Boss: Keep it running

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Quick check

What does continuous deployment add to continuous delivery?

  1. Every change that passes is released to production automatically
  2. Automated tests
  3. A staging environment
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Every change that passes is released to production automatically

Continuous delivery keeps every build releasable. Continuous deployment releases it, with no human step.

Read the plan

plan
# google_firestore_database#   .saves must be replaced-/+ resource ... "saves"Plan: 1 to add,  0 to change,  1 to destroy.

What will approving this plan do?

  1. Destroy the database and create a new one
  2. Change one setting in place
  3. Nothing
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Destroy the database and create a new one

"-/+" means destroy, then create a replacement. A new database starts empty.

Quick check

Why is a canary compared with the control rather than with yesterday?

  1. Time changes the numbers on its own
  2. Yesterday's data is deleted
  3. The control is always smaller
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Time changes the numbers on its own

Google's SRE workbook: "time is one of the biggest sources of change in observed metrics."

Quick check

In blue-green deployment, rolling back means switching the router back.

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True

The old environment is still running, so switching back is the rollback.

Quick check

Who is "the only group modifying the system during an incident"?

  1. Operations
  2. Communication
  3. Planning
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Operations

Communication talks to players and Planning handles longer-term issues. Only Operations changes the system.

Do the math

incident
RPO               1 hourlast backup        09:00disaster           12:00

Does this backup meet the RPO?

  1. No: 3 hours of data would be lost
  2. Yes
  3. Only if the RTO is met
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No: 3 hours of data would be lost

Everything from 09:00 to 12:00 is lost: 3 hours, three times the 1-hour RPO.

Quick check

Which is a reason to write a postmortem in Google's SRE book?

  1. An on-call engineer rolled back a release
  2. A release went out on time
  3. A new player signed up
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An on-call engineer rolled back a release

On-call intervention, such as a release rollback, is one of the book's triggers.

Quick check

What does Netflix's Chaos Monkey do?

  1. Randomly terminates instances in production
  2. Writes postmortems
  3. Forecasts capacity
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Randomly terminates instances in production

It stops servers at random, so services are built to survive it.