GH-3170: Change default requiredAcks to all

Author: Seungcheol Kwon (권승철)

binders/kafka-binder/spring-cloud-stream-binder-kafka-core/src/main/java/org/springframework/cloud/stream/binder/kafka/properties/KafkaBinderConfigurationProperties.java

@@ -110,7 +110,7 @@ public class KafkaBinderConfigurationProperties {
 
 	private boolean considerDownWhenAnyPartitionHasNoLeader = true;
 
-	private String requiredAcks = "1";
+	private String requiredAcks = "all";
 
 	private short replicationFactor = -1;
 

binders/kafka-binder/spring-cloud-stream-binder-kafka-core/src/test/java/org/springframework/cloud/stream/binder/kafka/properties/KafkaBinderConfigurationPropertiesTest.java

@@ -37,6 +37,16 @@
 
 class KafkaBinderConfigurationPropertiesTest {
 
+	@Test
+	@SuppressWarnings("unchecked")
+	void defaultRequiredAcksIsAll() {
+		KafkaProperties kafkaProperties = new KafkaProperties();
+		KafkaBinderConfigurationProperties kafkaBinderConfigurationProperties =
+				new KafkaBinderConfigurationProperties(kafkaProperties, mock(ObjectProvider.class));
+
+		assertThat(kafkaBinderConfigurationProperties.getRequiredAcks()).isEqualTo("all");
+	}
+
 	@Test
 	@SuppressWarnings("unchecked")
 	void mergedConsumerConfigurationFiltersGroupIdFromKafkaProperties() {

docs/modules/ROOT/pages/kafka/kafka-binder/config-options.adoc

@@ -43,7 +43,7 @@ spring.cloud.stream.kafka.binder.requiredAcks::
 The number of required acks on the broker.
 See the Kafka documentation for the producer `acks` property.
 +
-Default: `1`.
+Default: `all`.
 spring.cloud.stream.kafka.binder.minPartitionCount::
 Effective only if `autoCreateTopics` or `autoAddPartitions` is set.
 The global minimum number of partitions that the binder configures on topics on which it produces or consumes data.

docs/modules/ROOT/pages/kafka/kafka_overview.adoc

@@ -83,7 +83,7 @@ spring.cloud.stream.kafka.binder.requiredAcks::
 The number of required acks on the broker.
 See the Kafka documentation for the producer `acks` property.
 +
-Default: `1`.
+Default: `all`.
 spring.cloud.stream.kafka.binder.minPartitionCount::
 Effective only if `autoCreateTopics` or `autoAddPartitions` is set.
 The global minimum number of partitions that the binder configures on topics on which it produces or consumes data.