+++ /dev/null
-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.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 lombok.Getter;
-import lombok.extern.slf4j.Slf4j;
-import org.apache.kafka.clients.consumer.Consumer;
-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.producer.Producer;
-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.*;
-import java.util.*;
-import java.util.stream.IntStream;
-
-
-@Slf4j
-public class ChatRoomChannel implements Runnable, ConsumerRebalanceListener
-{
- private final String topic;
- private final Producer<String, AbstractMessageTo> producer;
- private final Consumer<String, AbstractMessageTo> 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, ChatRoomInfo>[] chatRoomInfo;
- private final Map<UUID, ChatRoomData>[] chatRoomData;
-
- private boolean running;
- @Getter
- private volatile boolean loadInProgress;
-
-
- public ChatRoomChannel(
- String topic,
- Producer<String, AbstractMessageTo> producer,
- Consumer<String, AbstractMessageTo> consumer,
- ZoneId zoneId,
- int numShards,
- int bufferSize,
- Clock clock)
- {
- log.debug(
- "Creating ChatRoomChannel for topic {} with {} partitions",
- topic,
- numShards);
- this.topic = topic;
- this.consumer = consumer;
- 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.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<>();
- });
- }
-
-
-
- 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,
- LocalDateTime timestamp,
- String text)
- {
- ZonedDateTime zdt = ZonedDateTime.of(timestamp, zoneId);
- return Mono.create(sink ->
- {
- ProducerRecord<String, AbstractMessageTo> record =
- new ProducerRecord<>(
- topic,
- null,
- zdt.toEpochSecond(),
- chatRoomId.toString(),
- EventChatMessageReceivedTo.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)
- {
- log.info("Newly assigned partitions! Pausing normal operations...");
- loadInProgress = true;
-
- consumer.endOffsets(partitions).forEach((topicPartition, currentOffset) ->
- {
- int partition = topicPartition.partition();
- isShardOwned[partition] = true;
- this.currentOffset[partition] = currentOffset;
-
- log.info(
- "Partition assigned: {} - loading messages: next={} -> current={}",
- partition,
- nextOffset[partition],
- currentOffset);
-
- consumer.seek(topicPartition, nextOffset[partition]);
- });
-
- consumer.resume(partitions);
- }
-
- @Override
- public void onPartitionsRevoked(Collection<TopicPartition> partitions)
- {
- partitions.forEach(topicPartition ->
- {
- int partition = topicPartition.partition();
- isShardOwned[partition] = false;
- log.info("Partition revoked: {} - next={}", partition, nextOffset[partition]);
- });
- }
-
- @Override
- public void onPartitionsLost(Collection<TopicPartition> partitions)
- {
- log.warn("Lost partitions: {}, partitions");
- // TODO: Muss auf den Verlust anders reagiert werden?
- onPartitionsRevoked(partitions);
- }
-
- @Override
- public void run()
- {
- running = true;
-
- while (running)
- {
- try
- {
- ConsumerRecords<String, AbstractMessageTo> records = consumer.poll(Duration.ofMinutes(5));
- log.info("Fetched {} messages", records.count());
-
- if (loadInProgress)
- {
- loadChatRoom(records);
-
- if (isLoadingCompleted())
- {
- log.info("Loading of messages completed! Pausing all owned partitions...");
- pauseAllOwnedPartions();
- log.info("Resuming normal operations...");
- loadInProgress = false;
- }
- }
- else
- {
- if (!records.isEmpty())
- {
- throw new IllegalStateException("All owned partitions should be paused, when no load is in progress!");
- }
- }
- }
- catch (WakeupException e)
- {
- log.info("Received WakeupException, exiting!");
- running = false;
- }
- }
-
- log.info("Exiting normally");
- }
-
- private void loadChatRoom(ConsumerRecords<String, AbstractMessageTo> records)
- {
- for (ConsumerRecord<String, AbstractMessageTo> record : records)
- {
- UUID chatRoomId = UUID.fromString(record.key());
-
- 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);
- loadChatMessage(
- chatRoomId,
- timestamp,
- record.offset(),
- (EventChatMessageReceivedTo) record.value(),
- record.partition());
- break;
-
- default:
- log.debug(
- "Ignoring message for chat-room {} with offset {}: {}",
- chatRoomId,
- record.offset(),
- record.value());
