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Previous episode Regional services: what an app spread over three zones still shares

Why one cloud outage takes down half the Internet

DNS failure: how one empty record stopped a cloud region

A cloud database can run perfectly and still be impossible to reach. How one empty DNS record cut off a whole AWS region, with no server down.

  1. 1 Before a copy of your app can talk to DynamoDB, it needs the IP addresses behind that name. It asks DNS, the system that turns a name into numbers, just as your phone does for any website.a copy of your appDNSdynamodb.us-east-1.amazonaws.com = ?

    Before a copy of your app can talk to DynamoDB, it needs the IP addresses behind that name. It asks DNS, the system that turns a name into numbers, just as your phone does for any website.

  2. 2 The answer comes from a DNS record: the name, and under it a list of addresses. AWS changes that list all the time, as machines join, leave or get busy.dynamodb.us-east-1.amazonaws.com198.51.100.7198.51.100.23203.0.113.40example numberskept up to date, day and night

    The answer comes from a DNS record: the name, and under it a list of addresses. AWS changes that list all the time, as machines join, leave or get busy.

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Next episode Race condition: why three copies of one program did not prevent the AWS outage

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