OT: why are LAMP sites slow?

[Tim Daneliuk]

Paul Rubin wrote:

> Tim Daneliuk <tundra at tundraware.com> writes:
> 
>>I worked for an Airline computer reservation system (CRS) for almost a
>>decade. There is nothing about today's laptops that remotely comes close
>>to the power of those CRS systems, even the old ones. CRS systems are
>>optimized for extremely high performance I/O and use an operating system
>>(TPF) specifically designed for high-performance transaction processing.
> 
> 
> Yeah, I've been interested for a while in learning a little bit about
> how TPF worked.  Does Gray's book that you mention say much about it?

I honestly do not recall.  TPF/PAARS is an odd critter unto itself
that may not be covered by much of anything other than IBM docs.

> 
> I think that the raw hardware of today's laptops dwarfs the old big
> iron.  An S/360 channel controller may have basically been a mainframe
> in its own right, but even a mainframe in those days was just a few
> MIPS.  The i/o systems and memory are lots faster too, though not by
> nearly the ratio by which storage capacity and cpu speed have
> increased.  E.g., a laptop disk these days has around 10 msec latency
> and 20 MB/sec native transfer speed, vs 50+ msec and a few MB/sec for
> a 3330-level drive (does that sound about right?.  

Again, I don't know.  The stuff we had was much newer (and faster) than
that.

> 
> 
>>Web servers are very sessions oriented: make a connection-pass the
>>unit of work-drop the connection. This is inherently slow (and not
>>how high performance TP is done). Moreover, really high perfomance
>>requires a very fine level of I/O tuning on the server - at the CRS
>>I worked for, they performance people actually only populated part
>>of the hard drives to minimize head seeks.
> 
> 
> Today I think most seeks can be eliminated by just using ram or SSD
> (solid state disks) instead of rotating disks.  But yeah, you wouldn't
> do that on a laptop.

But that still does not solve the latency problem of session establishment/
teardown over network fabric which is the Achilles Heel of
the web and web services.

> 
> 
>>For a good overview of TP design, see Jim Gray's book, "Transaction
>>Processing: Concepts and Techniques".
> 
> 
> Thanks, I'll look for this book.  Gray of course is one of the
> all-time database gurus and that book is probably something every
> serious nerd should read.  I've probably been a bad boy just for
> having not gotten around to it years ago.
> 
> 
>>P.S. AFAIK the first CRS systems of any note came into being in the 1970s not
>>      the 1960s, but I may be incorrect in the matter.
> 
> 
> From <http://en.wikipedia.org/wiki/Sabre_%28computer_system%29>:
> 
>     The system [SABRE] was created by American Airlines and IBM in the
>     1950s, after AA president C. R. Smith sat next to an IBM sales
>     representative on a transcontinental flight in 1953. Sabre's first
>     mainframe in Briarcliff Manor, New York went online in 1960. By
>     1964, Sabre was the largest private data processing system in the
>     world. Its mainframe was moved to an underground location in
>     Tulsa, Oklahoma in 1972.
> 
>     Originally used only by American, the system was expanded to travel
>     agents in 1976. It is currently used by a number of companies,
>     including Eurostar, SNCF, and US Airways. The Travelocity website is
>     owned by Sabre and serves as a consumer interface to the system.

I stand (sit) corrected ;)
-- 
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Tim Daneliuk     tundra at tundraware.com
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