- }
-
- nextOffset[record.partition()] = record.offset() + 1;
- }
- }
-
- 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,
- long offset,
- EventChatMessageReceivedTo chatMessageTo,
- int partition)
- {
- 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);
- KafkaChatMessageService kafkaChatRoomService =
- (KafkaChatMessageService) chatRoomData.getChatRoomService();
-
- kafkaChatRoomService.persistMessage(message);
- }
-
- private boolean isLoadingCompleted()
- {
- return IntStream
- .range(0, numShards)
- .filter(shard -> isShardOwned[shard])
- .allMatch(shard -> nextOffset[shard] >= currentOffset[shard]);
- }
-
- private void pauseAllOwnedPartions()
- {
- consumer.pause(IntStream
- .range(0, numShards)
- .filter(shard -> isShardOwned[shard])
- .mapToObj(shard -> new TopicPartition(topic, shard))
- .toList());
- }
-
-
- 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
- .range(0, numShards)
- .filter(shard -> isShardOwned[shard])
- .toArray();
- }
-
- Mono<ChatRoomData> getChatRoomData(int shard, UUID id)
- {
- if (loadInProgress)
- {
- return Mono.error(new LoadInProgressException());
- }
-
- if (!isShardOwned[shard])
- {
- return Mono.error(new ShardNotOwnedException(shard));
- }
-
- return Mono.justOrEmpty(chatRoomData[shard].get(id));
- }
-
- Flux<ChatRoomInfo> getChatRoomInfo()
- {
- 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));
- }
-}
--- /dev/null
+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.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 lombok.Getter;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.kafka.clients.consumer.Consumer;
+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.producer.Producer;
+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.*;
+import java.util.*;
+import java.util.stream.IntStream;
+
+
+@Slf4j
+public class ChatRoomChannel implements Runnable, ConsumerRebalanceListener
+{
+ private final String topic;
+ private final Producer<String, AbstractMessageTo> producer;
+ private final Consumer<String, AbstractMessageTo> 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, ChatRoomInfo>[] chatRoomInfo;
+ private final Map<UUID, ChatRoomData>[] chatRoomData;
+
+ private boolean running;
+ @Getter
+ private volatile boolean loadInProgress;
+
+
+ public ChatRoomChannel(
+ String topic,
+ Producer<String, AbstractMessageTo> producer,
+ Consumer<String, AbstractMessageTo> consumer,
+ ZoneId zoneId,
+ int numShards,
+ int bufferSize,
+ Clock clock)
+ {
+ log.debug(
+ "Creating ChatRoomChannel for topic {} with {} partitions",
+ topic,
+ numShards);
+ this.topic = topic;
+ this.consumer = consumer;
+ 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.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<>();
+ });
+ }
+
+
+
+ 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,
+ LocalDateTime timestamp,
+ String text)
+ {
+ ZonedDateTime zdt = ZonedDateTime.of(timestamp, zoneId);
+ return Mono.create(sink ->
+ {
+ ProducerRecord<String, AbstractMessageTo> record =
+ new ProducerRecord<>(
+ topic,
+ null,
+ zdt.toEpochSecond(),
+ chatRoomId.toString(),
+ EventChatMessageReceivedTo.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)
+ {
+ log.info("Newly assigned partitions! Pausing normal operations...");
+ loadInProgress = true;
+
+ consumer.endOffsets(partitions).forEach((topicPartition, currentOffset) ->
+ {
+ int partition = topicPartition.partition();
+ isShardOwned[partition] = true;
+ this.currentOffset[partition] = currentOffset;
+
+ log.info(
+ "Partition assigned: {} - loading messages: next={} -> current={}",
+ partition,
+ nextOffset[partition],
+ currentOffset);
+
+ consumer.seek(topicPartition, nextOffset[partition]);
+ });
+
+ consumer.resume(partitions);
+ }
+
+ @Override
+ public void onPartitionsRevoked(Collection<TopicPartition> partitions)
+ {
+ partitions.forEach(topicPartition ->
+ {
+ int partition = topicPartition.partition();
+ isShardOwned[partition] = false;
+ log.info("Partition revoked: {} - next={}", partition, nextOffset[partition]);
+ });
+ }
+
+ @Override
+ public void onPartitionsLost(Collection<TopicPartition> partitions)
+ {
+ log.warn("Lost partitions: {}, partitions");
+ // TODO: Muss auf den Verlust anders reagiert werden?
