Micrometer tracing: Propagate context to spring batch (spring boot 3) SimpleAsyncTaskExecutor tasks

I use Spring Boot 3, Spring Batch and micrometer for tracing.
I would like the trace id to be the same across all the parent and child flows and steps.
So I would like to propagate the context across the spring batch SimpleAsyncTaskExecutor tasks for distributed tracing by micrometer.

In my case, the main flow splits into parallel flow and back to main flow. I noticed the steps in the main flow have the same trace id, but the parallel flows have a different trace id.

Please advise.

The approach described in this answer could be adapted to propagate context (e.g. thread-local variables) to Spring Batch child flows or steps.

If you want to have one traceId in all steps or flows of the Spring Batch job, then

• set ContextPropagatingTaskDecorator to SimpleAsyncTaskExecutor:

@Bean
public TaskDecorator taskDecorator() {
    return new ContextPropagatingTaskDecorator();
}

@Bean
public TaskExecutor taskExecutor(TaskDecorator taskDecorator) {
    var taskExecutor = new SimpleAsyncTaskExecutor();
    executor.setTaskDecorator(taskDecorator);
    return taskExecutor;
}

• use the decorated executor in your flows/steps:

// example of flow
FlowBuilder<SimpleFlow>("parallelFlow")
    .split(taskExecutor)
// example of step
StepBuilder("mainStep", jobRepository)
    ...
    .taskExecutor(taskExecutor)

Another approach how to create a decorated executor suggested by the question's author:

@Bean
public TaskExecutor taskExecutor(TaskDecorator taskDecorator) {
    return new SimpleAsyncTaskExecutorBuilder()
        .threadNamePrefix("work-flow-")
        .taskDecorator(taskDecorator)
        .build();
}