# Tutoriales: creación de tablas globales
<a name="V2globaltables.tutorial"></a>

Esta sección proporciona instrucciones paso a paso para crear tablas globales de DynamoDB configuradas para su modo de coherencia preferido. Elija los modos de coherencia final de varias regiones (MREC) o coherencia alta de varias regiones (MRSC) según los requisitos de la aplicación.

Las tablas globales de MREC proporcionan una latencia de escritura más baja con coherencia final en todas las Regiones de AWS. Las tablas globales de MRSC proporcionan lecturas altamente coherentes en todas las regiones, con latencias de escritura ligeramente superiores a las de MREC. Elija el modo de coherencia que mejor se adapte a las necesidades de la aplicación en cuanto a coherencia de datos, latencia y disponibilidad.

**Topics**
+ [Creación de una tabla global configurada para MREC](#V2creategt_mrec)
+ [Creación de una tabla global configurada para MRSC](#create-gt-mrsc)

## Creación de una tabla global configurada para MREC
<a name="V2creategt_mrec"></a>

En esta sección se muestra cómo crear una tabla global con el modo de coherencia final de varias regiones (MREC). MREC es el modo de coherencia predeterminado para tablas globales y proporciona escrituras de baja latencia con replicación asincrónica en todas las Regiones de AWS. Los cambios realizados en un elemento de una región suelen replicarse en todas las demás regiones en un segundo. Esto hace que MREC sea ideal para aplicaciones que priorizan una baja latencia de escritura y pueden tolerar breves periodos en los que diferentes regiones pueden devolver versiones de datos ligeramente diferentes.

Puede crear tablas globales de MREC con réplicas en cualquier región de AWS donde DynamoDB esté disponible y agregar o eliminar réplicas en cualquier momento. Los ejemplos siguientes muestran cómo crear una tabla global de MREC con réplicas en varias regiones.

### Creación de una tabla global de MREC mediante la consola de DynamoDB
<a name="mrec-console"></a>

Siga estos pasos para crear una tabla global mediante la Consola de administración de AWS. En el ejemplo siguiente, se crea una tabla global con tablas de réplica en Estados Unidos y Europa.

1. Inicie sesión en la Consola de administración de AWS y abra la consola de DynamoDB en [https://console.aws.amazon.com/dynamodb/](https://console.aws.amazon.com/dynamodb/).

1. Para este ejemplo, elija **Este de EE. UU. (Ohio)** en el selector de regiones en la barra de navegación.

1. En el panel de navegación del lado izquierdo de la consola, elija **Tablas**.

1. Seleccione **Create Table (Crear tabla)**.

1. En la página **Crear tabla**:

   1. En **Nombre de la tabla**, introduzca **Music**.

   1. En **Partition key** (Clave de partición), ingrese **Artist**.

   1. Para **Clave de clasificación**, ingrese **SongTitle**.

   1. Deje los demás valores predeterminados y elija **Crear tabla**.

      Esta nueva tabla le servirá de primera tabla de réplica en una nueva tabla global. Será el prototipo para crear otras tablas de réplica que quiera añadir más tarde.

1. Cuando la tabla se active:

   1. Elija la tabla **Música** en la lista de tablas.

   1. Elija la pestaña **Tablas globales**.

   1. Elija **Create replica (Crear réplica)**.

1. En el menú desplegable **Regiones de replicación disponibles**, elija **Oeste de EE. UU. (Oregón) us-west-2**.

   La consola asegura que no haya ninguna tabla con el mismo nombre en la región seleccionada. Si ya existe una tabla con el mismo nombre, debe eliminar la tabla existente antes de crear una nueva tabla de réplica en esa región.

1. Elija **Create replica (Crear réplica)**. Esto comienza el proceso de creación de la tabla en la región Oeste de EE. UU (Oregón) us-west-2.

   La pestaña **Tablas globales** de la tabla **Música** (y de cualquier otra tabla de réplica) indica que la tabla se ha replicado en varias regiones.

1. Agregue otra región repitiendo los pasos anteriores, pero elija **Europa (Fráncfort) eu-central-1** como región.

1. Para probar la replicación:

   1. Asegúrese de que utiliza la Consola de administración de AWS en la región Este de EE. UU. (Ohio).

   1. Elija **Explorar elementos de la tabla**.

   1. Seleccione **Crear elemento**.

   1. Ingrese **item\$11** para **Artista** y **Song Value 1** para **Título de la canción**.

   1. Seleccione **Crear elemento**.

1. Compruebe la replicación cambiando a las otras regiones:

   1. En el selector de regiones en la esquina superior derecha, elija **Europa (Fráncfort)**.

   1. Compruebe que la tabla **Música** contiene el elemento que ha creado.

   1. Repita la verificación para **Oeste de EE. UU. (Oregón)**.

### Creación de una tabla global de MREC mediante AWS CLI o Java
<a name="mrec-cli-java"></a>

------
#### [ CLI ]

En el siguiente ejemplo de código, se muestra cómo administrar las tablas globales de DynamoDB con replicación de varias regiones con coherencia final (MREC).
+ Cree una tabla con replicación de varias regiones (MREC).
+ Coloque y obtenga elementos de las tablas de réplica.
+ Elimine réplicas una por una.
+ Efectúe una limpieza eliminando la tabla.

