* Posts by David Shone

5 posts • joined 30 Jul 2009

Facebook confirms Cambridge Analytica stole its data; it’s a plot, claims former director

David Shone

Re: Boo Hoo! @SVV


In any civilised society naive or uninformed people do indeed have to be protected so far as is reasonably possible (and from what I've read, I consider fb to be culpable in part here). But education is part of that protection; if your students only communicate via fb then perhaps they should be expected to learn to use email or whatever system your institution defines as a standard.

If you were aware of possible issues with fb, then due diligence would surely lead you to avoid it and to specify some other medium. Presumably you have a standard language that is mandatory for verbal and written communication with students, and I don't see why there's a problem in specifying other standards for communications, instead of pandering to the latest fad.

Story gone

David Shone

Interesting titbits but some enormous gaps

Even for a "potted" history, this article has some big holes - Service Bureaus and Grid computing to name just two.

IBM's Service Bureau Corporation and Lyons' LEO bureau are worthy of mention as an "economic concept" that underlies and predates Cloud, even if they weren't part of the direct technological lineage.

The total omission of Grid computing is even more bizarre; it was an important step beyond cycle stealing and the commodity compute clusters developed in academia - mostly for HPC - in the late 1980s/early '90s. Ian Foster's notion of the Grid was a computing utility grid; Cloud computing is largely an embodiment of that idea with some of the practical issues ironed-out (or maybe not).

SUPERCOMPUTER vs your computer in bang-for-buck battle

David Shone

Welcome to the 1980s

There is very little here that's new or surprising.

In the 1980s it was clear that a cluster of small systems (such as workstations) could often do the job of a supercomputer, so long as you could carve-up and distribute the work. Since then, this has been reinvented with many names: Beowulf, Grid, Map-Reduce etc.

The basic ideas - and related ones such as cycle-stealing - probably go back even further; however it was the arrival of microprocessor-based systems that changed the economics and architecture of supercomputing so that big systems are effectively clusters of small ones, with the added overhead of fast interconnects and other infrastructure.

UK, US ink boffinry pact on laser fusion 'star power'

David Shone

"Twee"? Certainly not!

Most definitely not "twee" when you understand the origin of the name:



MySQL startup targets SSDs

David Shone


While I agree in principle, in practice many systems are not always laid-out well, and after many years of troubleshooting some of these problems I've also found that even if they are well laid out, a common problem is shared storage, e.g., a big array on a SAN, where the physical disks are sliced to provide many spindles for IOPs, often leaving unused space. Some time later, the storage team allocates this space for another purpose (often another server) and the performance of the original application is degraded as the LUN latencies are increased.

Also, 90%+ hit ratio is all very well, but it's the cost of the misses that hurt you; if a miss takes 10x longer to service than a hit (and it's often worse), then the 10% of misses cost more than the 90% hits, halving the throughput.

SSDs - used appropriately - can make a huge difference and may turn out to be less expensive than lots of spindles that would otherwise have to be left mostly empty.

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