+ onPartitionsRevoked(partitions);
+ }
+
+ @Override
+ public void run()
+ {
+ running = true;
+
+ while (running)
+ {
+ try
+ {
+ ConsumerRecords<String, AbstractMessageTo> records = consumer.poll(Duration.ofMinutes(5));
+ log.info("Fetched {} messages", records.count());
+
+ if (loadInProgress)
+ {
+ loadChatRoom(records);
+
+ if (isLoadingCompleted())
+ {
+ log.info("Loading of messages completed! Pausing all owned partitions...");
+ pauseAllOwnedPartions();
+ log.info("Resuming normal operations...");
+ loadInProgress = false;
+ }
+ }
+ else
+ {
+ if (!records.isEmpty())
+ {
+ throw new IllegalStateException("All owned partitions should be paused, when no load is in progress!");
+ }
+ }
+ }
+ catch (WakeupException e)
+ {
+ log.info("Received WakeupException, exiting!");
+ running = false;
+ }
+ }
+
+ log.info("Exiting normally");
+ }
+
+ private void loadChatRoom(ConsumerRecords<String, AbstractMessageTo> records)
+ {
+ for (ConsumerRecord<String, AbstractMessageTo> record : records)
+ {
+ UUID chatRoomId = UUID.fromString(record.key());
+
+ 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);
+ loadChatMessage(
+ chatRoomId,
+ timestamp,
+ record.offset(),
+ (EventChatMessageReceivedTo) record.value(),
+ record.partition());
+ break;
+
+ default:
+ log.debug(
+ "Ignoring message for chat-room {} with offset {}: {}",
+ chatRoomId,
+ record.offset(),
+ record.value());
+ }
+
+ nextOffset[record.partition()] = record.offset() + 1;
+ }
+ }
+
+ 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,
+ long offset,
+ EventChatMessageReceivedTo chatMessageTo,
+ int partition)
+ {
+ 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);
+ KafkaChatMessageService kafkaChatRoomService =
+ (KafkaChatMessageService) chatRoomData.getChatRoomService();
+
+ kafkaChatRoomService.persistMessage(message);
+ }
+
+ private boolean isLoadingCompleted()
+ {
+ return IntStream
+ .range(0, numShards)
+ .filter(shard -> isShardOwned[shard])
+ .allMatch(shard -> nextOffset[shard] >= currentOffset[shard]);
+ }
+
+ private void pauseAllOwnedPartions()
+ {
+ consumer.pause(IntStream
+ .range(0, numShards)
+ .filter(shard -> isShardOwned[shard])
+ .mapToObj(shard -> new TopicPartition(topic, shard))
+ .toList());
+ }
+
+
+ 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
+ .range(0, numShards)
+ .filter(shard -> isShardOwned[shard])
+ .toArray();
+ }
+
+ Mono<ChatRoomData> getChatRoomData(int shard, UUID id)
+ {
+ if (loadInProgress)
+ {
+ return Mono.error(new LoadInProgressException());
+ }
+
+ if (!isShardOwned[shard])
+ {
+ return Mono.error(new ShardNotOwnedException(shard));
+ }
+
+ return Mono.justOrEmpty(chatRoomData[shard].get(id));
+ }
+
+ Flux<ChatRoomInfo> getChatRoomInfo()
+ {
+ 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));
+ }
+}
--- /dev/null
+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.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 lombok.Getter;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.kafka.clients.consumer.Consumer;
+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.producer.Producer;
+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.*;
+import java.util.*;
+import java.util.stream.IntStream;
+
+
+@Slf4j
+public class ChatRoomChannel implements Runnable, ConsumerRebalanceListener
+{
+ private final String topic;
+ private final Producer<String, AbstractMessageTo> producer;
+ private final Consumer<String, AbstractMessageTo> 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, ChatRoomInfo>[] chatRoomInfo;
+ private final Map<UUID, ChatRoomData>[] chatRoomData;
+
+ private boolean running;
+ @Getter
+ private volatile boolean loadInProgress;
+
+
+ public ChatRoomChannel(
+ String topic,
+ Producer<String, AbstractMessageTo> producer,
+ Consumer<String, AbstractMessageTo> consumer,
+ ZoneId zoneId,
+ int numShards,
+ int bufferSize,
+ Clock clock)
+ {
+ log.debug(
+ "Creating ChatRoomChannel for topic {} with {} partitions",
+ topic,
+ numShards);
+ this.topic = topic;
+ this.consumer = consumer;
