echauchot commented on code in PR #3: URL: https://github.com/apache/flink-connector-cassandra/pull/3#discussion_r1073554806
########## flink-connector-cassandra/src/main/java/org/apache/flink/connector/cassandra/source/split/SplitsGenerator.java: ########## @@ -0,0 +1,209 @@ +/* + * 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.flink.connector.cassandra.source.split; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.math.BigInteger; +import java.util.ArrayList; +import java.util.Collections; +import java.util.HashSet; +import java.util.List; + +/** + * This class generates {@link CassandraSplit}s by generating {@link RingRange}s based on Cassandra + * cluster partitioner and Flink source parallelism. + */ +public final class SplitsGenerator { + private static final Logger LOG = LoggerFactory.getLogger(SplitsGenerator.class); + + private final String partitioner; + private final BigInteger rangeMin; + private final BigInteger rangeMax; + private final BigInteger rangeSize; + + public SplitsGenerator(String partitioner) { + this.partitioner = partitioner; + rangeMin = getRangeMin(); + rangeMax = getRangeMax(); + rangeSize = getRangeSize(); + } + + private BigInteger getRangeMin() { + if (partitioner.endsWith("RandomPartitioner")) { + return BigInteger.ZERO; + } else if (partitioner.endsWith("Murmur3Partitioner")) { + return BigInteger.valueOf(2).pow(63).negate(); + } else { + throw new UnsupportedOperationException( + "Unsupported partitioner. " + "Only Random and Murmur3 are supported"); + } + } + + private BigInteger getRangeMax() { + if (partitioner.endsWith("RandomPartitioner")) { + return BigInteger.valueOf(2).pow(127).subtract(BigInteger.ONE); + } else if (partitioner.endsWith("Murmur3Partitioner")) { + return BigInteger.valueOf(2).pow(63).subtract(BigInteger.ONE); + } else { + throw new UnsupportedOperationException( + "Unsupported partitioner. " + "Only Random and Murmur3 are supported"); + } + } + + private BigInteger getRangeSize() { + return rangeMax.subtract(rangeMin).add(BigInteger.ONE); + } + + /** + * Given properly ordered list of Cassandra tokens, compute at least {@code totalSplitCount} + * splits. Each split can contain several token ranges in order to reduce the overhead of + * Cassandra vnodes. Currently, token range grouping is not smart and doesn't check if they + * share the same replicas. + * + * @param totalSplitCount requested total amount of splits. This function may generate more + * splits. + * @param ringTokens list of all start tokens in Cassandra cluster. They have to be in ring + * order. + * @return list containing at least {@code totalSplitCount} CassandraSplits. + */ + public List<CassandraSplit> generateSplits(long totalSplitCount, List<BigInteger> ringTokens) { + if (totalSplitCount == 1) { + RingRange totalRingRange = RingRange.of(rangeMin, rangeMax); + return Collections.singletonList( + new CassandraSplit(Collections.singleton(totalRingRange))); + } + int tokenRangeCount = ringTokens.size(); + + List<RingRange> ringRanges = new ArrayList<>(); + for (int i = 0; i < tokenRangeCount; i++) { + BigInteger start = ringTokens.get(i); + BigInteger stop = ringTokens.get((i + 1) % tokenRangeCount); + + if (isNotInRange(start) || isNotInRange(stop)) { + throw new RuntimeException( + String.format( + "Tokens (%s,%s) not in range of %s", start, stop, partitioner)); + } + if (start.equals(stop) && tokenRangeCount != 1) { + throw new RuntimeException( + String.format( + "Tokens (%s,%s): two nodes have the same token", start, stop)); + } + + BigInteger rangeSize = stop.subtract(start); + if (rangeSize.compareTo(BigInteger.ZERO) <= 0) { + // wrap around case + rangeSize = rangeSize.add(this.rangeSize); + } Review Comment: See my general comments about Apache Beam Cassandra partitionner ########## flink-connector-cassandra/src/main/java/org/apache/flink/connector/cassandra/source/split/SplitsGenerator.java: ########## @@ -0,0 +1,209 @@ +/* + * 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.flink.connector.cassandra.source.split; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.math.BigInteger; +import java.util.ArrayList; +import java.util.Collections; +import java.util.HashSet; +import java.util.List; + +/** + * This class generates {@link CassandraSplit}s by generating {@link RingRange}s based on Cassandra + * cluster partitioner and Flink source parallelism. + */ +public final class SplitsGenerator { + private static final Logger LOG = LoggerFactory.getLogger(SplitsGenerator.class); + + private final String partitioner; + private final BigInteger rangeMin; + private