[email protected] (Walt Farrell) writes: > If you consider ENQs such as the one ISPF created to protect updating > members of a partitioned data set, and that some other programs also use, > that ENQ is more obviously advisory.
re: http://www.garlic.com/~lynn/2010k.html#38 Unix systems and Serialization mechanism in that sense, ACP controller lock were advisory ... old email http://www.garlic.com/~lynn/2008i.html#email800325 in this post http://www.garlic.com/~lynn/2008i.html#39 American Airlines i.e. channel programs on loosely-coupled could execute w/o requiring locks ... but "LOCK READ CCW" and "WRITE UNLOCK CCW" set/unset logical locks in the controller. the value specified for logical locks can be arbitary value ... applications can establish the possible convention/meaning (and required cooperating application) by comparison reserve/release channel programs would prevent other processors from accessing device for i/o ... even if the other processors didn't execute a reserve. distributed lock manager I did for ha/cmp ... required cooperative DBMS (or other cooperative appilcations) on all the clustered processors http://www.garlic.com/~lynn/subtopic.html#hacmp and I did some amount of slight-of-hand to get scaleup performance in the ha/cmp distributed lock manager ... reference here http://www.garlic.com/~lynn/95.html#13 not so much mentioned in direct scaleup ... but there was also some hacks required to drastically cut down elapsed time for DLM recovery in various kinds of failure scenarios. and some old-email about cluster scaleup ... not just DBMS http://www.garlic.com/~lynn/lhwemail.html#medusa and http://www.garlic.com/~lynn/2009p.html#43 From The Annals of Release No Software Before Its Time http://www.garlic.com/~lynn/2009p.html#46 From The Annals of Release No Software Before Its Time more recent http://www.garlic.com/~lynn/2010k.html#3 Assembler programs was Re: Delete all members of a PDS that is allocated -- 42yrs virtualization experience (since Jan68), online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
