kafka MeteredSessionStore 源码

kafka MeteredSessionStore 代码

文件路径：/streams/src/main/java/org/apache/kafka/streams/state/internals/MeteredSessionStore.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.kafka.streams.state.internals;

import org.apache.kafka.common.metrics.Sensor;
import org.apache.kafka.common.serialization.Serde;
import org.apache.kafka.common.utils.Bytes;
import org.apache.kafka.common.utils.Time;
import org.apache.kafka.streams.errors.ProcessorStateException;
import org.apache.kafka.streams.kstream.Windowed;
import org.apache.kafka.streams.kstream.internals.Change;
import org.apache.kafka.streams.kstream.internals.WrappingNullableUtils;
import org.apache.kafka.streams.processor.ProcessorContext;
import org.apache.kafka.streams.processor.StateStore;
import org.apache.kafka.streams.processor.StateStoreContext;
import org.apache.kafka.streams.processor.TaskId;
import org.apache.kafka.streams.processor.internals.InternalProcessorContext;
import org.apache.kafka.streams.processor.internals.ProcessorContextUtils;
import org.apache.kafka.streams.processor.internals.SerdeGetter;
import org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl;
import org.apache.kafka.streams.query.FailureReason;
import org.apache.kafka.streams.query.PositionBound;
import org.apache.kafka.streams.query.Query;
import org.apache.kafka.streams.query.QueryConfig;
import org.apache.kafka.streams.query.QueryResult;
import org.apache.kafka.streams.query.WindowRangeQuery;
import org.apache.kafka.streams.query.internals.InternalQueryResultUtil;
import org.apache.kafka.streams.state.KeyValueIterator;
import org.apache.kafka.streams.state.SessionStore;
import org.apache.kafka.streams.state.StateSerdes;
import org.apache.kafka.streams.state.internals.StoreQueryUtils.QueryHandler;
import org.apache.kafka.streams.state.internals.metrics.StateStoreMetrics;

import java.util.Map;
import java.util.Objects;

import static org.apache.kafka.common.utils.Utils.mkEntry;
import static org.apache.kafka.common.utils.Utils.mkMap;
import static org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl.maybeMeasureLatency;

public class MeteredSessionStore<K, V>
    extends WrappedStateStore<SessionStore<Bytes, byte[]>, Windowed<K>, V>
    implements SessionStore<K, V> {

    private final String metricsScope;
    private final Serde<K> keySerde;
    private final Serde<V> valueSerde;
    private final Time time;
    private StateSerdes<K, V> serdes;
    private StreamsMetricsImpl streamsMetrics;
    private Sensor putSensor;
    private Sensor fetchSensor;
    private Sensor flushSensor;
    private Sensor removeSensor;
    private Sensor e2eLatencySensor;
    private InternalProcessorContext<?, ?> context;
    private TaskId taskId;

    @SuppressWarnings("rawtypes")
    private final Map<Class, QueryHandler> queryHandlers =
            mkMap(
                    mkEntry(
                            WindowRangeQuery.class,
                            (query, positionBound, config, store) -> runRangeQuery(query, positionBound, config)
                    )
            );


    MeteredSessionStore(final SessionStore<Bytes, byte[]> inner,
                        final String metricsScope,
                        final Serde<K> keySerde,
                        final Serde<V> valueSerde,
                        final Time time) {
        super(inner);
        this.metricsScope = metricsScope;
        this.keySerde = keySerde;
        this.valueSerde = valueSerde;
        this.time = time;
    }

    @Deprecated
    @Override
    public void init(final ProcessorContext context,
                     final StateStore root) {
        this.context = context instanceof InternalProcessorContext ? (InternalProcessorContext<?, ?>) context : null;
        taskId = context.taskId();
        initStoreSerde(context);
        streamsMetrics = (StreamsMetricsImpl) context.metrics();

        registerMetrics();
        final Sensor restoreSensor =
            StateStoreMetrics.restoreSensor(taskId.toString(), metricsScope, name(), streamsMetrics);

        // register and possibly restore the state from the logs
        maybeMeasureLatency(() -> super.init(context, root), time, restoreSensor);
    }

    @Override
    public void init(final StateStoreContext context,
                     final StateStore root) {
        this.context = context instanceof InternalProcessorContext ? (InternalProcessorContext<?, ?>) context : null;
        taskId = context.taskId();
        initStoreSerde(context);
        streamsMetrics = (StreamsMetricsImpl) context.metrics();

        registerMetrics();
        final Sensor restoreSensor =
            StateStoreMetrics.restoreSensor(taskId.toString(), metricsScope, name(), streamsMetrics);

