[HUDI-4488] Improve S3EventsHoodieIncrSource efficiency

hudi-utilities/src/main/java/org/apache/hudi/utilities/sources/S3EventsHoodieIncrSource.java

@@ -20,33 +20,41 @@
 
 import org.apache.hudi.DataSourceReadOptions;
 import org.apache.hudi.DataSourceUtils;
+import org.apache.hudi.common.config.SerializableConfiguration;
 import org.apache.hudi.common.config.TypedProperties;
 import org.apache.hudi.common.fs.FSUtils;
 import org.apache.hudi.common.model.HoodieRecord;
 import org.apache.hudi.common.util.Option;
 import org.apache.hudi.common.util.StringUtils;
 import org.apache.hudi.common.util.collection.Pair;
 import org.apache.hudi.exception.HoodieException;
+import org.apache.hudi.exception.HoodieIOException;
 import org.apache.hudi.utilities.schema.SchemaProvider;
 import org.apache.hudi.utilities.sources.helpers.IncrSourceHelper;
 
 import com.esotericsoftware.minlog.Log;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.log4j.LogManager;
 import org.apache.log4j.Logger;
 import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.api.java.function.MapPartitionsFunction;
 import org.apache.spark.sql.DataFrameReader;
 import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Encoders;
 import org.apache.spark.sql.Row;
 import org.apache.spark.sql.SparkSession;
 
 import java.io.IOException;
+import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 
 import static org.apache.hudi.utilities.sources.HoodieIncrSource.Config.DEFAULT_NUM_INSTANTS_PER_FETCH;
 import static org.apache.hudi.utilities.sources.HoodieIncrSource.Config.DEFAULT_READ_LATEST_INSTANT_ON_MISSING_CKPT;
@@ -172,37 +180,48 @@ public Pair<Option<Dataset<Row>>, String> fetchNextBatch(Option<String> lastCkpt
     String s3FS = props.getString(Config.S3_FS_PREFIX, "s3").toLowerCase();
     String s3Prefix = s3FS + "://";
 
-    // Extract distinct file keys from s3 meta hoodie table
-    final List<Row> cloudMetaDf = source
+    // Create S3 paths
+    final boolean checkExists = props.getBoolean(Config.ENABLE_EXISTS_CHECK, Config.DEFAULT_ENABLE_EXISTS_CHECK);
+    SerializableConfiguration serializableConfiguration = new SerializableConfiguration(sparkContext.hadoopConfiguration());
+    List<String> cloudFiles = source
         .filter(filter)
         .select("s3.bucket.name", "s3.object.key")
         .distinct()
-        .collectAsList();
-    // Create S3 paths
-    final boolean checkExists = props.getBoolean(Config.ENABLE_EXISTS_CHECK, Config.DEFAULT_ENABLE_EXISTS_CHECK);
-    List<String> cloudFiles = new ArrayList<>();
-    for (Row row : cloudMetaDf) {
-      // construct file path, row index 0 refers to bucket and 1 refers to key
-      String bucket = row.getString(0);
-      String filePath = s3Prefix + bucket + "/" + row.getString(1);
-      if (checkExists) {
-        FileSystem fs = FSUtils.getFs(s3Prefix + bucket, sparkSession.sparkContext().hadoopConfiguration());
-        try {
-          if (fs.exists(new Path(filePath))) {
-            cloudFiles.add(filePath);
-          }
-        } catch (IOException e) {
-          LOG.error(String.format("Error while checking path exists for %s ", filePath), e);
-        }
-      } else {
-        cloudFiles.add(filePath);
-      }
-    }
+        .mapPartitions((MapPartitionsFunction<Row, String>)  fileListIterator -> {
+          List<String> cloudFilesPerPartition = new ArrayList<>();
+          final Configuration configuration = serializableConfiguration.newCopy();
+          fileListIterator.forEachRemaining(row -> {
+            String bucket = row.getString(0);
+            String filePath = s3Prefix + bucket + "/" + row.getString(1);
+            String decodeUrl = null;
+            try {
+              decodeUrl = URLDecoder.decode(filePath, StandardCharsets.UTF_8.name());
+              if (checkExists) {
+                FileSystem fs = FSUtils.getFs(s3Prefix + bucket, configuration);
+                if (fs.exists(new Path(decodeUrl))) {
+                  cloudFilesPerPartition.add(decodeUrl);
+                }
+              } else {
+                cloudFilesPerPartition.add(decodeUrl);
+              }
+            } catch (IOException e) {
+              LOG.error(String.format("Error while checking path exists for %s ", decodeUrl), e);
+              throw new HoodieIOException(String.format("Error while checking path exists for %s ", decodeUrl), e);
+            } catch (Throwable e) {
+              LOG.warn("Failed to add cloud file ", e);
+              throw new HoodieException("Failed to add cloud file", e);
+            }
+          });
+          return cloudFilesPerPartition.iterator();
+        }, Encoders.STRING()).collectAsList();
+
     Option<Dataset<Row>> dataset = Option.empty();
     if (!cloudFiles.isEmpty()) {
       DataFrameReader dataFrameReader = getDataFrameReader(fileFormat);
       dataset = Option.of(dataFrameReader.load(cloudFiles.toArray(new String[0])));
     }
+    LOG.debug("Extracted distinct files " + cloudFiles.size()
+        + " and some samples " + cloudFiles.stream().limit(10).collect(Collectors.toList()));
     return Pair.of(dataset, queryTypeAndInstantEndpts.getRight().getRight());
   }
 }