final BigInteger rangeMax; + private final BigInteger rangeSize; + + public SplitsGenerator(String partitioner) { + this.partitioner = partitioner; + rangeMin = getRangeMin(); + rangeMax = getRangeMax(); + rangeSize = getRangeSize(); + } + + private BigInteger getRangeMin() { + if (partitioner.endsWith("RandomPartitioner")) { + return BigInteger.ZERO; + } else if (partitioner.endsWith("Murmur3Partitioner")) { + return BigInteger.valueOf(2).pow(63).negate(); + } else { + throw new UnsupportedOperationException( + "Unsupported partitioner. " + "Only Random and Murmur3 are supported"); + } + } + + private BigInteger getRangeMax() { + if (partitioner.endsWith("RandomPartitioner")) { + return BigInteger.valueOf(2).pow(127).subtract(BigInteger.ONE); + } else if (partitioner.endsWith("Murmur3Partitioner")) { + return BigInteger.valueOf(2).pow(63).subtract(BigInteger.ONE); + } else { + throw new UnsupportedOperationException( + "Unsupported partitioner. " + "Only Random and Murmur3 are supported"); + } + } + + private BigInteger getRangeSize() { + return rangeMax.subtract(rangeMin).add(BigInteger.ONE); + } + + /** + * Given properly ordered list of Cassandra tokens, compute at least {@code totalSplitCount} + * splits. Each split can contain several token ranges in order to reduce the overhead of + * Cassandra vnodes. Currently, token range grouping is not smart and doesn't check if they + * share the same replicas. + * + * @param totalSplitCount requested total amount of splits. This function may generate more + * splits. + * @param ringTokens list of all start tokens in Cassandra cluster. They have to be in ring + * order. + * @return list containing at least {@code totalSplitCount} CassandraSplits. + */ + public List<CassandraSplit> generateSplits(long totalSplitCount, List<BigInteger> ringTokens) { + if (totalSplitCount == 1) { + RingRange totalRingRange = RingRange.of(rangeMin, rangeMax); + return Collections.singletonList( + new CassandraSplit(Collections.singleton(totalRingRange))); + } + int tokenRangeCount = ringTokens.size(); + + List<RingRange> ringRanges = new ArrayList<>(); + for (int i = 0; i < tokenRangeCount; i++) { + BigInteger start = ringTokens.get(i); + BigInteger stop = ringTokens.get((i + 1) % tokenRangeCount); + + if (isNotInRange(start) || isNotInRange(stop)) { + throw new RuntimeException( + String.format( + "Tokens (%s,%s) not in range of %s", start, stop, partitioner)); + } + if (start.equals(stop) && tokenRangeCount != 1) { + throw new RuntimeException( + String.format( + "Tokens (%s,%s): two nodes have the same token", start, stop)); + } + + BigInteger rangeSize = stop.subtract(start); + if (rangeSize.compareTo(BigInteger.ZERO) <= 0) { + // wrap around case + rangeSize = rangeSize.add(this.rangeSize); + } + + // the below, in essence, does this: + // splitCount = Maths.ceil((rangeSize / cluster range size) * totalSplitCount) Review Comment: See my general comments about Apache Beam Cassandra partitionner ########## flink-connector-cassandra/src/main/java/org/apache/flink/connector/cassandra/source/split/SplitsGenerator.java: ########## @@ -0,0 +1,209 @@ +/* + * 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.flink.connector.cassandra.source.split; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.math.BigInteger; +import java.util.ArrayList; +import java.util.Collections; +import java.util.HashSet; +import java.util.List; + +/** + * This class generates {@link CassandraSplit}s by generating {@link RingRange}s based on Cassandra + * cluster partitioner and Flink source parallelism. + */ +public final class SplitsGenerator { + private static final Logger LOG = LoggerFactory.getLogger(SplitsGenerator.class); + + private final String partitioner; + private final BigInteger rangeMin; + private final BigInteger rangeMax; + private final BigInteger rangeSize; + + public SplitsGenerator(String partitioner) { + this.partitioner = partitioner; + rangeMin = getRangeMin(); + rangeMax = getRangeMax(); + rangeSize = getRangeSize(); + } + + private BigInteger getRangeMin() { + if (partitioner.endsWith("RandomPartitioner")) { + return BigInteger.ZERO; + } else if (partitioner.endsWith("Murmur3Partitioner")) { + return BigInteger.valueOf(2).pow(63).negate(); + } else { + throw new UnsupportedOperationException( + "Unsupported partitioner. " + "Only Random and Murmur3 are supported"); + } + } + + private BigInteger getRangeMax() { + if (partitioner.endsWith("RandomPartitioner")) { + return BigInteger.valueOf(2).pow(127).subtract(BigInteger.ONE); + } else if (partitioner.endsWith("Murmur3Partitioner")) { + return