Book/Release-It

Heuristic: useful metrics

Heuristic: useful metrics (src: Book_ release it! - Michael Nygard)

Heuristic: when to run your own software load balancer

if your organization treats load balancers as "those things over there" that some other team manages, then you might even think about implementing a layer of software load balancing under your control (src: Book_ release it! - Michael Nygard)

Heuristic: when to use automation

once we're talking about shutting down more than 50% of total server capacity, the automation probably ought to pause for some human confirmation automation has no judgement We should use automation for the things that humans are bad at: repetitive tasks and fast response. We should use humans for things automation is bad at: perceiving the whole situation at a higher level (src: Book_ release it! - Michael Nygard)

Model: 12-factor app

(src: Book_ release it! - Michael Nygard) (origin: https://12factor.net)

Model: health check

page or api call that reveals the application's internal view of it's own health (src: Book_ release it! - Michael Nygard)

Model: platform team

platform team should provide the capability that others use. monitoring team doesn't do the monitoring it provides the ability for others to do their own monitoring shift from ownership of the domain to offering a service to customers (src: Book_ release it! - Michael Nygard)

Model: push vs pull log collection

push push over network 🙂 containers no long-lived identity no local storage pull central machine reaches out to all known hosts services write to local files (src: Book_ release it! - Michael Nygard)

Pattern: canary deployments

small set of instances that get the new build first. For a period of time, instances running the new build coexist with instances running the old build If the canary instances behave oddly, or their metrics go south, then the build is not rolled out to the remaining population todo: ref handling versions - peaceful side-by side running of different versions (src: Book_ release it! - Michael Nygard)

Pattern: immutable infrastructure (aka phoenix server)

Don’t change runtime instances Destroy and recreate Always start from a stable, known base image (src: Book_ release it! - Michael Nygard) (src: Evolutionary Architecture - 9. Guidelines for Evolutionary Architecture)

Pattern: put all dependencies in a private repository

Pattern: put all dependencies in a private repository Code (eg. Maven) Pipeline (eg. Jenkins plugins) (src: Book_ release it! - Michael Nygard)