X-Git-Url: http://juplo.de/gitweb/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2Fchat%2Fbackend%2Fimplementation%2Fkafka%2FDataChannel.java;h=abe51f4a61aa5c737ab7d8ba793115e1cd29745e;hb=89b5eb1eaf7890c830848dbc4281add2bff41131;hp=e1754a157f978c33f5a617e16e9ea688f60fd5d6;hpb=0f13dc5e88722ca7c238258747041d9663251356;p=demos%2Fkafka%2Fchat

diff --git a/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/DataChannel.java b/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/DataChannel.java
index e1754a15..abe51f4a 100644
--- a/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/DataChannel.java
+++ b/src/main/java/de/juplo/kafka/chat/backend/implementation/kafka/DataChannel.java
@@ -1,11 +1,14 @@
 package de.juplo.kafka.chat.backend.implementation.kafka;
 
-import de.juplo.kafka.chat.backend.domain.*;
-import de.juplo.kafka.chat.backend.domain.exceptions.LoadInProgressException;
+import de.juplo.kafka.chat.backend.domain.ChatRoomData;
+import de.juplo.kafka.chat.backend.domain.ChatRoomInfo;
+import de.juplo.kafka.chat.backend.domain.Message;
+import de.juplo.kafka.chat.backend.domain.ShardingPublisherStrategy;
 import de.juplo.kafka.chat.backend.domain.exceptions.ShardNotOwnedException;
 import de.juplo.kafka.chat.backend.implementation.kafka.messages.AbstractMessageTo;
 import de.juplo.kafka.chat.backend.implementation.kafka.messages.data.EventChatMessageReceivedTo;
 import lombok.Getter;
+import lombok.ToString;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.kafka.clients.consumer.*;
 import org.apache.kafka.clients.producer.Producer;
@@ -15,12 +18,16 @@ import org.apache.kafka.common.errors.WakeupException;
 import reactor.core.publisher.Mono;
 
 import java.time.*;
-import java.util.*;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
 import java.util.stream.IntStream;
 
 
+@ToString(of = { "topic", "instanceId" })
 @Slf4j
-public class DataChannel implements Runnable, ConsumerRebalanceListener
+public class DataChannel implements Channel, ConsumerRebalanceListener
 {
   private final String instanceId;
   private final String topic;
@@ -29,7 +36,7 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
   private final ZoneId zoneId;
   private final int numShards;
   private final Duration pollingInterval;
-  private final int bufferSize;
+  private final int historyLimit;
   private final Clock clock;
   private final boolean[] isShardOwned;
   private final long[] currentOffset;
@@ -40,7 +47,7 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
 
   private boolean running;
   @Getter
-  private volatile boolean loadInProgress;
+  private volatile ChannelState channelState = ChannelState.STARTING;
 
 
   public DataChannel(
@@ -51,7 +58,7 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
     ZoneId zoneId,
     int numShards,
     Duration pollingInterval,
-    int bufferSize,
+    int historyLimit,
     Clock clock,
     ChannelMediator channelMediator,
     ShardingPublisherStrategy shardingPublisherStrategy)
@@ -68,7 +75,7 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
     this.zoneId = zoneId;
     this.numShards = numShards;
     this.pollingInterval = pollingInterval;
-    this.bufferSize = bufferSize;
+    this.historyLimit = historyLimit;
     this.clock = clock;
     this.isShardOwned = new boolean[numShards];
     this.currentOffset = new long[numShards];
@@ -129,7 +136,7 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
   public void onPartitionsAssigned(Collection<TopicPartition> partitions)
   {
     log.info("Newly assigned partitions! Pausing normal operations...");
-    loadInProgress = true;
+    channelState = ChannelState.LOAD_IN_PROGRESS;
 
     consumer.endOffsets(partitions).forEach((topicPartition, currentOffset) ->
     {
@@ -171,7 +178,13 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
       int partition = topicPartition.partition();
       isShardOwned[partition] = false;
       nextOffset[partition] = consumer.position(topicPartition);
+
       log.info("Partition revoked: {} - next={}", partition, nextOffset[partition]);
+
+      chatRoomData[partition]
+          .values()
+          .forEach(chatRoomData -> chatRoomData.deactivate());
+
       channelMediator.shardRevoked(partition);
     });
   }
@@ -196,29 +209,35 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
         ConsumerRecords<String, AbstractMessageTo> records = consumer.poll(pollingInterval);
         log.info("Fetched {} messages", records.count());
 
