Live Linux

A presentation prepared for the IBM Computer Users' Association's conference 3-5^th April 2000

Who I am

• Simon Brooke
  • Experienced software architect
  • Small company person
  • Technical Director, Weft Technology Ltd.

This presentation is available at http://www.jasmine.org.uk/bookshelf/papers/linux-cua/

What I do

• Design software systems
• Build software systems
• Advise people about software systems
• Occasionally, talk to conferences.

The Lessons of History

"Those who will not learn the lessons of history are condemned to repeat them."

• IBM dominated the industry in the 1970s
• Result:
  • slow technological development,
  • poor quality products,
  • high prices,
  • the Open Systems movement

• Microsoft dominates the industry now...

What I'm going to talk about

• Why I started using Linux
• Customers for whom I've delivered solutions using Linux

Why I started using Linux

• Common Knowledge
• National Schizophrenia Fellowship
• IRIS

Common Knowledge

• Specialist AI consultancy with killer-app in house toolkit
• Written in LISP
• Decided to productise
• Needed good, stable platform with good windowing system.

Development platforms: the options in '91

• Digital Research GEM
  • Not robust enough, limited memory map
• Microsoft Windows 2.0
  • Not robust enough, limited memory map
• Acorn RISC-OS
  • Not accepted by industry
• Macintosh
  • Not robust enough, not widely enough accepted
• OSF/Motif
  • Good... but expensive.

Development platforms in '91 [II]

• No brainer - OSF/Motif best...
  • ... but we couldn't afford it
• Borrowed machines: NCR, Data General
• Acorn R260
  • BSD 4.2 on ARM processor

And in the end

• Recession in 92, company ran out of money.

NSF: Putting a charity on the Net, 1994

• National Schizophrenia Fellowship (Scotland)
• Wanted EMail/Usenet feed
• Found SLS Linux
• 0.99 patch level 11 kernel
• 50 or so floppies
• It just worked

Comparison with BSD, 94

• BSD on ARM more reliable
• BSD on ARM much more memory efficient
• Linux (ext2) file system more reliable

IRIS: Starting E-Commerce 1996

• Internet start-up
• Targeting e-commerce from day one
• Concentrated on tourism industry
• Original Web server a Solaris box
  • But it died...
  • Couldn't afford to replace it
  • Had spare PC

Merrick: serious horsepower, 1997

• Data-driven tourism site with complex queries
• Needed powerful database engine
• Commercial options just too expensive
• Merrick, the first Linux server we'd built for all-out speed
  • Patched 1.2 kernel
  • Symmetrical multi-processor with twin Pentium Pro 200
  • Twin RAID arrays
  • Postgres 6.3
  • Approximately 380 MIPS for under £6,000 in 1997

Customers

• Early Technology
• BT

Who is Early Technology [i]

• My favorite customer!
• Michael Bennett-Levy
• Antique dealer and gadget enthusiast
• World expert on early television
• Owns the world's largest collection of pre-war televisions

Who is Early Technology [ii]

• One man business
• Operated out of a shop in Edinburgh's West Bow
• Many customers by word of mouth
• Much business by fax and telephone

EarlyTech on the Web

• Commissioned static Web site in 1995
• Did little business
• Came to me in late 1996 asking how to develop it.

DealerSys: a data driven site for (antique) dealers

• Administrative interface through Web forms
• Site personalised for users
• Automatic email alerts

DealerSys: the benefits

• First sale within twenty-four hours of going live.
• Early Technology shop now closed; Web-site principal focus of business.

DealerSys: the costs

• Server: £260
• Replacement chip fan: £8
• Replacement hard disk: £63
• Operating system: £0
• Database management system: £0
• Total software-related down-time in three years continuous running: nil.

Who is BT

• A major TelCo...

BT's Intranet

• Large and complex Intranet
• Corporate focus for communication
• Constantly changing

BT's Intranet core

• Core of intranet a directory of internal web sites and on-line resources
• Home page of every employee's browser
• Averages three changes per day

Doing it by hand

• Prior to LinkManager, all changes made by hand-editing HTML
• Changes often required update of several pages
  • Always involved change to alphabetical index
  • Often involved change to What's New
• Time consuming and error-prone
• Maintainers widely separated: Edinburgh, Leeds, London.

Building a solution

• Data-driven web-site, of course
• Cheap, standards-compliant client-server lego
• Using Java Servlets
• Using XML as an intermediate representation
• Using XSLT for final formatting of output

Why XML/XSL?

• Needed to separate content from format
  • To allow for re-designs
• XSL offered standards-based mechanism
• Probably adopted too early (May 1999), very bleeding edge
• But working very satisfactorily now.
• Have since delivered a second XML/XSL solution for BT

Delivering a solution

• LinkManager was supposed to be delivered on one of BT's Solaris-based servers
• Linux is not supposed to be used for production systems in BT
• LinkManager is running on Linux 'temporarily'
• Because suitably configured Solaris box has not been found
• It's getting to be a pretty long temporary.

Why Linux

• We develop on Linux
  • Primarily because it's reliable
  • But also because the tools we need are available
  • And also because it's cheap
  • Preferred distribution Mandrake
• Setting up a Linux box was inexpensive
• So didn't require much beurocracybeurocracy
• And now, it just works

Conclusion: why I use and recommend Linux

Most importantly, open

With an open system you cannot be locked in.

Next most importantly, reliable

Unreliable software costs time and money

But not insignificantly, inexpensive.

• Free system software
• Most service software free
• Most key software components free
• Makes optimal use of inexpensive hardware

People who can help you with Linux

Who am I again?

• Simon Brooke
  • Technical Director, Weft Technology Ltd.
    • simon@weft.co.uk