**AWS CLI con Bash script**  
Cree una tabla con replicación de varias regiones.  

```
# Step 1: Create a new table (MusicTable) in US East (Ohio), with DynamoDB Streams enabled (NEW_AND_OLD_IMAGES)
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 \
    --stream-specification StreamEnabled=true,StreamViewType=NEW_AND_OLD_IMAGES \
    --region us-east-2

# Step 2: Create an identical MusicTable table in US East (N. Virginia)
aws dynamodb update-table --table-name MusicTable --cli-input-json \
'{
  "ReplicaUpdates":
  [
    {
      "Create": {
        "RegionName": "us-east-1"
      }
    }
  ]
}' \
--region us-east-2

# Step 3: Create a table in Europe (Ireland)
aws dynamodb update-table --table-name MusicTable --cli-input-json \
'{
  "ReplicaUpdates":
  [
    {
      "Create": {
        "RegionName": "eu-west-1"
      }
    }
  ]
}' \
--region us-east-2
```
Describa la tabla de varias regiones.  

```
# Step 4: View the list of replicas created using describe-table
aws dynamodb describe-table \
    --table-name MusicTable \
    --region us-east-2 \
    --query 'Table.{TableName:TableName,TableStatus:TableStatus,MultiRegionConsistency:MultiRegionConsistency,Replicas:Replicas[*].{Region:RegionName,Status:ReplicaStatus}}'
```
Coloque elementos en una tabla de réplica.  

```
# Step 5: To verify that replication is working, add a new item to the Music table in US East (Ohio)
aws dynamodb put-item \
    --table-name MusicTable \
    --item '{"Artist": {"S":"item_1"},"SongTitle": {"S":"Song Value 1"}}' \
    --region us-east-2
```
Obtenga elementos de las tablas de réplica.  

```
# Step 6: Wait for a few seconds, and then check to see whether the item has been 
# successfully replicated to US East (N. Virginia) and Europe (Ireland)
aws dynamodb get-item \
    --table-name MusicTable \
    --key '{"Artist": {"S":"item_1"},"SongTitle": {"S":"Song Value 1"}}' \
    --region us-east-1

aws dynamodb get-item \
    --table-name MusicTable \
    --key '{"Artist": {"S":"item_1"},"SongTitle": {"S":"Song Value 1"}}' \
    --region eu-west-1
```
Elimine réplicas.  

```
# Step 7: Delete the replica table in Europe (Ireland) Region
aws dynamodb update-table --table-name MusicTable --cli-input-json \
'{
  "ReplicaUpdates":
  [
    {
      "Delete": {
        "RegionName": "eu-west-1"
      }
    }
  ]
}' \
--region us-east-2

# Delete the replica table in US East (N. Virginia) Region
aws dynamodb update-table --table-name MusicTable --cli-input-json \
'{
  "ReplicaUpdates":
  [
    {
      "Delete": {
        "RegionName": "us-east-1"
      }
    }
  ]
}' \
--region us-east-2
```
Efectúe una limpieza eliminando la tabla.  

```
# Clean up: Delete the primary table
aws dynamodb delete-table --table-name MusicTable --region us-east-2

echo "Global table demonstration complete."
```
+ Para obtener información sobre la API, consulte los siguientes temas en la *Referencia de comandos de AWS CLI*.
  + [CreateTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/CreateTable)
  + [DeleteTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/DeleteTable)
  + [DescribeTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/DescribeTable)
  + [GetItem](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/GetItem)
  + [PutItem](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/PutItem)
  + [UpdateTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/UpdateTable)

------
#### [ Java ]

En el ejemplo de código siguiente, se muestra cómo crear y administrar las tablas globales de DynamoDB con réplicas en varias regiones.
+ Cree una tabla con un índice secundario global y flujos de DynamoDB.
+ Agregue réplicas en diferentes regiones para crear una tabla global.
+ Elimine réplicas de una tabla global.
+ Agregue elementos de prueba para verificar la replicación en todas las regiones.
+ Describa la configuración de la tabla global y el estado de las réplicas.

