Why is my chip shop like SQL Server
Firstly for those of you not from the UK a chip shop is
takeaway where you can get Fish and Chips. A great feature that I miss when
abroad, anyway.
So I walk in to the local chip shop tonight just as the person behind the
counter rings up a £85 bill on the till for the couple by the counter. Now
£85s worth or fish and ships is a lot and this was OAP fish and chips which is
cheaper still.
So I'm thinking thats probably 26 fish and chips, oh bugger. I'm going to be
hear a long time.
So why is the chip shop like SQL Server well I though I would be waiting
until they had served all those portions of fish and chips but no to my suprise,
the couple were being served with a MAXDOP of 2. No this isn't the size of the
dollup of mayonaise, of the 3 staff behind the counter, only two were
involved in serving the couple.
This is great, that meant the 3rd person was left to serve the person in
front of me and me. Very much like the scheduler in SQL Server, whats more the
staff are very effecient and take requests even when they don't have enough
resource (i.e. chips and fish) they queue the requests up and server the
requests as the resources become available.
However the capacity planning of the chip shop wasn't that great, firstly
they only had didn't have an RAID arrays configured, they only had one chip
hopper, from which the staff could scoop up the chips. This meant there was an
slight queue as each person got some chips and wrapped them up. now they did
have a RAID 0 serving desk with two serving places which worked ok because
the bottleneck with the chip hopper meant this wasn't a bottle neck.
They could have had a RAID 0 chip displenser with two hoppers but that would
only have exaserpated the last issue which was running out of throughput. The
servers where wanting chips from the chip hopper quicker than the SAN (chip
cooker) could provide it. Fortunately all the SAN had to do was get some more
peeled potatoes and chuck them in the fryer to satisfy the need, a little more
difficult than extending a SAN if you run out of resource.
Finally my fish and chips were served and I as happy in the knowledge that I
had a chip shop with RAID 0 serving desks, a 3 processor unit with a scheuler
that is capable of parallel processing, with a single chip hopper HBA connected
to a deep fat fryer SAN. Whilst their capacity planning was a little lacking at
this point, this was an anomoly and you shouldn't really plan your capacity for
anomolies of this nature (Unless that 1 anomoly is when you've placed an Ad in
the superbowl and you need you website to cope).
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