I want to implement the TCP KeepAlive in order to check dropped connections by running a timer.
In my case, I have a TCP Client (using socket class) and a third party server (i have no control on it).
How can i use the TCP KeepAlive on my TCP Client in order to check the connection state?[code]...
Below is my code, but when i send the message thru client socket i receive Specified argument was out of the range of valid values. Parameter name: size
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim serverStream As NetworkStream = clientSocket.GetStream()
Dim outStream As Byte() = _
System.Text.Encoding.ASCII.GetBytes("0800822000000000000004000000000000000920092126012345001")
[CODE]...
I am Working on Teghax Component.Using This Component we want to find out Block title attribute of dwg file in a client server socket application.
1> We get Block title attributes properly of dwg file in windows application form using the getattribute function().
2> We get Block title Attributes properly in that way:-We take a class library where we take a class.in this class we use getattribute function().Then We access the particular class from another project
But when we use the same class(Keep same structure) in client server socket program.Then it gives an exception.i.e ,"Spaicfied cast is not valid"I am Not getting any reply form teghax developer..I attached exception screen sort.Give me Suggestion How to solve this Exception
Code given Bellow :
Public Function Get_DwgFileAttribute(ByVal Sender As ClsTcpConnection, ByVal msgTag As Byte, ByVal message As String) As String
Dictionary = GetHashtable(message)
Dim varfilepath As String = CStr(Dictionary.Item("filePath"))
[code]....
I wrote a Socket Client which will send the Socket Server some data and get some response from Server. This process will be running once in every 2 seconds.
Now what I need to know is How we can identify the connection lost between Server and Client?
I need this to be implemented in the Client side. If there is no connection then Client should automatically close the connection. Once the connection with the server is available in the next attempt it should connect automatically.
I made a simple TCP server (I've found the example on the web) in VB to receive data from about 40 TCP clients.The clients are not synchronized but sends data about every 18 minutes; the problem is sometimes several clients sends data at the same moment, so I can't receive data.I also made a second program that reads the data (server program writes data on a file, read from the second program) scheduled.
My question is this: I've seen on the web examples about Multithreaded Server Socket Program, so I suppose this could manage my 40 clients (but now the clients are syncronized and send data at the same time in client mode) or is better get data (I have a central client that asks data to all 40 devices in server mode)?
Second question: can I make a single program where I run both TCP client and TCP server at the same time?
i am using the client/server classes for file transfer by moeur.what i want to know is that once my client is connected to the server and after that the client machine goes off the network. now when my server trys to send a file or some message to the client i am not able to trap the error that the client is disconnected.how to do this. there might be a case where the client machine suddenly shuts down. in such cases how will my server know that the client has disconnected.
View 2 RepliesI'm working on a simple socket client application that transfers files from one PC to another. The flow is as follows.
Client sends message to Server
Client Listens for response
Server responds with command
Client sends file or message to Server
Client Listens for response
This sequence will repeat thousands if not tens of thousands of times. It runs great on my dev box but when I load it on another machine I get a StackOverFlowException. I know why I'm getting the stack overflow. It's because I have a Listen subroutine that calls a Send routine. When the Send routine is done it calls the Listen routine again. The process works for about 614 iterations and then bombs out with a stack overflow. I guess my question is, how can I code a socket application that can send-->listen-->send-->listen thousands of times without blowing the stack?
how to access client side activity i.e. which client is connected and which computer connected at the same time from server.
View 1 RepliesAm developing a server - client application using the system.net class , that will have more than 5000 simultenous client connection.what is the best way to manage multiple client connection like this?
View 3 RepliesI'm trying to build a multithreaded SMPP client with VS2008 and I'm getting bogged down in threading. Basically my main parent thread will interact with the windows service scheduler, get registry settings, and get a list of SMPP servers to connect to. Then it will launch a thread for each SMPP connection, which will need to keep it's TCP socket open to receive messages with, so the thread must remain running even if there aren't any events happening (no messages to receive)... but I can't seem to get it figured out.
[Code]...
