[HUDI-1425] Performance loss with the additional hoodieRecords.isEmpty() in HoodieSparkSqlWriter#write (#2296)

hudi-client/hudi-client-common/src/main/java/org/apache/hudi/client/AbstractHoodieWriteClient.java

@@ -172,6 +172,11 @@ public abstract class AbstractHoodieWriteClient<T extends HoodieRecordPayload, I
 
   public boolean commitStats(String instantTime, List<HoodieWriteStat> stats, Option<Map<String, String>> extraMetadata,
                              String commitActionType, Map<String, List<String>> partitionToReplaceFileIds) {
+    // Skip the empty commit if not allowed
+    if (!config.allowEmptyCommit() && stats.isEmpty()) {
+      return true;
+    }
+    LOG.info("Committing " + instantTime + " action " + commitActionType);
     // Create a Hoodie table which encapsulated the commits and files visible
     HoodieTable table = createTable(config, hadoopConf);
     HoodieCommitMetadata metadata = CommitUtils.buildMetadata(stats, partitionToReplaceFileIds,

hudi-client/hudi-client-common/src/main/java/org/apache/hudi/config/HoodieWriteConfig.java

@@ -367,6 +367,12 @@ public class HoodieWriteConfig extends HoodieConfig {
       .withDocumentation("When enabled, records in older schema are rewritten into newer schema during upsert,delete and background"
           + " compaction,clustering operations.");
 
+  public static final ConfigProperty<Boolean> ALLOW_EMPTY_COMMIT = ConfigProperty
+       .key("hoodie.allow.empty.commit")
+       .defaultValue(true)
+       .withDocumentation("Whether to allow generation of empty commits, even if no data was written in the commit. "
+          + "It's useful in cases where extra metadata needs to be published regardless e.g tracking source offsets when ingesting data");
+
   private ConsistencyGuardConfig consistencyGuardConfig;
 
   // Hoodie Write Client transparently rewrites File System View config when embedded mode is enabled
@@ -1275,6 +1281,10 @@ public class HoodieWriteConfig extends HoodieConfig {
     return getString(WRITE_META_KEY_PREFIXES_PROP);
   }
 
+  public boolean allowEmptyCommit() {
+    return getBooleanOrDefault(ALLOW_EMPTY_COMMIT);
+  }
+
   public static class Builder {
 
     protected final HoodieWriteConfig writeConfig = new HoodieWriteConfig();