+ 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.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<>();
+ });
+ }
+
+
+
+ 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,
+ LocalDateTime timestamp,
+ String text)
+ {
+ ZonedDateTime zdt = ZonedDateTime.of(timestamp, zoneId);
+ return Mono.create(sink ->
+ {
+ ProducerRecord<String, AbstractMessageTo> record =
+ new ProducerRecord<>(
+ topic,
+ null,
+ zdt.toEpochSecond(),
+ chatRoomId.toString(),
+ EventChatMessageReceivedTo.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)
+ {
+ log.info("Newly assigned partitions! Pausing normal operations...");
+ loadInProgress = true;
+
+ consumer.endOffsets(partitions).forEach((topicPartition, currentOffset) ->
+ {
+ int partition = topicPartition.partition();
+ isShardOwned[partition] = true;
+ this.currentOffset[partition] = currentOffset;
+
+ log.info(
+ "Partition assigned: {} - loading messages: next={} -> current={}",
+ partition,
+ nextOffset[partition],
+ currentOffset);
+
+ consumer.seek(topicPartition, nextOffset[partition]);
+ });
+
+ consumer.resume(partitions);
+ }
+
+ @Override
+ public void onPartitionsRevoked(Collection<TopicPartition> partitions)
+ {
+ partitions.forEach(topicPartition ->
+ {
+ int partition = topicPartition.partition();
+ isShardOwned[partition] = false;
+ log.info("Partition revoked: {} - next={}", partition, nextOffset[partition]);
+ });
+ }
+
+ @Override
+ public void onPartitionsLost(Collection<TopicPartition> partitions)
+ {
+ log.warn("Lost partitions: {}, partitions");
+ // TODO: Muss auf den Verlust anders reagiert werden?
+ onPartitionsRevoked(partitions);
+ }
+
+ @Override
+ public void run()
+ {
+ running = true;
+
+ while (running)
+ {
+ try
+ {
+ ConsumerRecords<String, AbstractMessageTo> records = consumer.poll(Duration.ofMinutes(5));
+ log.info("Fetched {} messages", records.count());
+
+ if (loadInProgress)
+ {
+ loadChatRoom(records);
+
+ if (isLoadingCompleted())
+ {
+ log.info("Loading of messages completed! Pausing all owned partitions...");
+ pauseAllOwnedPartions();
+ log.info("Resuming normal operations...");
+ loadInProgress = false;
+ }
+ }
+ else
+ {
+ if (!records.isEmpty())
+ {
+ throw new IllegalStateException("All owned partitions should be paused, when no load is in progress!");
+ }
+ }
+ }
+ catch (WakeupException e)
+ {
+ log.info("Received WakeupException, exiting!");
+ running = false;
+ }
+ }
+
+ log.info("Exiting normally");
+ }
+
+ private void loadChatRoom(ConsumerRecords<String, AbstractMessageTo> records)
+ {
+ for (ConsumerRecord<String, AbstractMessageTo> record : records)
+ {
+ UUID chatRoomId = UUID.fromString(record.key());
+
+ 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);
+ loadChatMessage(
+ chatRoomId,
+ timestamp,
+ record.offset(),
+ (EventChatMessageReceivedTo) record.value(),
+ record.partition());
+ break;
+
+ default:
+ log.debug(
+ "Ignoring message for chat-room {} with offset {}: {}",
+ chatRoomId,
+ record.offset(),
+ record.value());
+ }
+
+ nextOffset[record.partition()] = record.offset() + 1;
+ }
+ }
+
+ 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,
+ long offset,
+ EventChatMessageReceivedTo chatMessageTo,
+ int partition)
+ {
+ 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);
+ KafkaChatMessageService kafkaChatRoomService =
+ (KafkaChatMessageService) chatRoomData.getChatRoomService();
+
+ kafkaChatRoomService.persistMessage(message);
+ }
+
+ private boolean isLoadingCompleted()
+ {
+ return IntStream
+ .range(0, numShards)
+ .filter(shard -> isShardOwned[shard])
+ .allMatch(shard -> nextOffset[shard] >= currentOffset[shard]);
+ }
+
+ private void pauseAllOwnedPartions()
+ {
+ consumer.pause(IntStream
+ .range(0, numShards)
+ .filter(shard -> isShardOwned[shard])
+ .mapToObj(shard -> new TopicPartition(topic, shard))
+ .toList());
+ }
+
+
+ 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
+ .range(0, numShards)
+ .filter(shard -> isShardOwned[shard])
+ .toArray();
+ }
+
+ Mono<ChatRoomData> getChatRoomData(int shard, UUID id)
+ {
+ if (loadInProgress)
