Camel SFTP Route fails to continue onException - apache-camel

I've fairly simple looking route
sftp://hostname:22//incoming/folder/location/?username=username&password=xxxxx
&localWorkDirectory=/tmp&readLock=changed&readLockCheckInterval=2000
&move=processed/$simple{date:now:yyyy}/$simple{date:now:MM}/$simple{date:now:dd}${file:name}
&consumer.delay=450000&stepwise=false&streamDownload=true&disconnect=true
I also have an onException clause
onException(ValidationException.class)
.handled(true)
.logStackTrace(true)
.filter(header("VALIDATION_ERROR").isEqualTo(true))
.choice()
.when(header("CamelFileName").contains("Param1"))
.to(sftp://hostname:22//One/error/folder?password=xxxxxx&username=username)
.when(header("CamelFileName").contains("Param2"))
.to(sftp://hostname:22//Two/error/folder?password=xxxxxx&username=username)
.endChoice();
When I have single file, the route seems to work as expected. When more than one file and exception occurs, I get many different exceptions like
org.apache.camel.component.file.GenericFileOperationFailedException: Cannot list directory: incoming/folder/location
Caused by: java.lang.IndexOutOfBoundsException
I tried using all the attributes mentioned in the route viz. streamDownload, stepwise, readLock, localWorkDirectory et al. However, the error handling while multiple files is not working. I see the first file getting processed. However, it doesn't move to the processed folder once the exception occurs and then incoming/folder/location becomes non listable. I tried using continued(true) as well instead of handled(true)

The problem was with multiple files being handled in the same exchange. On exception, the route was trying to FTP back the error file on the same server. The solution was to split body into multiple exchanges so that each file has its own exchange and process them separately.
from(sftp://hostname:22//incoming/folder/location/?username=username&password=xxxxx
&localWorkDirectory=/tmp&readLock=changed&disconnect=true&stepwise=false
&move=processed/$simple{date:now:yyyy}/$simple{date:now:MM}/$simple{date:now:dd}${file:name}
&consumer.delay=450000).split(body()).processRef("incomingProcessor").end();

Related

Camel appears to ignore onException instruction - what am I doing wrong?

I have a Camel (2.21.2) route that gets an XML file via FTP and then splits it before processing further, somewhat like...
from("direct-vm:start")
.split()
.xtokenize("*/row", 'w', ns)
.streaming()
...
If an empty file is passed, I am getting a com.ctc.wstx.exc.WstxEOFException raised by the xtokenize step I presume, which seems perfectly reasonable.
However, when I try to put in an onException clause, it doesn't seem to be catching the exception.
I have:
onException(com.ctc.wstx.exc.WstxEOFException.class)
.handled(true)
.log(org.apache.camel.LoggingLevel.INFO,
"myLogger",
"File ${header.CamelFileName} is empty or invalid XML");
and yet the exception is resulting in the route failing with the exception, and my handler log message is never produced.
However, if I change the onException clause to java.lang.Exception.class, it does handle the exception.
I don't want this to handle any exception, just the one caused by an empty or incomplete file.
What I am doing wrong here? How do I get onException to handle only the exception I am interested in?
Thanks for looking!

