Idempotent filter in Mule

1. Idempotent Filter with Simple-file

2. Idempotent Filter is an important message filter in Mule platform which ensures that only unique
messages are received by a service by checking the unique ID of the incoming message.
We use Idempotent Filter to avoid any duplicate message in our Mule flow
We will be demonstrating a simple example of Idempotent Filter using simple-text-file-store.

3. Idempotent Filter with simple-text-file-store :-
We can configure it following way :-
Here you can see that we have configured our Idempotent Filter with simple-text-file-store. So, now
this filter will restrict any duplicates message it finds.
simple-text-file-store technique will store all the messages in file and will check the file to detect
duplicates whenever it receive a input message. For each message the files will be generated.

4. You will see that we will run our Mule application it will generate text file in our Mule application
where it will store all the message with ID to avoid the duplicate :-

5. Now, we can configure with any of the options shown here, we will get following Mule flow :-

6. Our Mule Config will be :-

7. So, we will test our application by hitting the following url http://localhost:8081/path/test for the first
time we will get :-
For the first time we will see browser display “passed” as the message payload
is new and unique (path/test is the message payload here)

8. And then if we hit the same url http://localhost:8081/path/test again, will get the following :-
For the second time we will see browser display “EXCEPTION” as the message
payload is now same and duplicate (path/test is the message payload here)

9. Hope I am able to make it clear on how to implement Idempotent Filter with different ways and you
can now try by your own and experiment with this powerful filter of Mule.
Hope you enjoyed this simpler version