**SDK para Java 2.x**  
Cree una tabla con un índice secundario global y flujos de DynamoDB mediante AWS SDK for Java 2.x.  

```
    public static CreateTableResponse createTableWithGSI(
        final DynamoDbClient dynamoDbClient, final String tableName, final String indexName) {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }
        if (indexName == null || indexName.trim().isEmpty()) {
            throw new IllegalArgumentException("Index name cannot be null or empty");
        }

        try {
            LOGGER.info("Creating table: " + tableName + " with GSI: " + indexName);

            CreateTableRequest createTableRequest = CreateTableRequest.builder()
                .tableName(tableName)
                .attributeDefinitions(
                    AttributeDefinition.builder()
                        .attributeName("Artist")
                        .attributeType(ScalarAttributeType.S)
                        .build(),
                    AttributeDefinition.builder()
                        .attributeName("SongTitle")
                        .attributeType(ScalarAttributeType.S)
                        .build())
                .keySchema(
                    KeySchemaElement.builder()
                        .attributeName("Artist")
                        .keyType(KeyType.HASH)
                        .build(),
                    KeySchemaElement.builder()
                        .attributeName("SongTitle")
                        .keyType(KeyType.RANGE)
                        .build())
                .billingMode(BillingMode.PAY_PER_REQUEST)
                .globalSecondaryIndexes(GlobalSecondaryIndex.builder()
                    .indexName(indexName)
                    .keySchema(KeySchemaElement.builder()
                        .attributeName("SongTitle")
                        .keyType(KeyType.HASH)
                        .build())
                    .projection(
                        Projection.builder().projectionType(ProjectionType.ALL).build())
                    .build())
                .streamSpecification(StreamSpecification.builder()
                    .streamEnabled(true)
                    .streamViewType(StreamViewType.NEW_AND_OLD_IMAGES)
                    .build())
                .build();

            CreateTableResponse response = dynamoDbClient.createTable(createTableRequest);
            LOGGER.info("Table creation initiated. Status: "
                + response.tableDescription().tableStatus());

            return response;

        } catch (DynamoDbException e) {
            LOGGER.severe("Failed to create table: " + tableName + " - " + e.getMessage());
            throw e;
        }
    }
```
Espere a que una tabla se active mediante AWS SDK for Java 2.x.  

```
    public static void waitForTableActive(final DynamoDbClient dynamoDbClient, final String tableName) {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }

        try {
            LOGGER.info("Waiting for table to become active: " + tableName);

            try (DynamoDbWaiter waiter =
                DynamoDbWaiter.builder().client(dynamoDbClient).build()) {
                DescribeTableRequest request =
                    DescribeTableRequest.builder().tableName(tableName).build();

                waiter.waitUntilTableExists(request);
                LOGGER.info("Table is now active: " + tableName);
            }

        } catch (DynamoDbException e) {
            LOGGER.severe("Failed to wait for table to become active: " + tableName + " - " + e.getMessage());
            throw e;
        }
    }
```
Agregue una réplica para crear o ampliar una tabla global mediante AWS SDK for Java 2.x.  

```
    public static UpdateTableResponse addReplica(
        final DynamoDbClient dynamoDbClient,
        final String tableName,
        final Region replicaRegion,
        final String indexName,
        final Long readCapacity) {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }
        if (replicaRegion == null) {
            throw new IllegalArgumentException("Replica region cannot be null");
        }
        if (indexName == null || indexName.trim().isEmpty()) {
            throw new IllegalArgumentException("Index name cannot be null or empty");
        }
        if (readCapacity == null || readCapacity <= 0) {
            throw new IllegalArgumentException("Read capacity must be a positive number");
        }

        try {
            LOGGER.info("Adding replica in region: " + replicaRegion.id() + " for table: " + tableName);

            // Create a ReplicationGroupUpdate for adding a replica
            ReplicationGroupUpdate replicationGroupUpdate = ReplicationGroupUpdate.builder()
                .create(builder -> builder.regionName(replicaRegion.id())
                    .globalSecondaryIndexes(ReplicaGlobalSecondaryIndex.builder()
                        .indexName(indexName)
                        .provisionedThroughputOverride(ProvisionedThroughputOverride.builder()
                            .readCapacityUnits(readCapacity)
                            .build())
                        .build())
                    .build())
                .build();

            UpdateTableRequest updateTableRequest = UpdateTableRequest.builder()
                .tableName(tableName)
                .replicaUpdates(replicationGroupUpdate)
                .build();

            UpdateTableResponse response = dynamoDbClient.updateTable(updateTableRequest);
            LOGGER.info("Replica addition initiated in region: " + replicaRegion.id());

            return response;

        } catch (DynamoDbException e) {
            LOGGER.severe("Failed to add replica in region: " + replicaRegion.id() + " - " + e.getMessage());
            throw e;
        }
    }
```
Elimine una réplica de una tabla global mediante AWS SDK for Java 2.x.  

```
    public static UpdateTableResponse removeReplica(
        final DynamoDbClient dynamoDbClient, final String tableName, final Region replicaRegion) {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }
        if (replicaRegion == null) {
            throw new IllegalArgumentException("Replica region cannot be null");
        }

        try {
            LOGGER.info("Removing replica in region: " + replicaRegion.id() + " for table: " + tableName);

            // Create a ReplicationGroupUpdate for removing a replica
            ReplicationGroupUpdate replicationGroupUpdate = ReplicationGroupUpdate.builder()
                .delete(builder -> builder.regionName(replicaRegion.id()).build())
                .build();

            UpdateTableRequest updateTableRequest = UpdateTableRequest.builder()
                .tableName(tableName)
                .replicaUpdates(replicationGroupUpdate)
                .build();

            UpdateTableResponse response = dynamoDbClient.updateTable(updateTableRequest);
            LOGGER.info("Replica removal initiated in region: " + replicaRegion.id());

            return response;

        } catch (DynamoDbException e) {
            LOGGER.severe("Failed to remove replica in region: " + replicaRegion.id() + " - " + e.getMessage());
            throw e;
        }
    }
```
Agregue elementos de prueba para verificar la replicación mediante AWS SDK for Java 2.x.  

```
    public static PutItemResponse putTestItem(
        final DynamoDbClient dynamoDbClient, final String tableName, final String artist, final String songTitle) {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }
        if (artist == null || artist.trim().isEmpty()) {
            throw new IllegalArgumentException("Artist cannot be null or empty");
        }
        if (songTitle == null || songTitle.trim().isEmpty()) {
            throw new IllegalArgumentException("Song title cannot be null or empty");
        }

        try {
            LOGGER.info("Adding test item to table: " + tableName);

            Map<String, software.amazon.awssdk.services.dynamodb.model.AttributeValue> item = new HashMap<>();
            item.put(
                "Artist",
                software.amazon.awssdk.services.dynamodb.model.AttributeValue.builder()
                    .s(artist)
                    .build());
            item.put(
                "SongTitle",
                software.amazon.awssdk.services.dynamodb.model.AttributeValue.builder()
                    .s(songTitle)
                    .build());

            PutItemRequest putItemRequest =
                PutItemRequest.builder().tableName(tableName).item(item).build();

            PutItemResponse response = dynamoDbClient.putItem(putItemRequest);
            LOGGER.info("Test item added successfully");

            return response;

        } catch (DynamoDbException e) {
            LOGGER.severe("Failed to add test item to table: " + tableName + " - " + e.getMessage());
            throw e;
        }
    }
```
Describa la configuración de la tabla global y las réplicas mediante AWS SDK for Java 2.x.  

```
    public static DescribeTableResponse describeTable(final DynamoDbClient dynamoDbClient, final String tableName) {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }

        try {
            LOGGER.info("Describing table: " + tableName);

            DescribeTableRequest request =
                DescribeTableRequest.builder().tableName(tableName).build();

            DescribeTableResponse response = dynamoDbClient.describeTable(request);

            LOGGER.info("Table status: " + response.table().tableStatus());
            if (response.table().replicas() != null
                && !response.table().replicas().isEmpty()) {
                LOGGER.info("Number of replicas: " + response.table().replicas().size());
                response.table()
                    .replicas()
                    .forEach(replica -> LOGGER.info(
                        "Replica region: " + replica.regionName() + ", Status: " + replica.replicaStatus()));
            }

            return response;

        } catch (ResourceNotFoundException e) {
            LOGGER.severe("Table not found: " + tableName + " - " + e.getMessage());
            throw e;
        } catch (DynamoDbException e) {
            LOGGER.severe("Failed to describe table: " + tableName + " - " + e.getMessage());
            throw e;
        }
    }
```
Ejemplo completo de operaciones de tablas globales mediante AWS SDK for Java 2.x.  

```
    public static void exampleUsage(final Region sourceRegion, final Region replicaRegion) {

        String tableName = "Music";
        String indexName = "SongTitleIndex";
        Long readCapacity = 15L;

        // Create DynamoDB client for the source region
        try (DynamoDbClient dynamoDbClient =
            DynamoDbClient.builder().region(sourceRegion).build()) {

            try {
                // Step 1: Create the initial table with GSI and streams
                LOGGER.info("Step 1: Creating table in source region: " + sourceRegion.id());
                createTableWithGSI(dynamoDbClient, tableName, indexName);

                // Step 2: Wait for table to become active
                LOGGER.info("Step 2: Waiting for table to become active");
                waitForTableActive(dynamoDbClient, tableName);

                // Step 3: Add replica in destination region
                LOGGER.info("Step 3: Adding replica in region: " + replicaRegion.id());
                addReplica(dynamoDbClient, tableName, replicaRegion, indexName, readCapacity);

                // Step 4: Wait a moment for replica creation to start
                Thread.sleep(5000);

                // Step 5: Describe table to view replica information
                LOGGER.info("Step 5: Describing table to view replicas");
                describeTable(dynamoDbClient, tableName);

                // Step 6: Add a test item to verify replication
                LOGGER.info("Step 6: Adding test item to verify replication");
                putTestItem(dynamoDbClient, tableName, "TestArtist", "TestSong");

                LOGGER.info("Global table setup completed successfully!");
                LOGGER.info("You can verify replication by checking the item in region: " + replicaRegion.id());

                // Step 7: Remove replica and clean up table
                LOGGER.info("Step 7: Removing replica from region: " + replicaRegion.id());
                removeReplica(dynamoDbClient, tableName, replicaRegion);
                DeleteTableResponse deleteTableResponse = dynamoDbClient.deleteTable(
                    DeleteTableRequest.builder().tableName(tableName).build());
                LOGGER.info("MREC global table demonstration completed successfully!");

            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
                throw new RuntimeException("Thread was interrupted", e);
            } catch (DynamoDbException e) {
                LOGGER.severe("DynamoDB operation failed: " + e.getMessage());
                throw e;
            }
        }
    }
```
+ Para obtener detalles sobre la API, consulte los siguientes temas en la *Referencia de la API de AWS SDK for Java 2.x*.
  + [CreateTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/CreateTable)
  + [DescribeTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/DescribeTable)
  + [PutItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/PutItem)
  + [UpdateTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/UpdateTable)

