skills that are much more appropriate for a developer, including specific knowledge of the companys unique technology.Some specifications are so unique and lofty that it seems the only qualified candidates would be former heads of development Realistically, the QA person you seek should have the adaptability, intelligence, and QA specific skills that will enable them to come up to speed on your project quickly.Relevant experience includes testing procedures, test writing, puzzle solving, follow through, communication, and the QA mindset.Unless they are testing a programming interface or scripting language, a QA persons role is to test the product from the end users perspective.Contrast this with developers, who look at the product from a code perspective.Consider the difference between being focused on making the code perform in a very specific way and wondering what would happen if you did this instead of that through the user interface.Download Movie Player Pro Activex Setup Disk And Install It there.Its remarkable that the people who are assigned to interview QA candidates tend to be anything but QA people themselves.Most often, developers and HR people do the bulk of the interviewing.Yet QA is a unique discipline, and candidates need to be evaluated from a QA point of view, as would accountants, advertising staff, and other specialized professionals.QA people often have the feeling that they need to have two sets of skills those that interview well with development engineers, and those that they actually need once they get the job.What Not to Do.
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