import de.juplo.kafka.chat.backend.domain.exceptions.LoadInProgressException;
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.CommandCreateChatRoomTo;
-import de.juplo.kafka.chat.backend.implementation.kafka.messages.EventChatMessageReceivedTo;
+import de.juplo.kafka.chat.backend.implementation.kafka.messages.data.EventChatMessageReceivedTo;
import lombok.Getter;
import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.clients.consumer.Consumer;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.common.TopicPartition;
import org.apache.kafka.common.errors.WakeupException;
-import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import java.time.*;
@Slf4j
-public class ChatRoomChannel implements Runnable, ConsumerRebalanceListener
+public class DataChannel implements Runnable, ConsumerRebalanceListener
{
+ private final String instanceId;
private final String topic;
private final Producer<String, AbstractMessageTo> producer;
private final Consumer<String, AbstractMessageTo> consumer;
private final boolean[] isShardOwned;
private final long[] currentOffset;
private final long[] nextOffset;
- private final Map<UUID, ChatRoomInfo>[] chatRoomInfo;
private final Map<UUID, ChatRoomData>[] chatRoomData;
+ private final InfoChannel infoChannel;
+ private final ShardingPublisherStrategy shardingPublisherStrategy;
private boolean running;
@Getter
private volatile boolean loadInProgress;
- public ChatRoomChannel(
+ public DataChannel(
+ String instanceId,
String topic,
Producer<String, AbstractMessageTo> producer,
- Consumer<String, AbstractMessageTo> consumer,
+ Consumer<String, AbstractMessageTo> dataChannelConsumer,
ZoneId zoneId,
int numShards,
int bufferSize,
- Clock clock)
+ Clock clock,
+ InfoChannel infoChannel,
+ ShardingPublisherStrategy shardingPublisherStrategy)
{
log.debug(
- "Creating ChatRoomChannel for topic {} with {} partitions",
+ "{}: Creating DataChannel for topic {} with {} partitions",
+ instanceId,
topic,
numShards);
+ this.instanceId = instanceId;
this.topic = topic;
- this.consumer = consumer;
+ this.consumer = dataChannelConsumer;
this.producer = producer;
this.zoneId = zoneId;
this.numShards = numShards;
this.isShardOwned = new boolean[numShards];
this.currentOffset = new long[numShards];
this.nextOffset = new long[numShards];
- this.chatRoomInfo = new Map[numShards];
this.chatRoomData = new Map[numShards];
IntStream
.range(0, numShards)
- .forEach(shard ->
- {
- this.chatRoomInfo[shard] = new HashMap<>();
- this.chatRoomData[shard] = new HashMap<>();
- });
+ .forEach(shard -> this.chatRoomData[shard] = new HashMap<>());
+ this.infoChannel = infoChannel;
+ this.shardingPublisherStrategy = shardingPublisherStrategy;
}
- Mono<ChatRoomInfo> sendCreateChatRoomRequest(
- UUID chatRoomId,
- String name)
- {
- CommandCreateChatRoomTo createChatRoomRequestTo = CommandCreateChatRoomTo.of(name);
- return Mono.create(sink ->
- {
- ProducerRecord<String, AbstractMessageTo> record =
- new ProducerRecord<>(
- topic,
- chatRoomId.toString(),
- createChatRoomRequestTo);
-
- producer.send(record, ((metadata, exception) ->
- {
- if (metadata != null)
- {
- log.info("Successfully send chreate-request for chat room: {}", createChatRoomRequestTo);
- ChatRoomInfo chatRoomInfo = new ChatRoomInfo(chatRoomId, name, record.partition());
- createChatRoom(chatRoomInfo);
- sink.success(chatRoomInfo);
- }
- else
- {
- // On send-failure
- log.error(
- "Could not send create-request for chat room (id={}, name={}): {}",
- chatRoomId,
- name,
- exception);
- sink.error(exception);
- }
- }));
- });
- }
-
Mono<Message> sendChatMessage(
UUID chatRoomId,
Message.MessageKey key,
currentOffset);
consumer.seek(topicPartition, nextOffset[partition]);
+ infoChannel.sendShardAssignedEvent(partition);
+ shardingPublisherStrategy
+ .publishOwnership(partition)
+ .doOnNext(instanceId -> log.info(
+ "Instance {} was published as owner of shard {}",
+ instanceId,
+ partition))
+ .subscribe();
});
consumer.resume(partitions);
{
int partition = topicPartition.partition();
isShardOwned[partition] = false;
+ nextOffset[partition] = consumer.position(topicPartition);
log.info("Partition revoked: {} - next={}", partition, nextOffset[partition]);
+ infoChannel.sendShardRevokedEvent(partition);
});
}
{
try
{
- ConsumerRecords<String, AbstractMessageTo> records = consumer.poll(Duration.ofMinutes(5));
+ ConsumerRecords<String, AbstractMessageTo> records = consumer.poll(Duration.ofMinutes(1));
log.info("Fetched {} messages", records.count());
if (loadInProgress)
