This document discusses how to use caching with the NonPersistentManagedObjectStore in Mule and invalidate the cache. It shows how to configure caching in a flow using the cache scope, retrieve data from the cache even after deleting it from the database, and invalidate the entire cache using another flow that calls invalidate-cache. Testing is done using SoapUI to call the web service and observe the cached response and fresh response after cache invalidation.

1. Caching and invalidating with
managed-store

2. Today’s topic we will be discussing the
NonPersistentManagedObjectStore and we will not be doing
any complex Caching configuration with spring beans in our
Mule config.
.

3. How ??? I will show you how
.

4. So, let us consider we have configured a web service with the Mule cache
scope in following way:-

5. <flow name="ServiceFlow" doc:name="ServiceFlow">
<http:inbound-endpoint exchange-pattern="request-response" host="localhost"
port="8082" path="mainData" doc:name="HTTP" />
<object-to-string-transformer doc:name="Object to String"/>
<ee:cache doc:name="Cache" cachingStrategy-ref="cachingStrategy" >
<vm:outbound-endpoint exchange-pattern="request-response" path="Flow1-WT-Main"
doc:name="VM"/>
<object-to-string-transformer doc:name="Object to String"/>
</ee:cache>
</flow>
<flow name="ServiceFlow2" doc:name="ServiceFlow2">
<vm:inbound-endpoint exchange-pattern="request-response" path="Flow1-WT-Main"
doc:name="VM"/>
<cxf:jaxws-service serviceClass="com.test.services.schema.maindata.v1.MainData"
doc:name="SOAP"/>
<component class="com.test.services.schema.maindata.v1.Impl.MainDataImpl"
doc:name="JavaMain_ServiceImpl"/>
</flow>
Corresponding Mule flow will be :-

6. Now we will configure our cachingStrategy with
NonPersistentManagedObjectStore as follows:-
<ee:object-store-caching-strategy name="cachingStrategy"
doc:name="cachingStrategy"> <managed-store
storeName="myNonPersistentManagedObjectStore" maxEntries="-1"
entryTTL="20000" expirationInterval="5000"/> </ee:object-store-
caching-strategy>
So it is very simple right ?

7. In next step we will be running and testing the application. This web
servicewill intereact with database retrieve a row from the database
and show the row value in the SOAP response.

8. Here how we will test the web service :-
You can see that we have used SoapUI to test the web service. Now when we hit
the service, you can see in the SOAP request, it takes id as input and then fetches all
the data from the database for that id.

9. Now, what we will do is manually deleting the entire row from the
database. In my case, I have used sql server and deleted the row
from the table using a SQL query:-

10. With this in place, if we again hit the service, we will get the same
response as we got earlier:-

11. You can see that, though the entire row is deleted from the
database table, it’s still showing the response, which means it is
fetching the response from cache and not hitting the actual
database

12. Now, let’s create a Mule flow that will invalidate and clear all the
Cache
So, with following flow we can clear all the Cache that has been
used:-

13. Corresponding Mule config will be :-
<flow name="cacheinvalidate" doc:name="cacheinvalidate">
<http:inbound-endpoint exchange-pattern="request-response"
address="http://localhost:8083/invalidate" doc:name="HTTP"/>
<object-to-string-transformer doc:name="Object to String"/>
<ee:invalidate-cache cachingStrategy-ref="cachingStrategy"/> <set-
payload value="All cache invalidated" doc:name="Set Payload"/>
</flow>
As we can see the above flow will use ee:invalidate-cache to clear all the
cache.

14. Now if we hit the url:- http://localhost:8083/invalidate following
way :-

15. So, we can hit the web service again to test the output.
So, now if we hit service again after the cache has been invalidated,
we will find the following result
As you can see, it clearly shows no records are there in the database, which means
the cache has invalidated successfully and the service is actually hitting the
database.

16. It’s simple example.. isn’t it … we don’t need to configure any
complex configuration for the cache as compared to the
configuration we need to do in case of using cache with EHCache.

17. Hope you enjoyed the simple usage of Cache with
NonPersistentManagedObjectStore and the way of invalidating it.