Batch operation doesn't get called
It worked after I added file to the $batch array.

function mymdoule_node_batch()
{
    $batch = array(
        'title'         =&gt; t("Migrating"),
        'operations'    =&gt; array(
            array('mycallback_001'),
            array('mycallback_002'),
        ),
        'finished'      =&gt; 'mycallback_finished',
        'init_message'  =&gt; t('Initializing...'),
        'error_message' =&gt; t('An error occurred.'),
        'file'          =&gt; 'mypatch.ops.inc',
    );

    batch_set($batch);
    drupal_set_message("step: 0");
}