The Start sub in the oChannel object does run, but once that sub is finished running the thread ends. In the Start sub, it calls other code that initiates a connection to the remote SMPP server, but that code asynchronously waits for an event to be raised regarding the connection status. Once the sub finishes, the async connection being attempted doesn't seem to be able to pin the thread down.
For almost a week I am reading and trying to find a solution for checking connection state using a TCP Client (using socket class) In my scenario I have a TCP Client that is connected to a server (it is not controlled by me) and i want that from time to time to check the connection state, and reconnect if necessary.I have read a lot of information on the internet but i did not find a suitable solution.Briefly, these are the methods that i have found on the internet and try to implement.But unfortunatelly, i have found some scenarios where the TCP Server is closed and the TCP Client is still saying Connected 1.Example from MSDN
[code]...
I want both the client and server to write and read resp. at a constant rate (which can be configured on the GUI of the client) to the buffer.I am able to send from the client at 150 bytes per packet Now, I should be able to read also at 150 bytes per packet on the server too Since, both are connected through a socket, can we retrieve the socket params (set on the client size, like 150 here) from the server end, using the tcpServer object.Or is it must to send an initial setup packet which tells about these client params and so accordingly the server can continue?
View 1 RepliesI have a TCP Socket Client (using the Socket Class) that is connected to a simple TCP socket server (just for testing)I have this code snippet :
Dim aSocket as Socket
While aSocket.Connected = True
byteRead = aSocket.Receive(dataByte) 'number of bytes
[code].....
I'm running into an issue where I have a lot of AsyncSends going on with dozens of client sockets, and at the moment if any remote client stops receiving but doesn't actually disconnect, the app quickly eat sup all of the SocketAsyncEventArgs (aka an sae) I have preallocated because they're not released since the SendAsync is not completing. The obvious solution to this is to implement a per-client send queue, which sounds easy enough but I am unclear as to the specifics. I have one sae allocated per client to receive, which works perfect, and ideally I'd love to allocate a single sae to the client's async sends.
I understand popping in and asking a question that is veiled request for a 'give me code' solution is looked down upon, but I honestly have not been able to turn up a lot, either on the .XAsync methods, which Microsoft has a horribly poor example for, nor for a send queue in general.
Edit for @J.N.
I forgot to mention it, but I -am- actually using a bunch of preallocated sae's stored in a managing class that internally uses a ConcurrentBag. With one connection, in a test scenario where 20 small messages are sent per second (this is slightly more than double how many messages would actually be sent in the production server), the server eats up 500 preallocated sae's in a few seconds. If I implement 'create if empty' code, the sae count quickly climbs into the thousands.
I understand the functionality that the async methods of the Socket class provides, but if there's a network hiccup or something similar, this issue will outright bomb the server within seconds. A send queue sounds like an great solution, but I have no idea whether it's a good idea to do in a high performance production environment or not.
The base problem remains, though, that with a dozen messages per second per client being sent out, any network congestion or other factor that lags the connection but does not disconnect it will quickly deteriorate into a laggy mess.
I think a solution I might be looking for is something that locks up the single sae being used for sending until the completion callback is reached, where that sae is then unlocked and then reused to send any pending data. The actual implementation of it eludes me though.
I am working on a chat client and server, and so far it works well, but when I close the client, the server throws an exception because it continues to try to do processes on the disconnected client. I have tried adding clientSocket.Close() in various places throughout the client and server with no luck. Does someone know how to add the disconnect code to either the server or client with this code?Server:
Imports System.Net.Sockets
Imports System.Text
Module Module1
[code].....
I am facing problem in asynchronous socket communication.
1)I wanted to perform connect(from client to server) operation on enter button and send the data whatever client want to send and disconnect from server. And again client should get connect to server whenever client wanted to send data. this is the mechanism.
i.e how to reuse the socket.
2)Again Server should able to send the data to client.
I have created a Client that can send and receive data via TCP sockets. The objects stored on the serverside are the *exact* same object used for the client. They use the same send and receive protocols.
Now, when i send a string from the server to the client , it does precisely what it should do. However when I send a string to the server.... I do receive the string as an equal length of NULL characters. I run the server and client locally.
