CODEWITHSUNDEEP
javaapache-camel
Jan Larsen
Jan Larsen

Reputation: 871

Apache Camel route hangs when file is deleted during processing

The program i am trying to build, consumes files on a Windows file share using Camel 2.18.5 and other programs occasionally add/modify/delete files in the share folder.

Building a simple test route 

        from("file:///C:/Temp/from?readLock=changed&readLockCheckInterval=10000&readLockTimeout=0")
            .routeId("SimpleFileRoute")
            .to("file:/C:/Temp/to");

then placing a file, test.txt, in the from folder, waiting for the route to make a test.txt.camelLock file and then manually deleting test.txt before the readLockCheckInterval has passed, will cause the route to hang indefinitely without throwing an exception or processing any other files.

"changed" seems to be the only appropriate readLock for the situation.

Is there any way to make the route throw an exception, clean up the lock file and continue consuming files?

Edit: The stack trace of the thread that seems to be the route is this:

Daemon Thread [Camel (camel-1) thread #2 - file:///C:/Temp/from] (Suspended)    
Thread.sleep(long) line: not available [native method]  
FileChangedExclusiveReadLockStrategy.sleep() line: 104  
FileChangedExclusiveReadLockStrategy.acquireExclusiveReadLock(GenericFileOperations<File>, GenericFile<File>, Exchange) line: 90    
GenericFileRenameProcessStrategy<T>(GenericFileProcessStrategySupport<T>).begin(GenericFileOperations<T>, GenericFileEndpoint<T>, Exchange, GenericFile<T>) line: 64    
GenericFileRenameProcessStrategy<T>.begin(GenericFileOperations<T>, GenericFileEndpoint<T>, Exchange, GenericFile<T>) line: 37  
FileConsumer(GenericFileConsumer<T>).processExchange(Exchange) line: 362    
FileConsumer(GenericFileConsumer<T>).processBatch(Queue<Object>) line: 223  
FileConsumer(GenericFileConsumer<T>).poll() line: 187   
FileConsumer(ScheduledPollConsumer).doRun() line: 174   
FileConsumer(ScheduledPollConsumer).run() line: 101 
Executors$RunnableAdapter<T>.call() line: 511   
ScheduledThreadPoolExecutor$ScheduledFutureTask<V>(FutureTask<V>).runAndReset() line: 308   
ScheduledThreadPoolExecutor$ScheduledFutureTask<V>.access$301(ScheduledThreadPoolExecutor$ScheduledFutureTask) line: 180    
ScheduledThreadPoolExecutor$ScheduledFutureTask<V>.run() line: 294  
RejectableScheduledThreadPoolExecutor(ThreadPoolExecutor).runWorker(ThreadPoolExecutor$Worker) line: 1142   
ThreadPoolExecutor$Worker.run() line: 617   
Thread.run() line: 745

Upvotes: 1

Views: 1153

Answers (1)

Claus Ibsen
Claus Ibsen

Reputation: 55750

Okay so the issue is that you use readLockTimeout=0 which then prevents the read lock to timeout if a lock on the file cannot be granted, for whatever reason. You should not really do this (bad idea) so set it to a higher timeout value.

On the other hand we can also improve camel-core to check if the file still exists when it checks for changed and if the file doesnt exists then it can exit the check also.

I have logged a ticket about this: https://issues.apache.org/jira/browse/CAMEL-13025

Upvotes: 2

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