gortiz commented on code in PR #12704: URL: https://github.com/apache/pinot/pull/12704#discussion_r1576205973
########## pinot-common/src/main/java/org/apache/pinot/common/datablock/V1MetadataBlock.java: ########## @@ -0,0 +1,165 @@ +/** + * 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.common.datablock; + +import com.fasterxml.jackson.annotation.JsonCreator; +import com.fasterxml.jackson.annotation.JsonIgnoreProperties; +import com.fasterxml.jackson.annotation.JsonProperty; +import com.fasterxml.jackson.core.JsonProcessingException; +import com.fasterxml.jackson.databind.ObjectMapper; +import com.google.common.annotations.VisibleForTesting; +import java.io.IOException; +import java.nio.ByteBuffer; +import java.util.HashMap; +import java.util.Map; + + +/** + * The datablock used before the introduction of {@link org.apache.pinot.common.datatable.StatMap}. + * <p> + * This version stored the metadata in a {@code Map<String, String>} which was encoded as JSON and stored in the + * variable size data buffer. + * <p> + * Instances of this class are not actually seen by the operators. Instead, they are converted to {@link MetadataBlock} + * in {@link MetadataBlock#deserialize(ByteBuffer, int)}. + * <p> + * The reason to keep it here is mostly for backwards compatibility and testing. In order to simplify the code, the + * stats engine just ignores the metadata of these objects, but we need to be able to deserialize them anyway. + */ +public class V1MetadataBlock extends BaseDataBlock { Review Comment: This is not only for testing proposes. We use this class to read metadata blocks send by servers running previous versions. By doing that we can read the actual metadata and do whatever we want with that. This metadata may be an error or an EOS with stats in the older format. The current implementation only cares about the error case. It is important to keep using that information (whose format wasn't changed in this PR) in order to correctly abort the execution if needed. Right now we ignore the stats because it doesn't seem worth it to translate the stats given the idea is to run with different versions only while the new release is being deployed, so losing some stats during that time seems acceptable. We can change that if we think it is important, but I would suggest to do that in another PR if needed. -- 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: commits-unsubscr...@pinot.apache.org 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