        // register and possibly restore the state from the logs
        maybeMeasureLatency(() -> super.init(context, root), time, restoreSensor);
    }

    private void registerMetrics() {
        putSensor = StateStoreMetrics.putSensor(taskId.toString(), metricsScope, name(), streamsMetrics);
        fetchSensor = StateStoreMetrics.fetchSensor(taskId.toString(), metricsScope, name(), streamsMetrics);
        flushSensor = StateStoreMetrics.flushSensor(taskId.toString(), metricsScope, name(), streamsMetrics);
        removeSensor = StateStoreMetrics.removeSensor(taskId.toString(), metricsScope, name(), streamsMetrics);
        e2eLatencySensor = StateStoreMetrics.e2ELatencySensor(taskId.toString(), metricsScope, name(), streamsMetrics);
    }


    private void initStoreSerde(final ProcessorContext context) {
        final String storeName = name();
        final String changelogTopic = ProcessorContextUtils.changelogFor(context, storeName, Boolean.FALSE);
        serdes = new StateSerdes<>(
            changelogTopic,
            WrappingNullableUtils.prepareKeySerde(keySerde, new SerdeGetter(context)),
            WrappingNullableUtils.prepareValueSerde(valueSerde, new SerdeGetter(context))
        );
    }

    private void initStoreSerde(final StateStoreContext context) {
        final String storeName = name();
        final String changelogTopic = ProcessorContextUtils.changelogFor(context, storeName, Boolean.FALSE);
        serdes = new StateSerdes<>(
            changelogTopic,
            WrappingNullableUtils.prepareKeySerde(keySerde, new SerdeGetter(context)),
            WrappingNullableUtils.prepareValueSerde(valueSerde, new SerdeGetter(context))
        );
    }

    @SuppressWarnings("unchecked")
    @Override
    public boolean setFlushListener(final CacheFlushListener<Windowed<K>, V> listener,
                                    final boolean sendOldValues) {
        final SessionStore<Bytes, byte[]> wrapped = wrapped();
        if (wrapped instanceof CachedStateStore) {
            return ((CachedStateStore<byte[], byte[]>) wrapped).setFlushListener(
                record -> listener.apply(
                    record.withKey(SessionKeySchema.from(record.key(), serdes.keyDeserializer(), serdes.topic()))
                        .withValue(new Change<>(
                            record.value().newValue != null ? serdes.valueFrom(record.value().newValue) : null,
                            record.value().oldValue != null ? serdes.valueFrom(record.value().oldValue) : null
                        ))
                ),
                sendOldValues);
        }
        return false;
    }

    @Override
    public void put(final Windowed<K> sessionKey,
                    final V aggregate) {
        Objects.requireNonNull(sessionKey, "sessionKey can't be null");
        Objects.requireNonNull(sessionKey.key(), "sessionKey.key() can't be null");
        Objects.requireNonNull(sessionKey.window(), "sessionKey.window() can't be null");

        try {
            maybeMeasureLatency(
                () -> {
                    final Bytes key = keyBytes(sessionKey.key());
                    wrapped().put(new Windowed<>(key, sessionKey.window()), serdes.rawValue(aggregate));
                },
                time,
                putSensor
            );
            maybeRecordE2ELatency();
        } catch (final ProcessorStateException e) {
            final String message = String.format(e.getMessage(), sessionKey.key(), aggregate);
            throw new ProcessorStateException(message, e);
        }
    }

    @Override
    public void remove(final Windowed<K> sessionKey) {
        Objects.requireNonNull(sessionKey, "sessionKey can't be null");
        Objects.requireNonNull(sessionKey.key(), "sessionKey.key() can't be null");
        Objects.requireNonNull(sessionKey.window(), "sessionKey.window() can't be null");

        try {
            maybeMeasureLatency(
                () -> {
                    final Bytes key = keyBytes(sessionKey.key());
                    wrapped().remove(new Windowed<>(key, sessionKey.window()));
                },
                time,
                removeSensor
            );
        } catch (final ProcessorStateException e) {
            final String message = String.format(e.getMessage(), sessionKey.key());
            throw new ProcessorStateException(message, e);
        }
    }

    @Override
    public V fetchSession(final K key, final long earliestSessionEndTime, final long latestSessionStartTime) {
        Objects.requireNonNull(key, "key cannot be null");
        return maybeMeasureLatency(
            () -> {
                final Bytes bytesKey = keyBytes(key);
                final byte[] result = wrapped().fetchSession(
                    bytesKey,
                    earliestSessionEndTime,
                    latestSessionStartTime
                );
                if (result == null) {
                    return null;
                }
                return serdes.valueFrom(result);
            },
            time,
            fetchSensor
        );
    }

