Applet socket server

Is it possible to have applet socket server? if so, pls tell me the method. Thanks.
regards,
Bala

applet socket server?hmm...i dont think so...this will produce an exception... but maybe you can try signing the applet....

Similar Messages

Chat Applet - Sockets - Server

Hello Fellows!
I hope u all r fine..
I am facing a problem in my client/sever application. The communication is Socket Based. i.e the server is using sockets and the client which is an Applet, uses sockets to communicate with the sever.
The application is working fine in the appletviewer. i.e the applet server communication, both can send and recieve messages.
BUT
When I use IE5 the client applet can send messages to the sever but is not able to read from the specified socket...
If Any one can help me out, i will be greatfull. If u need some code segment then let me know.
Looking forward for any suggestions.
Thanking You!
Ahmad.

Thanks!
for your contribution....
but now i realised that the problem is that the client socket thread is not running.
//////////////////////// Client Applet
public class Client extends Applet implements ActionListener
Thread thRead;
ClientSocket cs;
private Panel pnlHead = new Panel();
private Panel pnlMain = new Panel();
public static Vector vtrMembers;
public void init()
thRead = (Thread) new ClientSocket();
     cs = (ClientSocket) thRead;
     vtrMembers = new Vector();
thRead.start();
cs.out.println("INI ? INI");
////////////////////////////////////////Client scoket class
public class ClientSocket extends Thread
// public static Socket sClient;
public Socket sClient;
// A character-input stream to read from the socket.
public static BufferedReader in;
// A text-output stream to write to the socket.
public PrintWriter out ;
// String to store the input from the client
String strText;
// Boolean Flag to Check the read value
public boolean bFlag = true;
public ClientSocket ()
     try
     sClient = new Socket ("Ahmed" , 4000);
     // Initializing the Input straem used to read the socket.
in = new BufferedReader(new InputStreamReader(sClient.getInputStream()));
     // Initializing the Output straem used to write on the socket.
     out = new PrintWriter(sClient.getOutputStream(), true);
     catch (UnknownHostException uhe)
//     System.out.println (" Unknown Host Exception : " + uhe);
     catch (IOException ioe)
//     System.out.println (" I/O Exception : " + ioe);
public void run()
     for (;;)
     if (bFlag == true)
     Client.txtTry.setText("TRUE");
     else
     Client.txtTry.setText("False");
thRead.start() statment is executed but the thread does not stat running
because the text value is not set on the Client Applet.

Send string to socket server from applet

Am trying to send a string to socket server from my applet:
Server:
import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class Server extends JApplet
ServerSocket srvr;
Socket skt;
PrintWriter out;
BufferedReader in;
Server()
String data = "server";
try
srvr = new ServerSocket(5555);
skt = srvr.accept();
out = new PrintWriter(skt.getOutputStream(), true);
in = new BufferedReader(new InputStreamReader(skt.getInputStream()));
while (in.ready())
System.out.println(in.readLine());
out.print(data);
out.close();
in.close();
skt.close();
srvr.close();
catch(Exception e)
System.out.print(e);
public static void main(String[] aslan)
new Server();
My applet where I have my client:
Socket skt;
BufferedReader in;
PrintWriter out;
try
skt = new Socket("localhost", 5555);
out = new PrintWriter(skt.getOutputStream(),true);
in = new BufferedReader(new InputStreamReader(skt.getInputStream()));
while (in.ready())
System.out.println(in.readLine());
in.close();
catch(Exception e)
System.out.print(e);
public void actionPerformed( ActionEvent e )
if(e.getSource() == button)
out.println("test");
But when the button is pushed the client is supposed to send the string "test" to the server but nothing happens can someone plz help me with this?

Am trying to send a string to socket server from my
applet:
Server:
import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class Server extends JApplet
ServerSocket srvr;
Socket skt;
PrintWriter out;
BufferedReader in;
Server()
String data = "server";
try
srvr = new ServerSocket(5555);
skt = srvr.accept();
out = new PrintWriter(skt.getOutputStream(), true);
in = new BufferedReader(new
InputStreamReader(skt.getInputStream()));
while (in.ready())
System.out.println(in.readLine());
out.print(data);
out.close();
in.close();
skt.close();
srvr.close();
catch(Exception e)
System.out.print(e);
public static void main(String[] aslan)
new Server();
My applet where I have my client:
Socket skt;
BufferedReader in;
PrintWriter out;
try
skt = new Socket("localhost", 5555);
out = new PrintWriter(skt.getOutputStream(),true);
in = new BufferedReader(new
InputStreamReader(skt.getInputStream()));
while (in.ready())
System.out.println(in.readLine());
in.close();
catch(Exception e)
System.out.print(e);
public void actionPerformed( ActionEvent e )
if(e.getSource() == button)
out.println("test");
But when the button is pushed the client is supposed
to send the string "test" to the server but nothing
happens can someone plz help me with this? Your server code while (in.ready()) is going to block indefinitely.
Remove the while loop and just write your ouput and close the connection on the server.

