cases of software

1. Open Source Software: A Case Study
Scott A. James,
President
Computer Consulting Specialists, Inc.
Sarasota, Florida

2. Scott James Computer Consulting Specialists, Inc.
What is Open Source Software
• www.opensource.org says 10 things, but we summarize as:
• Software in a community that is:
• Freely Used (no warranty, no limits on usage)
• Freely Extended (must share source, represent original works and
owners)
• Many varieties of licenses, they ARE different.
Know what they mean.
• Check out www.opensource.org for large list and details of each.

3. Scott James Computer Consulting Specialists, Inc.
Summary
A case study of a project created with open source technology.
• Project analysis: Goals & Resources
• Technology: TCO, Evaluation & Decision
• Implementation: Building the project
• Lessons: What was learned
• Resources

4. Project Analysis
What are we doing? What do we have?

5. Scott James Computer Consulting Specialists, Inc.
Project Analysis: Goals
• Project – functional, scalable, simple.
• Timeline – when will each phase roll out?
• Budget – how much money do we have?
• Longevity – short term utility or long term application?
• Equity – invest time in ourselves, or dollars in outside vendors?
Inexpensive, Build Fast, Quality: pick any two.

6. Scott James Computer Consulting Specialists, Inc.
Project Analysis: Resources
• Staff Knowledge – what is current ability of staff?
• Time – how long do we have?
• Money – how much do we have?
• Technology – what is already in use?

7. Technology
An Evaluation of Open Source Software

8. Scott James Computer Consulting Specialists, Inc.
Technology: Total Cost of Ownership (TCO)
• Startup Time: days or weeks?
• Development Time: weeks, months, years?
• Startup Money: cost of acquisition
• Development Money: recurring costs and time.
• Equity: $ pay to outside, vs. pay to ourselves
• Risk: Dependency on outside trends?
• Support: availability? Cost?

9. Scott James Computer Consulting Specialists, Inc.
Technology: Investigation
• LAMP: Linux, Apache, MySQL, PHP
• Windows: ASP/ActiveX, .NET, SQL Server
• IBM WebSphere, Sun ONE, HP

10. Scott James Computer Consulting Specialists, Inc.
Technology: Evaluation for TCO
• Tech staff has both Windows and UNIX background
• We have time (several months ok)
• Low budget, little money to spend.
• Prefer to invest equity in ourselves.
• Would like to reduce risk from outside tech trends.
• Need solid, reliable server that requires little maintenance.
• Need development questions/problems solved, but not real time.

11. Scott James Computer Consulting Specialists, Inc.
Technology: Decision to use LAMP
• This is a new project (no migration necessary)
• Our staff has UNIX (Linux) experience
• Large user support community for core technology
• Invest into own technology equity
• Reduce risk of reliance on technology trends
• Low cost to entry (no license or hardware fees)

12. Implementation
Putting Open Source Software to Work

13. Scott James Computer Consulting Specialists, Inc.
Implementation: Development Environment
• Linux server, Windows 2000 & XP workstations.
• Apache, MySQL and PHP.
• CVS & e-mail/IM for configuration management.
• Smarty template engine (smarty.php.net)
• PEAR application framework (pear.php.net)
• SafeSQL - PHP Class to prepare SQL statements
Google to find. Written by author of Smarty.

14. Scott James Computer Consulting Specialists, Inc.
Implementation: Linux Server Preperation
• Linux Mandrake (www.mandrakesoft.com)
• Apache 2.0 (www.apache.org)
• MySQL 3.23 (www.mysql.com)
• PHP 4.2 (www.php.net)

15. Scott James Computer Consulting Specialists, Inc.
Implementation: Development Preparation
• CVS for version control on Linux server
• SAMBA for windows networking.
• TortoiseCVS on Windows (www.tortoisecvs.org)
Better than WinCVS (it’s a powerful shell extension)
• Language syntax sensitive editor (Ultra Edit, Multi-Edit, vim, etc.)
• Apache and PHP on local workstations for unit testing (Linux
version on server, Win32 versions on workstations).

