Multiple clients in SRM standalone server?

Hi,
I need to install SRM 5.0 standalone server.
Can i have mutiple clients activated in the same system?
Meaning one client from development and another client for unit testing etc..
Thanks
Ram

Hi,
See this related note:
Note 995771 - System Landscape Copy for SAP SRM 4.0 and 5.0
BR,
Disha.
Pls reward points for useful answers.

Similar Messages

RMI: multiple clients for one RMI server?

Hi,
We're thinking of making a RMI Server.
However, can multiple clients access the same RMI Server at the same moment?
So, if one client is connected to the RMI Server, what will happen with the other clients that want to work to do the same thing at the same moment ?

all over the same port?
so for example, 100 clients can work simultaneously on this simple server?
import java.rmi.Remote;
import java.rmi.RemoteException;
public interface OkServer extends Remote {
    public String getOk() throws RemoteException;
import java.rmi.server.UnicastRemoteObject;
import java.rmi.RMISecurityManager;
import java.rmi.RemoteException;
import java.rmi.Naming;
public class OkServerImpl extends UnicastRemoteObject implements OkServer {
    public OkServerImpl() throws RemoteException {
    public String getOk() {
     return "ok";
    public static void main (String args[]) throws Exception {
          System.setSecurityManager(new RMISecurityManager());
          OkServerImpl OkSvr = new OkServerImpl();
          Naming.bind("OkServer", OkSvr);
}

Purpose of Multiple Clients in Development Server

can anybody tell me the advantages and
disadvantages of having multiple clients in a
development server?

I don't think there is disadvantage when we have multiple clients for development system
DEV SAP system may have multiple clients..
Main pupose : Changes can be client dependent or client independent
Client-independent effects some clients.
Client-dependent effects all clients.
Let me say one example : Dev system has two clients
100 - Here we can write the code
200 - Testing will be here ( customizing will done here)
http://help.sap.com/saphelp_nw04/helpdata/en/8d/933d3c3a926614e10000000a11402f/frameset.htm
http://www.sap-img.com/general/what-is-sap--landscape.htm
http://help.sap.com/saphelp_nw2004s/helpdata/en/96/8a99386185c064e10000009b38f8cf/content.htm
Thanks
Seshu

File transfer to multiple clients from server socket

I have multiple clients connected to my server socket and I need to copy more than 200mb documents from server to all clients over socket. Can we design the issue considering scalability and performance factor? What I am thinking of we should use thread for transferring file from server to client. But at the same time if we have large number of clients then we can't initialize a thread for each client. I think in this case we should initialize less than 10 threads in the pool as the file size is very large. If we keep number of threads in the pool low then probably we have to read multiple times the large server file (once for each group) which might again be a performance bottleneck. Please pour in your suggestions.

File would be same for an instance only. For example say I have a "SEND File" button & �File Path� text box. In File Path suppose user enters the absolute path of the file and then clicks on Send File button. The responsibility of Send File button would be sending the file mentioned in the "File Path" text box to all connected client. But next time user can choose a different file.

Multiple clients on socket connection

Hi!
I understand that it is possible that multiple clients listen to one server (on the same port) and even write to it (then it should be a multi-threaded server).
But i would like to refuse connectios, if one client is connected. How can I do that?
In my case I have a (single threaded) server. Now one clients connects. The server waits to receive data from the client and answers, without ever closing the port. that works.
Now if I connect with a second client, the openicng of the socket in the second client works fine, although the server does not seem to notice the second client. Communication is not possible between the server and the second client, and the server doesn't answer to the first client anymore, although he receives data from it.
So, since the server does not seem to notice the second client (does not accept the connection) and I don't get an exception at the second client, what can I do?
Thank you for your help!
concerned Code (if you want to take a look at it):
CLIENT:
socket = new Socket(hostname, echo_port);
SERVER:
try
ServerSocket waitingsocket = new ServerSocket(echo_port);
try
     socket= waitingsocket.accept();
     System.out.println("Client connected");
     ReaderThread reader = new ReaderThread( this, socket );
     reader.start();
catch (Exception e)
READER:
public void run()
     while (true)
          try {
               int bytesRead = inStream.read(inputBuffer,
               0, inputBuffer.length);
               readCallback.tcpUpdate(inputBuffer,bytesRead);
          catch (Exception oops)
               readCallback.tcpUpdate(null,-1);


