RECORDS OMITTED FROM QUERY USING JPAPAGINGITEMREADER while reading - spring-batch

Question

<batch:job id="xyzJob" job-repository="jobRepository"
incrementer="jobParametersIncrementerImpl" restartable="false">
<batch:step id="feeStep">
<batch:tasklet transaction-manager="transactionManager" allow-start-if-complete="true">
<batch:chunk reader="xyzReader" processor="xyzProcessor"
writer="xyzWriter" commit-interval="4" >
<batch:streams>
<batch:stream ref="fileWriter"/>
</batch:streams>
</batch:chunk>
<batch:listeners>
<batch:listener ref="stepExecutionListener"/>
</batch:listeners>
</batch:tasklet>
</batch:step>
<batch:listeners>
<batch:listener ref="xyzJobListener" />
</batch:listeners>
</batch:job>
<bean id="xyzProcessor" class="com.batch.core.processor.XYZProcessor" scope="step">
<property name="fundDAO" ref="fundDAO"/>
<property name="loanDAO" ref="loanDAO"/>
<property name="aumBlnceDAO" ref="aumBalanceDAO"/>
---
--
</bean>
<bean id="xyzWriter" class="org.springframework.batch.item.support.CompositeItemWriter">
<property name="delegates">
<list>
<bean class="com.batch.core.writer.xyzWriter">
<property name="xyzDetailsDomain" ref="xyzDetailsDomain" />
<property name="xyzHistoryDomain" ref="xyzHistoryDomain"></property>
</bean>
<ref bean="fileWriter"/>
</list>
</property>
</bean>
<bean id="xyzReader" class="org.springframework.batch.item.database.JpaPagingItemReader" scope="step">
<property name="entityManagerFactory" ref="batchEntityManagerFactoryBean"/>
<property name="queryString">
<value><![CDATA[
SELECT pe, pap
FROM A pe, B pap
WHERE pap.userID =pe.userID and pe.status = 'E'
and pe.startDT <= '#{jobExecutionContext[previousQuarterEndDate]}'
and (pe.endDT is null
or pe.endDT > '#{jobExecutionContext[previousQuarterEndDate]}')]]>
</value>
</property>
<property name="pageSize" value="1000"/>
<property name="saveState" value="false" />
</bean>
When this spring batch is running what I have noticed sometimes its skipped some records while reading data from tables .. this issue not consistent... but out of 10 times it may occur 1 time.
Please help me to resolve this. Thanks in advance.!!

Answer 1

The JpaPagingItemReader does not skip records. What is probably happening in your case is that some records corresponding to your search criteria are added while your reader is reading data. This may lead to wrong page calculation and some items may seem to be skipped but it is not the case.
A batch processing job is by definition acting on a fixed data set. If your query returns a fixed data set while your job is running, the same pages should be returned for each run of your job. If on the other hand another process inserts data that can be returned by your query, then your issue can happen.
Hope this helps.