Applet socket connection

Hi,
I have an applet that connects to a server java console program through a socket connection which works fine from the command line using appletviewer but doesn't work when running in a html page. The applet is not signed however because the applet and server are running on the same machine it shouldn't need to be. I have used socket connections in applets before and have managed to make the connection to server without having it signed but this one is not working for some reason. I have checked the port is opened and again its the same one I have used before so I know its open.
I am getting the message java.security.AccessControlException: access denied (java.net.SocketPermission 127.0.0.1:5000 connect,resolve) when calling:
Socket s = new Socket(ip,port);I also have a java.policy.applet file in the project root directory which has the following in:
grant {
permission java.security.AllPermission;
};Does anyone know a reason why access could be restricted?

Night.Monkey wrote:
Hi,
I have an applet that connects to a server java console program through a socket connection which works fine from the command line using appletviewer but doesn't work when running in a html page. The applet is not signed however because the applet and server are running on the same machine it shouldn't need to be.Wrong. An unsigned applet can only connect back to the server from where it was downloaded. Your applet comes from www.javawebgames.co.uk and tries to connect to 127.0.0.1.
Would your server be at www.javawebgames.co.uk there should be no problem.
I also have a java.policy.applet file in the project root directory which has the following in:
grant {
permission java.security.AllPermission;
};I think this should have zero effect when you are running in the actual browser.

How to get started on java applet client/server game?

Hi,
I've googled, but didn't find any useful information about creating java applet client/server game. I've followed the example of Client/Server Tic-Tac-Toe Using a Multithreaded Server in Java How to Program from Deitel, but I when I tried on Applet, my cliet doesn't communicate with the server at all. Any help to get started with Applet would be great. Thanks!

well, i decided to put in portion of my codes to see if anyone can help me out. the problem I have here is the function excute() never gets called. here is my coding, see if you can help. Notice, I'm running this on Applet thru html page. This shouldn't be much different than running JFrame in term of coding right?
Server.java
    public void init()
        runGame = Executors.newFixedThreadPool(2);
        gameLock = new ReentrantLock();
        otherPlayerConnected = gameLock.newCondition();
        otherPlayerTurn = gameLock.newCondition();
        players = new Player[2];
        currentPlayer = Player1;
        try
            server = new ServerSocket(12345, 2);
        catch (IOException ie)
            stop();
        message = "Server awaiting connections";
    public void execute()
       JOptionPane.showMessageDialog(null, "I'm about to execute!", "Testing", JOptionPane.PLAIN_MESSAGE);
        for(int i = 0; i < players.length; i++)
            try
                players[i] = new Player(server.accept(), i);
                runGame.execute(players);
catch (IOException ie)
stop();
gameLock.lock();
try
players[Player1].setSuspended(false);
otherPlayerConnected.signal();
finally
gameLock.unlock();
Client.java
    public void init()
        startClient();
    public void startClient()
        try
            connection = new Socket(InetAddress.getByName(TienLenHost), 12345);
            input = new Scanner(connection.getInputStream());
            output = new Formatter(connection.getOutputStream());
        catch (IOException ie)
            stop();
        ExecutorService worker = Executors.newFixedThreadPool(1);
        worker.execute(this);
    }So after worker.execute(this), it should go to Server.java and run the function execute() right? But in my case, it doesn't. If you know how to fix this, please let me know. Thanks!

Firewall: Error sending to the socket, server is not responding.