Basicly what can influence the behaviour between two completely identical objects performing the exact same task? I wonder if there is some socketflag issue if the TCPlistener.accept function returns a completely different setup then the one I R used to.
(if it is of any interest, the send protocol is asynchronious)
I am using the Threading.Timer class to run multiple timers. After about a day, some of them stop. I read about the GC.KeepAlive property as a possibility of solving this problem, so the timers are never garbage collected. But I am unclear how often to use this command. It seems like it would be a property that would always take hold, because the variables holding the timers are global, but I see differing opinions in the articles I have been reading.From the Microsoft documentation:This method references the obj parameter, making that object ineligible for garbage collection from the start of the routine to the point, in execution order, where this method is called. Code this method at the end, not the beginning, of the range of instructions where obj must be available.But other articles say it just needs to be used after the initial start of the timer.Should I just put this command after every start and stop of the timer? Should the threading timers be highly reliable with this set?
View 2 RepliesI have been reading through Atheists posts in regards to client-server and TCP client/server connection's. But how do i go about writing a program with 1 client and server where the client side creates a text file.Once the server sees there is a text file it connects and downloads it to itself or the client pushes the text file to the server.Once on the server i will read the text file and put its info into a sql db.
View 14 RepliesWe have a compilation with GC.KeepAlive (Object) method.When we try to complile, there is an error GC variable not defined.We try to reference mscorlib.dll manually in the project but it doesn't work.
View 5 RepliesI have been struggling to find a solution for this problem. What I need to do is build a server application that accepts tcp client requests from different clients running on same port say:1003. I experimented by using asynchronous mode call backs etc. but it disconnects once connection is established and does not respond for further requests from the same client.
View 1 RepliesI wrote a server for a tcp/ip chat program using the system.net.sockets class. When I run the program and the client tries to connect to it, there's an error and it won't work. I am positive that the issue isn't with the client, as I have made a connection with the client before.
Imports System.Net
Imports System.Net.Sockets
Imports System.IO
Public Class Form1
Dim server As New TcpListener(IPAddress.Any, 60)
Dim client As New TcpClient
[Code] .....
I am creating a very simple Voting System, that will be use on electing new set of officer in a teacher cooperative...
So I have to create two separate program, a Server Program that will manage all the information in the election and a Client Program where voters will vote their selected candidate...
The election officers wanted that the Server Program will display the Voting Results at real time... So when the Voter finished voting, The Voting Result displayed by the Server Program will also be updated every time the Client Program Insert the data to Database....
An action listener in Server Program that will execute if new data is inserted in a Table in the Database made by the Client Program...
The problem I have is: When I click on cmdListen in the server form and cmdConnect in the client form,both programs won't respond and they crash for some reason I don't know.
Client source code:
Code:
Imports System.Net.Sockets
Imports System.Text
Public Class Form1
[CODE]...
Code:
Imports System.Net.Sockets
Imports System.Text
Public Class Form1
[CODE]...
I am trying to implement a timer in my program and i am unable to do so till now.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Static intCount As Integer
intCount = 10
While intCount <> 0
Dim fileReader As String
[Code] .....
How do I implement a timer that will close the IE after every 5 seconds till the count runs out?
I'm trying to implement a timer into my program, because I want to take a capture from a webcamdevice every x seconds.I've wandered around google all day and tried to implement all kind of timer classes (with system.threading because I can't use system.windows.forms.timer) but I won't figure it out!
View 14 RepliesI have an existing program, and it uses DLL files to do things I wish to implement a DLL in VB.NET the DLL's are not COM, they are standard call the method or function type DLL's
How would I implement the following in a VB.NET DLL extern "C" void __Export_TYPE HelloWorld(char *path)
I have the following function that loops through a directory and checks for a specified folder and file[code]...
View 1 RepliesI use VB.NET 2005 i need to implemente IMessageFilter for MSWord object.
View 8 RepliesI have an interface program written in VB .Net (VS2008xxx.dll). Is it possible to implement the Interface in a VB6 program (VB6xxx.exe)?
View 8 Replies