Aggregate after exception from ftp consumer: FatalFallbackErrorHandler

My camel route tries to pick up some files from sftp, transfer them to network, and delete them from sftp. If the sftp is unreachable after 3 attempts, I want the route to send an email warning the admin about the problem.
For this reason my sftp address has the following parameters:
maximumReconnectAttempts=2&throwExceptionOnConnectFailed=true&consumer.bridgeErrorHandler=true
In case the network location is not available, i want the route to notify the admin and not delete the files from sftp.
For this reason i have set .handled(false) in onException.
However, when connecting to sftp fails, aggregation also fails and no emails are coming. I have made a minimalist example below:
/configure
onException(Throwable.class)
.retryAttemptedLogLevel(LoggingLevel.WARN)
.redeliveryDelay(1000)
.handled(false)
.log(LoggingLevel.ERROR, LOG, "XXX - Error moving files")
.to(AGGREGATEROUTE)
.end();
from(downloadFrom)
.to(to)
.log(LoggingLevel.INFO, LOG, "XXX - Moving file OK")
.to(AGGREGATEROUTE);
from(AGGREGATEROUTE)
.log(LoggingLevel.INFO, LOG, "XXX - Starting aggregation.")
.aggregate(constant(true), new GroupedExchangeAggregationStrategy())
.completionFromBatchConsumer()
.completionTimeout(10000)
.log(LoggingLevel.INFO, LOG, "XXX - Aggregation completed, sending mail.");
In the logs i see:
16:02| ERROR | CamelLogger.java 156 | XXX - Error moving files
Then the logs for the Exception occurring during connection.
And then this:
16:02| ERROR | FatalFallbackErrorHandler.java 174 | Exception occurred while trying to handle previously thrown exception on exchangeId: ID-LP0641-1552662095664-0-2 using: [Pipeline[[Channel[Log(proefjes.camel_cursus.routebuilders.MoveWithPickupExceptions)[XXX - Error moving files]], Channel[sendTo(direct://aggregate)]]]].
16:02| ERROR | FatalFallbackErrorHandler.java 172 | \--> New exception on exchangeId: ID-LP0641-1552662095664-0-2
org.apache.camel.component.file.GenericFileOperationFailedException: Cannot connect to sftp://user#mycompany.nl:22
at org.apache.camel.component.file.remote.SftpOperations.connect(SftpOperations.java:149)
I do not see "XXX - Starting aggregation." which i would expect to see in the log. Does some kind of error occur befor aggregation? The breakpoint on aggregate(*, *) is never reached.
First, I just want to clarify something. You write "In case the network location is not available, i want the route to notify the admin and not delete the files from sftp", but shouldn't that be obvious anyhow? I mean, if the network location is not available, wouldn't deleting the files from sftp be impossible?
It's a little confusing that your exception handler is also routing .to(AGGREGATEROUTE). Given that you want to email an admin, shouldn't that be in the exception handler, not in the happy path? Why would you and how would you "aggregate" a connection failure?
Finally, and here I think is a real problem with your implementation, you may have misunderstood what handled(false) does. Setting this to false means routing should stop and propagate the exception returned to the caller. I'm not sure what having to the .to(AGGREGATEROUTE) would do in this case, but I'm not surprised it's not being called.
I suggest trying a few things. I don't have your code so I'm not sure which will work best. These are all related and any might work:
Change handled(false) to handled(true).
Replace handled with continued(true).
Use a Dead Letter Channel.
Reference:
Handle and Continue Exceptions
Dead Letter Channel
Since errorhandling is different depending on which endpoint causes the error, i have solved this by having two different versions of onException:
//configure exception on sft end
onException(Throwable.class)
.maximumRedeliveries(2)
.retryAttemptedLogLevel(LoggingLevel.WARN)
.redeliveryDelay(1000)
.onWhen(new hasSFTPErrorPredicate())
// .continued(true) // tries to connect once, mails and continues to aggregation with empty exchange
//.handled(false) // tries to connect twice but does not reach mail
.handled(true) // tries to connect once, does reach mail
// handled not defined: tries to connect twice but does not reach mail
.log(LoggingLevel.INFO, LOG, "XXX - SFTP exception")
.to(MAIL_ROUTE)
.end();
// exception anywhere else
onException(Throwable.class)
.maximumRedeliveries(2)
.retryAttemptedLogLevel(LoggingLevel.WARN)
.redeliveryDelay(1000)
.log(LoggingLevel.ERROR, LOG, "XXX - Error moving file ${file:name}: ${exception}")
.to(AGGREGATEROUTE)
.handled(false)
.end();
Exceptions occuring at the sftp end are handled in the first onException, because there the hasSFTPErrorPredicate returns 'true'. All this predicate does is check if any exception or their cause has "Cannot connect to sftp:" in the message.
No rollback is required in this case because nothing has happened yet.
Any other exception is handled by the second onException.

