[jira] [Created] (SYNCOPE-1386) Not committed managed objects can get into L2 cache.

["DmitriyB. (JIRA)" <ji...@apache.org>]

DmitriyB. created SYNCOPE-1386:
----------------------------------

             Summary: Not committed managed objects can get into L2 cache.
                 Key: SYNCOPE-1386
                 URL: https://issues.apache.org/jira/browse/SYNCOPE-1386
             Project: Syncope
          Issue Type: Bug
          Components: core
    Affects Versions: 2.0.8
            Reporter: DmitriyB.


Hi guys. I noticed the issue that leads to inconsitent data that comes in response.

In Apache Syncope the Application Scoped Entity manager is used for all operations with the database. Entity manager is created by appropriate Entity Manager Factory that matches a particular domain. Thus, the scope of Persistence Context is extended and also it is bound to a current thread.
Moreover, Entity Manager that is created by Entity Manager Factory is Transactional. Thus any execution using entity manager without opened transaction leads to exception like:
<pre>
java.lang.IllegalStateException: Could not find EntityManager for domain dbrashevets
at org.apache.syncope.core.persistence.jpa.dao.AbstractDAO.entityManager(AbstractDAO.java:41) ~[syncope-core-persistence-jpa-2.0.8.jar:?]
at org.apache.syncope.core.persistence.jpa.dao.JPAUserDAO.findByUsername(JPAUserDAO.java:209) ~[syncope-core-persistence-jpa-2.0.8.jar:?]
at sun.reflect.GeneratedMethodAccessor232.invoke(Unknown Source) ~[?:?]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:45005) ~[?:1.8.0_151]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_151]
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:333) ~[spring-aop-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207) ~[spring-aop-4.3.14.RELEASE.jar:4.3.14.RELEASE]
at com.sun.proxy.$Proxy74.findByUsername(Unknown Source) ~[?:?]
</pre>


In Apache Syncope L2 cache is enabled by default. 
syncope-core-persistence-jpa-2.0.8.jar!\domains.xml file has a property 
<pre>
<entry key="openjpa.DataCache" value="true"/>
</pre>


If the transaction is opened, the entity, that is fetched via Entity Manager with the method like
org.apache.syncope.core.persistence.api.dao.UserDAO#findByUsername, gets into L1 cache and L2 cache.

Than retrieved JPA entity can be modified in the scope of an opened transaction. And if an exception occurs transaction is rolled back. L1 cache is being destroyed because Entity Manager is bound to a current thread, but L2 cache can have this managed entity. 
It means that furtherly going HTTP requests can retrieve this corrupted entity from L2 cache.

 

Here is the use-case how to reproduce this:

1. Create user in Syncope
2. Do a request password reset action and make sure that token that is used for pwd reset action is generated and stored into database.
3. Restart your application to be sure that L2 cache is empty.
4. Confirm password reset action for this user and make sure that requested password doesn't apply the password rules. In my case password is too short. The exception like "InvalidUser:InvalidPassword: Password too short" should be thrown. 
5. Request the user by username. The user that comes in HTTP Response doesn't have "token" and "tokenExpireTime" attributes. But you may find "token" and "tokenExpireTime" value in SyncopeUser table for this user.

Here is my explanation why it happens:
org.apache.syncope.core.workflow.java.AbstractUserWorkflowAdapter#confirmPasswordReset removes token and tokenExpireTime values by triggering org.apache.syncope.core.persistence.api.entity.user.User#removeToken.
And it happens with the entity that is in "managed" state.
Then org.apache.syncope.core.persistence.jpa.dao.JPAUserDAO#doSave saves and flushes the entity. I guess save+flush adds this managed user into L2 cache as well. 
And then managed user is checked on policies and the outcome is "InvalidUser:InvalidPassword: Password too short"


In code https://github.com/apache/syncope/blob/443f5a38ea45f15c092c41abb202f897c795c5f2/core/persistence-jpa/src/main/java/org/apache/syncope/core/persistence/jpa/dao/JPAUserDAO.java#L397 I also noticed that `entityManager().remove(merged);` is called.


What is the purpose why you do this? The transaction is rolled back and changes are not added into database (even remove(merged) action doesn't work).
Maybe you need to detach the managed entity and also remove it from the L2 cache if it is enabled?
<pre>
entityManager().detach(merged);
if (entityManager().getEntityManagerFactory().getCache() != null) {
entityManager().getEntityManagerFactory().getCache().evict(JPAUser.class, merged.getKey());
} 
</pre>


Maybe you have other similar places in the code like above?


In our application, currently, I always clean the L2 cache when transaction is rolled back in
org.apache.syncope.core.persistence.jpa.spring.DomainTransactionInterceptor. Invoke method looks like this:
<pre>
@Override
public Object invoke(final MethodInvocation invocation) throws Throwable {
try {
return super.invoke(invocation);
} catch (Throwable e) {
EntityManagerFactory entityManagerFactory = EntityManagerFactoryUtils.findEntityManagerFactory(
ApplicationContextProvider.getBeanFactory(), AuthContextUtils.getDomain());
Cache l2Cache = entityManagerFactory.getCache();
if (l2Cache != null) {
l2Cache.evictAll();
}
LOG.debug("Error during {} invocation", invocation.getMethod(), e);
throw e;
}
}
</pre>
This is the guarantee for that correpted data won't come in response, but I'm destroting the cache all the time when exception is thrown from one of @Transactional methods.


I also noticed that ~ after 5 minutes left the L2 cache is gone. But I cannot find any l2CacheTimeOut setting in Syncope. Do you have such properties somehwere in configuration.

You can find an example in confirm_pwd_reset_action.sh script. You can run it by executing the command:
"./request_user.sh | tee temp.log"
Here I'm trying to do confirm-password-reset action after 5 minutes of waiting with the password that doesn't match the rules. And then I'm requesting user by username. In response it comes without "token" and "tokenExpireTime".



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