"In system operations the term rollback is often used to imply that arbitrary changes can be reversed i.e. ‘rolled back’ from an erroneous state to a previously known acceptable state. We show that this assumption is flawed and discuss error-correction schemes based on absolute rather than relative change."

"By formulating this problem algebraically, the discussion is distanced from the sometimes emotional standpoints that bind system administrators to the notion of rollback: desperately wanting does not make it possible. The discussion about totalisation of fields is particularly useful, as it maps nicely to the flaws in this thinking. To deal with the inverse of a many-to-one map, one must invoke a policy or arbitrary selection."

Amazon's deployment strategy

Using redis-repeater to propagate read-only queues

Capistrano deploys via bittorrent

Nice read, but *really* wish he would have included runit in his analyses.

Supervisor is a client/server system that allows its users to monitor and control a number of processes on UNIX-like operating systems.

It shares some of the same goals of programs like launchd, daemontools, and runit. Unlike some of these programs, it is not meant to be run as a substitute for init as "process id 1". Instead it is meant to be used to control processes related to a project or a customer, and is meant to start like any other program at boot time.

At its core, radmind operates as a tripwire. It is able to detect changes to any managed filesystem object, e.g. files, directories, links, etc. However, radmind goes further than just integrity checking: once a change is detected, radmind can optionally reverse the change.

Each managed machine may have its own loadset composed of multiple, layered overloads. This allows, for example, the operating system to be described separately from applications.

A talk on deploying more frequently

Chef is a systems integration framework, built to bring the benefits of configuration management to your entire infrastructure

Ruby Hit Squad's replacement for Capistrano. Also possibly the best logo ever.

A "movement" to simplify/replace Cap.

"To provide a coherent set of Java software packages for Linux, satisfying all quality requirements of other applications." "To establish an efficient and robust policy for Java software packaging and installation."

"Cfengine's principal promise is to be based on the very best and latest research. It does not aim to be user-friendly, but user-invisible."

New book from Pragmatic Programmers. I'm looking forward to reading this one.

"ControlTier provides a framework and toolset that allows development, QA and operations staff to collaboratively build and execute portable, model-driven automation that can be used to release, deploy and configure complex integrated applications in mult

Mongrel cluster load testing using Pen as a balancer