org.springframework.batch.core.JobExecutionException: Partition handler returned an unsuccessful step in Spring Batch - spring

Question

I am using Spring Batch using Spring Boot. In this example, I've implemented the Custom Partition since Employee Table has UUID value as a PK.
Error:
org.springframework.transaction.CannotCreateTransactionException: Could not open JDBC Connection for transaction; nested exception is java.sql.SQLTransientConnectionException: HikariPool-1 - Connection is not available, request timed out after 30002ms.
at org.springframework.jdbc.datasource.DataSourceTransactionManager.doBegin(DataSourceTransactionManager.java:307) ~[spring-jdbc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.transaction.support.AbstractPlatformTransactionManager.startTransaction(AbstractPlatformTransactionManager.java:400) ~[spring-tx-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:373) ~[spring-tx-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_171]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_171]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_171]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_171]
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:344) ~[spring-aop-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:198) ~[spring-aop-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.batch.core.configuration.annotation.SimpleBatchConfiguration$PassthruAdvice.invoke(SimpleBatchConfiguration.java:127) ~[spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at com.sun.proxy.$Proxy74.getTransaction(Unknown Source) ~[na:na]
at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:137) ~[spring-tx-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.batch.core.step.tasklet.TaskletStep$2.doInChunkContext(TaskletStep.java:273) ~[spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.core.scope.context.StepContextRepeatCallback.doInIteration(StepContextRepeatCallback.java:82) ~[spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.repeat.support.RepeatTemplate.getNextResult(RepeatTemplate.java:375) ~[spring-batch-infrastructure-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.repeat.support.RepeatTemplate.executeInternal(RepeatTemplate.java:215) ~[spring-batch-infrastructure-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.repeat.support.RepeatTemplate.iterate(RepeatTemplate.java:145) ~[spring-batch-infrastructure-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.core.step.tasklet.TaskletStep.doExecute(TaskletStep.java:258) ~[spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.core.step.AbstractStep.execute(AbstractStep.java:208) ~[spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.core.partition.support.TaskExecutorPartitionHandler$1.call(TaskExecutorPartitionHandler.java:138) [spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.core.partition.support.TaskExecutorPartitionHandler$1.call(TaskExecutorPartitionHandler.java:135) [spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_171]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_171]
Caused by: java.sql.SQLTransientConnectionException: HikariPool-1 - Connection is not available, request timed out after 30002ms.
at com.zaxxer.hikari.pool.HikariPool.createTimeoutException(HikariPool.java:689) ~[HikariCP-3.4.2.jar:na]
at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:196) ~[HikariCP-3.4.2.jar:na]
at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:161) ~[HikariCP-3.4.2.jar:na]
at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:128) ~[HikariCP-3.4.2.jar:na]
at org.springframework.jdbc.datasource.DataSourceTransactionManager.doBegin(DataSourceTransactionManager.java:263) ~[spring-jdbc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
... 25 common frames omitted
2020-05-16 20:55:22.675 INFO 31056 --- [cTaskExecutor-7] o.s.batch.core.step.AbstractStep : Step: [slaveStep:Thread--9] executed in 32s370ms
###################### 80
2020-05-16 20:55:22.787 INFO 31056 --- [TaskExecutor-10] org.mongodb.driver.connection : Opened connection [connectionId{localValue:2, serverValue:70}] to localhost:27017
2020-05-16 20:55:22.815 INFO 31056 --- [TaskExecutor-10] o.s.batch.core.step.AbstractStep : Step: [slaveStep:Thread--8] executed in 32s510ms
###################### 50
###################### 70
2020-05-16 20:55:22.839 INFO 31056 --- [cTaskExecutor-1] o.s.batch.core.step.AbstractStep : Step: [slaveStep:Thread--5] executed in 32s539ms
###################### 20
###################### 40
2020-05-16 20:55:22.845 INFO 31056 --- [cTaskExecutor-4] o.s.batch.core.step.AbstractStep : Step: [slaveStep:Thread--7] executed in 32s540ms
###################### 10
2020-05-16 20:55:22.851 INFO 31056 --- [cTaskExecutor-9] o.s.batch.core.step.AbstractStep : Step: [slaveStep:Thread--2] executed in 32s546ms
###################### 30
2020-05-16 20:55:22.856 INFO 31056 --- [cTaskExecutor-3] o.s.batch.core.step.AbstractStep : Step: [slaveStep:Thread--1] executed in 32s556ms
###################### 100
###################### 60
2020-05-16 20:55:22.860 INFO 31056 --- [cTaskExecutor-6] org.mongodb.driver.connection : Opened connection [connectionId{localValue:3, serverValue:71}] to localhost:27017
2020-05-16 20:55:22.864 INFO 31056 --- [cTaskExecutor-5] o.s.batch.core.step.AbstractStep : Step: [slaveStep:Thread--3] executed in 32s559ms
2020-05-16 20:55:22.867 INFO 31056 --- [cTaskExecutor-6] o.s.batch.core.step.AbstractStep : Step: [slaveStep:Thread--4] executed in 32s565ms
2020-05-16 20:55:22.874 INFO 31056 --- [cTaskExecutor-8] o.s.batch.core.step.AbstractStep : Step: [slaveStep:Thread--6] executed in 32s569ms
2020-05-16 20:55:22.883 INFO 31056 --- [cTaskExecutor-2] o.s.batch.core.step.AbstractStep : Step: [slaveStep:Thread--10] executed in 32s583ms
2020-05-16 20:55:22.885 ERROR 31056 --- [ main] o.s.batch.core.step.AbstractStep : Encountered an error executing step contactStepOne in job readContactJob
