Question

提前感谢您的支持。

我在我的java应用程序中使用JSCH来调用远程服务器（Red Hat OS）上的exe文件。我注意到，即使exe完成了它的工作，我的java应用程序也会挂起很长时间。

远程服务器上的exe文件执行时间超过20分钟，因为它需要处理大量文本文件。

在另一种情况下，如果我使用一个小的输入文件并且exe执行一分钟，则java应用程序不会挂起。

请告知申请暂停的原因。我是否需要在jsch代码中添加一些设置？

这是代码，

JSch jsch=null;
    Session session=null;
    java.util.Properties config=null;
    ChannelSftp sftpChannel=null;
    Channel channel=null;
    InputStream in=null,error=null;

    try
    {
        jsch=new JSch();
        session=jsch.getSession(USERNAME, IP, PORT);
        session.setPassword(PASSWORD);

        logBasic("Node="+NODE_ID+", Host IP="+IP+", Port="+PORT+",Username="+USERNAME+", Dump Command="+MIG_TOOL_COMMAND+", Remote Path="+MIG_TOOL_PATH+"\n");  
        scriptOutput.append("Node="+NODE_ID+", Host IP="+IP+", Port="+PORT+",Username="+USERNAME+", Dump Command="+MIG_TOOL_COMMAND+", Remote Path="+MIG_TOOL_PATH+"\n");   
        FILE_NAME=KETTLE_HOME+"/"+LOGS_DIR+"/"+NODE_ID+"_master_slave_execution.log";

        config = new java.util.Properties(); 
        config.put("StrictHostKeyChecking", "no");
        session.setConfig("PreferredAuthentications", 
                      "password");

        session.setConfig(config);
        session.setServerAliveInterval(60*60*60*1000);
        session.connect();

        channel=session.openChannel("exec");
        //((ChannelExec)channel).setCommand(JAVA_COMMAND);
        logBasic("Command = cd "+ MIG_TOOL_PATH+" && "+JAVA_COMMAND+" && "+MIG_TOOL_PATH+MIG_TOOL_COMMAND+" WORKING_MODE="+SLAVE_WORKING_MODE+" INPUT_FILE="+SDP_INPUT_FILENAME+".gz STAND_ALONE_FLAG="+STAND_ALONE_FLAG);
        ((ChannelExec)channel).setCommand("cd "+ MIG_TOOL_PATH+" && "+JAVA_COMMAND+" && "+MIG_TOOL_PATH+MIG_TOOL_COMMAND+" WORKING_MODE="+SLAVE_WORKING_MODE+" INPUT_FILE="+SDP_INPUT_FILENAME+".gz STAND_ALONE_FLAG="+STAND_ALONE_FLAG);

        in=channel.getInputStream();
        error=((ChannelExec)channel).getErrStream();
        channel.connect();


        scriptOutput.append("Error Ouput:\n");

        byte[] tmp=new byte[1024];

        boolean flag=true;
        while(flag)
        {
            while(error.available()>0)
            {
                int i=error.read(tmp, 0, 1024);
                if(i<0) break;
                scriptOutput.append(new String(tmp, 0, i));
            }
            if(channel.isClosed()) flag=false;
            try
            {
                Thread.sleep(threadSleepTime);
            }
            catch(Exception exception)
            {
                logError(exception.getMessage(), exception);
            }
        }

        scriptOutput.append("Log Ouput:\n");

        flag=true;

        while(flag)
        {
            while(in.available()>0)
            {
                int i=in.read(tmp, 0, 1024);
                if(i<0) break;
                scriptOutput.append(new String(tmp, 0, i));
            }
            if(channel.isClosed()) flag=false;
            try
            {
                Thread.sleep(threadSleepTime);
            }
            catch(Exception exception)
            {
                logError(exception.getMessage(), exception);
            }
        }

        channel.disconnect();
        channel=null;

        session.disconnect();

Answer 1

我尝试了我在评论中所说的内容并且工作正常如果您的超时时间少于100秒，请调整setServerAliveInterval(100)，如果您需要超过9999 x 100s，请修改setServerAliveCountMax(9999)

如果这不起作用，请检查服务器端的sshd_config文件，看看是否有任何设置不允许您保持连接活动。

Java：

JSch jsch;
Session session;
Properties config;
Channel channel;
InputStream in, error;
long threadSleepTime = 100;

try {
  jsch = new JSch();
  session = jsch.getSession("timeoutuser", "timeoutHost", 22);
  session.setPassword("pTimeout");

  config = new Properties();
  config.put("StrictHostKeyChecking", "no");
  session.setConfig("PreferredAuthentications", "password");

  session.setConfig(config);
  session.setServerAliveInterval(100);// Send null packet each 100s
  session.setServerAliveCountMax(9999);// Send 9999 max null packet
  session.connect(0);// No connection timeout

  channel = session.openChannel("exec");
  ((ChannelExec) channel).setCommand("./wait.sh");

  in = channel.getInputStream();
  error = ((ChannelExec) channel).getErrStream();
  channel.connect();
  byte[] tmp = new byte[1024];

  boolean flag = true;
  while (flag) {
    while (error.available() > 0) {
      int i = error.read(tmp, 0, 1024);
      if (i < 0) {
        break;
      }
      System.out.print(new String(tmp, 0, i));
    }

    if (channel.isClosed()) {
      flag = false;
    }

    try {
      Thread.sleep(threadSleepTime);
    } catch (InterruptedException ex) {
      System.err.println(ex.getMessage());
    }
  }

  System.out.print("\nLog Ouput:\n");

  flag = true;

  while (flag) {
    while (in.available() > 0) {
      int i = in.read(tmp, 0, 1024);
      if (i < 0) {
        break;
      }
      System.out.print(new String(tmp, 0, i));
    }

    if (channel.isClosed()) {
      flag = false;
    }

    try {
      Thread.sleep(threadSleepTime);
    } catch (InterruptedException ex) {
      System.err.println(ex.getMessage());
    }
  }

  channel.disconnect();

  session.disconnect();
} catch (JSchException | IOException ex) {
  System.err.println(ex.getMessage());
}

脚本wait.sh

#!/bin/bash

for i in {1..20}
do
  sleep 2m
  if [ $((RANDOM%5)) -gt 3 ]; then
    echo "Error $i in process" 1>&2
  fi
done
echo "Process done"

输出：

run:
Error 2 in process
Error 6 in process
Error 12 in process
Error 13 in process
Error 19 in process
Error 20 in process

Log Ouput:
Process done
BUILD SUCCESSFUL (total time: 40 minutes 0 seconds)

即使远程服务器上的脚本完成任务，Java应用程序也会挂起很长时间

1 个答案: