(Java) SSH Parallel Remote Commands on Multiple Servers

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Shows how to execute a command in parallel on multiple servers.

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import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // Executing a command on multiple servers simultaneously is straightforward.
    // It's just a matter of using one SSH object per server..
    CkSsh ssh1 = new CkSsh();
    CkSsh ssh2 = new CkSsh();
    CkSsh ssh3 = new CkSsh();

    int port = 22;
    boolean success = ssh1.Connect("ssh-server1.com",port);
    if (success != true) {
        System.out.println(ssh1.lastErrorText());
        return;
        }

    // Authenticate using login/password:
    success = ssh1.AuthenticatePw("sshLogin1","sshPassword1");
    if (success != true) {
        System.out.println(ssh1.lastErrorText());
        return;
        }

    // Connect and authenticate with 2 more servers.
    // For brevity, the success/failure won't be checked...
    success = ssh2.Connect("ssh-server2.com",port);
    success = ssh2.AuthenticatePw("sshLogin2","sshPassword2");
    success = ssh3.Connect("ssh-server3.com",port);
    success = ssh3.AuthenticatePw("sshLogin3","sshPassword3");

    // Note: If we wanted, we could've used ConnectAsync and AuthenticatePwAsync
    // to do the connecting and authenticating in parallel...

    // The command to be run on each SSH server will sleep for 5 seconds,
    // and then show the current system date/time.
    String cmd = "sleep 5; date";

    // Start each command
    int ssh1Channel = ssh1.QuickCmdSend(cmd);
    if (ssh1Channel < 0) {
        System.out.println(ssh1.lastErrorText());
        return;
        }

    // For brevity, we're not checking the return values here:
    int ssh2Channel = ssh2.QuickCmdSend(cmd);
    int ssh3Channel = ssh3.QuickCmdSend(cmd);

    // OK, at this point the command is running simultaneously on each server.

    // Now collect the results of each command.
    int pollTimeoutMs = 50;
    int numFinished = 0;
    int channel;
    // Note: You would rewrite this code to use arrays.
    boolean ssh1Finished = false;
    boolean ssh2Finished = false;
    boolean ssh3Finished = false;
    while (numFinished < 3) {
        // Check to see if anything has finished.
        // QuickCmdCheck returns -1 if there are no errors and nothing else finished
        // QuickCmdCheck returns -2 if there was an error (such as a lost connection)
        // QuickCmdCheck returns a channel number if a channel finished.
        if (ssh1Finished != true) {
            channel = ssh1.QuickCmdCheck(pollTimeoutMs);
            if (channel == -2) {
                System.out.println(ssh1.lastErrorText());
                return;
                }

            if (channel == ssh1Channel) {
                System.out.println("---- ssh1 channel " + channel + " finished ----");
                System.out.println(ssh1.getReceivedText(channel,"ansi"));
                numFinished = numFinished+1;
                ssh1Finished = true;
                }

            }

        if (ssh2Finished != true) {
            channel = ssh2.QuickCmdCheck(pollTimeoutMs);
            if (channel == -2) {
                System.out.println(ssh2.lastErrorText());
                return;
                }

            if (channel == ssh2Channel) {
                System.out.println("---- ssh2 channel " + channel + " finished ----");
                System.out.println(ssh2.getReceivedText(channel,"ansi"));
                numFinished = numFinished+1;
                ssh2Finished = true;
                }

            }

        if (ssh3Finished != true) {
            channel = ssh3.QuickCmdCheck(pollTimeoutMs);
            if (channel == -2) {
                System.out.println(ssh3.lastErrorText());
                return;
                }

            if (channel == ssh3Channel) {
                System.out.println("---- ssh3 channel " + channel + " finished ----");
                System.out.println(ssh3.getReceivedText(channel,"ansi"));
                numFinished = numFinished+1;
                ssh3Finished = true;
                }

            }

        }

    // --------------
    // Sample output:

    // 	---- ssh2 channel 101 finished ----
    // 	Fri Dec 23 00:25:48 UTC 2016
    // 
    // 	---- ssh3 channel 102 finished ----
    // 	Thu Dec 22 18:25:12 CST 2016
    // 
    // 	---- ssh1 channel 100 finished ----
    // 	Thu Dec 22 18:25:48 CST 2016
  }
}