Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: "Stephen Fuld" Newsgroups: comp.arch Subject: Re: architectural goals, Byte Addressability And Beyond Date: Fri, 7 Jun 2024 03:13:54 -0000 (UTC) Organization: A noiseless patient Spider Lines: 28 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Injection-Date: Fri, 07 Jun 2024 05:13:54 +0200 (CEST) Injection-Info: dont-email.me; posting-host="1f2c39597d6855cbc93f15bdbec06a26"; logging-data="2017750"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+9TUlXgxQ+ytURiCfCnzZIx93I0beOZXw=" User-Agent: XanaNews/1.21-f3fb89f (x86; Portable ISpell) Cancel-Lock: sha1:ZdutYzZOmp6LzMGuF2tJeXlSs+o= Bytes: 2308 Lawrence D'Oliveiro wrote: > On Thu, 6 Jun 2024 11:55:22 -0000 (UTC), John Levine wrote: > > > If you're doing something that is mostly read-only and easy to > > parallelize, then it makes sense to use a farm of cheap PCs. But if > > you are a bank or an airline, you need to be able to lock your > > database so that you debit a bank account or sell a plane seat > > exactly once. There is a rule of thumb that the cost of locking > > something grows roughly as the square of the number of things > > contending for the lock. > > Remember that the number of users actually buying a product at any > given time is only a small proportion (say 1%) of the number of users > currently accessing the site. I don't know where you got that number, but even if it is true for a retail storefront type site, I am pretty sure it isn't true for a bank (what John was talking about, and a substantial part of mainframes's user base). Few people "browse" bank's the products. :-) Even for an airline (the other example John gave.) I suspect that far more than 1% of the accesses are updates. -- - Stephen Fuld (e-mail address disguised to prevent spam)