Hi all,
I'm trying to connect AIX machine to NT DB2 Database through JDBC with a firewall. I'm using the standard port 6789 in JDBC Applet Server in NT DB2. But I've gotten the following message:
COM.ibm.db2.jdbc.DB2Exception: [IBM][JDBC Driver] CLI0614E Error sending to the socket, server is not responding. SQLSTATE=08S01
The connection chain I'm using for AIX side is:
jdbc:db2://192.168.3.4:6789/DATABASE
I've configured the firewal to allow the port 6789 to be used, and also the other port 51544 (it's for remote administration, I think). I've also checked that wires and other stuff is working fine, but stil I cannot connect to the Database.
I don't know if there's something missing on the firewall configuration. Before, everything was working without the firewall.
Any help will be apreciated, THanks.
Rodrigo, SPAIN

It looks like no port problem is happening, because we freed all the ports just to see if client tried to use some of them without our knowing. But it was still the same.
We were thinking about routing issues, but we were able to ping from client to server, and ports 6789 and 51544 were open as well. Maybe JDBC Client Driver is looking for an different IP address than 192.168.3.4. We know the firewall doesn't receive any query from JDBC Client, and that's very strange because if you see the routing tables in AIX machine, the default route is the firewall. Of course, there's not any other static defined route for the server (192.168.3.4), so it's supposed that default route is going to be used. But it's not.
We also restarted client machine from scratch but nothing. Maybe this problem happens because there's something wrong in AIX networking settings.
Rodrigo

Applet socket

I am trying to make a socket to a server. The code below works in a regular program, but when I paste it into the init method of my applet, it has an error.
try
Socket Sockets = new Socket (server, port);
PrintWriter Out = new PrintWriter (Sockets.getOutputStream (), true);
BufferedReader In = new BufferedReader (new InputStreamReader (Sockets.getInputStream ()));
Out.println (stuffitssending);
while (true)
System.out.println(In.readLine());
Message was edited by:
hnghcgcgmghc

Oh woops. I should have known that.
Applets are locked down pretty severely. You cant even
read/write a file and you certainly cant open a socket.
You have to sign your applet.
How do you sign an applet?
http://www.google.com/search?hl=en&q=how+sign+applet
Search the forums (theres even a whole section).

Assign unique id to client of socket server

HI
I am in the process of developing a xml socket server application and have hit on a problem. I have managed to create a server that listens for connections and once a request is recieved creates a new client on a seperate thread with the reference being stored in a vector in the server.
However I want to be able to assign an id to a client when it is created so that I can broadcast messages to specific users.

my apologies my question was poorly stated..
When i meant unique i mean that they will have already been prdefined i.e for example the following users
Name David
UserId *(Unique) 0138868
Name sarah
UserId *(Unique) 4138868
Name rob
UserId *(Unique) 7138868
what i want to be able to is when the users connect they can be refeneced by their Userid so that if rob wants to say something to sarah without david knowing. The problem I have is that I do not know how to provide the userid to the server such that the server can create a new client thread with a specified id.
Hope that makes sense ;>

Right way to communicate with a socket server (TCP/IP)

Hi,
I used to write data from my J2ME socket client to a J2EE socket server with writeUTF(). In this way I can send (and receive) directly Strings.
When I need an XML file I ask the server with something like os.writeUTF(GIVE_ME_XML_FILE) and I use an XML parser with this socket InputStream.
I was wondering if it's the right way to proceed ....?
How do you guys communicate with a server when you need "to talk" a lot ? Do you use only HTTP requests or (if you are allowed to) do you use Socket with writeUTF ?
Just to know if I'm completely wrong....and if I gonna have unsolicited issues ...
Thanks..

AdrienD wrote:
When I need an XML file I ask the server with something like os.writeUTF(GIVE_ME_XML_FILE) and I use an XML parser with this socket InputStream.
I was wondering if it's the right way to proceed ....?No, it is not. Read the writeUTF api docs, and you'll know why!
How do you guys communicate with a server when you need "to talk" a lot ? Do you use only HTTP requests or (if you are allowed to) do you use Socket with writeUTF ?There is answer to this question. it al depends on what data gets send where, how often, and how large..