-        if (loadInProgress)
+        switch (channelState)
         {
-          loadChatRoomData(records);
-
-          if (isLoadingCompleted())
+          case LOAD_IN_PROGRESS ->
           {
-            log.info("Loading of messages completed! Pausing all owned partitions...");
-            pauseAllOwnedPartions();
-            log.info("Resuming normal operations...");
-            loadInProgress = false;
+            loadChatRoomData(records);
+
+            if (isLoadingCompleted())
+            {
+              log.info("Loading of messages completed! Pausing all owned partitions...");
+              pauseAllOwnedPartions();
+              activateAllOwnedChatRooms();
+              log.info("Resuming normal operations...");
+              channelState = ChannelState.READY;
+            }
           }
-        }
-        else
-        {
-          if (!records.isEmpty())
+          case SHUTTING_DOWN -> log.info("Shutdown in progress: ignoring {} fetched messages.", records.count());
+          default ->
           {
-            throw new IllegalStateException("All owned partitions should be paused, when no load is in progress!");
+            if (!records.isEmpty())
+            {
+              throw new IllegalStateException("All owned partitions should be paused, when in state " + channelState);
+            }
           }
         }
       }
       catch (WakeupException e)
       {
         log.info("Received WakeupException, exiting!");
+        channelState = ChannelState.SHUTTING_DOWN;
         running = false;
       }
     }
@@ -301,6 +320,16 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
         .toList());
   }
 
+  private void activateAllOwnedChatRooms()
+  {
+    IntStream
+        .range(0, numShards)
+        .filter(shard -> isShardOwned[shard])
+        .forEach(shard -> chatRoomData[shard]
+            .values()
+            .forEach(chatRoomData -> chatRoomData.activate()));
+  }
+
 
   int[] getOwnedShards()
   {
@@ -312,14 +341,25 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
 
   void createChatRoomData(ChatRoomInfo chatRoomInfo)
   {
-    computeChatRoomData(chatRoomInfo.getId(), chatRoomInfo.getShard());
+    int shard = chatRoomInfo.getShard();
+
+    ChatRoomData chatRoomData = computeChatRoomData(
+        chatRoomInfo.getId(),
+        chatRoomInfo.getShard());
+
+    // TODO: Possible race-condition in case of an ongoing rebalance!
+    if (isShardOwned[shard])
+    {
+      chatRoomData.activate();
+    }
   }
 
   Mono<ChatRoomData> getChatRoomData(int shard, UUID id)
   {
-    if (loadInProgress)
+    ChannelState capturedState = channelState;
+    if (capturedState != ChannelState.READY)
     {
-      return Mono.error(new LoadInProgressException());
+      return Mono.error(new ChannelNotReadyException(capturedState));
     }
 
     if (!isShardOwned[shard])
@@ -342,9 +382,9 @@ public class DataChannel implements Runnable, ConsumerRebalanceListener
     }
     else
     {
-      log.info("Creating ChatRoomData {} with buffer-size {}", chatRoomId, bufferSize);
+      log.info("Creating ChatRoomData {} with history-limit {}", chatRoomId, historyLimit);
       KafkaChatMessageService service = new KafkaChatMessageService(this, chatRoomId);
-      chatRoomData = new ChatRoomData(clock, service, bufferSize);
+      chatRoomData = new ChatRoomData(clock, service, historyLimit);
       this.chatRoomData[shard].put(chatRoomId, chatRoomData);
     }