@Override
    public List<TaskModel> getTasks(List<String> taskIds) {
        Preconditions.checkNotNull(taskIds);
        Preconditions.checkArgument(taskIds.size() > 0, "Task ids list cannot be empty");
        String workflowId = lookupWorkflowIdFromTaskId(taskIds.get(0));
        if (workflowId == null) {
            return null;
        }
        return getWorkflow(workflowId, true).getTasks().stream()
                .filter(task -> taskIds.contains(task.getTaskId()))
                .collect(Collectors.toList());
    }
This is a dummy implementation and this feature is not implemented for Cassandra backed
Conductor
cassandra-persistence/src/main/java/com/netflix/conductor/cassandra/dao/CassandraExecutionDAO.java