Design question for database connection in multithreaded socket-server

Dear community,
I am programming a multithreaded socket server. The server creates a new thread for each connection.
The threads and several objects witch are instanced by each thread have to access database-connectivity. Therefore I implemented factory class which administer database connection in a pool. At this point I have a design question.
How should I access the connections from the threads? There are two options:
a) Should I implement in my server class a new method like "getDatabaseConnection" which calls the factory class and returns a pooled connection to the database? In this case each object has to know the server-object and have to call this method in order to get a database connection. That could become very complex as I have to safe a instance of the server object in each object ...
b) Should I develop a static method in my factory class so that each thread could get a database connection by calling the static method of the factory?
Thank you very much for your answer!
Kind regards,
Dak
Message was edited by:
dakger

So your suggestion is to use a static method from a
central class. But those static-methods are not realy
object oriented, are they?There's only one static method, and that's getInstance
If I use singleton pattern, I only create one
instance of the database pooling class in order to
cionfigure it (driver, access data to database and so
on). The threads use than a static method of this
class to get database connection?They use a static method to get the pool instance, getConnection is not static.
Kaj

CLI0615E Error receiving from socket, server is not responding.

We recently changed a web application using DB2 5.2 tables from ODBC to JDBC. We are using the COM.ibm.db2.jdbc.net.driver. We are using a
connection pool and running on iPlanet.
We are getting intermittant "CLI0615E Error receiving from socket, server is not responding errors". We have looked in the JDBC forum and DB2 support and cannot find a reasonable answer to this problem. It is NOT always on sql statements that take a long time to execute, so I don't think it is a timeout issue.
I read something about "stale connections". Does anyone know how to check to see if this is a problem?
When we first converted the app, we had a lot of problems also with "invalid handle or statement is closed" which we have determined was being caused by the user submitting the page again before it had time to finish the first time. We have put in javascript code to prevent multiple submits. Could this server not responding problem be caused by double submits that we have not located yet?
The error is NOT occuring on any one page, and the same page will run correctly once and the next time throw this error.
Any suggestions would be greatly appreciated.
Thanks.
[29/Apr/2003:11:00:20] info (42196): COM.ibm.db2.jdbc.net.DB2Exception: [IBM][JDBC Driver] CLI0615E Error receiving from socket, server is not responding. SQLSTATE=08S01
     at COM.ibm.db2.jdbc.net.SQLExceptionGenerator.throwReceiveError(SQLExceptionGenerator.java(Compiled Code))
     at COM.ibm.db2.jdbc.net.DB2Request.receive(DB2Request.java(Compiled Code))
     at COM.ibm.db2.jdbc.net.DB2Request.sendAndRecv(DB2Request.java(Compiled Code))
     at COM.ibm.db2.jdbc.net.DB2RowObject.next(DB2RowObject.java(Compiled Code))
     at COM.ibm.db2.jdbc.net.DB2ResultSet.next(DB2ResultSet.java(Compiled Code))
     at bom.Bom.getDefs(Bom.java(Compiled Code))
     at jsps.bbapps._eng._ENGJGLT0_jsp._jspService(_ENGJGLT0_jsp.java(Compiled Code))
     at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:119)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
     at com.iplanet.server.http.servlet.NSServletRunner.invokeServletService(NSServletRunner.java:897)
     at com.iplanet.server.http.servlet.NSServletRunner.Service(NSServletRunner.java:464)

hi,
lemme try to tell u what i thinkk..i dont think its' a solution
Usually this error code means that there was some problem while the driver tried establishsing a socket connection to the remote server. You could very well avoid this by tracking out what is preventing the socket connection.. it may be network congestion or some other onfiguration problems with the network, or with the DB2 server...
But if the same application could work perfectly with jdbc-odbc driver in same environment,then it needs some attention.either the ibm driver isn't throwing the error as expected by the iplanet or iplanet isn't acting as needed when such an error is thrown.
contact them and they may provide and explanation..
wishes,
Jer

