package de.juplo.kafka.chat.backend.persistence.kafka;
import de.juplo.kafka.chat.backend.domain.ChatRoom;
+import de.juplo.kafka.chat.backend.domain.ChatRoomInfo;
import de.juplo.kafka.chat.backend.domain.Message;
-import de.juplo.kafka.chat.backend.persistence.KafkaLikeShardingStrategy;
import lombok.Getter;
import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.clients.consumer.Consumer;
import org.apache.kafka.clients.producer.Producer;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.common.TopicPartition;
-import org.apache.kafka.common.errors.RecordDeserializationException;
import org.apache.kafka.common.errors.WakeupException;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import java.time.*;
-import java.util.Collection;
-import java.util.List;
-import java.util.Map;
-import java.util.UUID;
+import java.util.*;
import java.util.stream.IntStream;
public class ChatMessageChannel implements Runnable, ConsumerRebalanceListener
{
private final String topic;
- private final Consumer<String, MessageTo> consumer;
- private final Producer<String, MessageTo> producer;
+ private final Producer<String, AbstractTo> producer;
+ private final Consumer<String, AbstractTo> consumer;
private final ZoneId zoneId;
private final int numShards;
+ private final int bufferSize;
+ private final Clock clock;
private final boolean[] isShardOwned;
private final long[] currentOffset;
private final long[] nextOffset;
private final Map<UUID, ChatRoom>[] chatrooms;
- private final KafkaLikeShardingStrategy shardingStrategy;
private boolean running;
@Getter
public ChatMessageChannel(
String topic,
- Consumer<String, MessageTo> consumer,
- Producer<String, MessageTo> producer,
+ Producer<String, AbstractTo> producer,
+ Consumer<String, AbstractTo> consumer,
ZoneId zoneId,
- int numShards)
+ int numShards,
+ int bufferSize,
+ Clock clock)
{
log.debug(
"Creating ChatMessageChannel for topic {} with {} partitions",
this.producer = producer;
this.zoneId = zoneId;
this.numShards = numShards;
+ this.bufferSize = bufferSize;
+ this.clock = clock;
this.isShardOwned = new boolean[numShards];
this.currentOffset = new long[numShards];
this.nextOffset = new long[numShards];
this.chatrooms = new Map[numShards];
- this.shardingStrategy = new KafkaLikeShardingStrategy(numShards);
+ IntStream
+ .range(0, numShards)
+ .forEach(shard -> this.chatrooms[shard] = new HashMap<>());
+ }
+
+
+
+ Mono<ChatRoomInfo> sendCreateChatRoomRequest(
+ UUID chatRoomId,
+ String name)
+ {
+ CreateChatRoomRequestTo createChatRoomRequestTo = CreateChatRoomRequestTo.of(name);
+ return Mono.create(sink ->
+ {
+ ProducerRecord<String, CreateChatRoomRequestTo> 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 = ChatRoomInfo.of(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,
+ LocalDateTime timestamp,
+ String text)
+ {
+ ZonedDateTime zdt = ZonedDateTime.of(timestamp, zoneId);
+ return Mono.create(sink ->
+ {
+ ProducerRecord<String, AbstractTo> record =
+ new ProducerRecord<>(
+ topic,
+ null,
+ zdt.toEpochSecond(),
+ chatRoomId.toString(),
+ ChatMessageTo.of(key.getUsername(), key.getMessageId(), text));
+
+ producer.send(record, ((metadata, exception) ->
+ {
+ if (metadata != null)
+ {
+ // On successful send
+ Message message = new Message(key, metadata.offset(), timestamp, text);
+ log.info("Successfully send message {}", message);
+ sink.success(message);
+ }
+ else
+ {
+ // On send-failure
+ log.error(
+ "Could not send message for chat-room={}, key={}, timestamp={}, text={}: {}",
+ chatRoomId,
+ key,
+ timestamp,
+ text,
+ exception);
+ sink.error(exception);
+ }
+ }));
+ });
+ }
@Override
public void onPartitionsAssigned(Collection<TopicPartition> partitions)
@Override
public void run()
{
- consumer.subscribe(List.of(topic));
+ consumer.subscribe(List.of(topic), this);
running = true;
{
try
{
- ConsumerRecords<String, MessageTo> records = consumer.poll(Duration.ofMinutes(5));
+ ConsumerRecords<String, AbstractTo> records = consumer.poll(Duration.ofMinutes(5));
log.info("Fetched {} messages", records.count());
if (loadInProgress)
{
- loadMessages(records);
+ loadChatRoom(records);
if (isLoadingCompleted())
{
}
catch (WakeupException e)
{
- }
- catch (RecordDeserializationException e)
- {
+ log.info("Received WakeupException, exiting!");
+ running = false;
}
}
+
+ log.info("Exiting normally");
}
- void loadMessages(ConsumerRecords<String, MessageTo> records)
+ void loadChatRoom(ConsumerRecords<String, AbstractTo> records)
{
- for (ConsumerRecord<String, MessageTo> record : records)
+ for (ConsumerRecord<String, AbstractTo> record : records)
{
- nextOffset[record.partition()] = record.offset() + 1;
UUID chatRoomId = UUID.fromString(record.key());
- MessageTo messageTo = record.value();
-
- Message.MessageKey key = Message.MessageKey.of(messageTo.getUser(), messageTo.getId());
- Instant instant = Instant.ofEpochSecond(record.timestamp());
- LocalDateTime timestamp = LocalDateTime.ofInstant(instant, zoneId);
-
- Message message = new Message(key, record.offset(), timestamp, messageTo.getText());
-
- ChatRoom chatRoom = chatrooms[record.partition()].get(chatRoomId);
- if (chatRoom == null)
+ switch (record.value().getType())
{
- // Alles pausieren und erst von putChatRoom wieder resumen lassen!
