jamesyfshao commented on a change in pull request #5394: URL: https://github.com/apache/incubator-pinot/pull/5394#discussion_r446715996
########## File path: pinot-core/src/main/java/org/apache/pinot/core/data/manager/callback/DataManagerCallback.java ########## @@ -0,0 +1,106 @@ +/** + * 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.pinot.core.data.manager.callback; + +import org.apache.pinot.core.data.manager.SegmentDataManager; +import org.apache.pinot.spi.annotations.InterfaceStability; +import org.apache.pinot.spi.data.readers.GenericRow; +import org.apache.pinot.spi.stream.MessageBatch; +import org.apache.pinot.spi.stream.StreamPartitionMsgOffset; + +import java.io.IOException; + +/** + * Component inject to {@link org.apache.pinot.core.data.manager.SegmentDataManager} for handling extra logic for + * upsert-enabled pinot ingestion mode. + */ +@InterfaceStability.Evolving +public interface DataManagerCallback { + + void init() throws IOException; + + /** + * create a {@link IndexSegmentCallback} object to allow SegmentDataManager to create proper IndexSegment that supports + * either append/upsert mode + * + * In append-tables callback, this method will create a DefaultIndexSegmentCallback + * In upsert-tables callback, this method will create a UpsertDataManagerCallbackImpl + * + * The {@link IndexSegmentCallback} will be used in the constructor of IndexSegment + */ + IndexSegmentCallback getIndexSegmentCallback(); + + /** + * process the row after transformation in LLRealtimeSegmentDataManager.processStreamEvents(...) method + * it happens after the GenericRow has been transformed by RecordTransformer and before it is indexed by + * IndexSegmentImpl, to ensure we can provide other necessary data to the segment metadata. + * + * In append-tables callback, this method will do nothing + * In upsert-tables callback, this method will attach the offset object into the GenericRow object. + * + * The reason we need this particular logic is that in upsert table, we need to add offset data to the physical data + * this will help us to apply the update events from key coordinator to upsert table correctly as the offset + * is used as the index to identify which record's virtual column we want to update + * + * @param row the row of newly ingested and transformed data from upstream + * @param offset the offset of this particular pinot record + */ + void processTransformedRow(GenericRow row, StreamPartitionMsgOffset offset); + + /** + * process the row after indexing in LLRealtimeSegmentDataManager.processStreamEvents(...) method + * it happens after the MutableSegmentImpl has done the indexing of the current row in its physical storage + * + * In append-tables callback, this method will do nothing + * In upsert-tables callback, this method will emit an event to the message queue that will deliver the event to + * key coordinator. + * + * This method ensures that we can emit the metadata for an new entry that pinot just indexed to its internal storage + * and let key coordinator to be able to consume those events to process the updates correctly + * + * @param row the row we just index in the current segment + * @param offset the offset associated with the current row + */ + void postIndexProcessing(GenericRow row, StreamPartitionMsgOffset offset); + + /** + * perform any necessary finalize operation after the consumer loop finished in LLRealtimeSegmentDataManager.consumeLoop(...) + * method. It happens after the consumerloop exits the loop and reached the end criteria. + * + * In append-tables callback, this method will do nothing + * In upsert-tables callback, this method will flush the queue producer to ensure all pending messages are deliverd + * to the queue between pinot server and pinot key-coordinator + * + * this method will ensure that pinot server can send all events to key coordinator eventually before a segment + * is committed. If this does not happen we might lose data in case of machine failure. + */ + void postConsumeLoop(); + + /** + * perform any necessary clean up operation when the SegmentDataManager called its destroy() method. + * + * In append-tables callback, this method will do nothing + * In upsert-tables callback, this method will notify segmentUpdater to remove any registered reference for this + * dataManagerCallback. + * + * this method will ensure that segmentUpdater can keep track of which dataManager is still alive in the current pinot + * server so it can dispatch appropriate update events to only the alive pinot data manager + */ + void destroy(); Review comment: This method intends to be called when the destroy() method is called in the dataManager. One thing I want to note that the previous method and this method could be called at different times (consumption finished -> destroy could take seconds to minutes to fo finished, depends on controller logics), so we cannot re-use the previous method as they have different meaning. Also a DataManager that handles immutable segment will not call the previous method, but will call this one if an segment expired due to retention policy. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org
