snuyanzin commented on code in PR #235: URL: https://github.com/apache/flink-connector-jdbc/pull/235#discussion_r4065783599
########## flink-connector-jdbc-core/src/test/java/org/apache/flink/connector/jdbc/core/datastream/source/JdbcSourceTest.java: ########## @@ -0,0 +1,111 @@ +/* + * 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.jdbc.core.datastream.source; + +import org.apache.flink.api.common.typeinfo.TypeInformation; +import org.apache.flink.connector.base.source.reader.RecordsWithSplitIds; +import org.apache.flink.connector.base.source.reader.splitreader.SplitReader; +import org.apache.flink.connector.base.source.reader.splitreader.SplitsAddition; +import org.apache.flink.connector.jdbc.JdbcDataTestBase; +import org.apache.flink.connector.jdbc.core.datastream.source.reader.JdbcSourceSplitReader; +import org.apache.flink.connector.jdbc.core.datastream.source.reader.RecordAndOffset; +import org.apache.flink.connector.jdbc.core.datastream.source.split.JdbcSourceSplit; +import org.apache.flink.connector.testutils.source.reader.TestingReaderContext; + +import org.junit.jupiter.api.Test; + +import java.util.ArrayList; +import java.util.Collections; +import java.util.List; +import java.util.function.Supplier; + +import static org.apache.flink.connector.jdbc.JdbcTestFixture.INPUT_TABLE; +import static org.apache.flink.connector.jdbc.JdbcTestFixture.TEST_DATA; +import static org.apache.flink.connector.jdbc.JdbcTestFixture.TestEntry; +import static org.assertj.core.api.Assertions.assertThat; + +/** Test for {@link JdbcSource}. */ +class JdbcSourceTest extends JdbcDataTestBase { + + private static final String SQL = "select id, title, author, price, qty from " + INPUT_TABLE; + + @Test + void testSplitReadersDoNotShareAConnection() throws Exception { + // flink-connector-base builds a split reader per split fetcher and closes the reader of a + // finished split while the reader of the next split is already reading. A connection + // provider holds a single connection and is not thread safe, so every split reader needs + // its own: sharing one lets the finished reader close the running reader's result set. + JdbcSource<TestEntry> source = + JdbcSource.<TestEntry>builder() + .setTypeInformation(TypeInformation.of(TestEntry.class)) + .setSql(SQL) + .setDBUrl(getMetadata().getJdbcUrl()) + .setDriverName(getMetadata().getDriverClass()) + .setResultExtractor(extractor) + // One record per fetch, so the running reader still has an open result set + // when the finished one is closed. + .setSplitReaderFetchBatchSize(1) + .build(); + + Supplier<SplitReader<RecordAndOffset<TestEntry>, JdbcSourceSplit>> supplier = + source.splitReaderSupplier(new TestingReaderContext()); + + JdbcSourceSplitReader<TestEntry> finishedSplitReader = newSplitReader(supplier, "1"); + JdbcSourceSplitReader<TestEntry> runningSplitReader = newSplitReader(supplier, "2"); + + // The first fetch on each opens its result set, which is what establishes its connection. + drain(finishedSplitReader.fetch()); + List<TestEntry> records = new ArrayList<>(drain(runningSplitReader.fetch())); + + finishedSplitReader.close(); + + // The finished reader is gone; the running one must still read its split to the end. + // One record per fetch, so the remaining count is exactly the number of fetches left. + for (int i = records.size(); i < TEST_DATA.length; i++) { + records.addAll(drain(runningSplitReader.fetch())); + } + runningSplitReader.close(); + assertThat(records).containsExactlyInAnyOrder(TEST_DATA); + } + + @SuppressWarnings("unchecked") + private static JdbcSourceSplitReader<TestEntry> newSplitReader( + Supplier<SplitReader<RecordAndOffset<TestEntry>, JdbcSourceSplit>> supplier, + String splitId) { + JdbcSourceSplitReader<TestEntry> splitReader = + (JdbcSourceSplitReader<TestEntry>) supplier.get(); + splitReader.handleSplitsChanges( + new SplitsAddition<>( + Collections.singletonList(new JdbcSourceSplit(splitId, SQL, null, null)))); Review Comment: ```suggestion List.of(new JdbcSourceSplit(splitId, SQL, null, null)))); ``` -- This is an automated message from the Apache Git Service. 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