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https://issues.apache.org/jira/browse/NET-584?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15906152#comment-15906152
]
Sebb commented on NET-584:
--------------------------
The NOOPs are only (potentially) needed for long running data transfers which
pass through a router.
They should not be needed for talking directly to an FTP server, because the
server knows which control channels are associated with which data channels.
(If it does not, it is badly broken!)
Some routers are clever enough to do the same; some just see an idle channel
and assume it has been abandoned. These latter need NOOPs to try and prevent
disconnection.
FTPClient only sends the NOOPs if the wait time is > 0 and the command is one
of the retrieve/store operations that don't involve application interaction.
In other cases where the control channel may be idle for long periods, it is up
to the app to send NOOPs.
FTP servers that can support parallel control channel traffic will respond to
the NOOPs during the data transfer.
If not, then the replies will likely be sent when the transfer completes and
the server returns to processing the control channel.
FTPClient keeps a count of the number of unanswered NOOPs and tries to drain
these at the end of the transfer.
If any requests or responses got lost, then of course we get a timeout, which
is what I think we are seeing.
I guess the longer the data transfer, the more likely it is that they are lost.
This may explain the behaviour you are seeing with bigger files.
Note: the SNAPSHOT code now assumes that a timeout during cleanup means that
there are no more replies left and does not throw an exception (it writes to
stderr instead).
I think it is correct to ignore the timeout here; however writing to stderr is
no use for production code.
Need to either ignore the timeout or find a way to let the app know (or a way
for the app to find out).
Meanwhile it would be very helpful if you were able to try the updated code.
> Error with org.apache.commons.net.ftp.FTPClient
> ------------------------------------------------
>
> Key: NET-584
> URL: https://issues.apache.org/jira/browse/NET-584
> Project: Commons Net
> Issue Type: Bug
> Components: FTP
> Reporter: Kazantsev Andrey Sergeevich
>
> I have a question about using library commons-net-3.4.jar
> Question is about org.apache.commons.net.ftp.FTPClient method
> setControlKeepAliveTimeout.
> Read about using it on:
> https://commons.apache.org/proper/commons-net/apidocs/org/apache/commons/net/ftp/FTPClient.html
> When I use it in my code I get this error:
> {code}
> java.net.SocketTimeoutException: Read timed out
> at java.net.SocketInputStream.socketRead0(Native Method)
> at java.net.SocketInputStream.read(SocketInputStream.java:163)
> at java.net.SocketInputStream.read(SocketInputStream.java:133)
> at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:322)
> at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:364)
> at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:210)
> at java.io.InputStreamReader.read(InputStreamReader.java:205)
> at java.io.BufferedReader.fill(BufferedReader.java:165)
> at java.io.BufferedReader.read(BufferedReader.java:186)
> at
> org.apache.commons.net.io.CRLFLineReader.readLine(CRLFLineReader.java:58)
> at org.apache.commons.net.ftp.FTP.__getReply(FTP.java:313)
> at org.apache.commons.net.ftp.FTP.__getReplyNoReport(FTP.java:303)
> at org.apache.commons.net.ftp.FTPClient$CSL.cleanUp(FTPClient.java:3838)
> at org.apache.commons.net.ftp.FTPClient._storeFile(FTPClient.java:695)
> at org.apache.commons.net.ftp.FTPClient.__storeFile(FTPClient.java:643)
> at org.apache.commons.net.ftp.FTPClient.storeFile(FTPClient.java:2033)
> at ru.mdm.File.Transfer.FTP.PutRemoteFileBinary(FTP.java:192)
> at
> ru.mdm.File.Transfer.TimeLimit.Thread.Protocol.PutRemoteFileBinaryThread.actionsToExecute(PutRemoteFileBinaryThread.java:23)
> at
> ru.mdm.File.Transfer.TimeLimit.OperationThread.run(OperationThread.java:60)
> {code}
> Without enabling this option all works fine.