+ {
+ return Mono.error(new LoadInProgressException());
+ }
+
+ if (!isShardOwned[shard])
+ {
+ return Mono.error(new ShardNotOwnedException(shard));
+ }
+
+ return Mono.justOrEmpty(chatRoomData[shard].get(id));
+ }
+
+ Flux<ChatRoomInfo> getChatRoomInfo()
+ {
+ 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));
+ }
+}
+++ /dev/null
-package de.juplo.kafka.chat.backend.implementation.kafka.messages;
-
-
-import lombok.Getter;
-import lombok.RequiredArgsConstructor;
-
-
-@RequiredArgsConstructor
-public class AbstractMessageTo
-{
- public enum ToType {
- COMMAND_CREATE_CHATROOM,
- EVENT_CHATMESSAGE_RECEIVED,
- }
-
- @Getter
- private final ToType type;
-}
+++ /dev/null
-package de.juplo.kafka.chat.backend.implementation.kafka.messages;
-
-import lombok.*;
-
-
-@Getter
-@Setter
-@EqualsAndHashCode
-@ToString
-public class CommandCreateChatRoomTo extends AbstractMessageTo
-{
- private String name;
-
-
- public CommandCreateChatRoomTo()
- {
- super(ToType.COMMAND_CREATE_CHATROOM);
- }
-
-
- public static CommandCreateChatRoomTo of(String name)
- {
- CommandCreateChatRoomTo to = new CommandCreateChatRoomTo();
- to.name = name;
- return to;
- }
-}
+++ /dev/null
-package de.juplo.kafka.chat.backend.implementation.kafka.messages;
-
-import lombok.*;
-
-
-@Getter
-@Setter
-@EqualsAndHashCode
-@ToString
-public class EventChatMessageReceivedTo extends AbstractMessageTo
-{
- private String user;
- private Long id;
- private String text;
-
-
- public EventChatMessageReceivedTo()
- {
- super(ToType.EVENT_CHATMESSAGE_RECEIVED);
- }
-
-
- public static EventChatMessageReceivedTo of(String user, Long id, String text)
- {
- EventChatMessageReceivedTo to = new EventChatMessageReceivedTo();
- to.user = user;
- to.id = id;
- to.text = text;
- return to;
- }
-}
--- /dev/null
+package de.juplo.kafka.chat.backend.implementation.kafka.messages;
+
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+
+@RequiredArgsConstructor
+public class AbstractMessageTo
+{
+ public enum ToType {
+ COMMAND_CREATE_CHATROOM,
+ EVENT_CHATMESSAGE_RECEIVED,
+ }
+
+ @Getter
+ private final ToType type;
+}
--- /dev/null
+package de.juplo.kafka.chat.backend.implementation.kafka.messages;
+
+import lombok.*;
+
+
+@Getter
+@Setter
+@EqualsAndHashCode
+@ToString
+public class CommandCreateChatRoomTo extends AbstractMessageTo
+{
+ private String name;
+
+
+ public CommandCreateChatRoomTo()
+ {
+ super(ToType.COMMAND_CREATE_CHATROOM);
+ }
+
+
+ public static CommandCreateChatRoomTo of(String name)
+ {
+ CommandCreateChatRoomTo to = new CommandCreateChatRoomTo();
+ to.name = name;
+ return to;
+ }
+}
--- /dev/null
+package de.juplo.kafka.chat.backend.implementation.kafka.messages;
+
+import lombok.*;
+
+
+@Getter
+@Setter
+@EqualsAndHashCode
+@ToString
+public class EventChatMessageReceivedTo extends AbstractMessageTo
+{
+ private String user;
+ private Long id;
+ private String text;
+
+
+ public EventChatMessageReceivedTo()
+ {
+ super(ToType.EVENT_CHATMESSAGE_RECEIVED);
+ }
+
+
+ public static EventChatMessageReceivedTo of(String user, Long id, String text)
+ {
+ EventChatMessageReceivedTo to = new EventChatMessageReceivedTo();
+ to.user = user;
+ to.id = id;
+ to.text = text;
+ return to;
+ }
+}
--- /dev/null
+package de.juplo.kafka.chat.backend.implementation.kafka.messages.info;
+
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+
+@RequiredArgsConstructor
+public class AbstractInfoMessageTo
+{
+ public enum ToType {
+ EVENT_CHATROOM_CREATED,
+ }
+
+ @Getter
+ private final ToType type;
+}
--- /dev/null
+package de.juplo.kafka.chat.backend.implementation.kafka.messages.info;public class EventChatRoomCreated {
+}
+++ /dev/null
-package de.juplo.kafka.chat.backend.implementation.kafka.messages;
-
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.SerializationFeature;
-import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
-
-import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
-
-
-public class CommandCreateChatRoomToTest
-{
- final String json = """
- {
- "name": "Foo-Room!"