------

## Creación de una tabla global configurada para MRSC
<a name="create-gt-mrsc"></a>

En esta sección se muestra cómo crear una tabla global de coherencia alta de varias regiones (MRSC). Las tablas globales de MRSC replican de forma sincrónica los cambios de los elementos en todas las regiones, lo que garantiza que las operaciones de lectura altamente coherente en cualquier réplica siempre devuelvan la versión más reciente de un elemento. Al convertir una tabla de una sola región en una tabla global de MRSC, debe asegurarse de que la tabla esté vacía. No se admite la conversión de una tabla de una sola región en una tabla global de MRSC con los elementos existentes. Asegúrese de que no se escriba ningún dato en la tabla durante el proceso de conversión.

Puede configurar una tabla global de MRSC con tres réplicas o dos réplicas y un testigo. Al crear una tabla global de MRSC, debe elegir las regiones en las que se despliegan las réplicas y un testigo opcional. En el siguiente ejemplo, se crea una tabla global de MRSC con réplicas en las regiones Este de EE. UU. (Norte de Virginia) y Este de EE. UU. (Ohio), con un testigo en la región Oeste de EE. UU. (Oregón).

**nota**  
Antes de crear una tabla global, compruebe que los límites de rendimiento de la cuota de servicio sean coherentes en todas las regiones de destino, ya que es necesario para crear una tabla global. Para obtener más información sobre los límites de rendimiento de las tablas globales, consulte [Cuotas de tablas globales](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ServiceQuotas.html#gt-limits-throughput).

### Creación de una tabla global de MRSC mediante la consola de DynamoDB
<a name="mrsc_console"></a>

Siga estos pasos para crear una tabla global de MRSC mediante la Consola de administración de AWS.

1. Inicie sesión en la Consola de administración de AWS y abra la consola de DynamoDB en [https://console.aws.amazon.com/dynamodb/](https://console.aws.amazon.com/dynamodb/).

1. En el selector de regiones de la barra de navegación, elija una región en la que [se admiten](V2globaltables_HowItWorks.md#V2globaltables_HowItWorks.consistency-modes) tablas globales con MRSC, como **us-east-2**.

1. En el panel de navegación, elija **Tablas**.

1. Seleccione **Create table (Creación de tabla)**.

1. En la página **Crear tabla**:

   1. En **Nombre de la tabla**, introduzca **Music**.

   1. En **Clave de partición**, ingrese **Artist** y mantenga la **Cadena** predeterminada.

   1. En **Clave de clasificación**, ingrese **SongTitle** y mantenga el tipo de **Cadena** predeterminada.

   1. Deje los demás valores predeterminados y elija **Crear tabla**

      Esta nueva tabla le servirá de primera tabla de réplica en una nueva tabla global. Será el prototipo para crear otras tablas de réplica que quiera añadir más tarde.

1. Espere a que la tabla se active y luego selecciónela en la lista de tablas.

1. Elija la pestaña **Tablas globales** y, a continuación, seleccione **Crear réplica**.

1. En la página **Crear réplica**:

   1. En **Consistencia de varias regiones**, elija **Consistencia alta**.

   1. Para **Región de replicación 1**, elija **US East (N. Virginia) us-east-1**.

   1. Para **Región de replicación 2**, elija **US West (Oregon) us-west-2**.

   1. Compruebe **Configurar como testigo** para la región Oeste de EE. UU. (Oregón).

   1. Elija **Crear réplicas**.

1. Espere a que se complete el proceso de creación de la réplica y el testigo. El estado de la réplica se mostrará como **Activo** cuando la tabla esté lista para usarse.

### Creación de una tabla global de MRSC mediante la AWS CLI o Java
<a name="mrsc-cli-java"></a>

Antes de empezar, asegúrese de que la entidad principal de IAM tenga los permisos necesarios para crear una tabla global de MRSC con una región testigo.

