taherk77 commented on a change in pull request #969: [HUDI-251] JDBC
incremental load to HUDI DeltaStreamer
URL: https://github.com/apache/incubator-hudi/pull/969#discussion_r340633807
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File path:
hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/JDBCSource.java
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@@ -0,0 +1,239 @@
+package org.apache.hudi.utilities.sources;
+
+import java.util.Arrays;
+import java.util.Set;
+import java.util.stream.Collectors;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.hudi.DataSourceUtils;
+import org.apache.hudi.common.util.Option;
+import org.apache.hudi.common.util.StringUtils;
+import org.apache.hudi.common.util.TypedProperties;
+import org.apache.hudi.common.util.collection.Pair;
+import org.apache.hudi.exception.HoodieException;
+import org.apache.hudi.utilities.schema.SchemaProvider;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.Column;
+import org.apache.spark.sql.DataFrameReader;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.SparkSession;
+import org.apache.spark.sql.functions;
+import org.apache.spark.sql.types.DataTypes;
+import org.jetbrains.annotations.NotNull;
+
+
+public class JDBCSource extends RowSource {
+
+ private static Logger LOG = LogManager.getLogger(JDBCSource.class);
+
+ public JDBCSource(TypedProperties props, JavaSparkContext sparkContext,
SparkSession sparkSession,
+ SchemaProvider schemaProvider) {
+ super(props, sparkContext, sparkSession, schemaProvider);
+ }
+
+ private static DataFrameReader validatePropsAndGetDataFrameReader(final
SparkSession session,
+ final TypedProperties properties)
+ throws HoodieException {
+ DataFrameReader dataFrameReader = null;
+ FSDataInputStream passwordFileStream = null;
+ try {
+ dataFrameReader = session.read().format("jdbc");
+ dataFrameReader = dataFrameReader.option(Config.URL_PROP,
properties.getString(Config.URL));
+ dataFrameReader = dataFrameReader.option(Config.USER_PROP,
properties.getString(Config.USER));
+ dataFrameReader = dataFrameReader.option(Config.DRIVER_PROP,
properties.getString(Config.DRIVER_CLASS));
+ dataFrameReader = dataFrameReader
+ .option(Config.RDBMS_TABLE_PROP,
properties.getString(Config.RDBMS_TABLE_NAME));
+
+ if (properties.containsKey(Config.PASSWORD) && !StringUtils
+ .isNullOrEmpty(properties.getString(Config.PASSWORD))) {
+ LOG.info("Reading JDBC password from properties file....");
+ dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP,
properties.getString(Config.PASSWORD));
+ } else if (properties.containsKey(Config.PASSWORD_FILE) && !StringUtils
+ .isNullOrEmpty(properties.getString(Config.PASSWORD_FILE))) {
+ LOG.info(
+ String.format("Reading JDBC password from password file %s",
properties.getString(Config.PASSWORD_FILE)));
+ FileSystem fileSystem = FileSystem.get(new Configuration());
+ passwordFileStream = fileSystem.open(new
Path(properties.getString(Config.PASSWORD_FILE)));
+ byte[] bytes = new byte[passwordFileStream.available()];
+ passwordFileStream.read(bytes);
+ dataFrameReader = dataFrameReader.option(Config.PASSWORD_PROP, new
String(bytes));
+ } else {
+ throw new IllegalArgumentException(String.format("JDBCSource needs
either a %s or %s to connect to RDBMS "
+ + "datasource", Config.PASSWORD_FILE, Config.PASSWORD));
+ }
+
+ addExtraJdbcOptions(properties, dataFrameReader);
+
+ if (properties.getBoolean(Config.IS_INCREMENTAL)) {
+ DataSourceUtils.checkRequiredProperties(properties,
