Task :
Design a distributed application using Socket. Application consists of a server which requests CPU loads to n clients and finds the maximum and minimum loaded systems.
To find CPU load of a single local machine, see
this previous post .
Server.java :
public class Server extends Thread
{
private ServerSocket serverSocket;
public Server(int port) throws IOException
{
serverSocket = new ServerSocket(port);
serverSocket.setSoTimeout(30000);
}
public void run()
{
int p1=0,p2=0;
float max,min;
int j=0,i;
float a[]=new float [10];
String clients[]=new String [10];
while(true)
{
try
{
clients[j]="";
String cmd="";
float y;
System.out.println("Port ready to connect: " + serverSocket.getLocalPort());
Socket server = serverSocket.accept();
System.out.println("Connected");
DataInputStream in = new DataInputStream(server.getInputStream());
DataOutputStream out = new DataOutputStream(server.getOutputStream());
out.writeUTF("mpstat");
cmd=in.readUTF();
y=Float.parseFloat(cmd);
y=100-y;
clients[j]=""+server.getRemoteSocketAddress();
a[j]=y;
j++;
System.out.println("CPU load:"+y);
server.close();
}catch(SocketTimeoutException s)
{
System.out.println("Socket timed out!");
break;
}catch(IOException e)
{
System.out.println(e);
break;
}
}
max=a[0];
min=a[0];
for(i=1; i
{
if(max < a[i]){
max=a[i];
p1=i;
}
else if(min > a[i]){
min=a[i];
p2=i;
}
System.out.println();
System.out.println("\nMax Load: "+max+" from "+clients[p1]);
System.out.println("Min Load: "+min+" from "+clients[p2]);
}
}
public static void main(String [] args)
{
int port = 5555;
try
{
Thread t = new Server(port);
t.start();
}catch(IOException e)
{
e.printStackTrace();
}
}
}
Client.java :
public class Client
{
public static void main(String [] args)
{
String serverName = "server_ip";
int port = 5555;
try
{
System.out.println("Connecting to " + serverName + " on port " + port);
Socket client = new Socket(serverName, port);
System.out.println("connected");
OutputStream outToServer = client.getOutputStream();
DataOutputStream out = new DataOutputStream(outToServer);
InputStream inFromServer = client.getInputStream();
DataInputStream in = new DataInputStream(inFromServer);
String x=in.readUTF();
Process p=Runtime.getRuntime().exec(x);
BufferedReader inbuf=new BufferedReader(new InputStreamReader(p.getInputStream()));
String l=null;
int i=1;
String y="";
while((l=inbuf.readLine()) != null && i < 4)
i++;
if(i>1)
System.out.println("Action completed");
for(i=l.length()-5; i < l.length(); i++)
y=y+l.charAt(i);
out.writeUTF(y);
client.close();
}catch(IOException e)
{
e.printStackTrace();
}
}
}
