From: Kai Moritz <kai@juplo.de>
Date: Sat, 23 Jul 2022 13:35:01 +0000 (+0200)
Subject: Merge der überarbeiteten Compose-Konfiguration ('counting-consumer')
X-Git-Tag: sumup-requests---lvm-2-tage~5^2^2~1
X-Git-Url: http://juplo.de/gitweb/?a=commitdiff_plain;h=66863e3169440f73ff450c7ba8ea4b9662b180e0;hp=f9c0ba7779552d8fcfc9cb29c8b689e20c314904;p=demos%2Fkafka%2Ftraining

Merge der überarbeiteten Compose-Konfiguration ('counting-consumer')
---

diff --git a/README.sh b/README.sh
index c14f45b..13176d2 100755
--- a/README.sh
+++ b/README.sh
@@ -47,6 +47,7 @@ http -v :8081/seen
 sleep 1
 http -v :8081/seen
 
+docker-compose stop producer
 docker-compose exec -T cli bash << 'EOF'
 echo "Altering number of partitions from 3 to 7..."
 # tag::altertopic[]
@@ -55,7 +56,7 @@ kafka-topics --bootstrap-server kafka:9092 --describe --topic test
 # end::altertopic[]
 EOF
 
-docker-compose restart producer
+docker-compose start producer
 sleep 1
 http -v :8081/seen
 sleep 1
diff --git a/docker-compose.yml b/docker-compose.yml
index f9eeedd..1b067cd 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -39,7 +39,7 @@ services:
   producer:
     image: juplo/endless-producer:1.0-SNAPSHOT
     ports:
-      - 8000:8080
+      - 8080:8080
     environment:
       server.port: 8080
       producer.bootstrap-server: kafka:9092
diff --git a/src/main/java/de/juplo/kafka/DriverController.java b/src/main/java/de/juplo/kafka/DriverController.java
index 06e562c..1fb2a1b 100644
--- a/src/main/java/de/juplo/kafka/DriverController.java
+++ b/src/main/java/de/juplo/kafka/DriverController.java
@@ -1,9 +1,9 @@
 package de.juplo.kafka;
 
 import lombok.RequiredArgsConstructor;
-import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.http.HttpStatus;
 import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.ResponseStatus;
 import org.springframework.web.bind.annotation.RestController;
diff --git a/src/main/java/de/juplo/kafka/EndlessConsumer.java b/src/main/java/de/juplo/kafka/EndlessConsumer.java
index 2310ccd..c2d4447 100644
--- a/src/main/java/de/juplo/kafka/EndlessConsumer.java
+++ b/src/main/java/de/juplo/kafka/EndlessConsumer.java
@@ -1,19 +1,17 @@
 package de.juplo.kafka;
 
 import lombok.extern.slf4j.Slf4j;
+import org.apache.kafka.clients.consumer.ConsumerRebalanceListener;
 import org.apache.kafka.clients.consumer.ConsumerRecord;
 import org.apache.kafka.clients.consumer.ConsumerRecords;
 import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.common.TopicPartition;
 import org.apache.kafka.common.errors.WakeupException;
 import org.apache.kafka.common.serialization.StringDeserializer;
 
 import javax.annotation.PreDestroy;
 import java.time.Duration;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Optional;
-import java.util.Properties;
+import java.util.*;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.locks.Condition;
@@ -39,7 +37,7 @@ public class EndlessConsumer implements Runnable
   private KafkaConsumer<String, String> consumer = null;
 
 
-  private Map<Integer, Map<String, Integer>> seen;
+  private final Map<Integer, Map<String, Integer>> seen = new HashMap<>();
 
 
   public EndlessConsumer(
@@ -75,9 +73,37 @@ public class EndlessConsumer implements Runnable
       this.consumer = new KafkaConsumer<>(props);
 
       log.info("{} - Subscribing to topic {}", id, topic);
-      consumer.subscribe(Arrays.asList(topic));
+      consumer.subscribe(Arrays.asList(topic), new ConsumerRebalanceListener()
+      {
+        @Override
+        public void onPartitionsRevoked(Collection<TopicPartition> partitions)
+        {
+          partitions.forEach(tp ->
+          {
+            log.info("{} - removing partition: {}", id, tp);
+            Map<String, Integer> removed = seen.remove(tp.partition());
+            for (String key : removed.keySet())
+            {
+              log.info(
+                  "{} - Seen {} messages for partition={}|key={}",
+                  id,
+                  removed.get(key),
+                  tp.partition(),
+                  key);
+            }
+          });
+        }
 
-      seen = new HashMap<>();
+        @Override
+        public void onPartitionsAssigned(Collection<TopicPartition> partitions)
+        {
+          partitions.forEach(tp ->
+          {
+            log.info("{} - adding partition: {}", id, tp);
+            seen.put(tp.partition(), new HashMap<>());
+          });
+        }
+      });
 
       while (true)
       {
@@ -101,10 +127,6 @@ public class EndlessConsumer implements Runnable
 
           Integer partition = record.partition();
           String key = record.key() == null ? "NULL" : record.key();
-
-          if (!seen.containsKey(partition))
-            seen.put(partition, new HashMap<>());
-
           Map<String, Integer> byKey = seen.get(partition);
 
           if (!byKey.containsKey(key))
@@ -130,31 +152,10 @@ public class EndlessConsumer implements Runnable
     {
       log.info("{} - Closing the KafkaConsumer", id);
       consumer.close();
-
-      for (Integer partition : seen.keySet())
-      {
-        Map<String, Integer> byKey = seen.get(partition);
-        for (String key : byKey.keySet())
-        {
-          log.info(
-              "{} - Seen {} messages for partition={}|key={}",
-              id,
-              byKey.get(key),
-              partition,
-              key);
-        }
-      }
-      seen = null;
-
       log.info("{} - Consumer-Thread exiting", id);
     }
   }
 
-  public Map<Integer, Map<String, Integer>> getSeen()
-  {
-    return seen;
-  }
-
   private void shutdown()
   {
     shutdown(null);
@@ -175,6 +176,11 @@ public class EndlessConsumer implements Runnable
     }
   }
 
+  public Map<Integer, Map<String, Integer>> getSeen()
+  {
+    return seen;
+  }
+
   public void start()
   {
     lock.lock();