raminqaf commented on code in PR #15601: URL: https://github.com/apache/kafka/pull/15601#discussion_r1545727392
########## streams/src/main/java/org/apache/kafka/streams/kstream/internals/KStreamKStreamJoin.java: ########## @@ -16,276 +16,98 @@ */ package org.apache.kafka.streams.kstream.internals; +import static org.apache.kafka.streams.StreamsConfig.InternalConfig.EMIT_INTERVAL_MS_KSTREAMS_OUTER_JOIN_SPURIOUS_RESULTS_FIX; +import static org.apache.kafka.streams.processor.internals.metrics.TaskMetrics.droppedRecordsSensor; + +import java.util.Optional; import org.apache.kafka.common.metrics.Sensor; -import org.apache.kafka.streams.KeyValue; import org.apache.kafka.streams.StreamsConfig; import org.apache.kafka.streams.kstream.ValueJoinerWithKey; import org.apache.kafka.streams.kstream.internals.KStreamImplJoin.TimeTracker; import org.apache.kafka.streams.kstream.internals.KStreamImplJoin.TimeTrackerSupplier; import org.apache.kafka.streams.processor.api.ContextualProcessor; -import org.apache.kafka.streams.processor.api.Processor; import org.apache.kafka.streams.processor.api.ProcessorContext; import org.apache.kafka.streams.processor.api.ProcessorSupplier; -import org.apache.kafka.streams.processor.api.Record; import org.apache.kafka.streams.processor.internals.InternalProcessorContext; import org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl; -import org.apache.kafka.streams.state.KeyValueIterator; import org.apache.kafka.streams.state.KeyValueStore; import org.apache.kafka.streams.state.WindowStore; -import org.apache.kafka.streams.state.WindowStoreIterator; import org.apache.kafka.streams.state.internals.LeftOrRightValue; import org.apache.kafka.streams.state.internals.TimestampedKeyAndJoinSide; -import org.slf4j.Logger; -import org.slf4j.LoggerFactory; - -import java.util.Optional; - -import static org.apache.kafka.streams.StreamsConfig.InternalConfig.EMIT_INTERVAL_MS_KSTREAMS_OUTER_JOIN_SPURIOUS_RESULTS_FIX; -import static org.apache.kafka.streams.processor.internals.metrics.TaskMetrics.droppedRecordsSensor; - -class KStreamKStreamJoin<K, V1, V2, VOut> implements ProcessorSupplier<K, V1, K, VOut> { - private static final Logger LOG = LoggerFactory.getLogger(KStreamKStreamJoin.class); +abstract class KStreamKStreamJoin<K, V1, V2, VOut> implements ProcessorSupplier<K, V1, K, VOut> { + protected final ValueJoinerWithKey<? super K, ? super V1, ? super V2, ? extends VOut> joiner; + protected final long joinGraceMs; + protected final boolean outer; + protected final long joinBeforeMs; + protected final long joinAfterMs; private final String otherWindowName; - private final long joinBeforeMs; - private final long joinAfterMs; - private final long joinGraceMs; private final boolean enableSpuriousResultFix; private final long windowsBeforeMs; private final long windowsAfterMs; - - private final boolean outer; - private final boolean isLeftSide; private final Optional<String> outerJoinWindowName; - private final ValueJoinerWithKey<? super K, ? super V1, ? super V2, ? extends VOut> joiner; private final TimeTrackerSupplier sharedTimeTrackerSupplier; - KStreamKStreamJoin(final boolean isLeftSide, - final String otherWindowName, - final JoinWindowsInternal windows, - final ValueJoinerWithKey<? super K, ? super V1, ? super V2, ? extends VOut> joiner, - final boolean outer, - final Optional<String> outerJoinWindowName, - final TimeTrackerSupplier sharedTimeTrackerSupplier) { - this.isLeftSide = isLeftSide; + KStreamKStreamJoin(final String otherWindowName, + final JoinWindowsInternal windows, + final long joinBeforeMs, + final long joinAfterMs, + final ValueJoinerWithKey<? super K, ? super V1, ? super V2, ? extends VOut> joiner, + final Optional<String> outerJoinWindowName, + final TimeTrackerSupplier sharedTimeTrackerSupplier, + final boolean outer) { this.otherWindowName = otherWindowName; - if (isLeftSide) { - this.joinBeforeMs = windows.beforeMs; - this.joinAfterMs = windows.afterMs; - } else { - this.joinBeforeMs = windows.afterMs; - this.joinAfterMs = windows.beforeMs; - } this.windowsAfterMs = windows.afterMs; this.windowsBeforeMs = windows.beforeMs; - this.joinGraceMs = windows.gracePeriodMs(); + this.joinBeforeMs = joinBeforeMs; + this.joinAfterMs = joinAfterMs; this.enableSpuriousResultFix = windows.spuriousResultFixEnabled(); this.joiner = joiner; - this.outer = outer; + this.joinGraceMs = windows.gracePeriodMs(); this.outerJoinWindowName = outerJoinWindowName; this.sharedTimeTrackerSupplier = sharedTimeTrackerSupplier; + this.outer = outer; } - @Override - public Processor<K, V1, K, VOut> get() { - return new KStreamKStreamJoinProcessor(); - } - - private class KStreamKStreamJoinProcessor extends ContextualProcessor<K, V1, K, VOut> { - private WindowStore<K, V2> otherWindowStore; - private Sensor droppedRecordsSensor; - private Optional<KeyValueStore<TimestampedKeyAndJoinSide<K>, LeftOrRightValue<V1, V2>>> outerJoinStore = Optional.empty(); - private InternalProcessorContext<K, VOut> internalProcessorContext; - private TimeTracker sharedTimeTracker; + protected abstract class KStreamKStreamJoinProcessor extends ContextualProcessor<K, V1, K, VOut> { + protected WindowStore<K, V2> otherWindowStore; + protected Sensor droppedRecordsSensor; + protected Optional<KeyValueStore<TimestampedKeyAndJoinSide<K>, LeftOrRightValue<V1, V2>>> leftOuterJoinStore = + Optional.empty(); + protected Optional<KeyValueStore<TimestampedKeyAndJoinSide<K>, LeftOrRightValue<V2, V1>>> rightOuterJoinStore = + Optional.empty(); + protected InternalProcessorContext<K, VOut> internalProcessorContext; + protected TimeTracker sharedTimeTracker; @Override public void init(final ProcessorContext<K, VOut> context) { super.init(context); internalProcessorContext = (InternalProcessorContext<K, VOut>) context; final StreamsMetricsImpl metrics = (StreamsMetricsImpl) context.metrics(); - droppedRecordsSensor = droppedRecordsSensor(Thread.currentThread().getName(), context.taskId().toString(), metrics); + droppedRecordsSensor = + droppedRecordsSensor(Thread.currentThread().getName(), context.taskId().toString(), metrics); otherWindowStore = context.getStateStore(otherWindowName); sharedTimeTracker = sharedTimeTrackerSupplier.get(context.taskId()); if (enableSpuriousResultFix) { - outerJoinStore = outerJoinWindowName.map(context::getStateStore); + leftOuterJoinStore = outerJoinWindowName.map(context::getStateStore); + rightOuterJoinStore = outerJoinWindowName.map(context::getStateStore); sharedTimeTracker.setEmitInterval( - StreamsConfig.InternalConfig.getLong( - context.appConfigs(), - EMIT_INTERVAL_MS_KSTREAMS_OUTER_JOIN_SPURIOUS_RESULTS_FIX, - 1000L - ) + StreamsConfig.InternalConfig.getLong( + context.appConfigs(), + EMIT_INTERVAL_MS_KSTREAMS_OUTER_JOIN_SPURIOUS_RESULTS_FIX, + 1000L + ) ); } } - @SuppressWarnings("unchecked") - @Override - public void process(final Record<K, V1> record) { - final long inputRecordTimestamp = record.timestamp(); - final long timeFrom = Math.max(0L, inputRecordTimestamp - joinBeforeMs); - final long timeTo = Math.max(0L, inputRecordTimestamp + joinAfterMs); - sharedTimeTracker.advanceStreamTime(inputRecordTimestamp); - - if (outer && record.key() == null && record.value() != null) { - context().forward(record.withValue(joiner.apply(record.key(), record.value(), null))); - return; - } else if (StreamStreamJoinUtil.skipRecord(record, LOG, droppedRecordsSensor, context())) { - return; - } - - // Emit all non-joined records which window has closed - if (inputRecordTimestamp == sharedTimeTracker.streamTime) { - outerJoinStore.ifPresent(store -> emitNonJoinedOuterRecords(store, record)); - } - - boolean needOuterJoin = outer; - try (final WindowStoreIterator<V2> iter = otherWindowStore.fetch(record.key(), timeFrom, timeTo)) { - while (iter.hasNext()) { - needOuterJoin = false; - final KeyValue<Long, V2> otherRecord = iter.next(); - final long otherRecordTimestamp = otherRecord.key; - - outerJoinStore.ifPresent(store -> { - // use putIfAbsent to first read and see if there's any values for the key, - // if yes delete the key, otherwise do not issue a put; - // we may delete some values with the same key early but since we are going - // range over all values of the same key even after failure, since the other window-store - // is only cleaned up by stream time, so this is okay for at-least-once. - store.putIfAbsent(TimestampedKeyAndJoinSide.make(!isLeftSide, record.key(), otherRecordTimestamp), null); - }); - - context().forward( - record.withValue(joiner.apply(record.key(), record.value(), otherRecord.value)) - .withTimestamp(Math.max(inputRecordTimestamp, otherRecordTimestamp))); - } - - if (needOuterJoin) { - // The maxStreamTime