Spring Batch — Multi-File-Resource — Takes same time as single Thread?

问题

I am using Spring Batch for data migration from XML to Oracle Database.

With Single Thread execution, process takes 80-90 Mins to insert 20K users approx.

I want to reduce it to more than half but even using Multi File Resource, I am not able to achieve that.

I have a single XML to be processed so I started simply by adding

task executor and making Reader synchronized but not able to achieve gain.

So what I am doing, I split XML into multiple XMLS and want to try with Multi File Resource. Here is the configuration.

<batch:job id="importJob">

        <batch:step id="step1Master">
            <batch:partition handler="handler" partitioner="partitioner" />
        </batch:step>

</batch:job>

<bean id="handler"
        class="org.springframework.batch.core.partition.support.TaskExecutorPartitionHandler">
        <property name="taskExecutor" ref="taskExecutor" />
        <property name="step" ref="slaveStep" />
        <property name="gridSize" value="20" />
    </bean>

    <batch:step id="slaveStep">
        <batch:tasklet transaction-manager="transactionManager"
            allow-start-if-complete="true">
            <batch:chunk reader="reader" writer="writer"
                processor="processor" commit-interval="1000" skip-limit="1500000">
                <batch:skippable-exception-classes>
                    <batch:include class="java.lang.Exception" />
                </batch:skippable-exception-classes>
            </batch:chunk>


        </batch:tasklet>

    </batch:step>

    <bean id="taskExecutor"
        class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
        <property name="corePoolSize" value="100" />
        <property name="maxPoolSize" value="300" />
        <property name="allowCoreThreadTimeOut" value="true" />
    </bean>


    <bean id="partitioner"
        class="org.springframework.batch.core.partition.support.MultiResourcePartitioner"
        scope="step">
        <property name="keyName" value="inputFile" />
        <property name="resources"
            value="file:/.../*.xml" />
    </bean>



    <bean id="processor"
        class="...Processor"
        scope="step" />

    <bean id="reader" class="org.springframework.batch.item.xml.StaxEventItemReader"
        scope="step">
        <property name="fragmentRootElementName" value="user" />
        <property name="unmarshaller" ref="userDetailUnmarshaller" />
        <property name="resource" value="#{stepExecutionContext[inputFile]}" />
    </bean>

My Single XML file contains users around 1000 and I am trying by having 20 files.

I kept commit-interval=1000 as each file has 1000 records to be insert in DB.

Do commit-interval needs to adjusted accordingly?

I am using ORACLE DB, Do I need to do any pool management there. Current Pool of ORACLE DB configured in JBOSS Min Pool = 100 Max Pool = 300

I see logging like

17:01:50,553 DEBUG [Writer] (taskExecutor-11) [UserDetailWriter] | user added
17:01:50,683 DEBUG [Writer] (taskExecutor-15) [UserDetailWriter] | user added
17:01:51,093 DEBUG [Writer] (taskExecutor-11) [UserDetailWriter] | user added
17:01:59,795 DEBUG [Writer] (taskExecutor-12) [UserDetailWriter] | user added
17:02:00,385 DEBUG [Writer] (taskExecutor-12) [UserDetailWriter] | user added
17:02:00,385 DEBUG [Writer] (taskExecutor-12) [UserDetailWriter] | user added

It seems multiple threads are being created but still I am not seeing any performance improvement here?

Please suggest what I am doing wrong?