Just to make sure this is clear: You can NOT have multiple clients on a given socket connection. You CAN have multiple clients connected to a particular port on a given server, but each client will be communicating with the server through a different of socket.
The usual approach here is to set up a listening ServerSocket on the desired port, call accept() on it, then process the communication from the returned Socket object. This is usually done by spawning a new thread and allowing it to handle the socket communication, while the ServerSocket loops around to another accept() for the next communication.
Here's an excellent intro to the concepts (the code is really ugly and poorly implemented, but it does a good job of explaining the overall concept). I used this as a starting point, and now (after a whole lot of development) have a pretty sweet extensible web server class that handles template expansion, etc... (I use this as a quick and dirty UI for some of my apps, instead of requiring the user to install a JSP container):
http://developer.java.sun.com/developer/technicalArticles/Networking/Webserver/
- K

Controlling Multiples Clients

Hi, i trying to know if i can manage multiple clients on a RMI Server, i think yes (with threads?)
The server have to mantain multiples rooms, and each room can have from 2 to 10 clients (people). The server have to mantain about 1 to 20 rooms of this rooms and all the clients, and 1 expecific client like an administrator client.
Abour the people client i think i can make an applet or use JWS.
I was asking about use RMI, someone says to me to use EJB or Web Services but i think theres too complicated to my scenario.
Oh...the server have to controll a data base too lol... to much for me and my little english, thanks in advance!

Hi,
I need to know a couple of things.
1. Do I need to use multithreads to an rmi project where multiple clients access the server simultaneously
2. In case I establish that ( or even if RMI has it by default ), do i need to worry about sharing resources for these threads. ( For example, if we have a text file the remote object reads from & writes to , can I make sure there is no clash for accessing it???)

How to control one server with multiple clients via TCP/IP

I am wanting to control a single server with multiple clients. Only one client would be active at a time, so there would be no conflict. I want to use TCP/IP. So far, I have programmed a cluster that passes data back to the server with no problems. The challenge come in when a second client is added to the mix. I have't been able to figure out how to turn each client on and send the appropriate data and then turn it off so it doesn't keep sending the same data to the server.
Here are the things that I have considered and did some preliminary testing, but don't really know how to impliment:
1. Send a numeric on the front of the cluster packet that tells the server that data is on the way.
2. Send a boolean on the front of the cluster packet to somehow turn the server TCP/IP on.
The problem I have found is that LabVIEW TCP/IP doesn't like to be turned on and off. If it doesn't get the data it expects, it goes into a reset mode and that kills the response time.
Any help?

You should consider implementing a set of simple one-byte commands that can be sent back and forth between the Server and the Clients. You can base all of these ideas off the example in the Example Finder under Networking >> TCP and UDP called Multiple Connections - Server.
You will have two loops in the server VI: one to wait for new connections, and one to send and receive data from the existing connections. For instance, after one of the clients connects, it can request control of the server to send data to it by sending the character "R" for request. Every time the send/receive loop of the Server executes, the first thing it can do is to check all the existing connections to see if any of the clients have sent a control request ("R"). If so, it will create a buffer (array) of control requests. This could be in the form of Connection IDs or indexes in the array for a particular Connection ID. Your choice.
After the Server receives a request for contol, if it is not already under control by another client, then it can send a response to the first client on the control request list. For instance, the server could send the first client a "S" command for send. Note that after the clients send their control request, they should execute a TCP Read and wait indefinitely for the server to respond with the one-byte "S" command. Then, once the client in control is finished sending data to the server, it could send the character "X" telling the Server to release it from control.
The example I mentioned above already does a similar thing. Note how when a client wants to disconnect, they send the letter "Q". You can see this in the Multiple Connections - Client VI. The Server then checks each individual connection to see if it's received this one-byte command, and if it has, it closes the connection to the client. This is what you would want to implement, but instead of having just one command, you'll have to distinguish between a few and build up a buffer of control requests.
Finally, if a client does decide to disconnect in your application, they could send the command "Q" just like the example above. At this point, close the connection and remove that Connection ID from the array of connections. You will also have to handle the case that this client was in the request control waiting line when it disconnected, in which case you need to delete it from that array as well.
This will definitely work for you, but it will take some work. Best of luck!
Jarrod S.
National Instruments

