Create and manage DynamoDB global tables with Multi-Region Strong Consistency using Amazon Command Line Interface v2

Create a table with Multi-Region Strong Consistency.

# Step 1: Create a new table in us-east-2 (primary region for MRSC)
# Note: Table must be empty when enabling MRSC
aws dynamodb create-table \
    --table-name MusicTable \
    --attribute-definitions \
        AttributeName=Artist,AttributeType=S \
        AttributeName=SongTitle,AttributeType=S \
    --key-schema \
        AttributeName=Artist,KeyType=HASH \
        AttributeName=SongTitle,KeyType=RANGE \
    --billing-mode PAY_PER_REQUEST \
    --region us-east-2

# Wait for table to become active
aws dynamodb wait table-exists --table-name MusicTable --region us-east-2

# Step 2: Add replica and witness with Multi-Region Strong Consistency
# MRSC requires exactly three replicas in supported regions
aws dynamodb update-table \
    --table-name MusicTable \
    --replica-updates '[{"Create": {"RegionName": "us-east-1"}}]' \
    --global-table-witness-updates '[{"Create": {"RegionName": "us-west-2"}}]' \
    --multi-region-consistency STRONG \
    --region us-east-2

Verify MRSC configuration and replica status.

# Verify the global table configuration and MRSC setting
aws dynamodb describe-table \
    --table-name MusicTable \
    --region us-east-2 \
    --query 'Table.{TableName:TableName,TableStatus:TableStatus,MultiRegionConsistency:MultiRegionConsistency,Replicas:Replicas[*],GlobalTableWitnesses:GlobalTableWitnesses[*].{Region:RegionName,Status:ReplicaStatus}}'

Test strong consistency with immediate reads across Regions.

# Write an item to the primary region
aws dynamodb put-item \
    --table-name MusicTable \
    --item '{"Artist": {"S":"The Beatles"},"SongTitle": {"S":"Hey Jude"},"Album": {"S":"The Beatles 1967-1970"},"Year": {"N":"1968"}}' \
    --region us-east-2

# Read the item from replica region to verify strong consistency (cannot read or write to witness)
# No wait time needed - MRSC provides immediate consistency
echo "Reading from us-east-1 (immediate consistency):"
aws dynamodb get-item \
    --table-name MusicTable \
    --key '{"Artist": {"S":"The Beatles"},"SongTitle": {"S":"Hey Jude"}}' \
    --consistent-read \
    --region us-east-1

Perform conditional writes with MRSC guarantees.

# Perform a conditional update from a different region
# This demonstrates that conditions work consistently across all regions
aws dynamodb update-item \
    --table-name MusicTable \
    --key '{"Artist": {"S":"The Beatles"},"SongTitle": {"S":"Hey Jude"}}' \
    --update-expression "SET #rating = :rating" \
    --condition-expression "attribute_exists(Artist)" \
    --expression-attribute-names '{"#rating": "Rating"}' \
    --expression-attribute-values '{":rating": {"N":"5"}}' \
    --region us-east-1

Clean up MRSC global table resources.

# Remove replica tables (must be done before deleting the primary table)
aws dynamodb update-table \
    --table-name MusicTable \
    --replica-updates '[{"Delete": {"RegionName": "us-east-1"}}]' \
    --global-table-witness-updates '[{"Delete": {"RegionName": "us-west-2"}}]' \
    --region us-east-2

# Wait for replicas to be deleted
echo "Waiting for replicas to be deleted..."
sleep 30

# Delete the primary table
aws dynamodb delete-table \
    --table-name MusicTable \
    --region us-east-2