I think it is because you have configured too few passive ports (3). Every file transfer/list command locks a port until the data transfer completes. So, if you have 3 concurrent users transferring files and a 4th one comes in, it will error out.
You might want to increase the passive port range based on the load you expect. Sai Pullabhotla www.jMethods.com 2009/6/9 Gérard Frédéric <[email protected]> > Hi All > > We now use ftpserver for more than one year (Dec 10 2007 incubator version) > Everything goes well on linux, solaris and windows > But sometimes I cannot explain this exception which occurs very > infrequently, on linux here : > > 12:10:43,034 INFO listener.FtpProtocolHandler pool-2-thread-4 - Open > connection - 10.24.231.113 > 12:10:43,303 INFO command.PASS pool-2-thread-4 - Login success - user1 > 12:10:43,722 WARN command.PASV pool-2-thread-4 - Failed to open passive > data connection > org.apache.ftpserver.DataConnectionException: > FtpDataConnection.setPasvCommand() > at > org.apache.ftpserver.IODataConnectionFactory.initPassiveDataConnection(IODataConnectionFactory.java:182) > at org.apache.ftpserver.command.PASV.execute(PASV.java:69) > at > org.apache.ftpserver.listener.FtpProtocolHandler.service(FtpProtocolHandler.java:203) > at > org.apache.ftpserver.listener.FtpProtocolHandler.onRequestReceived(FtpProtocolHandler.java:130) > at > org.apache.ftpserver.listener.mina.MinaFtpProtocolHandler.messageReceived(MinaFtpProtocolHandler.java:109) > at > org.apache.mina.common.support.AbstractIoFilterChain$TailFilter.messageReceived(AbstractIoFilterChain.java:569) > at > org.apache.mina.common.support.AbstractIoFilterChain.callNextMessageReceived(AbstractIoFilterChain.java:298) > at > org.apache.mina.common.support.AbstractIoFilterChain.access$1100(AbstractIoFilterChain.java:53) > at > org.apache.mina.common.support.AbstractIoFilterChain$EntryImpl$1.messageReceived(AbstractIoFilterChain.java:647) > at > org.apache.mina.filter.executor.ExecutorFilter.processEvent(ExecutorFilter.java:220) > at > org.apache.mina.filter.executor.ExecutorFilter$ProcessEventsRunnable.run(ExecutorFilter.java:266) > at > edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1061) > at > edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:575) > at java.lang.Thread.run(Thread.java:595) > 12:10:43,782 INFO listener.FtpProtocolHandler pool-2-thread-4 - Close > connection : 10.24.231.113 - user1 > > > 3 ports are configured for passive connections, in addition to the listener > There is not an explicit reason about this behavior, could it be a java > memory issue or any lack of resources ? > > Thanks > > Frédéric > > > > ________________________________ > > Ce message et les pièces jointes sont confidentiels et réservés à l'usage > exclusif de ses destinataires. Il peut également être protégé par le secret > professionnel. Si vous recevez ce message par erreur, merci d'en avertir > immédiatement l'expéditeur et de le détruire. L'intégrité du message ne > pouvant être assurée sur Internet, la responsabilité du groupe Atos Origin > ne pourra être recherchée quant au contenu de ce message. Bien que les > meilleurs efforts soient faits pour maintenir cette transmission exempte de > tout virus, l'expéditeur ne donne aucune garantie à cet égard et sa > responsabilité ne saurait être recherchée pour tout dommage résultant d'un > virus transmis. > > This e-mail and the documents attached are confidential and intended solely > for the addressee; it may also be privileged. If you receive this e-mail in > error, please notify the sender immediately and destroy it. As its integrity > cannot be secured on the Internet, the Atos Origin group liability cannot be > triggered for the message content. Although the sender endeavours to > maintain a computer virus-free network, the sender does not warrant that > this transmission is virus-free and will not be liable for any damages > resulting from any virus transmitted. >