Saving string from multiple clients on a server data structue

I have a server which receives updates from multiple clients ( in this example, football scores which are updated periodically by the clients.)
When the server receives the scores it needs to store them and at certain time intervals send the complete list of scores to multiple terminals at various locations.
I am approaching this task in stages...
stage 1.
..create the clients and server ...test the clients can send the data and the server can receive the data and output to screen..
this is completed
stage 2...
a/ on the server side store the received scores in a data structure (ArrayList<String> is what I'm thinking.)
b/ periodically output all scores to the screen (maybe every 30 seconds) and empty the ArrayList..am looking at the Timer class for this part..
stage 3
create the monitors and output scores to monitors periodically..
======================================================
right now I'm at stage 2a ie trying to store the received scores in a data structure.
i've created a method saveScore in the StoreScore class which is called by the StoreScore run method...
The saveScore method creates an ArrayList and adds the score to it...
Question
does every thread create a new instance of storedScores and therefore the scores are stored in a multitude of data structures?
I think the answer is yes and if so then this is not the solution...
What I'm thinking is , as all scores can be outputted to the server screen via System.out.println, is there not a way of saving all these scores in a single data structure?
The code below is the server code..
any advice much appreciated....thank you
/*=============================================================== */
import java.io.*;
import java.net.*;
import java.util.*;
import java.util.concurrent.*;
class ScoresServer1{
final static int portNum = 1234; // any number > 1024
final static int numThreads = 10;
static ExecutorService pool;
public static void main(String[] args){
pool = Executors.newFixedThreadPool(numThreads);
System.out.println("Server running ...");
try{
ServerSocket servesock = new ServerSocket(portNum);
// for service requests on port
while (true){
// wait for a service request on port portNum
Socket socket = servesock.accept();
// submit request to pool
pool.submit(new StoreScore(socket));
}catch(IOException e){}
class StoreScore implements Runnable {
BufferedReader reader;
Socket sock;
public StoreScore(Socket clientSOcket) {
try {
sock = clientSOcket;
InputStreamReader isReader = new InputStreamReader(sock.getInputStream());
reader = new BufferedReader(isReader);
} catch (Exception ex) { ex.printStackTrace(); }
public void run() {
String message;
try {
while ((message = reader.readLine()) != null) {
// System.out.println("latest score: " + message);
saveScore(message);
} catch (Exception ex) { ex.printStackTrace(); }
public void saveScore(String message){
     ArrayList<String> storedScores = new ArrayList<String>();
     storedScores.add(message);
     Iterator<String> t = storedScores.iterator();
          while(t.hasNext()){
               String s = t.next();
               System.out.println(s);
}

does every thread create a new instance of storedScores and therefore the scores are stored in a multitude of data structures?
I think the answer is yes and if so then this is not the solution...The answer is yes. However, threads can share data, if they were properly synchronized. You should read the threading tutorial before creating a lot of hard to debug mistakes.
[http://java.sun.com/docs/books/tutorial/essential/concurrency/]

Multiple clients with same account on a single IMAP server

Hi,
I am connecting to a IMAP server using same account but from 2 different machines. From one machine a mark a message as SEEN=FALSE. But on the second machine, the flag will still be TRUE.
Is there any way to co-ordinate between multiple clients so that all the clients are in sync.
Regards,
Nitin.

I was able to resolve the problem using addMessageCountListener and messagesAdded method, as suggested by you.
I am now facing another problem. Whenever a new message is received, code inside messagesAdded method gets executed. Here I am trying to spawn another thread and do some stuff. But this new thread is not starting at all. It goes into some JavaMail:EventQueue and does nothing. What is the concept of EventQueue here? How can I get this new thread executed?
Also will there be synchronization problems in messagesAdded method. Say I received a message and I am processing it in the messagesAdded method. In the mean time another message comes up. How will this behave.