+ case CREATE_CHATROOM_REQUEST:
+ createChatRoom(
+ chatRoomId,
+ (CreateChatRoomRequestTo) record.value(),
+ record.partition());
+ break;
+
+ case MESSAGE_SENT:
+ Instant instant = Instant.ofEpochSecond(record.timestamp());
+ LocalDateTime timestamp = LocalDateTime.ofInstant(instant, zoneId);
+ loadChatMessage(
+ chatRoomId,
+ timestamp,
+ record.offset(),
+ (ChatMessageTo) record.value(),
+ record.partition());
+ break;
+
+ default:
+ log.debug(
+ "Ignoring message for chat-room {} with offset {}: {}",
+ chatRoomId,
+ record.offset(),
+ record.value());
}
- KafkaChatRoomService kafkaChatRoomService =
- (KafkaChatRoomService) chatRoom.getChatRoomService();
- kafkaChatRoomService.persistMessage(message);
+ nextOffset[record.partition()] = record.offset() + 1;
}
}
+ void createChatRoom(
+ UUID chatRoomId,
+ CreateChatRoomRequestTo createChatRoomRequestTo,
+ int partition)
+ {
+ putChatRoom(ChatRoomInfo.of(
+ chatRoomId,
+ createChatRoomRequestTo.getName(),
+ partition));
+ }
+
+
+ void createChatRoom(ChatRoomInfo chatRoomInfo)
+ {
+ UUID id = chatRoomInfo.getId();
+ String name = chatRoomInfo.getName();
+ int shard = chatRoomInfo.getShard();
+ log.info("Creating ChatRoom {} with buffer-size {}", id, bufferSize);
+ KafkaChatRoomService service = new KafkaChatRoomService(this, id);
+ ChatRoom chatRoom = new ChatRoom(id, name, shard, clock, service, bufferSize);
+ putChatRoom(chatRoom);
+ }
+
+ void loadChatMessage(
+ UUID chatRoomId,
+ LocalDateTime timestamp,
+ long offset,
+ ChatMessageTo chatMessageTo,
+ int partition)
+ {
+ Message.MessageKey key = Message.MessageKey.of(chatMessageTo.getUser(), chatMessageTo.getId());
+ Message message = new Message(key, offset, timestamp, chatMessageTo.getText());
+
+ ChatRoom chatRoom = chatrooms[partition].get(chatRoomId);
+ KafkaChatRoomService kafkaChatRoomService =
+ (KafkaChatRoomService) chatRoom.getChatRoomService();
+
+ kafkaChatRoomService.persistMessage(message);
+ }
+
boolean isLoadingCompleted()
{
return IntStream
.range(0, numShards)
.filter(shard -> isShardOwned[shard])
- .mapToObj(shard -> nextOffset[shard] >= currentOffset[shard])
- .collect(
- () -> Boolean.TRUE, // TODO: Boolean is immutable
- (acc, v) -> Boolean.valueOf(acc && v), // TODO: Boolean is immutable
- (a, b) -> Boolean.valueOf(a && b)); // TODO: Boolean is immutable
+ .allMatch(shard -> nextOffset[shard] >= currentOffset[shard]);
}
void pauseAllOwnedPartions()
.toList());
}
- Mono<Message> sendMessage(
- UUID chatRoomId,
- Message.MessageKey key,
- LocalDateTime timestamp,
- String text)
+
+ private void putChatRoom(ChatRoom chatRoom)
{
- int shard = this.shardingStrategy.selectShard(chatRoomId);
- TopicPartition tp = new TopicPartition(topic, shard);
- ZonedDateTime zdt = ZonedDateTime.of(timestamp, zoneId);
- return Mono.create(sink ->
+ Integer partition = chatRoom.getShard();
+ UUID chatRoomId = chatRoom.getId();
+ if (chatrooms[partition].containsKey(chatRoomId))
{
- ProducerRecord<String, MessageTo> record =
- new ProducerRecord<>(
- tp.topic(),
- tp.partition(),
- zdt.toEpochSecond(),
- chatRoomId.toString(),
- MessageTo.of(key.getUsername(), key.getMessageId(), text));
-
- producer.send(record, ((metadata, exception) ->
- {
- if (metadata != null)
- {
- // On successful send
- Message message = new Message(key, metadata.offset(), timestamp, text);
- log.info("Successfully send message {}", message);
- sink.success(message);
- }
- else
- {
- // On send-failure
- log.error(
- "Could not send message for chat-room={}, key={}, timestamp={}, text={}: {}",
- chatRoomId,
- key,
- timestamp,
- text,
- exception);
- sink.error(exception);
- }
- }));
- });
- }
-
+ log.warn("Ignoring existing chat-room: " + chatRoom);
+ }
+ else
+ {
+ log.info(
+ "Adding new chat-room to partition {}: {}",
+ partition,
+ chatRoom);
- void putChatRoom(ChatRoom chatRoom)
- {
- chatrooms[chatRoom.getShard()].put(chatRoom.getId(), chatRoom);
+ chatrooms[partition].put(chatRoomId, chatRoom);
+ }
}
Mono<ChatRoom> getChatRoom(int shard, UUID id)
{
return Mono.justOrEmpty(chatrooms[shard].get(id));
}
-
- Flux<ChatRoom> getChatRooms(int shard)
- {
- return Flux.fromStream(chatrooms[shard].values().stream());
- }
}
projects / demos / kafka / chat / blobdiff