contains the max time observed in both sides of the join. - // Having access to the time observed in the other join side fixes the following - // problem: - // - // Say we have a window size of 5 seconds - // 1. A non-joined record with time T10 is seen in the left-topic (maxLeftStreamTime: 10) - // The record is not processed yet, and is added to the outer-join store - // 2. A non-joined record with time T2 is seen in the right-topic (maxRightStreamTime: 2) - // The record is not processed yet, and is added to the outer-join store - // 3. A joined record with time T11 is seen in the left-topic (maxLeftStreamTime: 11) - // It is time to look at the expired records. T10 and T2 should be emitted, but - // because T2 was late, then it is not fetched by the window store, so it is not processed - // - // See KStreamKStreamLeftJoinTest.testLowerWindowBound() tests - // - // This condition below allows us to process the out-of-order records without the need - // to hold it in the temporary outer store - if (!outerJoinStore.isPresent() || timeTo < sharedTimeTracker.streamTime) { - context().forward(record.withValue(joiner.apply(record.key(), record.value(), null))); - } else { - sharedTimeTracker.updatedMinTime(inputRecordTimestamp); - outerJoinStore.ifPresent(store -> store.put( - TimestampedKeyAndJoinSide.make(isLeftSide, record.key(), inputRecordTimestamp), - LeftOrRightValue.make(isLeftSide, record.value()))); - } - } - } - } - - @SuppressWarnings("unchecked") - private void emitNonJoinedOuterRecords( - final KeyValueStore<TimestampedKeyAndJoinSide<K>, LeftOrRightValue<V1, V2>> store, - final Record<K, V1> record) { - - // calling `store.all()` creates an iterator what is an expensive operation on RocksDB; - // to reduce runtime cost, we try to avoid paying those cost - - // only try to emit left/outer join results if there _might_ be any result records - if (sharedTimeTracker.minTime + joinAfterMs + joinGraceMs >= sharedTimeTracker.streamTime) { - return; - } - // throttle the emit frequency to a (configurable) interval; - // we use processing time to decouple from data properties, - // as throttling is a non-functional performance optimization - if (internalProcessorContext.currentSystemTimeMs() < sharedTimeTracker.nextTimeToEmit) { - return; - } - - // Ensure `nextTimeToEmit` is synced with `currentSystemTimeMs`, if we dont set it everytime, - // they can get out of sync during a clock drift - sharedTimeTracker.nextTimeToEmit = internalProcessorContext.currentSystemTimeMs(); - sharedTimeTracker.advanceNextTimeToEmit(); - - // reset to MAX_VALUE in case the store is empty - sharedTimeTracker.minTime = Long.MAX_VALUE; - - try (final KeyValueIterator<TimestampedKeyAndJoinSide<K>, LeftOrRightValue<V1, V2>> it = store.all()) { - TimestampedKeyAndJoinSide<K> prevKey = null; - - while (it.hasNext()) { - boolean outerJoinLeftBreak = false; - boolean outerJoinRightBreak = false; - final KeyValue<TimestampedKeyAndJoinSide<K>, LeftOrRightValue<V1, V2>> next = it.next(); - final TimestampedKeyAndJoinSide<K> timestampedKeyAndJoinSide = next.key; - final LeftOrRightValue<V1, V2> value = next.value; - final K key = timestampedKeyAndJoinSide.getKey(); - final long timestamp = timestampedKeyAndJoinSide.getTimestamp(); - sharedTimeTracker.minTime = timestamp; - - // Skip next records if window has not closed - final long outerJoinLookBackTimeMs = getOuterJoinLookBackTimeMs(timestampedKeyAndJoinSide); - if (sharedTimeTracker.minTime + outerJoinLookBackTimeMs + joinGraceMs >= sharedTimeTracker.streamTime) { - if (timestampedKeyAndJoinSide.isLeftSide()) { - outerJoinLeftBreak = true; // there are no more candidates to emit on left-outerJoin-side - } else { - outerJoinRightBreak = true; // there are no more candidates to emit on right-outerJoin-side - } - if (outerJoinLeftBreak && outerJoinRightBreak) { - break; // there are no more candidates to emit on left-outerJoin-side and - // right-outerJoin-side - } else { - continue; // there are possibly candidates left on the other outerJoin-side - } - } - - final VOut nullJoinedValue; - if (isLeftSide) { - nullJoinedValue = joiner.apply(key, - value.getLeftValue(), - value.getRightValue()); - } else { - nullJoinedValue = joiner.apply(key, - (V1) value.getRightValue(), - (V2) value.getLeftValue()); - } - - context().forward( - record.withKey(key).withValue(nullJoinedValue).withTimestamp(timestamp) - ); - - if (prevKey != null && !prevKey.equals(timestampedKeyAndJoinSide)) { - // blind-delete the previous key from the outer window store now it is emitted; - // we do this because this delete would remove the whole list of values of the same key, - // and hence if we delete eagerly and then fail, we would miss emitting join results of the later - // values in the list. - // we do not use delete() calls since it would incur extra get() - store.put(prevKey, null); - } - - prevKey = timestampedKeyAndJoinSide; - } - - // at the end of the iteration, we need to delete the last key - if (prevKey != null) { - store.put(prevKey, null); - } - } - } - - private long getOuterJoinLookBackTimeMs(final TimestampedKeyAndJoinSide<K> timestampedKeyAndJoinSide) { + protected long getOuterJoinLookBackTimeMs(final TimestampedKeyAndJoinSide<K> timestampedKeyAndJoinSide) { // depending on the JoinSide we fill in the outerJoinLookBackTimeMs - if (timestampedKeyAndJoinSide.isLeftSide()) { + if (timestampedKeyAndJoinSide.getJoinSide() == JoinSide.LEFT) { Review Comment: A side note: This decision could not be removed. In the KStreamKStreamRightJoin, there are some tests that fetch the value from the rightOuterStore, and the value contains the left-side value. In the KStreamKStreamLeftJoin this call was not needed. ########## streams/src/main/java/org/apache/kafka/streams/kstream/internals/KStreamKStreamLeftJoin.java: ########## @@ -0,0 +1,201 @@ +/* + * 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.kstream.internals; + +import java.util.Optional; +import org.apache.kafka.streams.KeyValue; +import org.apache.kafka.streams.kstream.ValueJoinerWithKey; +import org.apache.kafka.streams.kstream.internals.KStreamImplJoin.TimeTrackerSupplier; +import org.apache.kafka.streams.processor.api.Processor; +import org.apache.kafka.streams.processor.api.Record; +import org.apache.kafka.streams.state.KeyValueIterator; +import org.apache.kafka.streams.state.KeyValueStore; +import org.apache.kafka.streams.state.WindowStoreIterator; +import org.apache.kafka.streams.state.internals.LeftOrRightValue; +import org.apache.kafka.streams.state.internals.TimestampedKeyAndJoinSide; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +class KStreamKStreamLeftJoin<K, V1, V2, VOut> extends KStreamKStreamJoin<K, V1, V2, VOut> { + private static final Logger LOG = LoggerFactory.getLogger(KStreamKStreamJoin.class); + + KStreamKStreamLeftJoin(final String otherWindowName, + final JoinWindowsInternal windows, + final ValueJoinerWithKey<? super K, ? super V1, ? super V2, ? extends VOut> joiner, + final boolean outer, + final Optional<String> outerJoinWindowName, + final TimeTrackerSupplier sharedTimeTrackerSupplier) { + super(otherWindowName, windows, windows.beforeMs, windows.afterMs, joiner, outerJoinWindowName, + sharedTimeTrackerSupplier, outer); + } + + @Override + public Processor<K, V1, K, VOut> get() { + return new KStreamKStreamLeftJoinProcessor(); + } + + private class KStreamKStreamLeftJoinProcessor extends KStreamKStreamJoinProcessor { + @Override + public void process(final Record<K, V1> leftRecord) { + final long inputRecordTimestamp = leftRecord.timestamp(); + final long timeFrom = Math.max(0L, inputRecordTimestamp - joinBeforeMs); + final long timeTo = Math.max(0L, inputRecordTimestamp + joinAfterMs); + sharedTimeTracker.advanceStreamTime(inputRecordTimestamp); + + if (outer && leftRecord.key() == null && leftRecord.value() != null) { + final VOut leftJoinValue = joiner.apply(leftRecord.key(), leftRecord.value(), null); + context().forward(leftRecord.withValue(leftJoinValue)); + return; + } else if (StreamStreamJoinUtil.skipRecord(leftRecord, LOG, droppedRecordsSensor, context())) { + return; + } + + // Emit all non-joined records which window has closed + if (inputRecordTimestamp == sharedTimeTracker.streamTime) { + leftOuterJoinStore.ifPresent(store -> emitNonJoinedOuterRecords(store, leftRecord)); + } + + boolean needOuterJoin = outer; + try (final WindowStoreIterator<V2> iter = otherWindowStore.fetch(leftRecord.key(), timeFrom, timeTo)) { Review Comment: I also have a couple of questions. When is this store getting filled? I couldn't find anywhere where we call `.put()` for this window store. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org