    @Override
    public KeyValueIterator<Windowed<K>, V> fetch(final K key) {
        Objects.requireNonNull(key, "key cannot be null");
        return new MeteredWindowedKeyValueIterator<>(
            wrapped().fetch(keyBytes(key)),
            fetchSensor,
            streamsMetrics,
            serdes::keyFrom,
            serdes::valueFrom,
            time);
    }

    @Override
    public KeyValueIterator<Windowed<K>, V> backwardFetch(final K key) {
        Objects.requireNonNull(key, "key cannot be null");
        return new MeteredWindowedKeyValueIterator<>(
            wrapped().backwardFetch(keyBytes(key)),
            fetchSensor,
            streamsMetrics,
            serdes::keyFrom,
            serdes::valueFrom,
            time
        );
    }

    @Override
    public KeyValueIterator<Windowed<K>, V> fetch(final K keyFrom,
                                                  final K keyTo) {
        return new MeteredWindowedKeyValueIterator<>(
            wrapped().fetch(keyBytes(keyFrom), keyBytes(keyTo)),
            fetchSensor,
            streamsMetrics,
            serdes::keyFrom,
            serdes::valueFrom,
            time);
    }

    @Override
    public KeyValueIterator<Windowed<K>, V> backwardFetch(final K keyFrom,
                                                          final K keyTo) {
        return new MeteredWindowedKeyValueIterator<>(
            wrapped().backwardFetch(keyBytes(keyFrom), keyBytes(keyTo)),
            fetchSensor,
            streamsMetrics,
            serdes::keyFrom,
            serdes::valueFrom,
            time
        );
    }

    @Override
    public KeyValueIterator<Windowed<K>, V> findSessions(final K key,
                                                         final long earliestSessionEndTime,
                                                         final long latestSessionStartTime) {
        Objects.requireNonNull(key, "key cannot be null");
        final Bytes bytesKey = keyBytes(key);
        return new MeteredWindowedKeyValueIterator<>(
            wrapped().findSessions(
                bytesKey,
                earliestSessionEndTime,
                latestSessionStartTime),
            fetchSensor,
            streamsMetrics,
            serdes::keyFrom,
            serdes::valueFrom,
            time);
    }

    @Override
    public KeyValueIterator<Windowed<K>, V> backwardFindSessions(final K key,
                                                                 final long earliestSessionEndTime,
                                                                 final long latestSessionStartTime) {
        Objects.requireNonNull(key, "key cannot be null");
        final Bytes bytesKey = keyBytes(key);
        return new MeteredWindowedKeyValueIterator<>(
            wrapped().backwardFindSessions(
                bytesKey,
                earliestSessionEndTime,
                latestSessionStartTime
            ),
            fetchSensor,
            streamsMetrics,
            serdes::keyFrom,
            serdes::valueFrom,
            time
        );
    }

    @Override
    public KeyValueIterator<Windowed<K>, V> findSessions(final K keyFrom,
                                                         final K keyTo,
                                                         final long earliestSessionEndTime,
                                                         final long latestSessionStartTime) {
        final Bytes bytesKeyFrom = keyBytes(keyFrom);
        final Bytes bytesKeyTo = keyBytes(keyTo);
        return new MeteredWindowedKeyValueIterator<>(
            wrapped().findSessions(
                bytesKeyFrom,
                bytesKeyTo,
                earliestSessionEndTime,
                latestSessionStartTime),
            fetchSensor,
            streamsMetrics,
            serdes::keyFrom,
            serdes::valueFrom,
            time);
    }

    @Override
    public KeyValueIterator<Windowed<K>, V> findSessions(final long earliestSessionEndTime,
                                                         final long latestSessionEndTime) {
        return new MeteredWindowedKeyValueIterator<>(
                wrapped().findSessions(earliestSessionEndTime, latestSessionEndTime),
                fetchSensor,
                streamsMetrics,
                serdes::keyFrom,
                serdes::valueFrom,
                time);
    }

    @Override
    public KeyValueIterator<Windowed<K>, V> backwardFindSessions(final K keyFrom,
                                                                 final K keyTo,
                                                                 final long earliestSessionEndTime,
                                                                 final long latestSessionStartTime) {
        final Bytes bytesKeyFrom = keyBytes(keyFrom);
        final Bytes bytesKeyTo = keyBytes(keyTo);
        return new MeteredWindowedKeyValueIterator<>(
            wrapped().backwardFindSessions(
                bytesKeyFrom,
                bytesKeyTo,
                earliestSessionEndTime,
                latestSessionStartTime
            ),
            fetchSensor,
            streamsMetrics,
            serdes::keyFrom,
            serdes::valueFrom,
            time
        );
    }