{
- loadChatRoom(records);
+ loadChatRoomData(records);
if (isLoadingCompleted())
{
log.info("Exiting normally");
}
- private void loadChatRoom(ConsumerRecords<String, AbstractMessageTo> records)
+ private void loadChatRoomData(ConsumerRecords<String, AbstractMessageTo> records)
{
for (ConsumerRecord<String, AbstractMessageTo> record : records)
{
switch (record.value().getType())
{
- case COMMAND_CREATE_CHATROOM:
- createChatRoom(
- chatRoomId,
- (CommandCreateChatRoomTo) record.value(),
- record.partition());
- break;
-
case EVENT_CHATMESSAGE_RECEIVED:
Instant instant = Instant.ofEpochSecond(record.timestamp());
LocalDateTime timestamp = LocalDateTime.ofInstant(instant, zoneId);
}
}
- private void createChatRoom(
- UUID chatRoomId,
- CommandCreateChatRoomTo createChatRoomRequestTo,
- Integer partition)
- {
- log.info(
- "Loading ChatRoom {} for shard {} with buffer-size {}",
- chatRoomId,
- partition,
- bufferSize);
- KafkaChatMessageService service = new KafkaChatMessageService(this, chatRoomId);
- ChatRoomData chatRoomData = new ChatRoomData(
- clock,
- service,
- bufferSize);
- putChatRoom(
- chatRoomId,
- createChatRoomRequestTo.getName(),
- partition,
- chatRoomData);
- }
-
-
- private void createChatRoom(ChatRoomInfo chatRoomInfo)
- {
- UUID id = chatRoomInfo.getId();
- log.info("Creating ChatRoom {} with buffer-size {}", id, bufferSize);
- KafkaChatMessageService service = new KafkaChatMessageService(this, id);
- ChatRoomData chatRoomData = new ChatRoomData(clock, service, bufferSize);
- putChatRoom(
- chatRoomInfo.getId(),
- chatRoomInfo.getName(),
- chatRoomInfo.getShard(),
- chatRoomData);
- }
-
private void loadChatMessage(
UUID chatRoomId,
LocalDateTime timestamp,
Message.MessageKey key = Message.MessageKey.of(chatMessageTo.getUser(), chatMessageTo.getId());
Message message = new Message(key, offset, timestamp, chatMessageTo.getText());
- ChatRoomData chatRoomData = this.chatRoomData[partition].get(chatRoomId);
+ ChatRoomData chatRoomData = this
+ .chatRoomData[partition]
+ .computeIfAbsent(chatRoomId, this::computeChatRoomData);
KafkaChatMessageService kafkaChatRoomService =
(KafkaChatMessageService) chatRoomData.getChatRoomService();
+ log.debug(
+ "Loaded message from partition={} at offset={}: {}",
+ partition,
+ offset,
+ message);
kafkaChatRoomService.persistMessage(message);
}
return IntStream
.range(0, numShards)
.filter(shard -> isShardOwned[shard])
- .allMatch(shard -> nextOffset[shard] >= currentOffset[shard]);
+ .allMatch(shard ->
+ {
+ TopicPartition partition = new TopicPartition(topic, shard);
+ long position = consumer.position(partition);
+ return position >= currentOffset[shard];
+ });
}
private void pauseAllOwnedPartions()
}
- private void putChatRoom(
- UUID chatRoomId,
- String name,
- Integer partition,
- ChatRoomData chatRoomData)
- {
- if (this.chatRoomInfo[partition].containsKey(chatRoomId))
- {
- log.warn(
- "Ignoring existing chat-room for {}: {}",
- partition,
- chatRoomId);
- }
- else
- {
- log.info(
- "Adding new chat-room to partition {}: {}",
- partition,
- chatRoomData);
-
- this.chatRoomInfo[partition].put(
- chatRoomId,
- new ChatRoomInfo(chatRoomId, name, partition));
- this.chatRoomData[partition].put(chatRoomId, chatRoomData);
- }
- }
-
int[] getOwnedShards()
{
return IntStream
if (!isShardOwned[shard])
{
- return Mono.error(new ShardNotOwnedException(shard));
+ return Mono.error(new ShardNotOwnedException(instanceId, shard));
}
- return Mono.justOrEmpty(chatRoomData[shard].get(id));
+ return infoChannel
+ .getChatRoomInfo(id)
+ .map(chatRoomInfo ->
+ chatRoomData[shard].computeIfAbsent(id, this::computeChatRoomData));
}
- Flux<ChatRoomInfo> getChatRoomInfo()
+ private ChatRoomData computeChatRoomData(UUID chatRoomId)
{
- return Flux
- .fromStream(IntStream.range(0, numShards).mapToObj(i -> Integer.valueOf(i)))
- .filter(shard -> isShardOwned[shard])
- .flatMap(shard -> Flux.fromIterable(chatRoomInfo[shard].values()));
- }
-
- Mono<ChatRoomInfo> getChatRoomInfo(int shard, UUID id)
- {
- if (loadInProgress)
- {
- return Mono.error(new LoadInProgressException());
- }
-
- if (!isShardOwned[shard])
- {
- return Mono.error(new ShardNotOwnedException(shard));
- }
-
- return Mono.justOrEmpty(chatRoomInfo[shard].get(id));
+ log.info("Creating ChatRoom {} with buffer-size {}", chatRoomId, bufferSize);
+ KafkaChatMessageService service = new KafkaChatMessageService(this, chatRoomId);
+ return new ChatRoomData(clock, service, bufferSize);
}
}
projects / demos / kafka / chat / blobdiff