In Talend ESB, I am troubled to figure out how to call another route from one route.
I have done quite a bit of search and found exactly the same question asked by someone else but it doesn't have any answer. So I thought It might be a good idea to post a question here. :)
Here's the link of the question:
https://www.talendforge.org/forum/viewtopic.php?id=32416
Would be really appreciated if anyone could help!
Thanks
You can use cDirectVM and cSEDA. cDirectVM will send the exchange to another cDirectVM endpoint with the same name and block the first route until the second finish (synchronous). cSEDA is asynchronous, the first route will not wait for the second route to process the exchange.
Documentation for cDirectVM : https://help.talend.com/display/TalendESBMediationComponentsReferenceGuide60EN/cDirectVM
Be aware that this is not testable in studio, when you start 2 routes inside the studio, they will run in separate JVM and thus they will not see each other and cDirectVM will fail. But if you launch the 2 routes on the Talend runtime, cDirectVM will work between the 2 routes.
One other solution is to use JMS (ActiveMQ is seeded with Talend and works fine).
The last enndpoint of your first route will be a cJMS that sends the message body to the MQ Broker, then this queue will be the entry of your 2nd route.
Of you could do the same with file endpoints as well, or CXF (webservices) too.
Related
We already have project which received request on REST EndPoint and by
using FINITE STATE Machine evaluate next action with Transition and
call action class accordingly.
I am assigned to evaluate possibility to migrate this part to apache camel.
But i am not seeing any value addition as in camel we already defined
routes and we can also use dynamic routing for evaluating next
endpoint.
I googled but couldnt find any Apache Camel example using FSM.
I need comments any use case where we can use FSM in Apache Camel or
we dont require due to nature of Camel.
if anyone found any links for google please share it to.
https://dzone.com/articles/why-developers-never-use-state
Regards,
When I got an error inside an Endpoint URI the camel context wont start.
It seems like Camel validates in a first step every Endpoint URI before starting the context.
Can someone pleas tell me, how this works?
Am I right?
I cant figure it out.
Yes Camel validates that it has been configured correctly when it startup. This happens as part of starting the Camel routes.
Its like misconfiguring any other software which will report an error for you to fix.
There is some tooling which you can use to validate your source code to find endpoints that has been misconfigured. I wrote a blog entry about this: http://www.davsclaus.com/2016/01/cheers-fabric8-camel-maven-plugin-to.html
I currently have a camel route that exposes a cxf endpoint. When a messages comes through the endpoint I would first enrich that message with some information from another webservice and then do more processing afterwards. However, I want make the first half of this route synchronous so I can send back a response to whomever called my exposed cxf endpoint.
The route looks something like this:
from(cxf:CxfEndpoint)
.process(someProcessing)
.to(cxf:ExternalCxfEndpoint)
.to(activemq:queue:somequeue)
//return a response back to caller here
from(activemq:queue:somequeue)
... //additional processing here
...
The reason for this is because when a message comes via my exposed cxf endpoint I don't know if it's a valid message. I need to first validate it with the message enrichment. Once the message is enriched, I want let whomever sent the message know that their message is accepted but don't want them to wait for the message to make it through the whole route as that could take hours.
Does anyone know how this would work?
Thanks in advance!
I believe all you need to do is set exchangePattern to InOnly a.k.a. make it an Event Message. This should have your route not wait for a reply from ActiveMQ. Camel exchange will default to InOut when it's originating from a web service, as in your case.
A related question with an answer from a Camel dev here.
Also see this one for some details on the behavior when your broker is down.
Yes definitely , 100% possible. A simple example would be this :
From cxf endpoint
Store your request in a camel property or header
To xslt - generate xslt for cxf endpoint - Synchronous flow
Reset your original payload using set body.
Wiretap Endpoint - to any endpoint downstream or even a route , this becomes asynchronous . This won't take part in the above sync response .
Note- step 2 & 4 may not be required, it depends on your use case .
There are whole lots of things you can do, I just gave a very simple example . It doesn't need to be wiretap as well, but wiretap helps us not to write any additional custom exceptional handling.
I'm looking for a best practise how to monitor the functionality of camel routes.
I know there are monitoring tools like hawtio and camelwatch, but that's not exactly what I'm looking for.
I want to know if a route is "working" as aspected, for example you have a route which listens on a queue(from("jms...")). Maybe there are messages in the queue, but the listener is not able to dequeue them because of some db issues or something else(depends on the jms provider). With the monitoring tools mentioned above you just see inflight/failed/completed messages but you don't see if the listener is able to get the messages -> so the route is not "working".
I know there is also apache BAM, maybe I have to do some more research, but somehow it looks like BAM creates new routes and you can't monitor existing routes. I also don't want to implement/define such business cases for each route, I look for a more generic way. It's also mentioned on the camel 3.0 idea board that BAM wasn't touched for 5 years, so I think people don't use it that often(which means for me it doesn't fit their needs exactly).
I had similar requirement some time ago and at the end I developed a small Camel application for monitoring.
It run on timer, query different Camel applications installed in remote servers through JMX/Jolokia and if LastExchangeCompletedTimestamp of the route I am interested in is older than some time interval, send a mail to administrators.
Maybe this approach is too simple for your scenario, but could be an option.
(Edit: more details added)
Principal points:
Main routes queries DB for entities to control and spawns controlling routes
Controlling routes fires on quartz and http post the following url
.to("http://server:port/app/jolokia/?"+
"maxDepth=7&maxCollectionSize=500&ignoreErrors=true&canonicalNaming=false")
sending the following jsonRequest body
LinkedHashMap<String,Object> request=new LinkedHashMap<String,Object>();
request.put("type","read");
request.put("mbean","org.apache.camel:"+entity.getRouteId());
jsonRequest=mapper.writeValueAsString(request);
As response you get another JSON, parse it and get LastExchangeCompletedTimestamp value
Can i download with camel a specific file list from a sftp server and then shutdown the service?
I know this should be a common question but i can't figure out how to do it without waiting the context stopping.
In some way, camel can ensure data integrity?
I guess you can do something like this using a direct route, pollEnrich and a template
from("direct:grabOneFile")
.pollEnrich("sftp://somewhere/blah/blah?fileName=foobar");
then from some java code somewhere, just grab a camel template and invoke the "direct:grabOneFile route.
String ret = template.requestBody("direct:grabOneFile","",String.class);
In this case, you don't have to worry about when to shut down the camel context with the chance of having multiple files etc.
Camel ftp component can only poll directories.
You can use a combination of maxMessagesPerPoll and fileName, like
from("ftp://.../xyz?maxMessagesPerPoll=x&fileName=y");
Also take a look at this.
This link has examples regarding shutdown.
Did you check this out at the bottom of the Camel FTP page.