Spring Batch JSR-352 重启错误的分区

Spring Batch JSR-352 restarts the wrong partitions

我使用 Spring Batch JSR-352 实现创建了一个简单的批处理。该批处理使用 PartitionMapper 为每个块注入一个单独的 属性。 根据 JSR-352 规范(当 partitionsOverride = False 时)当其中一个分区块失败并且批处理重新启动时 只有 失败的分区块应该重新启动。

例如,如果我们有 3 个分区:partition0、partition1 和 partition2。 如果 partition1 和 partition2 失败,批处理应该只用它们自己的批处理属性重新启动 partition1 和 partion2。

但是我注意到,当使用 Spring Batch JSR-352 实现(最新版本 3.0.3.Release)时,重新启动批处理将重新启动 partition0 和 partition1 而不是 partition1 和 partition2。因此,它正确地检测到两个分区发生故障,但它错误地重新启动了前(两个)分区,而不是它应该重新启动的失败分区。

这是 Spring 批处理实施中的错误还是我遗漏了什么?

参见 JSR-352 文档第 10.8.5 节: http://download.oracle.com/otn-pub/jcp/batch-1_0_revA-mrel-spec/JSR_352-v1.0_Rev_a-Maintenance_Release.pdf

这是我使用的代码:

/META-INF/batch-jobs/sampleBatch.xml

<?xml version="1.0" encoding="UTF-8"?>
<job id="sampleBatch" version="1.0" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/jobXML_1_0.xsd">

<step id="sampleStep">
    <chunk item-count="100">
        <reader ref="com.springapp.batch.SampleReader">
            <properties>
                <property name="sample" value="#{partitionPlan['sample']}"/>
            </properties>
        </reader>
        <writer ref="com.springapp.batch.SampleWriter">
            <properties>
                <property name="sample" value="#{partitionPlan['sample']}"/>
            </properties>
        </writer>
    </chunk>
    <partition>
        <mapper ref="com.springapp.batch.SamplePartitionMapper"/>
    </partition>
</step>
</job>

com.springapp.batch.SamplePartitionMapper:

package com.springapp.batch;

import java.util.Properties;
import javax.batch.api.partition.PartitionMapper;
import javax.batch.api.partition.PartitionPlan;
import javax.batch.api.partition.PartitionPlanImpl;

public class SamplePartitionMapper implements PartitionMapper {

@Override
public PartitionPlan mapPartitions() throws Exception {
    final PartitionPlan partitionPlan = new PartitionPlanImpl();

    int size = 3;
    Properties[] partitionProps = new Properties[size];

    for (int i=0; i<size; i++) {
        final Properties properties = new Properties();
        properties.put("sample", ""+i);
        partitionProps[i] = properties;
        System.out.println("mapPartitions: " + i);
    }

    partitionPlan.setThreads(1);
    partitionPlan.setPartitions(partitionProps.length);
    partitionPlan.setPartitionProperties(partitionProps);

    return partitionPlan;
}
}

com.springapp.batch.SampleReader:

public class SampleReader extends AbstractItemReader {

@Inject
@BatchProperty
private String sample;

Iterator<Integer> iter;

@Override
public void open(Serializable checkpoint) throws Exception {
    System.out.println("open for reading sample: " + sample);
    ArrayList list = new ArrayList<Integer>();
    for(int i=0; i<Integer.parseInt(sample); i++) {
        list.add(new Integer(i));
    }
    iter = list.iterator();
}

@Override
public Integer readItem() throws Exception {
    if(iter.hasNext())
        return iter.next();
    else
        return null;
}
}

com.springapp.batch.SampleWriter:

public class SampleWriter extends AbstractItemWriter {

@Inject
@BatchProperty
private String sample;

@Override
public void writeItems(List<Object> items) throws Exception {
    System.out.println("writeItems sample: " + sample);

    if(sample.equals("1")) {
        throw new Exception("FAIL PARTITION 1");
    }
    if(sample.equals("2")) {
        throw new Exception("FAIL PARTITION 2");
    }

    for (Object itemObj : items) {
        Integer item = (Integer) itemObj;
        System.out.println(item);
    }
}
}

TestJob 测试运行者:

package com.springapp.batch;

import java.util.Properties;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

import javax.batch.operations.JobOperator;
import javax.batch.runtime.BatchRuntime;
import javax.batch.runtime.JobExecution;
import javax.inject.Inject;

import junit.framework.Assert;
import org.junit.Test;

//@RunWith(SpringJUnit4ClassRunner.class)
//@ContextConfiguration("classpath:spring-config.xml")
public class AppTests {

@Test
public void testJob() throws Exception {
    JobOperator jobOperator = BatchRuntime.getJobOperator();
    long jobExecution = jobOperator.start("sampleBatch", new Properties());

    int attempt = 0;
    while (true) {
        JobExecution execution = jobOperator.getJobExecution(jobExecution);
        if (execution.getEndTime() != null) {
            //check status
            if( "FAILED".equals(execution.getExitStatus()) && attempt < 3 ) {
                attempt++;
                System.out.println("Batch failed, trying to restart (attempt " + attempt + ")..");
                jobExecution = jobOperator.restart(jobExecution,  new Properties());
                continue;
            }
            System.out.println("Batch ended with status: " + execution.getExitStatus());
            break;
        }
    }
    Assert.assertEquals("COMPLETED", jobOperator.getJobExecution(jobExecution).getExitStatus());
}
}

看着这个,它看起来像一个错误。我已经记录了 Jira 问题 BATCH-2364 来跟踪它。