import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.common.serialization.Serdes;
import org.apache.kafka.streams.*;
-import org.apache.kafka.streams.kstream.Consumed;
-import org.apache.kafka.streams.kstream.KStream;
-import org.apache.kafka.streams.kstream.KTable;
-import org.apache.kafka.streams.kstream.Materialized;
+import org.apache.kafka.streams.kstream.*;
import org.apache.kafka.streams.state.HostInfo;
import org.apache.kafka.streams.state.KeyValueBytesStoreSupplier;
import org.apache.kafka.streams.state.QueryableStoreTypes;
@Slf4j
public class QueryStreamProcessor
{
- public static final String STORE_NAME = "rankings-by-username";
+ public static final String USER_STORE_NAME = "users";
+ public static final String RANKING_STORE_NAME = "rankings";
public final KafkaStreams streams;
public final HostInfo hostInfo;
HostInfo applicationServer,
String usersInputTopic,
String rankingInputTopic,
- KeyValueBytesStoreSupplier storeSupplier)
+ KeyValueBytesStoreSupplier userStoreSupplier,
+ KeyValueBytesStoreSupplier rankingStoreSupplier)
{
Topology topology = buildTopology(
usersInputTopic,
rankingInputTopic,
- storeSupplier);
+ userStoreSupplier,
+ rankingStoreSupplier);
streams = new KafkaStreams(topology, props);
hostInfo = applicationServer;
- storeParameters = StoreQueryParameters.fromNameAndType(STORE_NAME, QueryableStoreTypes.keyValueStore());;
+ storeParameters = StoreQueryParameters.fromNameAndType(RANKING_STORE_NAME, QueryableStoreTypes.keyValueStore());;
}
static Topology buildTopology(
String usersInputTopic,
String rankingInputTopic,
- KeyValueBytesStoreSupplier storeSupplier)
+ KeyValueBytesStoreSupplier userStoreSupplier,
+ KeyValueBytesStoreSupplier rankingStoreSupplier)
{
StreamsBuilder builder = new StreamsBuilder();
- KTable<String, User> users = builder.table(usersInputTopic);
- KStream<String, Ranking> rankings = builder.stream(rankingInputTopic);
+ KTable<String, User> users = builder
+ .stream(
+ usersInputTopic,
+ Consumed.with(Serdes.String(), new JsonSerde().copyWithType(User.class)))
+ .toTable(
+ Materialized
+ .<String, User>as(userStoreSupplier)
+ .withKeySerde(Serdes.String())
+ .withValueSerde(new JsonSerde().copyWithType(User.class)));
+ KStream<String, Ranking> rankings = builder
+ .<Key, Ranking>stream(rankingInputTopic)
+ .map((key, value) -> new KeyValue<>(key.getUser(), value));
rankings
.join(users, (ranking, user) -> UserRanking.of(
user.getFirstName(),
user.getLastName(),
- ranking.getEntries()))
+ ranking.getEntries()),
+ Joined.keySerde(Serdes.String()))
.toTable(
Materialized
- .<String, UserRanking>as(storeSupplier)
+ .<String, UserRanking>as(rankingStoreSupplier)
+ .withKeySerde(Serdes.String())
.withValueSerde(new JsonSerde().copyWithType(UserRanking.class)));
Topology topology = builder.build();
public Optional<URI> getRedirect(String username)
{
- KeyQueryMetadata metadata = streams.queryMetadataForKey(STORE_NAME, username, Serdes.String().serializer());
+ KeyQueryMetadata metadata = streams.queryMetadataForKey(RANKING_STORE_NAME, username, Serdes.String().serializer());
HostInfo activeHost = metadata.activeHost();
log.debug("Local store for {}: {}, {}:{}", username, metadata.partition(), activeHost.host(), activeHost.port());