Spring Data Neo4j transactions mixed with Hibernate transactions

[leonardo.moreno]

Hi

I have a project with a bunch of relational tables mapped with hibernate, using spring managed transactions and everything was working fine until I added Spring Data Neo4j. After that, I could interact with my Neo4j graph db but cannot write to my relational db. No exception, no warning, nothing. Just the request hangs in the call to a method marked with @Transactional.

I supose that I need to handle differently the transactions, but can't find how to do that.

Is there a wat yo make SDN transactions work together with Hibernate transactions?

Thanks in advance

[MichaelHunger]

Could you try to use @Neo4jTransactional or @Transactional("neo4jTransactionManager")

Neo4j defines a transaction manager and only aliases it as transactionManager but your hibernate tx-manager bean definition named "transactionManager" should have precedence.

[leonardo.moreno]

That's exactly the problem, the hibernate transactionManager doesn't take precedence.

My workaround was to copy the class Neo4jConfiguration, remove the transactionManager alias and use @Neo4jTransactional. With this I can use both transactions managers, but I really don't want to have my own version of that class. What can I do to avoid that conflict?

[bytor99999]

I thought the Neo4J transaction manager was a JTA transactionManager. Or maybe you can define a JTA Transaction Manager and wrap the two transaction managers in the JTA one, and then name the JTA one "transactionManager" I had to do something along these lines to have both Spring Data Neo4J and Spring Batch (which has relational tables) in my project.

Mark

[bytor99999]

Yeah, I had put this in my config

<bean id="neo4jTransactionManager"
    	   class="org.springframework.transaction.jta.JtaTransactionManager">
        <property name="transactionManager">
            <bean class="org.neo4j.kernel.impl.transaction.SpringTransactionManager">
                <constructor-arg ref="graphDatabaseService"/>
            </bean>
        </property>
        <property name="userTransaction">
            <bean class="org.neo4j.kernel.impl.transaction.UserTransactionImpl">
                <constructor-arg ref="graphDatabaseService"/>
            </bean>
        </property>
        <property name="allowCustomIsolationLevels" value="true"/>
    </bean>

And I have

<beans:bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <beans:property name="dataSource" ref="dataSource"/>
    </beans:bean>

for Jdbc to the Batch tables, in order to get both Neo4J and Batch to work together.

Hope that helps

Mark

[leonardo.moreno]

Hi Mark, thanks for your time.

How did you configure neo4j? with <neo4j:config ...>? Because the problem I have is that the Neo4JConfiguration class declares the transaction manager with 2 aliases neo4jTransactionManager and transactionManager and because hibernate looks for the bean named transactionManager, it hangs when trying to the obtain a transaction.

If that is going to generate a conflict the developers must be aware of that, don't you think?

Leonardo

[bytor99999]

Hi Mark, thanks for your time.

How did you configure neo4j? with <neo4j:config ...>? Because the problem I have is that the Neo4JConfiguration class declares the transaction manager with 2 aliases neo4jTransactionManager and transactionManager and because hibernate looks for the bean named transactionManager, it hangs when trying to the obtain a transaction.

If that is going to generate a conflict the developers must be aware of that, don't you think?

Leonardo

Yeah, I made a bean for my GraphDatabaseService. So I have

<bean id="graphDatabaseService" class="org.neo4j.kernel.EmbeddedGraphDatabase"
            destroy-method="shutdown">
        <constructor-arg index="0" value="${neo4j.location}"/>
        <constructor-arg index="1">
            <map>
                <entry key="allow_store_upgrade" value="${neo4j.upgrade}"/>
            </map>
        </constructor-arg>
    </bean>

    <neo4j:config graphDatabaseService="graphDatabaseService"/>

    <neo4j:repositories base-package="com.perfectworldprogramming.eventgate"/>