How do I connect multiple telnet clients to a telnet server in LabVIEW?

Good afternoon,
I'm writing a telnet server in LabView 6.1 that needs to handle multiple clients. To do this, I modified the "viserver\runvi.llb" example to use the telnet VI's from the Internet Toolkit instead of the TCP VI's. Then I changed the Open VI Reference to point to my telnet handler. Right now my handler just echoes the characters received from the client.
My software works ok for the first connection. After the server accepts two or more connections, characters typed in one client get echoed to all clients. In addition, only one client will accept characters at a time. The client accepting input changes randomly every few seconds as characters are entered.
Has anyon
e gotten the telnet VI's to run in parallel? Not sure if they are thread-safe or not. If you have some experience with this, I have attached my llb if you think you can help.
Thanks!
Chris Norris
Carrier Access Corp.
[email protected]
(303) 218-5826
Attachments:
CAC_Telnet_Server.llb ‏92 KB

I don't think there's a problem with the TCP/connection portion of things. My feeling is that the problem is lurking somewhere in the timing of the application, or in the way LabVIEW task scheduling/multitasking is working compared to the way you expect it to work.
For instance, I'm wondering why you stuck with 25 seconds (25000 ms) as the timeout value for the Telnet Read in Telnet Handler.vi. I assume you're expecting LabVIEW to quickly "sleep" that while loop and move on to check on the while loops of any other Telnet Handler.vi instances that might have been spawned as a result of connection requests from other remote clients.
Instead, it seems to me (on my system, anyway, with three simultaneous connections active) that LabVIEW is not cyc
ling through the other Telnet Handler.vi instances as you expect, but is only getting to them to read a byte at a time each time the main loop iterates in response to a byte appearing from the first of the three remote clients.
If you change the Telnet Read timeout to 50 ms instead, the behavior is closer to what you might expect, but still not perfect.
Because timing/threading/scheduling is a complicated subject in LabVIEW, I'm going to give LabVIEW the benefit of the doubt and assume it's operating as designed. Maybe someone else can provide more insight into what's happening in this particular case, and whether reentrancy or something else is affecting things.
One option I would consider if I were in your shoes: program a simpler version of things that mimics Date Server.vi and cycles through a queue of connections to service them without relying on spawning new reentrant instances of a handler VI.
I realize that your version of things (along with the reentrancy example
that ships with LabVIEW) is expressly intended to handle this daemon-style situation, but simpler may be better for the purposes of debugging and development ease.
My two cents,
John Lum
National Instruments

How does create a server with multiple Clients ?

Any people can lead me .
How does create a server with multiple Clients ?
Thanks

For a multithreaded server you will need a thread to listen and at least one thread per client. If the conversation is half duplex, one thread per client works very well, if it's full duplex you will find one thread to send and one to receive much easier to program.
I posted a Simple Socket Server that uses 1+2*clients threads.

