I have the scenario below.
Request Web Services from client system. This request is that the file will be copied.
Receive request by cxf component in application.
Response the return code that means success after receiving request immediately.
After send response, the application will fetch the file.
So, I implemented route.
<route>
<from uri="cxf:bean:FileTransferServiceEndPoint"/>
<multicast parellelProcessing="true">
<toD uri="direct:bean"/>
<toD uri="direct:fetchFile"/>
</multicast>
</route>
<route>
<from uri="direct:bean"/>
<bean method="process" ref="returnMsg"/>
<end>
</route>
<route>
<from uri="direct:fetchFile"/>
<pollEnrich>
<simple>file:/test/inBox</simple>
</pollEnrich>
<toD uri="file:/test/outBox"/>
</route>
I faced to have some problem.
Originally, I think that response will be return by returnMsg Bean.
But Response Message was not respond until the file is completely processed.
I want the message delivered immediately to the client. And at the same time, I want the files to be processed.
How should I implement a route to fulfill my scenario?
Please let me know this solution.
Thank you.
Consider using SEDA component (take a look at the option waitForTaskToComplete) or WireTap EIP (it makes a "lite" copy of the message but you can customize its behavior) to fetch the file.
PS 1.: Caution with the usage of pollEnrich without setting a timeout.
PS 2.: Depending upon the way you receive the body message, you may face a stream closed issue by using it more than once, as you end up doing in multicast.
If you want your "direct" routes to be executed independently of each other, consider to use wireTap
<route>
<from uri="cxf:bean:FileTransferServiceEndPoint"/>
<wireTap uri="direct:bean"/>
<to uri="direct:fetchFile"/>
</route>
from the "Camel in Action" book:
By using the wireTap method in the Java DSL, you can send a copy of the exchange
to a secondary destination without affecting the behavior of the rest of the route
Related
I have created route that accept request from multiple producers and send to a remote server by using netty4 with request-response. However, when camel is sending a request to remote server and waiting for response, next incoming request is received and want to send to remote server but got IOException as camel cannot receive response.
So, how to set Camel-Netty4 send request and wait for response before send next.
The route configuration:
from("direct:DirectProcessOut?block=true")
.to("netty4:tcp://192.168.1.2:8000?sync=true&synchronous=true&reuseChannel=true")
I actually ran into a similar issue trying to send out several messages at a time based on rows in a database table. The calls wouldn't wait for each other to complete and essentially stepped on each other and either hung or blew up.
The solution I eventually found was to use a message queue. Take in your requests and route them into a single activemq route.
So something like:
<camelContext xmlns="http://camel.apache.org/schema/blueprint">
<route>
<from uri="direct:direct:DirectProcessOut"/>
<to uri="activemq://processOutQueue"/>
</route>
</camelContext>
<camelContext xmlns="http://camel.apache.org/schema/blueprint">
<route>
<from uri="activemq://processOutQueue"/>
<to uri="netty4:tcp://192.168.1.2:8000?sync=true&synchronous=true&reuseChannel=true"/>
</route>
</camelContext>
My case was a little different, so I'm not sure if this will preserve your message you want to send. But hopefully it gives you a place to start.
In my Camel application there are 2 CXF endpoints that are handled by the same processing route, and AFAIK each endpoint may produce Exchanges in parallel depending on incoming HTTP requests.
Both endpoints forward the request through the same route using direct: component, which is sometimes described as the Camel equivalent of calling a method.
The direct: component provides direct, synchronous invocation of any consumers when a producer sends a message exchange.
My questions:
Does direct: component run different requests in parallel? (each request has its own Exchange and is executed by a different java Thread)
If not, how do I handle CXF requests in parallel?
This is my situation:
<route id="CxfRoute1">
<from uri="cxf:bean:endpoint1" />
<to uri="direct:handle" />
</route>
<route id="CxfRoute2">
<from uri="cxf:bean:endpoint2" />
<to uri="direct:handle" />
</route>
<route id="HandleStuffRoute" />
<from uri="direct:handle" />
<to uri="bean:stuffHandler" />
</route>
It works like a direct method call, eg Foo foo = ... ; foo.callSomeMethod() which uses the current thread to call. So you get parallel from the consumer in this example CXF, so if 2+ clients call CXF at the same time, each calls runs in its own thread, and each of them call direct as a direct method invocation and all that can run in parallel.