Apache Camel route with no "to" endpoint

I am using Apache Camel to assist with capturing message data emitted by a third party software package. In this particular instance, I only need to capture what is produced by the software, there is no receiver on the other end (really no "end" to go to).
So, I tried to set up a route with just the "from" endpoint and no "to" endpoint. Apparently this is incorrect usage as I received the following exception:
[2018-08-15 11:08:03.205] ERROR: string.Launcher:191 - Exception
org.apache.camel.FailedToCreateRouteException: Failed to create route route1 at: >>> From[mina:udp://localhost:9877?sync=false] <<< in route: Route(route1)[[From[mina:udp://localhost:9877?sync=false]] -... because of Route route1 has no output processors. You need to add outputs to the route such as to("log:foo").
at org.apache.camel.model.RouteDefinition.addRoutes(RouteDefinition.java:1063)
at org.apache.camel.model.RouteDefinition.addRoutes(RouteDefinition.java:196)
at org.apache.camel.impl.DefaultCamelContext.startRoute(DefaultCamelContext.java:974)
at org.apache.camel.impl.DefaultCamelContext.startRouteDefinitions(DefaultCamelContext.java:3301)
at org.apache.camel.impl.DefaultCamelContext.doStartCamel(DefaultCamelContext.java:3024)
at org.apache.camel.impl.DefaultCamelContext.access$000(DefaultCamelContext.java:175)
at org.apache.camel.impl.DefaultCamelContext$2.call(DefaultCamelContext.java:2854)
at org.apache.camel.impl.DefaultCamelContext$2.call(DefaultCamelContext.java:2850)
at org.apache.camel.impl.DefaultCamelContext.doWithDefinedClassLoader(DefaultCamelContext.java:2873)
at org.apache.camel.impl.DefaultCamelContext.doStart(DefaultCamelContext.java:2850)
at org.apache.camel.support.ServiceSupport.start(ServiceSupport.java:61)
at org.apache.camel.impl.DefaultCamelContext.start(DefaultCamelContext.java:2819)
at {removed}.Launcher.startCamel(Launcher.java:189)
at {removed}.Launcher.main(Launcher.java:125)
Caused by: java.lang.IllegalArgumentException: Route route1 has no output processors. You need to add outputs to the route such as to("log:foo").
at org.apache.camel.model.RouteDefinition.addRoutes(RouteDefinition.java:1061)
... 13 more
How do I set up a camel route that allows me to intercept (capture) the message traffic coming from the source, and not send it "to" anything? There is no need for a receiver. What would be an appropriate "to" endpoint that just drops everything it receives?
The exception suggestion of to("log:foo"). What does this do?
You can see if the Stub component can help
http://camel.apache.org/stub.html
Example:
from("...")
.to("stub:nowhere");
The exception suggestion of to("log:foo"). What does this do?
It sends your route messages to an endpoint with a component of type log:
(http://camel.apache.org/log.html) - component which basically dumps message contents (body and/or headers and/or properties) to your log file using appropriate log category.
If you just want to drop everything received, it's a good choice:
to("log:com.company.camel.sample?level=TRACE&showAll=true&multiline=true")
Apparently if you're under Linux or Unix, you can also redirect to /dev/null like in this example:
to( "file:/dev?fileName=null")
I am not sure it can be used on Windows but I don't think so.
Note that the syntax: to( "file:/dev/null") does not work as it point to a directory called null but with the fileName option it will work.

Camel errorHandler / deadLetterChannel REST response

I have a Camel rest endpoint (Jetty) which validates and processes incoming requests. Besides specific Exception handlers (onException) it uses a DLQ error handler (errorHandler(deadLetterChannel...)) which is setup to retry 3 times - if unsuccessful the message is moved to the DLQ.
My question is, how do I still return a user friendly error message back to the client if an unexpected Exception occurs rather than the full Exception body? Is there some config I'm missing on the errorHandler?
I've tried to find some examples on the camel unit tests (DeadLetterChannelHandledExampleTest) and camel in action 2 (Chapter 11) but none seemed to have specific examples for this scenario.
Code is:
.from(ROUTE_URI)
.errorHandler(deadLetterChannel("{{activemq.webhook.dlq.queue}}")
.onPrepareFailure(new FailureProcessor())
.maximumRedeliveries(3)
.redeliveryDelay(1000))
.bean(ParcelProcessor.class, "process");
Thank you for your help!
Use a 2nd route as the DLQ, eg direct:dead and then send the message first to the real DLQ, and then do the message transformation afterwards to return a friendly response.
errorHandler(deadLetterChannel("direct:dead")
from("direct:dead")
.to("{{activemq.webhook.dlq.queue}}")
.transform(constant("Sorry something was wrong"));

onCompletion in Camel 2.14

I'd like to wrap the result of a processed message into some reply-object to answer a webservice. This is my test-route:
this.from("cxf:someEndpoint")
.process(new SomeProcessorThatMightThrowAnException())
.process(new SomeOtherProcessorThatMightThrowAnException())
.log("normal end of route");
Nevermind if there was an exception or not, the result should be wrapped in some object, that is given back to the caller of my ws.
In camel 2.13.x I did this by adding an other processor to the end of the route and to do the same in 'onException'.
Now I tried to simplify this (technical thing and handle it outside of the 'functional route') in camel 2.14 (2.14 because of 'modeBeforeConsumer'), and added this to my routebuilder:
onCompletion()
.modeBeforeConsumer()
.process(new ConvertToWsReplyProcessor());
This ConvertToWsReplyProcessor should handle an Exception, but I found no way to see, if there was an Exception, because exchange.getProperty(Exchange.EXCEPTION_CAUGHT, Throwable.class) is allways null.
Questions:
1) Is there a way to find out if there was an excetion in onCompletion()?
2) The only way I found to prevent camel from dumping a stacktrace is to use onException(Ex...).handled(true), are there others?
3) How are these onXY processed? Do they get a copy of the exchange? And is onCompletion called last?
OnCompletionProcessor just remove some exchange properties before processing the exchange, that could explain why you cannot fine the exception here.
As camel use onException to handle the exception, I'm afraid you have to do it that way.

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