Blog

Current reading


Wadler's influential "monads" paper for Haskell. It seems like a classic case of making something simple sound profound and mysterious.  And companion paper by Hughes on "why functional programming matters" . See also some comments above. McCarthy's original LISP paper.  Just terrible. He made a serious error picking Lambda calculus as…

Chang-Maxemchuk atomic broadcast


The Chang-Maxemchuk algorithm (US Patent 4,725,834 ) solves atomic broadcast (and in-order broadcast) problems for distributed networks in a far simpler and more efficient way than some popular alternatives. In fact, the obscurity of this method is hard to understand given the current interest in distributed consensus. The basic idea is simple…

Time out of joint


Financial trading venues and trading systems operate so quickly and rely on clocks so deeply that events like the one noted in this FINRA report are more common than many understand The findings stated that the firm transmitted to OATS New Order Reports and related subsequent reports where the timestamp…

Data base design criteria: ease of use


Regarding ease-of-use, it’s often struck me when reviewing data systems papers that the evaluation sections are full of performance and correctness criteria, but only rarely is there any discussion of how well a system helps its target users achieve their goals: how easy is it to build, maintain, and debug…

Making Paxos face facts


Lamport's  "Paxos Made Simple" paper is notoriously hard to understand but at least part of the difficulty is that the algorithm  changes radically in the middle of the presentation.  The first part of the paper presents a subtle (maybe too subtle) method to permit multiple processes or network sites to agree…

state equations in practice


  When people think of mathematical models of state for programs and other computer systems, it's natural and conventional to consider state as a map from symbolic names of state variable to values. This is an error for a number of reasons including, most critically, the lack of any compositional…