> Here is the code:
> {code}
> package ru.mdm.File.Transfer;
> import bin.ru.osa.common.utils.*;
> import java.util.List;
> import java.io.*;
> import com.ibm.broker.javacompute.MbJavaComputeNode;
> import com.ibm.broker.plugin.*;
> import org.apache.commons.net.ftp.*;
> import org.apache.commons.net.*;
> import ru.mdm.File.Transfer.Options.OptionsXMLProcessor;
> public class FTP implements Protocol
> {
>
> FTPClient client = new FTPClient();
>
> OptionsXMLProcessor optionsXMLProcessor;
>
>
> boolean st;
> String LastMessage = new String();
>
> boolean ignoreErrors = false;
>
>
> public FTP()
> {
> super();
> }
>
> protected void finalize() { disconnect(); }
>
> public void connect(String CntName,
> String Host,
> String Port,
> String L,
> String P) throws Exception
> {
> try
> {
> client.setControlKeepAliveTimeout(300);
> client.connect(Host);
> client.login(L, P);
> CheckState();
> }
> catch(Exception e)
> {
> LastMessage=client.getReplyString();
> if(LastMessage == null) LastMessage = e.getMessage();
>
> e.printStackTrace();
>
> throw e;
> }
> }
>
> public void disconnect()
> {
> try
> {
> if(client.isConnected())
> {
> client.logout();
> client.disconnect();
> }
> }
> catch(Exception e)
> {
> e.printStackTrace();
> }
> }
>
> public void chmod(String RemoteFile, String Rights) throws Exception
> {
> client.sendSiteCommand("chmod "+RemoteFile+" "+Rights);
> CheckState();
> }
>
>
> public void lsMB(MbElement InputDir,MbElement filelist) throws
> Exception, MbException
> {
> MbElement xfile;
>
> for (FTPFile file :
> client.listFiles((String)InputDir.evaluateXPath("string(SOURCE_PATH)")))
> {
> if(!file.isFile()) continue; //-- No sub-dirs, No Symlinks !
>
>
> xfile=filelist.createElementAsLastChild(MbElement.TYPE_NAME,
> "File", null);
> xfile.createElementAsLastChild(MbElement.TYPE_NAME, "FileName",
> file.getName());
> xfile.createElementAsLastChild(MbElement.TYPE_NAME, "FileSize",
> file.getSize());
> xfile.createElementAsLastChild(MbElement.TYPE_NAME, "SourcePath",
> (String)InputDir.evaluateXPath("string(SOURCE_PATH)"));
> xfile.createElementAsLastChild(MbElement.TYPE_NAME,
> "SourceGateway", (String)InputDir.evaluateXPath("string(GATEWAY_NAME)"));
> }
> }
>
> public void mkdir(String RemotePath) throws Exception
> {
> client.makeDirectory(RemotePath);
> CheckState();
> }
>
> public void chdir(String RemotePath) throws Exception
> {
> client.changeWorkingDirectory(RemotePath);
> CheckState();
> }
>
> public void delete(String RemotePath) throws Exception
> {
> client.deleteFile(RemotePath);
> CheckState();
> }
>
>
>
> public void rename(String RemoteFileSrc, String RemoteFileDst)
> throws Exception
> {
> client.rename(RemoteFileSrc, RemoteFileDst);
> CheckState();
> }
>
>
> public void GetRemoteFileBinary(String RemoteFile, String LocalFile)
> throws Exception
> {
> client.enterLocalPassiveMode();
> client.setFileType(FTPClient.BINARY_FILE_TYPE);
> client.retrieveFile(RemoteFile,
> new FileOutputStream(LocalFile));
>
>
> CheckState();
> }
>
> public void PutRemoteFileBinary(String LocalFile, String RemoteFile)
> throws Exception
> {
> client.enterLocalPassiveMode();
> client.setFileType(FTPClient.BINARY_FILE_TYPE);
> client.storeFile(RemoteFile,
> new FileInputStream(LocalFile));
> CheckState();
> }
>
>
> public void ignoreErrors(boolean x) { ignoreErrors=x; }
>
>
> public boolean isOK() { return st; }
>
> public boolean isConnected()
> {
> boolean answer=false;
> try {
> answer = client.sendNoOp();
> } catch (IOException e) {
> // TODO Auto-generated catch block
> e.printStackTrace();
> }
> st = answer;
> return answer;
>
> }
>
>
> public String LastMessage() { return LastMessage; };
>
>
> public void CheckState(boolean state) throws Exception
> {
> int reply = client.getReplyCode();
> if(FTPReply.isPositiveCompletion(reply)) st=true;
> else st=false;
>
> LastMessage=client.getReplyString();
>
> if(!st && !ignoreErrors)
> throw new Exception(LastMessage);
> }
>
> public void CheckState() throws Exception
> {
> int reply = client.getReplyCode();
> if(FTPReply.isPositiveCompletion(reply)) st=true;
> else st=false;
>
> LastMessage=client.getReplyString();
>
> if(!st && !ignoreErrors)
> throw new Exception(LastMessage);
> }
>
> public void attachOptions(OptionsXMLProcessor optionsXMLProcessor)
> throws Exception
> {
> this.optionsXMLProcessor = optionsXMLProcessor;
> }
>
> public String getIP() {
>
> return "";
> }
>
> public boolean isIgnoreErrors()
> {
> return ignoreErrors;
> }
> }
> {code}
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