Camel: File operation failed: Connection closed without indication.. Code: 421

Question

I'm using Camel 2.15.2 with Apache Commons Net 3.3 on Java 8 deployed into a Tomcat container.

The issue is that consistently after processing just over 200 files (> 4000 files in the directory) the route stops, the FTP client disconnects and the following message is logged out:

[ogs.sharp-stream.com:21/root/] FtpConsumer                    WARN  Error processing file RemoteFile[route/to/file] due to File operation failed:  Connection closed without indication.. Code: 421. Caused by: [org.apache.camel.component.file.GenericFileOperationFailedException - File operation failed:  Connection closed without indication.. Code: 421] 
org.apache.camel.component.file.GenericFileOperationFailedException: File operation failed:  Connection closed without indication.. Code: 421 
        at org.apache.camel.component.file.remote.FtpOperations.getCurrentDirectory(FtpOperations.java:713) 
        at org.apache.camel.component.file.remote.FtpOperations.retrieveFileToFileInLocalWorkDirectory(FtpOperations.java:440) 
        at org.apache.camel.component.file.remote.FtpOperations.retrieveFile(FtpOperations.java:310) 
        at org.apache.camel.component.file.GenericFileConsumer.processExchange(GenericFileConsumer.java:384) 
        at org.apache.camel.component.file.remote.RemoteFileConsumer.processExchange(RemoteFileConsumer.java:137) 
        at org.apache.camel.component.file.GenericFileConsumer.processBatch(GenericFileConsumer.java:211) 
        at org.apache.camel.component.file.GenericFileConsumer.poll(GenericFileConsumer.java:175) 
        at org.apache.camel.impl.ScheduledPollConsumer.doRun(ScheduledPollConsumer.java:187) 
        at org.apache.camel.impl.ScheduledPollConsumer.run(ScheduledPollConsumer.java:114) 
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) 
        at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) 
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) 
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) 
        at java.lang.Thread.run(Thread.java:745) 
Caused by: org.apache.commons.net.ftp.FTPConnectionClosedException: Connection closed without indication. 
        at org.apache.commons.net.ftp.FTP.__getReply(FTP.java:317) 
        at org.apache.commons.net.ftp.FTP.__getReply(FTP.java:294) 
        at org.apache.commons.net.ftp.FTP.sendCommand(FTP.java:483) 
        at org.apache.commons.net.ftp.FTP.sendCommand(FTP.java:608) 
        at org.apache.commons.net.ftp.FTP.sendCommand(FTP.java:582) 
        at org.apache.commons.net.ftp.FTP.pwd(FTP.java:1454) 
        at org.apache.commons.net.ftp.FTPClient.printWorkingDirectory(FTPClient.java:2658) 
        at org.apache.camel.component.file.remote.FtpOperations.getCurrentDirectory(FtpOperations.java:709) 
        ... 15 more 

This is the URI used at the begining of the related route.

As you can tell from the URI I'm also using a FileIdempotentRepository. It's defined like this

            <property name="fileStore" value="target/fileidempotent/.filestore1.dat" />

            <property name="maxFileStoreSize" value="512000" />

            <property name="cacheSize" value="250" />
    </bean>

Any ideas why the connection might be closing before all files are processed?

Answer 1

You need to add following parameter to you ftp/ftps url

disconnect=true

This will result in disconnecting from your remote host after file(s) are transferred and a fresh connection being attempted whenever the route is triggered again . (instead of using the stale one , which might have been closed by remote host/firewall)