Spring-batch flow / split after a step

I've stumbled upon this question asking about how split works, and maybe this answer arrives a bit (one year) late, but here I go...

The issue there is "split" is not a step by itself, but you were naming (and referencing) it as it was:

<batch:job id="webServiceJob2">
    <batch:step id="step1" next="step2"></batch:step>
    <batch:split id="step2" next="step3"></batch:split> <!-- This is not a step -->
    <batch:step id="step3"></batch:step>
</batch:job>

The correct syntax would be:

<batch:job id="webServiceJob2">
    <batch:step id="step1" next="step2"></batch:step>
    <batch:split id="split_step2" next="step3">
        <flow> 
             <step id="step2_A_1" ... next="step2_A_2"/>
             <step id="step2_A_2" ... />
        </flow>
        <flow> 
             <step id="step2_B_1" ... />
        </flow>
    </batch:split>
    <batch:step id="step3"></batch:step>
</batch:job>

But this is not what you want to achieve, because by split declarations you have to set in compile time the exact number of parallel steps that will be executed, and the purpose of split is using different steps in each flow instead calling several times the same one.

You should check the documentation about Scaling and Parallel processes, the partition step seems a good candidate for your requirements.