Arrays.asList(Config.INCREMENTAL_COLUMN));
+ }
+ return dataFrameReader;
+ } catch (Exception e) {
+ throw new HoodieException(e);
+ } finally {
+ IOUtils.closeStream(passwordFileStream);
+ }
+ }
+
+ private static void addExtraJdbcOptions(TypedProperties properties,
DataFrameReader dataFrameReader) {
+ Set<Object> objects = properties.keySet();
+ for (Object property : objects) {
+ String prop = (String) property;
+ if (prop.startsWith(Config.EXTRA_OPTIONS)) {
+ String key = Arrays.asList(prop.split(Config.EXTRA_OPTIONS)).stream()
+ .collect(Collectors.joining());
+ String value = properties.getString(prop);
+ if (!StringUtils.isNullOrEmpty(value)) {
+ LOG.info(String.format("Adding %s -> %s to jdbc options", key,
value));
+ dataFrameReader.option(key, value);
+ } else {
+ LOG.warn(String.format("Skipping %s jdbc option as value is null or
empty", key));
+ }
+ }
+ }
+ }
+
+ @Override
+ protected Pair<Option<Dataset<Row>>, String> fetchNextBatch(Option<String>
lastCkptStr, long sourceLimit) {
+ try {
+ DataSourceUtils.checkRequiredProperties(props, Arrays.asList(Config.URL,
Config.DRIVER_CLASS, Config.USER,
+ Config.RDBMS_TABLE_NAME, Config.IS_INCREMENTAL));
+ Option<String> lastCheckpoint =
+ lastCkptStr.isPresent() ? lastCkptStr.get().isEmpty() ?
Option.empty() : lastCkptStr : Option.empty();
+ return fetch(lastCheckpoint);
+ } catch (Exception e) {
+ LOG.error("Exception while running JDBCSource ", e);
+ return Pair.of(Option.empty(), null);
+ }
+ }
+
+ @NotNull
+ private Pair<Option<Dataset<Row>>, String> fetch(Option<String>
lastCheckpoint) {
+ Dataset<Row> dataset;
+ boolean isIncremental = props.getBoolean(Config.IS_INCREMENTAL);
+ if (lastCheckpoint.equals(Option.empty()) ||
StringUtils.isNullOrEmpty(lastCheckpoint.get())) {
+ LOG.info("No checkpoint references found... Doing a full rdbms table
fetch");
+ dataset = fullFetch();
+ } else {
+ dataset = incrementalFetch(lastCheckpoint);
+ }
+ return Pair.of(Option.of(dataset), checkpoint(dataset, isIncremental));
+ }
+
+ @NotNull
+ private Dataset<Row> incrementalFetch(Option<String> lastCheckpoint) {
+ try {
+ final String ppdQuery = "(select * from %s where %s >= \"%s\")
rdbms_table";
+ String query = String
+ .format(ppdQuery, props.getString(Config.RDBMS_TABLE_NAME),
props.getString(Config.INCREMENTAL_COLUMN),
+ lastCheckpoint.get());
+ LOG.info(String
+ .format("Referenced last checkpoint and prepared new predicate
pushdown query for jdbc pull %s", query));
+ return validatePropsAndGetDataFrameReader(sparkSession, props)
+ .option(Config.RDBMS_TABLE_PROP, query).load();
+ } catch (Exception e) {
+ LOG.error("Error while performing an incremental fetch... \n Note: Not
all database support the PPD query we "
+ + "generate to do na incremental scan", e);
+ LOG.warn("Falling back to full scan.......");
+ return fullFetch();
+ }
+ }
+
+ private Dataset<Row> fullFetch() {
+ return validatePropsAndGetDataFrameReader(sparkSession, props).load();
+ }
+
+ private String checkpoint(Dataset<Row> rowDataset, boolean isIncremental) {
+ try {
+ if (isIncremental) {
+ Column incrementalColumn =
rowDataset.col(props.getString(Config.INCREMENTAL_COLUMN));
+ final String max =
rowDataset.agg(functions.max(incrementalColumn).cast(DataTypes.StringType)).first()
Review comment:
Sure for now should we cache in the fetch() method, get the max of
checkpointing, uncache and then return the df?
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