La política de IAM de ejemplo siguiente le permite crear una tabla de DynamoDB (`MusicTable`) en Este de EE. UU. (Ohio) con una réplica en Este de EE. UU. (Norte de Virginia) y una región testigo en Oeste de EE. UU. (Oregón):

------
#### [ JSON ]

****  

```
{
    "Version":"2012-10-17",		 	 	 
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "dynamodb:CreateTable",
                "dynamodb:CreateTableReplica",
                "dynamodb:CreateGlobalTableWitness",
                "dynamodb:DescribeTable",
                "dynamodb:UpdateTable",
                "dynamodb:DeleteTable",
                "dynamodb:DeleteTableReplica",
                "dynamodb:DeleteGlobalTableWitness",
                "dynamodb:Scan",
                "dynamodb:Query",
                "dynamodb:UpdateItem",
                "dynamodb:PutItem",
                "dynamodb:GetItem",
                "dynamodb:DeleteItem",
                "dynamodb:BatchWriteItem"
            ],
            "Resource": [
                "arn:aws:dynamodb:us-east-1:123456789012:table/MusicTable",
                "arn:aws:dynamodb:us-east-2:123456789012:table/MusicTable",
                "arn:aws:dynamodb:us-west-2:123456789012:table/MusicTable"
            ]
        },
        {
            "Effect": "Allow",
            "Action": "iam:CreateServiceLinkedRole",
            "Resource": "arn:aws:iam::*:role/aws-service-role/replication.dynamodb.amazonaws.com/AWSServiceRoleForDynamoDBReplication",
            "Condition": {
                "StringLike": {
                    "iam:AWSServiceName": "replication.dynamodb.amazonaws.com"
                }
            }
        }
    ]
}
```

------

Los ejemplos de código siguientes, muestran cómo crear y administrar las tablas globales de DynamoDB con coherencia alta de varias regiones (MRSC).
+ Cree una tabla con coherencia alta de varias regiones.
+ Verifique la configuración de MRSC y el estado de la réplica.
+ Pruebe la coherencia alta entre regiones con lecturas inmediatas.
+ Realice escrituras condicionales con garantías de MRSC.
+ Limpie los recursos de la tabla global de MRSC.

------
#### [ Bash ]

**AWS CLI con Bash script**  
Cree una tabla con coherencia alta de varias regiones.  

```
# 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
```
Verifique la configuración de MRSC y el estado de la réplica.  

```
# 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}}'
```
Pruebe la coherencia alta con lecturas inmediatas entre regiones.  

```
# 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
```
Realice escrituras condicionales con garantías de MRSC.  

```
# 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
```
Limpie los recursos de la tabla global de MRSC.  

```
# 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
```
+ Para obtener información sobre la API, consulte los siguientes temas en la *Referencia de comandos de AWS CLI*.
  + [CreateTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/CreateTable)
  + [DeleteTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/DeleteTable)
  + [DescribeTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/DescribeTable)
  + [GetItem](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/GetItem)
  + [PutItem](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/PutItem)
  + [UpdateItem](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/UpdateItem)
  + [UpdateTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/UpdateTable)

------
#### [ Java ]