16. Scott James Computer Consulting Specialists, Inc.
Implementation: Development
• Data model with subject matter experts, talk through 1-to-Many
relationships, sanity check.
• Design PHP class hierarchy for business N-tier layer.
• Create shim PHP classes for web designers to use while building
and testing HTML templates. This provides ability to develop GUI in
parallel.
• Smarty template syntax can be HTML syntax compliant for use with
Dreamweaver.

17. Scott James Computer Consulting Specialists, Inc.
Implementation: Open Source value, case in point
• We found a useful PHP class for preparing SQL statements called
SafeSQL.
• However, it did not provide all the functionality we wanted.
• In about 2 hours we modified the source to add our features.
• We then e-mailed a copy back to the author; that these features
may be included in future versions (as he my decide).
• We enjoy similar features added by other developers.

18. Scott James Computer Consulting Specialists, Inc.
Implementation: Use the Support Channels
• Docs (www.apache.org, www.php.net)
Save time with on-line look-up (MySQL, PHP)
RTFM (Read The Fine Manual)
• www.google.com - Best way to search the Internet.
Search for specifics like: functions, methods and error numbers
• Forums (www.phpinsider.com, www.devshed.com)
Register early, try to skim articles regularly.
• Wiki – web page self regulated by community, very useful.
The Smarty template engine has a great Wiki.
• Plan for time to interact with open source community
-- support is usually not real time.

19. Scott James Computer Consulting Specialists, Inc.
Implementation: Flexible environment for unit testing
• Perform unit testing on local Windows workstations using Windows
versions of Apache, PHP and MySQL.
• Regression testing is desirable, use automated methods as much
as possible.
• CVS provides “hooks” to execute scripts on files as they are
committed to repository.

20. Scott James Computer Consulting Specialists, Inc.
Implementation: Deployment on servers
• Deploy using automated script – fewer human actions means fewer
mistakes.
• Look at using SSH, TAR, RSYNC for ways to move software
between hosts.
• Use CVS to ‘tag’ releases for consistent software bundling. Avoid
temptation to copy individual files.
• Adopt versioning nomenclature like: 1.2.4.0-beta1
(major.minor.fix.build)
• Batch bugs/features into small groups of changes for frequent
(sometimes weekly) updates.

21. Lessons Learned
What have we learned from our experience?

22. Scott James Computer Consulting Specialists, Inc.
Lessons Learned: Support
• Subscribe to on-line newsletters early on. Look for digest versions
and skim for understanding of product and current support.
• Plan time for support from open source community. Response time
may be days.
• Don’t be afraid to ask for help. Be courteous to the open source
community.

23. Scott James Computer Consulting Specialists, Inc.
Lessons Learned: Development
• Do a small project (a prototype) to test development staff and
environment. Set goals, and track progress.
• Schedule tasks in parallel to allow for workflow snags and
interacting with open source community.
• Use in-source documentation tools (www.doxygen.org,
www.phpdoc.de) to aid staff and to monitor progress.
• Tap into local support network early in the project:
user groups, business associates, consultants.

24. Scott James Computer Consulting Specialists, Inc.
Lessons Learned: Configuration Management
• Frequently commit (check-in) files to CVS and tag frequently
(release).
• Goal: Only commit working code, and never tag broken code.
• Use CVS for all files, including docs, libraries, binaries. Makes for
easy reproduction of whole environment for reliable testing.
• Do unit testing on local workstations with Apache & PHP running
locally. Build this into the design.
• Have fun, and learn a lot!

25. Scott James Computer Consulting Specialists, Inc.
Resources
• Philosophy & Legal:
www.opensource.org
• Fun:
www.slashdot.org
For these slides and more visit:
Computer Consulting Specialists, Inc.
www.computercsi.com
Scott@computercsi.com
941-320-7937