Machine Learning: The High-Interest Credit Card of Technical Debt

February 29, 2016 ~ Adrian Colyer ~ 9 Comments

Machine Learning: The High-Interest Credit Card of Technical Debt - Sculley et al. 2014 Today's paper offers some pragmatic advice for the developers and maintainers of machine learning systems in production. It's easy to rush out version 1.0 the authors warn us, but making subsequent improvements can be unexpectedly difficult. You very much get the ... Continue Reading

Distributed Consistency and Session Anomalies

February 26, 2016 ~ Adrian Colyer ~ 13 Comments

Since we've spent the last couple of days sketching anomaly diagrams and looking at isolation levels, I wanted to finish the week off with a quick recap of session anomalies and consistency levels for distributed stores. In terms of papers, I've drawn primary material for this from: Highly Available Transactions: Virtues and Limitations, and Linearizability ... Continue Reading

Generalized Isolation Level Definitions

February 25, 2016 ~ Adrian Colyer ~ 5 Comments

Generalized Isolation Level Definitions - Adya et al. 2000 Following on from yesterday's critique of ANSI SQL isolation levels, today's paper also gives a precise definition of isolation levels - but does so in a way that is inclusive of optimistic and general multi-version concurrency control strategies instead of being dependent on locking. Where Berenson ... Continue Reading

A Critique of ANSI SQL Isolation Levels

February 24, 2016 ~ Adrian Colyer ~ 25 Comments

A Critique of ANSI SQL Isolation Levels - Berenson et al. 1995 udpate: 2 minor corrections in the section on A5A per the comment from 'banks' - thanks! The ANSI SQL isolation levels were originally defined in prose, in terms of three specific anomalies that they were designed to prevent. Unsurprisingly, it turns out that ... Continue Reading

Not-quite-so-broken TLS: lessons in re-engineering a security protocol specification and implementation

February 23, 2016 ~ Adrian Colyer ~ 7 Comments

Not-quite-so-broken TLS: lessons in re-engineering a security protocol specification and implementation - Kaloper-Meršinjak et al. 2015 Update: fixed broken paper link above. On the surface this is a paper about a TLS implementation, but the really interesting story to me is the attempt to 'do it right,' and the techniques and considerations involved in that ... Continue Reading

IncludeOS: A minimal, resource efficient unikernel for cloud systems

February 22, 2016 ~ Adrian Colyer ~ 2 Comments

IncludeOS: A minimal, resource efficient unikernel for cloud systems - Bratterud et al. 2015 There has been lots of excitement around unikernels over the last year, and especially with the recent acquisition of the Unikernel Systems team by Docker (MirageOS, Mergeable Persistent Data Structures, Jitsu: Just-in time summoning of Unikernels). Whereas MirageOS is built around ... Continue Reading

Formal Requirements for Virtualizable Third Generation Architectures

February 19, 2016 ~ Adrian Colyer ~ 2 Comments

Formal Requirements for Virtualizable Third Generation Architectures - Popek & Goldberg 1974. With thanks to Alfred Bratterud for pointing me at this paper. What exactly is a virtual machine? What does a virtual machine monitor do? And how do we now whether a given piece of hardware can support virtualization or not? In today's paper ... Continue Reading

Ownership and Reference Counting Based Garbage Collection in the Actor World

February 18, 2016 ~ Adrian Colyer ~ Leave a comment

Ownership and Reference Counting Based Garbage Collection in the Actor World - Clebsch et al. 2015 Yesterday we looked at the reference capability based type system of the Pony language. Pony is a safe (data race free), fast actor language. Today we're looking at another aspect of how Pony achieves its speed and clean programming ... Continue Reading

Deny Capabilities for Safe, Fast Actors

February 17, 2016 ~ Adrian Colyer ~ 11 Comments

Deny Capabilities for Safe, Fast Actors - Clebsch et al. 2015 Do you remember Herb Sutter's 'The Free Lunch is Over' article? (Hard to believe that was written over 11 years ago!). Herb Sutter also posted a great update in 2012, 'Welcome to the Jungle'. In the conclusion of that piece Sutter writes: Mainstream hardware ... Continue Reading

Capability Myths Demolished

February 16, 2016 ~ Adrian Colyer ~ 4 Comments

Capability Myths Demolished - Miller et. al 2003 Pretty much everyone is familiar with an ACL-based approach to security. Despite having been around for a very long time, the capabilities approach to security is less well-known. Today's paper choice provides an excellent introduction to the capabilities model and how it compares to ACLs. Along the ... Continue Reading

the morning paper

a random walk through Computer Science research, by Adrian Colyer

Month: February 2016