    @Override
    public void flush() {
        maybeMeasureLatency(super::flush, time, flushSensor);
    }

    @Override
    public void close() {
        try {
            wrapped().close();
        } finally {
            streamsMetrics.removeAllStoreLevelSensorsAndMetrics(taskId.toString(), name());
        }
    }

    @SuppressWarnings("unchecked")
    @Override
    public <R> QueryResult<R> query(final Query<R> query,
                                    final PositionBound positionBound,
                                    final QueryConfig config) {
        final long start = time.nanoseconds();
        final QueryResult<R> result;

        final QueryHandler handler = queryHandlers.get(query.getClass());
        if (handler == null) {
            result = wrapped().query(query, positionBound, config);
            if (config.isCollectExecutionInfo()) {
                result.addExecutionInfo(
                    "Handled in " + getClass() + " in " + (time.nanoseconds() - start) + "ns");
            }
        } else {
            result = (QueryResult<R>) handler.apply(
                query,
                positionBound,
                config,
                this
            );
            if (config.isCollectExecutionInfo()) {
                result.addExecutionInfo(
                    "Handled in " + getClass() + " with serdes "
                        + serdes + " in " + (time.nanoseconds() - start) + "ns");
            }
        }
        return result;
    }

    @SuppressWarnings("unchecked")
    private <R> QueryResult<R> runRangeQuery(final Query<R> query,
                                             final PositionBound positionBound,
                                             final QueryConfig config) {
        final QueryResult<R> result;
        final WindowRangeQuery<K, V> typedQuery = (WindowRangeQuery<K, V>) query;
        if (typedQuery.getKey().isPresent()) {
            final WindowRangeQuery<Bytes, byte[]> rawKeyQuery =
                WindowRangeQuery.withKey(
                    Bytes.wrap(serdes.rawKey(typedQuery.getKey().get()))
                );
            final QueryResult<KeyValueIterator<Windowed<Bytes>, byte[]>> rawResult =
                wrapped().query(rawKeyQuery, positionBound, config);
            if (rawResult.isSuccess()) {
                final MeteredWindowedKeyValueIterator<K, V> typedResult =
                    new MeteredWindowedKeyValueIterator<>(
                        rawResult.getResult(),
                        fetchSensor,
                        streamsMetrics,
                        serdes::keyFrom,
                        StoreQueryUtils.getDeserializeValue(serdes, wrapped()),
                        time
                    );
                final QueryResult<MeteredWindowedKeyValueIterator<K, V>> typedQueryResult =
                    InternalQueryResultUtil.copyAndSubstituteDeserializedResult(rawResult, typedResult);
                result = (QueryResult<R>) typedQueryResult;
            } else {
                // the generic type doesn't matter, since failed queries have no result set.
                result = (QueryResult<R>) rawResult;
            }
        } else {

            result = QueryResult.forFailure(
                FailureReason.UNKNOWN_QUERY_TYPE,
                "This store (" + getClass() + ") doesn't know how to"
                    + " execute the given query (" + query + ") because"
                    + " SessionStores only support WindowRangeQuery.withKey."
                    + " Contact the store maintainer if you need support"
                    + " for a new query type."
            );
        }
        return result;
    }

    private Bytes keyBytes(final K key) {
        return key == null ? null : Bytes.wrap(serdes.rawKey(key));
    }

    private void maybeRecordE2ELatency() {
        // Context is null if the provided context isn't an implementation of InternalProcessorContext.
        // In that case, we _can't_ get the current timestamp, so we don't record anything.
        if (e2eLatencySensor.shouldRecord() && context != null) {
            final long currentTime = time.milliseconds();
            final long e2eLatency =  currentTime - context.timestamp();
            e2eLatencySensor.record(e2eLatency, currentTime);
        }
    }
}

相关信息

kafka 源码目录

相关文章

kafka AbstractDualSchemaRocksDBSegmentedBytesStore 源码

kafka AbstractMergedSortedCacheStoreIterator 源码

kafka AbstractRocksDBSegmentedBytesStore 源码

kafka AbstractRocksDBTimeOrderedSegmentedBytesStore 源码

kafka AbstractSegments 源码

kafka AbstractStoreBuilder 源码

kafka BatchWritingStore 源码

kafka BlockBasedTableConfigWithAccessibleCache 源码

kafka BufferKey 源码

kafka BufferValue 源码