Stream based socket , server implementation

Please help me with this simple server and socket problem.
SERVER_
package com.supratim;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
public class SocketServer {
     private static ServerSocket server;
     public static void main(String[] args) throws IOException {
          server = new ServerSocket(9999);
          new SocketServer().go();
     private void go() throws IOException {
     while(true) {
          Socket socket = server.accept();
          DataInputStream dataInputStream = new DataInputStream(socket.getInputStream());
          DataOutputStream dataOutputStream = new DataOutputStream(socket.getOutputStream());
          byte[] buff=new byte[dataInputStream.available()];
          int i;
          while((i=dataInputStream.read())>0) {
               dataInputStream.read(buff, 0, buff.length);
          String inputMessage="INPUT MESSAGE OBTAINED : "+new String(buff);
          byte[]outputBuffer = inputMessage.getBytes();
          dataOutputStream.write(outputBuffer);
          dataOutputStream.flush();
          socket.close();
CLIENT+
package com.supratim;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.UnknownHostException;
public class SocketClient {
     public static void main(String[] args) throws UnknownHostException, IOException {
          new SocketClient().go();
     private void go() throws UnknownHostException, IOException {
          Socket socket = new Socket("localhost",9999);
          InputStream dataInputStream = socket.getInputStream();
          OutputStream dataOutputStream = socket.getOutputStream();
          String inputMessage="ABCDEFGHIJKLMNOPQRSTWXYZ";
          byte[]outputBuffer = inputMessage.getBytes();
          dataOutputStream.write(outputBuffer);
          dataOutputStream.flush();
          byte[] buff=new byte[dataInputStream.available()];
          int i;
          while((i=dataInputStream.read())>0) {
               dataInputStream.read(buff, 0, buff.length);
          System.out.println("RESPONSE : "+new String(buff));
          socket.close();
}When I try to connect to the SERVER from CLIENT, nothing happens. As soon as I terminate the CLIENT, the following stack trace comes...
       Exception in thread "main" java.net.SocketException: Connection reset
        at java.net.SocketInputStream.read(SocketInputStream.java:168)
        at java.net.SocketInputStream.read(SocketInputStream.java:182)
        at java.io.FilterInputStream.read(FilterInputStream.java:66)
        at com.supratim.SocketServer.go(SocketServer.java:26)
        at com.supratim.SocketServer.main(SocketServer.java:14)Please tell me, am I missing something??
I dont want to use PrintWriter,BufferedReader,BufferedWriter...

jverd wrote:
supratim wrote:
jverd wrote:
supratim wrote:
tjacobs01 wrote:
          while((i=dataInputStream.read())>0) {
               dataInputStream.read(buff, 0, buff.length);
          }This is your problem. InputStream.read is going to block progressif it is so...how am I suppose to check the end of the stream....what is the way out??I'm not really sure what problem you're having or what you're asking. However, if your problem is that you want your server to be able to accept new connections while it's servicing an earlier conneciton--that is, service multiple requests at once--then, clearly, you need to use multiple threads. At the very least, one for accepting connections and one for servicing the requests that come on those connections.The problem is when the client is connecting to send a message as a byte stream...the message does not reach there..eventually the connection resets... why is that?? which part of the SocketServer is being blocked...and what is its way out??
Let's say it is used in a single threaded environment..only one client is connecting at a time...Does the client flush()? Does it close() the Socket's OutputStream?
If you don't flush(), data that you have sent may not be received.
If you don't close(), the server won't know the client is done sending, so he'll never get the -1.
(Or, alternative to calling OutputStream.close(), you could call Socket.shutdownOutput(), I think.)
Edited by: jverd on Jul 12, 2011 10:49 AMplease check the code...flushing...closing are all there...

Can't connect java socket server in MAC OS

Does any know what settings need to be done in order to connect socket server written in java on MACOS.
my socket server is running on 5000 port, i've tried on running server on linux, and my program is able to receive the request from remote unix server.
but when the server is running on mac OS, the the unix server couldn' connect to the socket.
is this a port blocking problem?
can someone tell me what to do to make server on MAC OS available for receiving request?
Thanks

Who is the sys/net admin for the Mac?

