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
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
Distributed consensus and network reliability
All of the distributed consensus algorithms I have been reviewing recently (Paxos, Raft, Zab, Chang Maxemchuck, Viewstamped, … ) are based on a number of assumptions about the network environment, including the assumption that messages may be lost but are
The replicated state machine method of fault tolerance from 1980s
The first time I saw this method was when I went to work for Parallel Computer Systems, , later called Auragen, in the famous tech startup center of Englewood Cliffs, New Jersey. I commuted there from the East Village*. The company built
circularity problems in distributed consensus
Distributed consensus involves organizing a collection of independent agents – processes or network sites – to agree on some value or sequence of values. Many distributed consensus methods depend on a leader-follower scheme in which the leader is an agent
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
State equations
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Cutting and pasting about Kodak’s demise
This graph from Peter Diamandis about how Kodak entered the sinkhole is kind of amazing. Diamandis explains Kodak’s failure to swerve in what is I think the orthodox Silicon Valley analysis: [in 1996] Kodak had a $28 billion market cap and
RTLinux
Some old stuff I found in the office
Synchronous processors
Imagine a processor with no interrupts. We can do a lot better and get rid of most exceptions (e.g. system calls, page faults etc.), most peripheral devices/buses, and even cache misses, but let’s start with interrupts. Modern micro-processors are bloated