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.domain.ChatRoomInfo;
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 de.juplo.kafka.chat.backend.implementation.kafka.messages.info.EventChatRoomCreated;
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.HashMap;
+import java.util.Map;
+import java.util.UUID;
import java.util.stream.IntStream;
@Slf4j
-public class ChatRoomChannel implements Runnable, ConsumerRebalanceListener
+public class InfoChannel implements Runnable
{
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 final Map<UUID, ChatRoomInfo> chatRoomInfo;
private boolean running;
- @Getter
- private volatile boolean loadInProgress;
- public ChatRoomChannel(
+ public InfoChannel(
String topic,
Producer<String, AbstractMessageTo> producer,
- Consumer<String, AbstractMessageTo> consumer,
- ZoneId zoneId,
- int numShards,
- int bufferSize,
- Clock clock)
+ Consumer<String, AbstractMessageTo> infoChannelConsumer)
{
log.debug(
- "Creating ChatRoomChannel for topic {} with {} partitions",
- topic,
- numShards);
+ "Creating InfoChannel for topic {}",
+ topic);
this.topic = topic;
- this.consumer = consumer;
+ this.consumer = infoChannelConsumer;
this.producer = producer;
- this.zoneId = zoneId;
- this.numShards = numShards;
- this.bufferSize = bufferSize;
- this.clock = clock;
- this.isShardOwned = new boolean[numShards];
+ this.chatRoomInfo = new HashMap<>();
+
+ this.numShards = consumer
+ .partitionsFor(topic)
+ .size();
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(partition -> this.nextOffset[partition] = -1l);
}
+ boolean loadInProgress()
+ {
+ return IntStream
+ .range(0, numShards)
+ .anyMatch(partition -> nextOffset[partition] < currentOffset[partition]);
+ }
- Mono<ChatRoomInfo> sendCreateChatRoomRequest(
+ Mono<ChatRoomInfo> sendChatRoomCreatedEvent(
UUID chatRoomId,
- String name)
+ String name,
+ int shard)
{
- CommandCreateChatRoomTo createChatRoomRequestTo = CommandCreateChatRoomTo.of(name);
+ EventChatRoomCreated to = EventChatRoomCreated.of(chatRoomId, name, shard);
return Mono.create(sink ->
{
ProducerRecord<String, AbstractMessageTo> record =
new ProducerRecord<>(
topic,
- chatRoomId.toString(),
- createChatRoomRequestTo);
+ Integer.toString(shard),
+ to);
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);
+ log.info("Successfully sent chreate-request for chat room: {}", to);
+ ChatRoomInfo chatRoomInfo = new ChatRoomInfo(chatRoomId, name, shard);
sink.success(chatRoomInfo);
}
else
});
}
- 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;
+ consumer
+ .endOffsets(consumer.assignment())
+ .entrySet()
+ .stream()
+ .forEach(entry -> this.currentOffset[entry.getKey().partition()] = entry.getValue());
+ IntStream
+ .range(0, numShards)
+ .forEach(partition -> this.nextOffset[partition] = 0l);
+
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!");
- }
- }
+ ConsumerRecords<String, AbstractMessageTo> records = consumer.poll(Duration.ofMinutes(1));
+ log.debug("Fetched {} messages", records.count());
+ handleMessages(records);
}
catch (WakeupException e)
{
log.info("Exiting normally");
}
- private void loadChatRoom(ConsumerRecords<String, AbstractMessageTo> records)
+ private void handleMessages(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());
+ case EVENT_CHATROOM_CREATED:
+ EventChatRoomCreated eventChatRoomCreated =
+ (EventChatRoomCreated) record.value();
+ createChatRoom(eventChatRoomCreated.toChatRoomInfo());
break;
default:
log.debug(
- "Ignoring message for chat-room {} with offset {}: {}",
- chatRoomId,
+ "Ignoring message for key={} with offset={}: {}",
+ record.key(),
record.offset(),
record.value());
}
}
}
- 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());
- }
+ UUID chatRoomId = chatRoomInfo.getId();
+ Integer partition = chatRoomInfo.getShard();
-
- private void putChatRoom(
- UUID chatRoomId,
- String name,
- Integer partition,
- ChatRoomData chatRoomData)
- {
- if (this.chatRoomInfo[partition].containsKey(chatRoomId))
+ if (this.chatRoomInfo.containsKey(chatRoomId))
{
log.warn(
"Ignoring existing chat-room for {}: {}",
else
{
log.info(
- "Adding new chat-room to partition {}: {}",
+ "Adding new chat-room for 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());
- }
+ chatRoomId);
- if (!isShardOwned[shard])
- {
- return Mono.error(new ShardNotOwnedException(shard));
+ this.chatRoomInfo.put(chatRoomId, chatRoomInfo);
}
-
- 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()));
+ return Flux.fromIterable(chatRoomInfo.values());
}
- Mono<ChatRoomInfo> getChatRoomInfo(int shard, UUID id)
+ Mono<ChatRoomInfo> getChatRoomInfo(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));
+ return Mono.fromSupplier(() -> chatRoomInfo.get(id));
}
}
projects / demos / kafka / chat / blobdiff