Spring ID Metric Tag (PAYINP-3419)

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.36.0] - 2025-08-25
+
+### Changed
+- Add the `spring.id` tag to the kafka client metrics, for created kafka producers, to avoid warnings about registering meters with different tag keys
+  on Spring Boot 3.4+
+
 ## [0.35.0] - 2025-06-18
 
 ### Changed

gradle.properties

@@ -1 +1 @@
-version=0.35.0
+version=0.36.0

tw-tkms-starter/src/main/java/com/transferwise/kafka/tkms/config/TkmsKafkaProducerProvider.java

@@ -3,6 +3,7 @@
 import com.transferwise.common.gracefulshutdown.GracefulShutdownStrategy;
 import com.transferwise.kafka.tkms.api.TkmsShardPartition;
 import com.transferwise.kafka.tkms.config.TkmsProperties.ShardProperties;
+import io.micrometer.core.instrument.ImmutableTag;
 import io.micrometer.core.instrument.MeterRegistry;
 import io.micrometer.core.instrument.binder.kafka.KafkaClientMetrics;
 import java.time.Duration;
@@ -66,9 +67,10 @@ public Producer<String, byte[]> getKafkaProducer(TkmsShardPartition shardPartiti
       configs.put(ProducerConfig.MAX_BLOCK_MS_CONFIG, "5000");
       configs.put(ProducerConfig.REQUEST_TIMEOUT_MS_CONFIG, "5000");
       configs.put(ProducerConfig.DELIVERY_TIMEOUT_MS_CONFIG, "10000");
-      configs.put(ProducerConfig.CLIENT_ID_CONFIG,
-          "tw-tkms-" + shardPartition.getShard() + "-" + shardPartition.getPartition() + "-" + useCase.name().toLowerCase()
-              + "-" + sequence.incrementAndGet());
+
+      final var clientId = "tw-tkms-" + shardPartition.getShard() + "-" + shardPartition.getPartition() + "-" + useCase.name().toLowerCase()
+          + "-" + sequence.incrementAndGet();
+      configs.put(ProducerConfig.CLIENT_ID_CONFIG, clientId);
 
       if (useCase == UseCase.PROXY) {
         // We use large lingering time, because we are calling the `.flush()` anyway.
@@ -92,7 +94,9 @@ public Producer<String, byte[]> getKafkaProducer(TkmsShardPartition shardPartiti
       }
 
       final var producer = getKafkaProducer(configs);
-      final var kafkaClientMetrics = new KafkaClientMetrics(producer);
+      // Spring id is added to be compatible with Spring Boot Actuator's Kafka metrics, which from 3.4 onwards include the spring.id tag. Without
+      // warnings may be generated on service startup, about registering meters with different sets of tag keys
+      final var kafkaClientMetrics = new KafkaClientMetrics(producer, List.of(new ImmutableTag("spring.id", clientId)));
       kafkaClientMetrics.bindTo(meterRegistry);
 
       return new ProducerEntry().setProducer(producer).setKafkaClientMetric(kafkaClientMetrics);