final RunInstancesRequest request = createOnDemandInstancesRequest(pool, execution);
// TODO allow for more options (e.g. monitoring & termination protection etc.)
LOG.info(">> Sending RunInstances request: {}", request);
RunInstancesResult result = client.runInstances(request);
LOG.info("<< Got RunInstances result: {}", result);
// TODO tag instances: managed-by: Axemblr Provisionr, business-key: ID etc.
execution.setVariable(ProcessVariables.RESERVATION_ID,
result.getReservation().getReservationId());
execution.setVariable(ProcessVariables.INSTANCE_IDS,
collectInstanceIdsAsList(result.getReservation().getInstances()));
}