org.springframework.batch.core.JobExecutionException: Partition handler returned an unsuccessful step
at org.springframework.batch.core.partition.support.PartitionStep.doExecute(PartitionStep.java:112) ~[spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.core.step.AbstractStep.execute(AbstractStep.java:208) ~[spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.core.job.SimpleStepHandler.handleStep(SimpleStepHandler.java:148) [spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.core.job.AbstractJob.handleStep(AbstractJob.java:410) [spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.core.job.SimpleJob.doExecute(SimpleJob.java:136) [spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.core.job.AbstractJob.execute(AbstractJob.java:319) [spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.batch.core.launch.support.SimpleJobLauncher$1.run(SimpleJobLauncher.java:147) [spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.core.task.SyncTaskExecutor.execute(SyncTaskExecutor.java:50) [spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.batch.core.launch.support.SimpleJobLauncher.run(SimpleJobLauncher.java:140) [spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_171]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_171]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_171]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_171]
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:344) [spring-aop-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:198) [spring-aop-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) [spring-aop-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.batch.core.configuration.annotation.SimpleBatchConfiguration$PassthruAdvice.invoke(SimpleBatchConfiguration.java:127) [spring-batch-core-4.2.1.RELEASE.jar:4.2.1.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) [spring-aop-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) [spring-aop-5.2.4.RELEASE.jar:5.2.4.RELEASE]
at com.sun.proxy.$Proxy71.run(Unknown Source) [na:na]
at com.example.PostgresMongoContactsMigrationApplication.run(PostgresMongoContactsMigrationApplication.java:49) [classes/:na]
at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:784) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]
at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:768) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:322) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.2.5.RELEASE.jar:2.2.5.RELEASE]
at com.example.PostgresMongoContactsMigrationApplication.main(PostgresMongoContactsMigrationApplication.java:38) [classes/:na]
EmployeePartitions.java
public class EmployeePartitions implements Partitioner {
#Override
public Map<String, ExecutionContext> partition(int gridSize) {
Map<String, ExecutionContext> partitionMap = new HashMap<>();
int limit = 10;
int offset = 0;
int increment = 10;
int counter = 0;
for (int i = 0; i < 100; i += increment) {
counter++;
if (i == 0)
offset = i;
else
offset = i + 1;
limit = i + increment;
System.out.println("OFFSET " + offset + ", LIMIT = " + limit);
ExecutionContext context = new ExecutionContext();
context.put("limit", limit);
context.put("offset", offset);
partitionMap.put("Thread--" + counter, context);
System.out.println(partitionMap);
}
System.out.println(partitionMap.size());
return partitionMap;
}
}
EmployeeJob.java
#Configuration
public class EmployeeJob {
private static final Integer chunkSize = 200;
#Autowired
private DataSource dataSource;
#Autowired
private Environment env;
#Autowired
private JobBuilderFactory jobBuilderFactory;
#Autowired
private StepBuilderFactory stepBuilderFactory;
#Bean
public EmployeesPartitions EmployeesPartition() {
return new EmployeesPartitions();
}
#Bean("readEmployeeJob")
public Job readEmployeeJob() throws Exception {
return jobBuilderFactory.get("readEmployeeJob")
.incrementer(new RunIdIncrementer())
.start(EmployeeStepOne())
.build();
}
#Bean
public Step EmployeeStepOne() throws Exception {
return stepBuilderFactory.get("EmployeeStepOne")
.partitioner(slaveStep().getName(), EmployeesPartition())
.step(slaveStep())
.gridSize(1)
.taskExecutor(new SimpleAsyncTaskExecutor())
.build();
}
// slave step
#Bean
public Step slaveStep() throws Exception {
return stepBuilderFactory.get("slaveStep")
.<EmployeesDTO, EmployeesDTO>chunk(chunkSize)
.reader(EmployeeReader(null, null))
.writer(EmployeeWriter())
.build();
}
#Bean(destroyMethod = "")
#StepScope
public JdbcCursorItemReader<EmployeesDTO> EmployeeReader(
#Value("#{stepExecutionContext['limit']}") Long limit,
#Value("#{stepExecutionContext['offset']}") Long offset) throws Exception {
JdbcCursorItemReader<EmployeesDTO> reader = new JdbcCursorItemReader<>();
reader.setDataSource(this.dataSource);
reader.setSql("select * from scv_owner.Employees order by Employee_id limit "+ limit +" offset "+offset);
reader.setRowMapper(new EmployeeRowMapper());
reader.afterPropertiesSet();
return reader;
}
#Bean
public ItemProcessor<EmployeesDTO, EmployeesDTO> EmployeeProcessor() {
return new EmployeesProcessor();
}
#Bean
public ItemWriter<EmployeesDTO> EmployeeWriter() {
return new EmployeeWriter();
}
}

Answer 1

what would be the best size ?
There is no best size, it depends on the use case. For maximum throughput, you should set the pool size such as each partition can have its own connection if you want maximum throughput, otherwise choose the timeout depending on how long a partition would take to finish.
For example, if you have 10 partitions and a pool size of 5, 5 partitions will be working and 5 others will be waiting. Now if a partition takes at most 1 minute to finish, the timeout could be set to 1 minute (or probably a bit longer) such that waiting partitions are not timed out, aka a connection is returned to the pool before the timeout.