**SDK para Java 2.x**  
Cree una tabla regional lista para la conversión de MRSC con AWS SDK for Java 2.x.  

```
    public static CreateTableResponse createRegionalTable(final DynamoDbClient dynamoDbClient, final String tableName) {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }

        try {
            LOGGER.info("Creating regional table: " + tableName + " (must be empty for MRSC)");

            CreateTableRequest createTableRequest = CreateTableRequest.builder()
                .tableName(tableName)
                .attributeDefinitions(
                    AttributeDefinition.builder()
                        .attributeName("Artist")
                        .attributeType(ScalarAttributeType.S)
                        .build(),
                    AttributeDefinition.builder()
                        .attributeName("SongTitle")
                        .attributeType(ScalarAttributeType.S)
                        .build())
                .keySchema(
                    KeySchemaElement.builder()
                        .attributeName("Artist")
                        .keyType(KeyType.HASH)
                        .build(),
                    KeySchemaElement.builder()
                        .attributeName("SongTitle")
                        .keyType(KeyType.RANGE)
                        .build())
                .billingMode(BillingMode.PAY_PER_REQUEST)
                .build();

            CreateTableResponse response = dynamoDbClient.createTable(createTableRequest);
            LOGGER.info("Regional table creation initiated. Status: "
                + response.tableDescription().tableStatus());

            return response;

        } catch (DynamoDbException e) {
            LOGGER.severe("Failed to create regional table: " + tableName + " - " + e.getMessage());
            throw DynamoDbException.builder()
                .message("Failed to create regional table: " + tableName)
                .cause(e)
                .build();
        }
    }
```
Convierta una tabla regional en MRSC utilizando réplicas y testigos con AWS SDK for Java 2.x.  

```
    public static UpdateTableResponse convertToMRSCWithWitness(
        final DynamoDbClient dynamoDbClient,
        final String tableName,
        final Region replicaRegion,
        final Region witnessRegion) {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }
        if (replicaRegion == null) {
            throw new IllegalArgumentException("Replica region cannot be null");
        }
        if (witnessRegion == null) {
            throw new IllegalArgumentException("Witness region cannot be null");
        }

        try {
            LOGGER.info("Converting table to MRSC with replica in " + replicaRegion.id() + " and witness in "
                + witnessRegion.id());

            // Create replica update using ReplicationGroupUpdate
            ReplicationGroupUpdate replicaUpdate = ReplicationGroupUpdate.builder()
                .create(CreateReplicationGroupMemberAction.builder()
                    .regionName(replicaRegion.id())
                    .build())
                .build();

            // Create witness update
            GlobalTableWitnessGroupUpdate witnessUpdate = GlobalTableWitnessGroupUpdate.builder()
                .create(CreateGlobalTableWitnessGroupMemberAction.builder()
                    .regionName(witnessRegion.id())
                    .build())
                .build();

            UpdateTableRequest updateTableRequest = UpdateTableRequest.builder()
                .tableName(tableName)
                .replicaUpdates(List.of(replicaUpdate))
                .globalTableWitnessUpdates(List.of(witnessUpdate))
                .multiRegionConsistency(MultiRegionConsistency.STRONG)
                .build();

            UpdateTableResponse response = dynamoDbClient.updateTable(updateTableRequest);
            LOGGER.info("MRSC conversion initiated. Status: "
                + response.tableDescription().tableStatus());
            LOGGER.info("UpdateTableResponse full object: " + response);
            return response;

        } catch (DynamoDbException e) {
            LOGGER.severe("Failed to convert table to MRSC: " + tableName + " - " + e.getMessage());
            throw DynamoDbException.builder()
                .message("Failed to convert table to MRSC: " + tableName)
                .cause(e)
                .build();
        }
    }
```
Describa la configuración de una tabla global de MRSC con AWS SDK for Java 2.x.  

```
    public static DescribeTableResponse describeMRSCTable(final DynamoDbClient dynamoDbClient, final String tableName) {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }

        try {
            LOGGER.info("Describing MRSC global table: " + tableName);

            DescribeTableRequest request =
                DescribeTableRequest.builder().tableName(tableName).build();

            DescribeTableResponse response = dynamoDbClient.describeTable(request);

            LOGGER.info("Table status: " + response.table().tableStatus());
            LOGGER.info("Multi-region consistency: " + response.table().multiRegionConsistency());

            if (response.table().replicas() != null
                && !response.table().replicas().isEmpty()) {
                LOGGER.info("Number of replicas: " + response.table().replicas().size());
                response.table()
                    .replicas()
                    .forEach(replica -> LOGGER.info(
                        "Replica region: " + replica.regionName() + ", Status: " + replica.replicaStatus()));
            }

            if (response.table().globalTableWitnesses() != null
                && !response.table().globalTableWitnesses().isEmpty()) {
                LOGGER.info("Number of witnesses: "
                    + response.table().globalTableWitnesses().size());
                response.table()
                    .globalTableWitnesses()
                    .forEach(witness -> LOGGER.info(
                        "Witness region: " + witness.regionName() + ", Status: " + witness.witnessStatus()));
            }

            return response;

        } catch (ResourceNotFoundException e) {
            LOGGER.severe("Table not found: " + tableName + " - " + e.getMessage());
            throw DynamoDbException.builder()
                .message("Table not found: " + tableName)
                .cause(e)
                .build();
        } catch (DynamoDbException e) {
            LOGGER.severe("Failed to describe table: " + tableName + " - " + e.getMessage());
            throw DynamoDbException.builder()
                .message("Failed to describe table: " + tableName)
                .cause(e)
                .build();
        }
    }
```
Agregue elementos de prueba para verificar la coherencia alta de MRSC con AWS SDK for Java 2.x.  

```
    public static PutItemResponse putTestItem(
        final DynamoDbClient dynamoDbClient,
        final String tableName,
        final String artist,
        final String songTitle,
        final String album,
        final String year) {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }
        if (artist == null || artist.trim().isEmpty()) {
            throw new IllegalArgumentException("Artist cannot be null or empty");
        }
        if (songTitle == null || songTitle.trim().isEmpty()) {
            throw new IllegalArgumentException("Song title cannot be null or empty");
        }

        try {
            LOGGER.info("Adding test item to MRSC global table: " + tableName);

            Map<String, AttributeValue> item = new HashMap<>();
            item.put("Artist", AttributeValue.builder().s(artist).build());
            item.put("SongTitle", AttributeValue.builder().s(songTitle).build());

            if (album != null && !album.trim().isEmpty()) {
                item.put("Album", AttributeValue.builder().s(album).build());
            }
            if (year != null && !year.trim().isEmpty()) {
                item.put("Year", AttributeValue.builder().n(year).build());
            }

            PutItemRequest putItemRequest =
                PutItemRequest.builder().tableName(tableName).item(item).build();

            PutItemResponse response = dynamoDbClient.putItem(putItemRequest);
            LOGGER.info("Test item added successfully with strong consistency");

            return response;

        } catch (DynamoDbException e) {
            LOGGER.severe("Failed to add test item to table: " + tableName + " - " + e.getMessage());
            throw DynamoDbException.builder()
                .message("Failed to add test item to table: " + tableName)
                .cause(e)
                .build();
        }
    }
```
Lea los elementos con lecturas coherentes de las réplicas de MRSC con AWS SDK for Java 2.x.  

```
