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The Commit Interval
As mentioned previously, a step reads in and writes out items, periodically committing
by using the supplied PlatformTransactionManager
. With a commit-interval
of 1, it
commits after writing each individual item. This is less than ideal in many situations,
since beginning and committing a transaction is expensive. Ideally, it is preferable to
process as many items as possible in each transaction, which is completely dependent upon
the type of data being processed and the resources with which the step is interacting.
For this reason, you can configure the number of items that are processed within a commit.
-
Java
-
XML
The following example shows a step
whose tasklet
has a commit-interval
value of 10 as it would be defined in Java:
@Bean
public Job sampleJob(JobRepository jobRepository, Step step1) {
return new JobBuilder("sampleJob", jobRepository)
.start(step1)
.build();
}
@Bean
public Step step1(JobRepository jobRepository, PlatformTransactionManager transactionManager) {
return new StepBuilder("step1", jobRepository)
.<String, String>chunk(10, transactionManager)
.reader(itemReader())
.writer(itemWriter())
.build();
}
The following example shows a step
whose tasklet
has a commit-interval
value of 10 as it would be defined in XML:
<job id="sampleJob">
<step id="step1">
<tasklet>
<chunk reader="itemReader" writer="itemWriter" commit-interval="10"/>
</tasklet>
</step>
</job>
In the preceding example, 10 items are processed within each transaction. At the
beginning of processing, a transaction is begun. Also, each time read
is called on the
ItemReader
, a counter is incremented. When it reaches 10, the list of aggregated items
is passed to the ItemWriter
, and the transaction is committed.