OT: why are LAMP sites slow?

[Tim Daneliuk]

Paul Rubin wrote:

<SNIP>

> I've only worked on one serious site of this type and it was "SAJO"
> (Solaris Apache Java Oracle) rather than LAMP, but the concepts are
> the same.  I just feel like something bogus has to be going on.  I
> think even sites like Slashdot handle fewer TPS than a 1960's airline
> reservation that ran on hardware with a fraction of the power of one
> of today's laptops.

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.

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.

The point is that *everything* has to be tuned for high performance
TP - the OS, the language constructs (we used assembler for most things),
the protocols, and the overall architecture.  THis is why, IMHO,
things like SOAP a laughable - RPC is a poor foundation for reliable,
durable, and high-performance TP.  It might be fine for sending an
order or invoice now and then, but sustained throughput of the sort
I think of as "high" performance is likely never going to be accomplished
with session-oriented architectures.

For a good overview of TP design, see Jim Gray's book, "Transaction Processing:
Concepts and Techniques".

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.
-- 
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Tim Daneliuk     tundra at tundraware.com
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