    public static GetItemResponse getItemWithConsistentRead(
        final DynamoDbClient dynamoDbClient, final String tableName, final String artist, final String songTitle) {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }
        if (artist == null || artist.trim().isEmpty()) {
            throw new IllegalArgumentException("Artist cannot be null or empty");
        }
        if (songTitle == null || songTitle.trim().isEmpty()) {
            throw new IllegalArgumentException("Song title cannot be null or empty");
        }

        try {
            LOGGER.info("Reading item from MRSC global table with consistent read: " + tableName);

            Map<String, AttributeValue> key = new HashMap<>();
            key.put("Artist", AttributeValue.builder().s(artist).build());
            key.put("SongTitle", AttributeValue.builder().s(songTitle).build());

            GetItemRequest getItemRequest = GetItemRequest.builder()
                .tableName(tableName)
                .key(key)
                .consistentRead(true)
                .build();

            GetItemResponse response = dynamoDbClient.getItem(getItemRequest);

            if (response.hasItem()) {
                LOGGER.info("Item found with strong consistency - no wait time needed");
            } else {
                LOGGER.info("Item not found");
            }

            return response;

        } catch (DynamoDbException e) {
            LOGGER.severe("Failed to read item from table: " + tableName + " - " + e.getMessage());
            throw DynamoDbException.builder()
                .message("Failed to read item from table: " + tableName)
                .cause(e)
                .build();
        }
    }
```
Realice actualizaciones condicionales con garantías de MRSC mediante AWS SDK for Java 2.x.  

```
    public static UpdateItemResponse performConditionalUpdate(
        final DynamoDbClient dynamoDbClient,
        final String tableName,
        final String artist,
        final String songTitle,
        final String rating) {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }
        if (artist == null || artist.trim().isEmpty()) {
            throw new IllegalArgumentException("Artist cannot be null or empty");
        }
        if (songTitle == null || songTitle.trim().isEmpty()) {
            throw new IllegalArgumentException("Song title cannot be null or empty");
        }
        if (rating == null || rating.trim().isEmpty()) {
            throw new IllegalArgumentException("Rating cannot be null or empty");
        }

        try {
            LOGGER.info("Performing conditional update on MRSC global table: " + tableName);

            Map<String, AttributeValue> key = new HashMap<>();
            key.put("Artist", AttributeValue.builder().s(artist).build());
            key.put("SongTitle", AttributeValue.builder().s(songTitle).build());

            Map<String, String> expressionAttributeNames = new HashMap<>();
            expressionAttributeNames.put("#rating", "Rating");

            Map<String, AttributeValue> expressionAttributeValues = new HashMap<>();
            expressionAttributeValues.put(
                ":rating", AttributeValue.builder().n(rating).build());

            UpdateItemRequest updateItemRequest = UpdateItemRequest.builder()
                .tableName(tableName)
                .key(key)
                .updateExpression("SET #rating = :rating")
                .conditionExpression("attribute_exists(Artist)")
                .expressionAttributeNames(expressionAttributeNames)
                .expressionAttributeValues(expressionAttributeValues)
                .build();

            UpdateItemResponse response = dynamoDbClient.updateItem(updateItemRequest);
            LOGGER.info("Conditional update successful - demonstrates strong consistency");

            return response;

        } catch (ConditionalCheckFailedException e) {
            LOGGER.warning("Conditional check failed: " + e.getMessage());
            throw e;
        } catch (DynamoDbException e) {
            LOGGER.severe("Failed to perform conditional update: " + tableName + " - " + e.getMessage());
            throw DynamoDbException.builder()
                .message("Failed to perform conditional update: " + tableName)
                .cause(e)
                .build();
        }
    }
```
Espere a que las réplicas de MRSC y los testigos se activen mediante AWS SDK for Java 2.x.  

```
    public static void waitForMRSCReplicasActive(
        final DynamoDbClient dynamoDbClient, final String tableName, final int maxWaitTimeSeconds)
        throws InterruptedException {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }
        if (maxWaitTimeSeconds <= 0) {
            throw new IllegalArgumentException("Max wait time must be positive");
        }

        try {
            LOGGER.info("Waiting for MRSC replicas and witnesses to become active: " + tableName);

            final long startTime = System.currentTimeMillis();
            final long maxWaitTimeMillis = maxWaitTimeSeconds * 1000L;
            int backoffSeconds = 5; // Start with 5 second intervals
            final int maxBackoffSeconds = 30; // Cap at 30 seconds

            while (System.currentTimeMillis() - startTime < maxWaitTimeMillis) {
                DescribeTableResponse response = describeMRSCTable(dynamoDbClient, tableName);

                boolean allActive = true;
                StringBuilder statusReport = new StringBuilder();

                if (response.table().multiRegionConsistency() == null
                    || !MultiRegionConsistency.STRONG
                        .toString()
                        .equals(response.table().multiRegionConsistency().toString())) {
                    allActive = false;
                    statusReport
                        .append("MultiRegionConsistency: ")
                        .append(response.table().multiRegionConsistency())
                        .append(" ");
                }
                if (response.table().replicas() == null
                    || response.table().replicas().isEmpty()) {
                    allActive = false;
                    statusReport.append("No replicas found. ");
                }
                if (response.table().globalTableWitnesses() == null
                    || response.table().globalTableWitnesses().isEmpty()) {
                    allActive = false;
                    statusReport.append("No witnesses found. ");
                }

                // Check table status
                if (!"ACTIVE".equals(response.table().tableStatus().toString())) {
                    allActive = false;
                    statusReport
                        .append("Table: ")
                        .append(response.table().tableStatus())
                        .append(" ");
                }

                // Check replica status
                if (response.table().replicas() != null) {
                    for (var replica : response.table().replicas()) {
                        if (!"ACTIVE".equals(replica.replicaStatus().toString())) {
                            allActive = false;
                            statusReport
                                .append("Replica(")
                                .append(replica.regionName())
                                .append("): ")
                                .append(replica.replicaStatus())
                                .append(" ");
                        }
                    }
                }

                // Check witness status
                if (response.table().globalTableWitnesses() != null) {
                    for (var witness : response.table().globalTableWitnesses()) {
                        if (!"ACTIVE".equals(witness.witnessStatus().toString())) {
                            allActive = false;
                            statusReport
                                .append("Witness(")
                                .append(witness.regionName())
                                .append("): ")
                                .append(witness.witnessStatus())
                                .append(" ");
                        }
                    }
                }

                if (allActive) {
                    LOGGER.info("All MRSC replicas and witnesses are now active: " + tableName);
                    return;
                }

                LOGGER.info("Waiting for MRSC components to become active. Status: " + statusReport.toString());
                LOGGER.info("Next check in " + backoffSeconds + " seconds...");

                tempWait(backoffSeconds);

                // Exponential backoff with cap
                backoffSeconds = Math.min(backoffSeconds * 2, maxBackoffSeconds);
            }

            throw DynamoDbException.builder()
