jmckenzie-dev commented on code in PR #347: URL: https://github.com/apache/cassandra-sidecar/pull/347#discussion_r3244132731
########## server/src/main/java/org/apache/cassandra/sidecar/cdc/SidecarReplicationFactorSupplier.java: ########## @@ -0,0 +1,73 @@ +/* + * 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.cassandra.sidecar.cdc; + +import java.util.Comparator; +import java.util.Set; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.cassandra.cdc.api.CdcOptions; +import org.apache.cassandra.cdc.api.SchemaSupplier; +import org.apache.cassandra.cdc.sidecar.ReplicationFactorSupplier; +import org.apache.cassandra.cdc.sidecar.SidecarCommitLogProvider; +import org.apache.cassandra.spark.data.CqlTable; +import org.apache.cassandra.spark.data.ReplicationFactor; +import org.apache.cassandra.spark.utils.FutureUtils; + +/** + * {@link ReplicationFactorSupplier} implementation that reads the actual replication factor + * from Cassandra cluster metadata via {@link CdcOptions}, rather than using the default RF=1 + * SimpleStrategy fallback. Used by {@link SidecarCommitLogProvider} to build a correctly + * replicated {@link org.apache.cassandra.spark.data.partitioner.CassandraRing}. + */ +public class SidecarReplicationFactorSupplier implements ReplicationFactorSupplier +{ + private static final Logger LOGGER = LoggerFactory.getLogger(SidecarReplicationFactorSupplier.class); + private final CdcOptions cdcOptions; + private final SchemaSupplier schemaSupplier; + + public SidecarReplicationFactorSupplier(CdcOptions cdcOptions, SchemaSupplier schemaSupplier) + { + this.cdcOptions = cdcOptions; + this.schemaSupplier = schemaSupplier; + } + + @Override + public ReplicationFactor getReplicationFactor(String keyspace) + { + return cdcOptions.replicationFactor(keyspace); + } + + @Override + public ReplicationFactor getMaximalReplicationFactor() + { + String dc = cdcOptions.dc(); + Set<CqlTable> tables = FutureUtils.get(schemaSupplier.getCdcEnabledTables()); + return tables.stream() + .map(CqlTable::replicationFactor) + .filter(rf -> rf.getOptions().containsKey(dc)) + .max(Comparator.comparingInt(rf -> rf.getOptions().get(dc))) + .orElseGet(() -> { + LOGGER.warn("No CDC-enabled tables found for DC '{}'; falling back to RF=1 SimpleStrategy", dc); Review Comment: To be honest I have no clue. 😀 That's why I asked why it was here because I have no frame of reference to know if this is the right thing to do or not. If we try and get a maximal replication factor but straight up can't hit the system to pull it out, defaulting to the most permissive (RF=1) instead of the general default (RF=3) feels like a land-mine waiting to blow up in someone's face down the road doesn't it? `getMinimalReplicationFactor` defaulting to 1 I could see. But `getMaximalReplicationFactor` having a fallback to 1 feels... :suspect: @yifan-c - any chance you have any context here? -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