One Server Multiple Clients

Hello,
This server code accepts only one client connection at a time. However, I have several lines that are specifically for the server to accept more than one client. What do I need to do in addition for the server to recognize that it can accept more than one client at a time?
import java.io.EOFException;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import java.util.concurrent.Executors;
import java.util.concurrent.ExecutorService;
import javax.swing.JFrame;
public class ServerTest
   public static void main( String args[] )
      Server application = new Server();
      application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
      application.runServer();
class Server extends JFrame
   private JTextField enterField;
   private JTextArea displayArea;
   private ObjectOutputStream output;
   private ObjectInputStream input;
   private ServerSocket server;
   private Socket connection;
   private int counter = 1;
   private ExecutorService serverExecutor;
   private MultiServer clients[];
   public Server()
      super( "Server" );
      enterField = new JTextField();
      enterField.setEditable( false );
      enterField.addActionListener(
         new ActionListener()
            public void actionPerformed( ActionEvent event )
               sendData( event.getActionCommand() );
               enterField.setText( "" );
      add( enterField, BorderLayout.NORTH );
      displayArea = new JTextArea();
      add( new JScrollPane( displayArea ), BorderLayout.CENTER );
      setSize( 300, 150 );
      setVisible( true );
   public void runServer()
      serverExecutor = Executors.newCachedThreadPool();
      try
         server = new ServerSocket( 12345, 100 );
         while ( true )
            try
               waitForConnection();
               getStreams();
               processConnection();
            catch ( EOFException eofException )
               displayMessage( "\nServer terminated connection" );
            finally
               closeConnection();
               counter++;
      catch ( IOException ioException )
         ioException.printStackTrace();
   private void waitForConnection() throws IOException
      displayMessage( "Waiting for connection\n" );
      connection = server.accept();
      serverExecutor.execute( new MultiServer(server, connection));
      displayMessage( "Connection " + counter + " received from: " + connection.getInetAddress().getHostName() );
   private void getStreams() throws IOException
      output = new ObjectOutputStream( connection.getOutputStream() );
      output.flush();
      input = new ObjectInputStream( connection.getInputStream() );
      displayMessage( "\nGot I/O streams\n" );
   private void processConnection() throws IOException
      String message = "Connection successful";
      sendData( message );
      setTextFieldEditable( true );
      serverExecutor.execute(new MultiServer(server, connection));
      do
         try
            message = ( String ) input.readObject();
            displayMessage( "\n" + message );
         catch ( ClassNotFoundException classNotFoundException )
            displayMessage( "\nUnknown object type received" );
      } while ( !message.equals( "CLIENT>>> TERMINATE" ) );
   private void closeConnection()
      displayMessage( "\nTerminating connection\n" );
      setTextFieldEditable( false );
      try
         output.close();
         input.close();
         connection.close();
      catch ( IOException ioException )
         ioException.printStackTrace();
   private void sendData( String message )
      try
         output.writeObject( "SERVER>>> " + message );
         output.flush();
         displayMessage( "\nSERVER>>> " + message );
      catch ( IOException ioException )
         displayArea.append( "\nError writing object" );
   private void displayMessage( final String messageToDisplay )
      SwingUtilities.invokeLater(
         new Runnable()
            public void run()
               displayArea.append( messageToDisplay );
   private void setTextFieldEditable( final boolean editable )
      SwingUtilities.invokeLater(
         new Runnable()
            public void run()
               enterField.setEditable( editable );
class MultiServer extends Thread
public MultiServer(ServerSocket servers, Socket connection)
      servers = server;
public void run(){System.out.print("Yes");}
}

Check out the "Supporting Multiple Clients" bit here: http://java.sun.com/docs/books/tutorial/networking/sockets/clientServer.html
Start a Thread for each client. I'd recommend you create a class:
class Client
    Socket socket;
    ObjectOutputStream out;
    ObjectInputStream in;
    ...any other client-specific data you need...
    public void sendMessage(String s) { ...send to this client...; }
   ...any other client-specific methods you need...;
}Create one of those when accept() gets a new connection, then start the thread for that client.
You may want to keep a LinkedList that contains all the Client objects. E.g. if you want to send a message to all clients you'd loop over the LinkedList and send to each in turn. Synchronize the list appropriately. Removing clients from the list when they close down can be interesting :-) so be careful.

Multiple client chat server

Thanks to the help I got from the good people of this forum today I modified the chat server program which I am making and now it is working a bit better. Right now it can accept several (up to 8) clients and store their open sockets in a SocketCollection list which can later be accessed so that messages get sent to all of them. Problem is that when I send a message, it is displayed instantaneously on the client that sent that message (my machine), but is displayed only after the other clients press enter on the other clients' machines (for testing purposes it was the same machine, different port opened for communication with server which is also on the same machine). To clarify that - all clients and server are the same machine (that shouldn't be a problem, right?). Code for printing incoming data for client program is below:
while ((fromServer = in.readLine()) != null) {
            if (fromServer!=null){
                   System.out.println(fromServer);
                   System.out.println("print on client screen msg received from server");
            fromUser = stdIn.readLine();
            if (fromUser != null) {
          System.out.println("Client: " + fromUser);
          out.println(fromUser);
}Code to deliver the message to all clients from the server application is below as well:
while ((inputLine = in.readLine()) != null) {
                 PrintWriter multiOut;
               for (int x=0; x<8; x++){
                     System.out.println("INSIDE MULTI-TELL FOR LOOP");
                     if (socketCollection[x]!=null){
                           Socket c=socketCollection[x];
                           try{
                               System.out.println("tried to send to all\nSocket c = " + c);
                               out=new PrintWriter(c.getOutputStream(), true);
                                   out.println(c.getInetAddress() + inputLine);
                            catch(IOException ioe){}
}In the server's DOS window I can clearly see that it enters to display the message to multiple clients and it should send it. The sockets are all different and they point to different ports on different clients' machines. Maybe the problem is just in the client program's code. If you could help me out, it will be greatly appreciated. Thank you very much.

