Merge der überarbeiteten Compose-Konfiguration ('endless-stream-consumer')

[demos/kafka/training] / src / main / java / de / juplo / kafka / EndlessConsumer.java

diff --git a/src/main/java/de/juplo/kafka/EndlessConsumer.java b/src/main/java/de/juplo/kafka/EndlessConsumer.java
index f25e93c..2310ccd 100644 (file)
--- a/src/main/java/de/juplo/kafka/EndlessConsumer.java
+++ b/src/main/java/de/juplo/kafka/EndlessConsumer.java
@@ -10,11 +10,15 @@ 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.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Future;
-import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
 
 
 @Slf4j
@@ -27,10 +31,16 @@ public class EndlessConsumer implements Runnable
   private final String topic;
   private final String autoOffsetReset;
 
-  private AtomicBoolean running = new AtomicBoolean();
+  private final Lock lock = new ReentrantLock();
+  private final Condition condition = lock.newCondition();
+  private boolean running = false;
+  private Exception exception;
   private long consumed = 0;
   private KafkaConsumer<String, String> consumer = null;
-  private Future<?> future = null;
+
+
+  private Map<Integer, Map<String, Integer>> seen;
+
 
   public EndlessConsumer(
       ExecutorService executor,
@@ -58,6 +68,7 @@ public class EndlessConsumer implements Runnable
       props.put("group.id", groupId);
       props.put("client.id", id);
       props.put("auto.offset.reset", autoOffsetReset);
+      props.put("metadata.max.age.ms", "1000");
       props.put("key.deserializer", StringDeserializer.class.getName());
       props.put("value.deserializer", StringDeserializer.class.getName());
 
@@ -66,6 +77,8 @@ public class EndlessConsumer implements Runnable
       log.info("{} - Subscribing to topic {}", id, topic);
       consumer.subscribe(Arrays.asList(topic));
 
+      seen = new HashMap<>();
+
       while (true)
       {
         ConsumerRecords<String, String> records =
@@ -85,47 +98,119 @@ public class EndlessConsumer implements Runnable
               record.key(),
               record.value()
           );
+
+          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))
+            byKey.put(key, 0);
+
+          int seenByKey = byKey.get(key);
+          seenByKey++;
+          byKey.put(key, seenByKey);
         }
       }
     }
     catch(WakeupException e)
     {
       log.info("{} - RIIING!", id);
+      shutdown();
     }
     catch(Exception e)
     {
       log.error("{} - Unexpected error: {}", id, e.toString(), e);
-      running.set(false); // Mark the instance as not running
+      shutdown(e);
     }
     finally
     {
       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;
+  }
 
-  public synchronized void start()
+  private void shutdown()
   {
-    boolean stateChanged = running.compareAndSet(false, true);
-    if (!stateChanged)
-      throw new IllegalStateException("Consumer instance " + id + " is already running!");
+    shutdown(null);
+  }
 
-    log.info("{} - Starting - consumed {} messages before", id, consumed);
-    future = executor.submit(this);
+  private void shutdown(Exception e)
+  {
+    lock.lock();
+    try
+    {
+      running = false;
+      exception = e;
+      condition.signal();
+    }
+    finally
+    {
+      lock.unlock();
+    }
+  }
+
+  public void start()
+  {
+    lock.lock();
+    try
+    {
+      if (running)
+        throw new IllegalStateException("Consumer instance " + id + " is already running!");
+
+      log.info("{} - Starting - consumed {} messages before", id, consumed);
+      running = true;
+      exception = null;
+      executor.submit(this);
+    }
+    finally
+    {
+      lock.unlock();
+    }
   }
 
   public synchronized void stop() throws ExecutionException, InterruptedException
   {
-    boolean stateChanged = running.compareAndSet(true, false);
-    if (!stateChanged)
-      throw new IllegalStateException("Consumer instance " + id + " is not running!");
-
-    log.info("{} - Stopping", id);
-    consumer.wakeup();
-    future.get();
-    log.info("{} - Stopped - consumed {} messages so far", id, consumed);
+    lock.lock();
+    try
+    {
+      if (!running)
+        throw new IllegalStateException("Consumer instance " + id + " is not running!");
+
+      log.info("{} - Stopping", id);
+      consumer.wakeup();
+      condition.await();
+      log.info("{} - Stopped - consumed {} messages so far", id, consumed);
+    }
+    finally
+    {
+      lock.unlock();
+    }
   }
 
   @PreDestroy
@@ -149,4 +234,33 @@ public class EndlessConsumer implements Runnable
       log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
     }
   }
+
+  public boolean running()
+  {
+    lock.lock();
+    try
+    {
+      return running;
+    }
+    finally
+    {
+      lock.unlock();
+    }
+  }
+
+  public Optional<Exception> exitStatus()
+  {
+    lock.lock();
+    try
+    {
+      if (running)
+        throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
+
+      return Optional.ofNullable(exception);
+    }
+    finally
+    {
+      lock.unlock();
+    }
+  }
 }