SEKE 2012 Proceedings - Knowledge Systems Institute

A Variability Management Method for Software
Configuration Files
Hiroaki Tanizaki, Toshiaki Aoki, Takuya Katayama
Japan Advanced Institute of Science and Technology
1-1 Asahidai, Nomi, Ishikawa, Japan
Email: {tani-h, toshiaki, katayama}@jaist.ac.jp
Abstract—Configuration files of software systems should be
made correctly when software systems are operated. However, it
is hard to figure out syntax and constraints of configuration files
due to their complexity and size. Therefore, it becomes hard to
make correct configuration files.
We focus on two problems. One is syntax error that configuration
file description is invalid. The other is semantic error that
required functions do not perform due to mismatch between
requirements and configuration file description. One solution to
prevent these errors is to manage variability of configuration files.
We propose a method which manages variability of configuration
files. In particular, we use a model which organizes variability and
constraints of configuration file description. Requirements and
dependencies between requirements and organized information
are also included in the model. The model is described by using
the feature diagram. By using the feature diagram to describe
the model, it becomes possible to check consistency between the
model and a configuration file. Our method deals with detection
and correction of errors of configuration files.
I. INTRODUCTION
Configuration files take an important role when software
systems are operated because functions and performances of
software systems depend on configuration file descriptions.
When software systems are developed, specifications or source
code are verified in order to check whether software systems
have no error. Besides it is important to verify whether
configuration files are correct. If configuration files have errors,
software systems do not operate or functions which are needed
by users do not execute. Errors of configuration files are
syntax and semantic error [7]. One of causes of syntax error
is scale and complexity of configuration files. Semantic error
means that mismatch between user’s purpose and configuration
file descriptions. User’s purpose means functions which are
needed by users and is a kind of requirement for configuration
files. One of causes of semantic error is that correspondence
relations between configuration file descriptions and requirements
are not clear. In order to make correct configuration
files, variability of configuration files should be managed.
Variability consists of syntax and correspondence relations
between requirements. However, it is not easy to manage
variability of configuration files because the complexity of
configuration files is becoming higher and higher according
to the increase of their size[2]. Besides, errors have to be
corrected, but error correction is also not easy for users and
administrators.
The purpose of our research is to propose a method which
supports users and administrators to make correct configuration
files. In order to make correct configuration files, our
method detects syntax and semantic errors and corrects them.
In particular, syntax and candidate of configuration file description
and correspondence relations between requirements
are modeled, and our method checks consistency between the
model and a configuration file.
In this paper, we show our approach in the following way. In
Section II, we introduce configuration files. Section III shows
outline of our approach. In Section IV, we propose a model
which organizes configuration file descriptions and requirements.
In Section V, we explain a method for support making
configuration files. Section VI shows an experiment using our
approach. In Section VII, we discuss about the effectiveness
of our approach. Section VIII shows related works. In Section
IX, we conclude this paper.
II. CONFIGURATION FILES
Configuration files are widely used in software systems such
as operating system, middleware software and application software.
We focus on configuration files of servers. Configuration
files of servers are directly made by users or administrators and
should be made correctly.
Configuration files are used to customize configuration and
functions of software systems. So, reliability of configuration
files is important to operate software systems, and should be
verified. Although there are some formats for configuration
files, basically combinations of setting item and parameters
are written. Each setting item has candidates of parameter.
Besides, a combination of setting item and parameter may
need other specific combinations in order to perform functions.
A. Requirements for configuration files
Users and administrators have their own purposes when they
make configuration files. Their purposes mean that specific
functions are performed. Therefore, we consider that purposes
are requirements for making configuration files.
For server software, configuration which is appropriate to
application which performs on the server is needed. For
example, when administrators make configuration files of
web servers and application servers which are used for a
web application execution environment, administrators should
configure functions for application which is executed on the
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