The sockets get created one by one when each client connects. Afterwards when the thread is made, that socket gets copied into the SocketCollection array which can afterwards be accessed in order for the server to distribute the message to all its connected clients.
The for loop in the second code example where it takes SocketCollection[x] and gets its outputStream and all that is where it prints the message and sends it to each client (sends it but it is not displayed on the client side until the client sends a message to the server again). My question is how to make it so the client does not have to send a message in order to see the server message (message to all clients) that was sent before.

Send data to multiple clients from a server

My problem statement is this:
A server is created, say X. Multiple clients are created, say A, B & C. If X sends a message to A it should reach only A and should not go to B or C. Similarly if X sends message to B it should not reach A or C. I made a one to one communication with the following code:
//Server
import java.io.*;
import java.net.*;
class X
public static void main(String args[])throws Exception
ServerSocket ss=new ServerSocket(4321);
try
Socket s=ss.accept();
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
DataOutputStream out = new DataOutputStream(s.getOutputStream());
String str=in.readLine();
out.writeBytes(str+"\n");
s.close();
ss.close();
catch (IOException e){}
//Client A
import java.io.*;
import java.net.*;
class A
public static void main(String args[])throws Exception
try
Socket s=new Socket("localhost",4321);
BufferedReader in=new BufferedReader(new InputStreamReader(s.getInputStream()));
System.out.println(in.readLine());
s.close();
catch(Exception e){}
}But i dont know how to keep track of each client. Because all the clients sockets are created at the same port, ie. 4321. I think thread will help. But even then i dont know how to identify each client. Somebody please help. Thanks in advance.
Edited by: sowndar on Dec 5, 2009 1:21 AM

YoungWinston wrote:
sowndar wrote:
Ok. I think i have to attach an unique ID to each client message. So that, with the help of that ID, the server can identify each client. Have i caught ur point?If you don't mind using a port per client, you could do something like a receptionist taking incoming calls (on 4321 only).
- Hi I'm Client xyz.
- Hi Client xyz, please call me back on port abcd and I'll put you straight through to our server.
Since 4321 is an "open line" you might have to have some sort of ID so that Clients know which return messages are meant for them, but messages on the other ports would all be direct Client to Server. Also, the Server is then is charge of port allocation and communication on the "open" port is kept to a minimum.4321 is the socket that the server is listening to. It's not what the actual communication will be carried out over. Run this, then telnet to port 12345 a few times
public class TestServerSocket {
public static void main(String[] args) throws Exception {
          ServerSocket server = new ServerSocket(12345);
          while (true) {
               Socket socket = server.accept();
               System.err.println(socket.getPort());
}Notice how each inbound connection is allocated a unique outbound socket.

Multiple-client, same server, different configurations

Hi experts,
Recently we have got a project of IS-U Electricity where it has been planned that the same server we used for the last project will be used for this upcoming project where the configurations are diffrent from each other but both of them will run together in same development, quality and production servers.
My question is whether we would be able to configure sap as per the requirements for the upcoming project to a particular client whereas the rest of the clients will use old configurations for the existing project in the same server. Will there be any cross-client configuration conflicts?
- Arghya

Arghya:
The answer to this question is unrelated the industry solution. Multiple client scenarios are used in many solutions. Some configuration is client dependent and so would be different in each client; other configuration is client independent and would be used in all clients. That would be part of the analysis to determine if multiple clients or multiple systems is the correct approach.
regards,
bill.

Multiple clients in SRM standalone server?

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