BigInteger.valueOf(2).pow(63).subtract(BigInteger.ONE); + } else { + throw new UnsupportedOperationException( + "Unsupported partitioner. " + "Only Random and Murmur3 are supported"); + } + } + + private BigInteger getRangeSize() { + return rangeMax.subtract(rangeMin).add(BigInteger.ONE); + } + + /** + * Given properly ordered list of Cassandra tokens, compute at least {@code totalSplitCount} + * splits. Each split can contain several token ranges in order to reduce the overhead of + * Cassandra vnodes. Currently, token range grouping is not smart and doesn't check if they + * share the same replicas. + * + * @param totalSplitCount requested total amount of splits. This function may generate more + * splits. + * @param ringTokens list of all start tokens in Cassandra cluster. They have to be in ring + * order. + * @return list containing at least {@code totalSplitCount} CassandraSplits. + */ + public List<CassandraSplit> generateSplits(long totalSplitCount, List<BigInteger> ringTokens) { + if (totalSplitCount == 1) { + RingRange totalRingRange = RingRange.of(rangeMin, rangeMax); + return Collections.singletonList( + new CassandraSplit(Collections.singleton(totalRingRange))); + } + int tokenRangeCount = ringTokens.size(); + + List<RingRange> ringRanges = new ArrayList<>(); + for (int i = 0; i < tokenRangeCount; i++) { + BigInteger start = ringTokens.get(i); + BigInteger stop = ringTokens.get((i + 1) % tokenRangeCount); + + if (isNotInRange(start) || isNotInRange(stop)) { + throw new RuntimeException( + String.format( + "Tokens (%s,%s) not in range of %s", start, stop, partitioner)); + } + if (start.equals(stop) && tokenRangeCount != 1) { + throw new RuntimeException( + String.format( + "Tokens (%s,%s): two nodes have the same token", start, stop)); + } + + BigInteger rangeSize = stop.subtract(start); + if (rangeSize.compareTo(BigInteger.ZERO) <= 0) { + // wrap around case + rangeSize = rangeSize.add(this.rangeSize); + } + + // the below, in essence, does this: + // splitCount = Maths.ceil((rangeSize / cluster range size) * totalSplitCount) + BigInteger[] splitCountAndRemainder = + rangeSize + .multiply(BigInteger.valueOf(totalSplitCount)) + .divideAndRemainder(this.rangeSize); + + int splitCount = + splitCountAndRemainder[0].intValue() + + (splitCountAndRemainder[1].equals(BigInteger.ZERO) ? 0 : 1); + + LOG.debug("Dividing token range [{},{}) into {} splits", start, stop, splitCount); + + // Make BigInteger list of all the endpoints for the splits, including both start and + // stop + List<BigInteger> endpointTokens = new ArrayList<>(); + for (int j = 0; j <= splitCount; j++) { + BigInteger offset = + rangeSize + .multiply(BigInteger.valueOf(j)) + .divide(BigInteger.valueOf(splitCount)); + BigInteger token = start.add(offset); + if (token.compareTo(rangeMax) > 0) { + token = token.subtract(this.rangeSize); + } + // Long.MIN_VALUE is not a valid token and has to be silently incremented. + // See https://issues.apache.org/jira/browse/CASSANDRA-14684 + endpointTokens.add( + token.equals(BigInteger.valueOf(Long.MIN_VALUE)) + ? token.add(BigInteger.ONE) + : token); + } + + // Append the ringRanges between the endpoints + for (int j = 0; j < splitCount; j++) { + ringRanges.add(RingRange.of(endpointTokens.get(j), endpointTokens.get(j + 1))); + LOG.debug( + "Split #{}: [{},{})", + j + 1, + endpointTokens.get(j), + endpointTokens.get(j + 1)); + } + } + + BigInteger total = BigInteger.ZERO; + for (RingRange split : ringRanges) { + BigInteger size = split.span(rangeSize); + total = total.add(size); + } + if (!total.equals(rangeSize)) { + throw new RuntimeException( + "Some tokens are missing from the splits. This should not happen."); + } + return coalesceRingRanges(getTargetSplitSize(totalSplitCount), ringRanges); + } + + private boolean isNotInRange(BigInteger token) { + return token.compareTo(rangeMin) < 0 || token.compareTo(rangeMax) > 0; + } + + private List<CassandraSplit> coalesceRingRanges( + BigInteger targetSplitSize, List<RingRange> ringRanges) { + List<CassandraSplit> coalescedSplits = new ArrayList<>(); + List<RingRange> tokenRangesForCurrentSplit = new ArrayList<>(); + BigInteger tokenCount = BigInteger.ZERO; + + for (RingRange tokenRange : ringRanges) { + if (tokenRange.span(rangeSize).add(tokenCount).compareTo(targetSplitSize) > 0 + && !tokenRangesForCurrentSplit.isEmpty()) { + // enough tokens in that segment Review Comment: See my general comments about Apache Beam Cassandra partitionner -- 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. 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