- }""";
-
- ObjectMapper mapper;
-
- @BeforeEach
- public void setUp()
- {
- mapper = new ObjectMapper();
- mapper.registerModule(new JavaTimeModule());
- mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
- }
-
- @Test
- public void testDeserialization() throws Exception
- {
- CommandCreateChatRoomTo message = mapper.readValue(json, CommandCreateChatRoomTo.class);
- assertThat(message.getName()).isEqualTo("Foo-Room!");
- }
-}
+++ /dev/null
-package de.juplo.kafka.chat.backend.implementation.kafka.messages;
-
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.SerializationFeature;
-import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
-
-import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
-
-
-public class EventChatMessageReceivedToTest
-{
- final String json = """
- {
- "id": 1,
- "text": "Hallo, ich heiße Peter!",
- "user": "Peter"
- }""";
-
- ObjectMapper mapper;
-
- @BeforeEach
- public void setUp()
- {
- mapper = new ObjectMapper();
- mapper.registerModule(new JavaTimeModule());
- mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
- }
-
- @Test
- public void testDeserialization() throws Exception
- {
- EventChatMessageReceivedTo message = mapper.readValue(json, EventChatMessageReceivedTo.class);
- assertThat(message.getId()).isEqualTo(1l);
- assertThat(message.getText()).isEqualTo("Hallo, ich heiße Peter!");
- assertThat(message.getUser()).isEqualTo("Peter");
- }
-}
--- /dev/null
+package de.juplo.kafka.chat.backend.implementation.kafka.messages;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
+
+
+public class CommandCreateChatRoomToTest
+{
+ final String json = """
+ {
+ "name": "Foo-Room!"
+ }""";
+
+ ObjectMapper mapper;
+
+ @BeforeEach
+ public void setUp()
+ {
+ mapper = new ObjectMapper();
+ mapper.registerModule(new JavaTimeModule());
+ mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
+ }
+
+ @Test
+ public void testDeserialization() throws Exception
+ {
+ CommandCreateChatRoomTo message = mapper.readValue(json, CommandCreateChatRoomTo.class);
+ assertThat(message.getName()).isEqualTo("Foo-Room!");
+ }
+}
--- /dev/null
+package de.juplo.kafka.chat.backend.implementation.kafka.messages;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
+
+
+public class EventChatMessageReceivedToTest
+{
+ final String json = """
+ {
+ "id": 1,
+ "text": "Hallo, ich heiße Peter!",
+ "user": "Peter"
+ }""";
+
+ ObjectMapper mapper;
+
+ @BeforeEach
+ public void setUp()
+ {
+ mapper = new ObjectMapper();
+ mapper.registerModule(new JavaTimeModule());
+ mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
+ }
+
+ @Test
+ public void testDeserialization() throws Exception
+ {
+ EventChatMessageReceivedTo message = mapper.readValue(json, EventChatMessageReceivedTo.class);
+ assertThat(message.getId()).isEqualTo(1l);
+ assertThat(message.getText()).isEqualTo("Hallo, ich heiße Peter!");
+ assertThat(message.getUser()).isEqualTo("Peter");
+ }
+}
projects / demos / kafka / chat / commitdiff