                .message("Timeout waiting for MRSC replicas to become active after " + maxWaitTimeSeconds + " seconds")
                .build();

        } catch (DynamoDbException | InterruptedException e) {
            LOGGER.severe("Failed to wait for MRSC replicas to become active: " + tableName + " - " + e.getMessage());
            throw e;
        }
    }
```
Limpie las réplicas y los testigos de MRSC mediante AWS SDK for Java 2.x.  

```
    public static UpdateTableResponse cleanupMRSCReplicas(
        final DynamoDbClient dynamoDbClient,
        final String tableName,
        final Region replicaRegion,
        final Region witnessRegion) {

        if (dynamoDbClient == null) {
            throw new IllegalArgumentException("DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }
        if (replicaRegion == null) {
            throw new IllegalArgumentException("Replica region cannot be null");
        }
        if (witnessRegion == null) {
            throw new IllegalArgumentException("Witness region cannot be null");
        }

        try {
            LOGGER.info("Cleaning up MRSC replicas and witnesses for table: " + tableName);

            // Remove replica using ReplicationGroupUpdate
            ReplicationGroupUpdate replicaUpdate = ReplicationGroupUpdate.builder()
                .delete(DeleteReplicationGroupMemberAction.builder()
                    .regionName(replicaRegion.id())
                    .build())
                .build();

            // Remove witness
            GlobalTableWitnessGroupUpdate witnessUpdate = GlobalTableWitnessGroupUpdate.builder()
                .delete(DeleteGlobalTableWitnessGroupMemberAction.builder()
                    .regionName(witnessRegion.id())
                    .build())
                .build();

            UpdateTableRequest updateTableRequest = UpdateTableRequest.builder()
                .tableName(tableName)
                .replicaUpdates(List.of(replicaUpdate))
                .globalTableWitnessUpdates(List.of(witnessUpdate))
                .build();

            UpdateTableResponse response = dynamoDbClient.updateTable(updateTableRequest);
            LOGGER.info("MRSC cleanup initiated - removing replica and witness. Response: " + response);

            return response;

        } catch (DynamoDbException e) {
            LOGGER.severe("Failed to cleanup MRSC replicas: " + tableName + " - " + e.getMessage());
            throw DynamoDbException.builder()
                .message("Failed to cleanup MRSC replicas: " + tableName)
                .cause(e)
                .build();
        }
    }
```
Complete la demostración del flujo de trabajo de MRSC mediante AWS SDK for Java 2.x.  

```
    public static void demonstrateCompleteMRSCWorkflow(
        final DynamoDbClient primaryClient,
        final DynamoDbClient replicaClient,
        final String tableName,
        final Region replicaRegion,
        final Region witnessRegion)
        throws InterruptedException {

        if (primaryClient == null) {
            throw new IllegalArgumentException("Primary DynamoDB client cannot be null");
        }
        if (replicaClient == null) {
            throw new IllegalArgumentException("Replica DynamoDB client cannot be null");
        }
        if (tableName == null || tableName.trim().isEmpty()) {
            throw new IllegalArgumentException("Table name cannot be null or empty");
        }
        if (replicaRegion == null) {
            throw new IllegalArgumentException("Replica region cannot be null");
        }
        if (witnessRegion == null) {
            throw new IllegalArgumentException("Witness region cannot be null");
        }

        try {
            LOGGER.info("=== Starting Complete MRSC Workflow Demonstration ===");

            // Step 1: Create an empty single-Region table
            LOGGER.info("Step 1: Creating empty single-Region table");
            createRegionalTable(primaryClient, tableName);

            // Use the existing GlobalTableOperations method for basic table waiting
            LOGGER.info("Intermediate step: Waiting for table [" + tableName + "] to become active before continuing");
            GlobalTableOperations.waitForTableActive(primaryClient, tableName);

            // Step 2: Convert to MRSC with replica and witness
            LOGGER.info("Step 2: Converting to MRSC with replica and witness");
            convertToMRSCWithWitness(primaryClient, tableName, replicaRegion, witnessRegion);

            // Wait for MRSC conversion to complete using MRSC-specific waiter
            LOGGER.info("Waiting for MRSC conversion to complete...");
            waitForMRSCReplicasActive(primaryClient, tableName);

            LOGGER.info("Intermediate step: Waiting for table [" + tableName + "] to become active before continuing");
            GlobalTableOperations.waitForTableActive(primaryClient, tableName);

            // Step 3: Verify MRSC configuration
            LOGGER.info("Step 3: Verifying MRSC configuration");
            describeMRSCTable(primaryClient, tableName);

            // Step 4: Test strong consistency with data operations
            LOGGER.info("Step 4: Testing strong consistency with data operations");

            // Add test item to primary region
            putTestItem(primaryClient, tableName, "The Beatles", "Hey Jude", "The Beatles 1967-1970", "1968");

            // Immediately read from replica region (no wait needed with MRSC)
            LOGGER.info("Reading from replica region immediately (strong consistency):");
            GetItemResponse getResponse =
                getItemWithConsistentRead(replicaClient, tableName, "The Beatles", "Hey Jude");

            if (getResponse.hasItem()) {
                LOGGER.info("✓ Strong consistency verified - item immediately available in replica region");
            } else {
                LOGGER.warning("✗ Item not found in replica region");
            }

            // Test conditional update from replica region
            LOGGER.info("Testing conditional update from replica region:");
            performConditionalUpdate(replicaClient, tableName, "The Beatles", "Hey Jude", "5");
            LOGGER.info("✓ Conditional update successful - demonstrates strong consistency");

            // Step 5: Cleanup
            LOGGER.info("Step 5: Cleaning up resources");
            cleanupMRSCReplicas(primaryClient, tableName, replicaRegion, witnessRegion);

            // Wait for cleanup to complete using basic table waiter
            LOGGER.info("Waiting for replica cleanup to complete...");
            GlobalTableOperations.waitForTableActive(primaryClient, tableName);

            // "Halt" until replica/witness cleanup is complete
            DescribeTableResponse cleanupVerification = describeMRSCTable(primaryClient, tableName);
            int backoffSeconds = 5; // Start with 5 second intervals
            while (cleanupVerification.table().multiRegionConsistency() != null) {
                LOGGER.info("Waiting additional time (" + backoffSeconds + " seconds) for MRSC cleanup to complete...");
                tempWait(backoffSeconds);

                // Exponential backoff with cap
                backoffSeconds = Math.min(backoffSeconds * 2, 30);
                cleanupVerification = describeMRSCTable(primaryClient, tableName);
            }

            // Delete the primary table
            deleteTable(primaryClient, tableName);

            LOGGER.info("=== MRSC Workflow Demonstration Complete ===");
            LOGGER.info("");
            LOGGER.info("Key benefits of Multi-Region Strong Consistency (MRSC):");
            LOGGER.info("- Immediate consistency across all regions (no eventual consistency delays)");
            LOGGER.info("- Simplified application logic (no need to handle eventual consistency)");
            LOGGER.info("- Support for conditional writes and transactions across regions");
            LOGGER.info("- Consistent read operations from any region without waiting");

        } catch (DynamoDbException | InterruptedException e) {
            LOGGER.severe("MRSC workflow failed: " + e.getMessage());
            throw e;
        }
    }
```
+ Para obtener detalles sobre la API, consulte los siguientes temas en la *Referencia de la API de AWS SDK for Java 2.x*.
  + [CreateTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/CreateTable)
  + [DeleteTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/DeleteTable)
  + [DescribeTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/DescribeTable)
  + [GetItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/GetItem)
  + [PutItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/PutItem)
  + [UpdateItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/UpdateItem)
  + [UpdateTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/UpdateTable)

------