Keep a Socket Server connection/port open for incoming requests

Hi,
I have a socket server which listens to the incoming messages. The problem is that the socket server terminates the socket connection once it receives a message.
I want this Socket server to keep on running and process all the requests it receives.
Can you please advise which stream shall be kept open for this to be achieved? Below is the code for your reference.
Thanks!
import java.net.*;
import java.io.*;
public class SocketServer
     public static void main(String[] args) throws IOException
             ServerSocket serverSocket = null;
             String result = null;
             SocketServer sockServer = new SocketServer();
             try
                      serverSocket = new ServerSocket(4444);
             catch (IOException e)
                      System.exit(1);
             Socket clientSocket = null;
             try
                  clientSocket = serverSocket.accept();
                      clientSocket.setSoTimeout(30000);
             catch (IOException e)
                  System.exit(1);
             PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
             BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
             String inputLine;
             inputLine = in.readLine();
             if((inputLine == null) || (inputLine.length() < 1))
                      throw new IOException("could not read from request stream");
             else
                      result = sockServer.parseString(inputLine);
                      out.println("|0|OK|");
          InputStream is = null;
              FileOutputStream fout=null;
              BufferedInputStream bufIn = null;
              HttpURLConnection con = null;
              ByteArrayOutputStream baos = null;
                try
               URL url = new URL("http","10.176.96.64",8080,result);
               con = (HttpURLConnection)url.openConnection();
               is = con.getInputStream();
               bufIn = new BufferedInputStream(is);
               fout=new FileOutputStream("Z:\\Clips\\Cache\\"+result);
               baos = new ByteArrayOutputStream();
               int c = bufIn.read();
               while(c != -1)
                    baos.write(c);
                    c = bufIn.read();
               baos.writeTo(fout);
          catch(MalformedURLException mue)
               System.err.println ("*********In Download File: Invalid URL");
          catch (IOException ioe)
               System.err.println ("*********In Download File: I/O Error - " + ioe);
          finally
               try
                    baos.close();
                    bufIn.close();
                    fout.close();
                    is.close();
                    con.disconnect();
               catch(Exception ex)
                    System.out.println("*********In Download File: Exception Occured: "+ex.toString());
                  out.close();
                  in.close();
                  clientSocket.close();
                  serverSocket.close();
}

In a truly unexpected turn of events.. this question has been crossposted.
http://forum.java.sun.com/thread.jspa?threadID=5127579
Good job singalg. I highly recommend that instead of accepting that there is anything wrong with your understanding of how this should work and reviewing the tutorials you should instead repost this question daily, Each day choosing a different forum.

Problem with data socket server

We have developed a program (from LabVIEW 6.1 running on Windows NT) consisting of a main executable and four other executables dedicated to collecting various i/o information. The four i/o executables convert raw data into process data and pass it on to the main executable using Data Sockets. The data is assembled as a cluster, then flattened into a string, which is published to a data socket variable. The data cluster contains a time stamp used by the main executable to verify i/o is being updated periodically (at least once a second). The main executable generates an alarm if the timestamp gets to be more than 5 to 15 seconds old, depending on the expected data. Typically, this alarm never happens, unless an i/o device is powered down o
r disconnected, or an executable or Data Socket Server is terminated.
The problem we are is experiencing is that false alarms are being generated, at precise intervals of exactly 5 days, 18 hours, 1 minute, and 1 second. The alarm condition occurs then clears immediately. The only thing I can think of is the data socket is somehow "cleared" for some reason at this interval, causing the main executable to momentarily read a time stamp of zero, and generate an alarm. Is there anything that might be corrupting the data sockets at a long interval like this? The worst thing is that the alarm horn gets falsely triggered, so we are trying to resolve this but can not see anything in any of the code to cause such an occurrence.
Thanks in advance for your help.
Brian Hajder
Despatch Industries
8860 207th Street West
Lakeville, MN 55044
Phone: 952.469.8111
Fax: 952.469.4513
[email protected]

Hello Matt,
Thank you for reading & responding. I should try to summarize this specific application in a little more detail.
We have built a manufacturing tool for a customer that is controlled by a single Windows NT PC, for which we have developed 5 executables using LabView 6.1. The main executable provides the user interface. The other four executables are dedicated to control & monitoring of specific i/o devices (serial or IEEE-488). The i/o executables pass data to and receive commands from the main using data sockets. The PC is not on any type of network. The main executable supports an optional SEMI standard host link through its ethernet port, but that is not currently active or connected. A total of 13 data sockets are used, to implement si
mple "one way" traffic through any socket, making buffering unnecessary. Some data sockets (i/o data to and from main) are updated a few times a second at most, commands from the main may only be updated a few times a day.
Data from each of the i/o executables includes a time stamp indicating the last valid i/o hardware read time. The main uses this data from each i/o executable to determine whether i/o hardware is responding properly - if the timestamp gets to be anywhere from 5 to 15 seconds old (depending on which i/o is being checked), an i/o failure alarm for that device is raised.
What seems to be happening is that, periodically, precisely every 496,861 seconds, two or more of the timestamps are found to be too old; I am assuming some external event is momentarily clearing socket data & the zero value timestamps look very old, thus triggering alarms at the exact same second. The alarm conditions clear up in less than one second.
I wonder what you mean by "the datasocket
server resetting"? Is this documented anywhere?
Thanks for plowing through this wordy description, I appreciate any help you can suggest.
Brian

Applet socket server

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