In your case yes it should run the different requests in parallel.
You can probably create a Camel unit test that tests this. In your route test class you can create a new route that is timer based and then create some dummy body and call your route endpoints like this:
.parallelProcessing().to("cxf1", "cxf2", "cxf3")
and then observe the results.
I guess another way is to use JMeter and create a test against your cxf endpoints and observe.
For handling parallel requests in the same way as using direct you can use "seda" instead. Details at http://camel.apache.org/seda
As far as I understand both the servlet and the jetty endpoints in Camel are a Request Reply message exchanges (InOut) expecting an out-message.
Therefore I assume that when I send a HTTP request to those endpoints the response will only be send back once all processors of the route have finished.
Is it possible to call these endpoints in a fire-and-forget fashion, i.e. to just trigger the route and get an immediate response back without waiting for all the processing to be done?
sure, you just need to put some asynchronous step (EIP or component) in the route...
for example...this route will send all requests to a JMS queue (or seda, etc) which can be processed asynchronously and ACK back to the HTTP client once the message is in the queue...
from("http://localhost:9001/inbound")
.to("activemq:inboundQ");
from("activemq:inboundQ")
.to(...inbound processing...);
At the end I used "seda" to make it async. Note that this only ran async when I used the inOnly-tag:
<route autoStartup="true" id="x-service">
<from uri="servlet:/xService"/>
<inOnly uri="seda:x-service-execute-async" />
<transform>
<constant>OK</constant>
</transform>
</route>
<route autoStartup="true" id="x-service-execute-async">
<from uri="seda:x-service-execute-async"/>
...
</route>
I can see that many Camel route examples are initiated with a "direct" component. For example:
<camelContext xmlns="http://camel.apache.org/schema/spring">
<route id="myroute">
<from uri="direct:start"/>
<setBody>
<simple>Hello World!</simple>
</setBody>
<log message="${body}"/>
<to uri="mock:result"/>
</route>
</camelContext>
However, by running a route like this (mvn camel:run) the route is not started and Camel keeps hanging forever. Is it not meant to be used directly this kind the direct component?
Thanks
Its not hanging. You need to send a message to the direct endpoint before its routed. eg like in java code to do a direct method invocation from a client by calling a java method.
Instead of direct you can use a timer if you want to route a message automatic every X time etc.
To send a message to the direct endpoint (or any other Camel endpoint) then read about the producer template. For example from the getting started guide: http://camel.apache.org/walk-through-an-example.html
I'm trying to setup simple VM queue test between two servlets without success. The problem is that the request always timeouts as there is no response, OUT message, within expected timeframe.
"org.apache.camel.ExchangeTimedOutException: The OUT message was not received within: 30000 millis."
The servlets are running in Tomcat and are both deploying Apache Camel. Both apps are defining camel context and simple routes. The basic setup should be fine as simple routes like following are working:
<route>
<from uri="servlet:///hello?servletName=app1" />
<transform>
<simple>Hello world</simple>
</transform>
</route>
<route>
<from uri="servlet:///hello?servletName=app2" />
<transform>
<simple>Hello world</simple>
</transform>
</route>
First of all I'm not sure if the message ever reaches the app2 as the same timout happens even if the requested route wouldn't be even defined (the app2 would be missing the VM route). So the problem could be in how to define the route between two servlets using VM queue.
If the route between the servlets is fine then the problem should be in the missing/incorrect reply. I do understand that the receiving end should return the reply as the incoming requst from web server is inOut type, but I don't know how to achieve that.
The route in app1 receiving the web request:
<route>
<from uri="servlet:///test?servletName=app1" />
<to uri="vm:test">
</route>
and the other end in servlet app2:
<route>
<from uri="vm:test" />
// Tested here: output with <simple>, 'To', 'inOut'... the result is always timeout
</route>
As I'm new with Apache Camel the root cause is most likely very simple. Any help would be highly appreciated.
The question is simply, how to setup VM queue between two servlet apps?
The vm component works in the same classloader, eg kinda what we say on the vm documentation page: http://camel.apache.org/vm.html
This component differs from the SEDA component in that VM supports
communication across CamelContext instances - so you can use this
mechanism to communicate across web applications (provided that
camel-core.jar is on the system/boot classpath).
So if you use Apache Tomcat, you need to have camel-core JAR as shared JAR. Such as in the boot classpath somewhere.