Impact of availability zone outage on EMR launched with instance fleet

Question

Suppose, while creating an EMR I have selected two instance types for primary and core fleet, one in us-east-1a and the second in us-east-1b.....Now, if the cluster got launched in us-east-1a and after sometime the availability zone us-east-1a goes down, then what will happen if I relaunch the cluster? Will it get launched in us-east-1b?

Accepted Answer

Hello,

The short answer is Yes, if one AZ is down/out of capacity/anything that wont satisfy your desired capacity, EMR automatically choose the next available AZ that you configured in the EMR cluster.

A bit explanatory way,  When EMR launches the cluster with instance fleet of multiple subnets included, it looks across those subnets(AZs) to find the instances and purchasing options that you specify. Basically your cluster can access a `deeper Amazon EC2 capacity pool analysis` when compared to clusters in a single subnet being provisioned.

In that way, if any one of the AZs not satisfied the assessment, the might be excluded and try to place the cluster on the subnet that is very close to your requirement. Please refer here for more information - https://docs.aws.amazon.com/emr/latest/ManagementGuide/emr-flexibility.html#emr-flexibility-az

Impact of availability zone outage on EMR launched with instance fleet

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