Crea e gestisci tabelle globali DynamoDB dimostrando MREC utilizzando un SDK AWS - Amazon DynamoDB

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Crea e gestisci tabelle globali DynamoDB dimostrando MREC utilizzando un SDK AWS

Il seguente esempio di codice mostra come creare e gestire tabelle globali DynamoDB con repliche in più regioni.

  • Crea una tabella con Global Secondary Index e DynamoDB Streams.

  • Aggiungi repliche in diverse regioni per creare una tabella globale.

  • Rimuovi le repliche da una tabella globale.

  • Aggiungi elementi di test per verificare la replica tra le regioni.

  • Descrivi la configurazione globale della tabella e lo stato della replica.

Java
SDK per Java 2.x

Crea una tabella con Global Secondary Index e DynamoDB Streams utilizzando. 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; } }

Attendi che una tabella diventi attiva utilizzando. 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; } }

Aggiungi una replica per creare o estendere una tabella globale utilizzando 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; } }

Rimuovi una replica da una tabella globale utilizzando. 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; } }

Aggiungi elementi di test per verificare la replica utilizzando. 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; } }

Descrivi la configurazione globale della tabella e le repliche utilizzando. 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; } }

Esempio completo di operazioni su tabelle globali utilizzando 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; } } }

Per un elenco completo delle guide per sviluppatori AWS SDK e degli esempi di codice, consultaUtilizzo di DynamoDB con un SDK AWS. Questo argomento include anche informazioni su come iniziare e dettagli sulle versioni precedenti dell'SDK.