2PC and staging output

native/core/src/execution/operators/parquet_writer.rs

@@ -202,6 +202,9 @@ pub struct ParquetWriterExec {
     job_id: Option<String>,
     /// Task attempt ID for this specific task
     task_attempt_id: Option<i32>,
+    /// Complete staging file path from FileCommitProtocol.newTaskTempFile()
+    /// When set, writes directly to this path for proper 2PC support
+    staging_file_path: Option<String>,
     /// Compression codec
     compression: CompressionCodec,
     /// Partition ID (from Spark TaskContext)
@@ -225,6 +228,7 @@ impl ParquetWriterExec {
         work_dir: String,
         job_id: Option<String>,
         task_attempt_id: Option<i32>,
+        staging_file_path: Option<String>,
         compression: CompressionCodec,
         partition_id: i32,
         column_names: Vec<String>,
@@ -246,6 +250,7 @@ impl ParquetWriterExec {
             work_dir,
             job_id,
             task_attempt_id,
+            staging_file_path,
             compression,
             partition_id,
             column_names,
@@ -439,6 +444,7 @@ impl ExecutionPlan for ParquetWriterExec {
                 self.work_dir.clone(),
                 self.job_id.clone(),
                 self.task_attempt_id,
+                self.staging_file_path.clone(),
                 self.compression.clone(),
                 self.partition_id,
                 self.column_names.clone(),
@@ -465,7 +471,9 @@ impl ExecutionPlan for ParquetWriterExec {
         let runtime_env = context.runtime_env();
         let input = self.input.execute(partition, context)?;
         let input_schema = self.input.schema();
+        let output_path = self.output_path.clone();
         let work_dir = self.work_dir.clone();
+        let staging_file_path = self.staging_file_path.clone();
         let task_attempt_id = self.task_attempt_id;
         let compression = self.compression_to_parquet()?;
         let column_names = self.column_names.clone();
@@ -481,15 +489,25 @@ impl ExecutionPlan for ParquetWriterExec {
             .collect();
         let output_schema = Arc::new(arrow::datatypes::Schema::new(fields));
 
-        // Generate part file name for this partition
-        // If using FileCommitProtocol (work_dir is set), include task_attempt_id in the filename
-        let part_file = if let Some(attempt_id) = task_attempt_id {
+        // Determine output file path:
+        // 1. If staging_file_path is set (proper 2PC), use it directly
+        // 2. If work_dir is set, use work_dir-based path construction
+        // 3. Otherwise use output_path directly
+        let base_dir = if !work_dir.is_empty() {
+            work_dir
+        } else {
+            output_path
+        };
+
+        let part_file = if let Some(ref staging_path) = staging_file_path {
+            staging_path.clone()
+        } else if let Some(attempt_id) = task_attempt_id {
             format!(
                 "{}/part-{:05}-{:05}.parquet",
-                work_dir, self.partition_id, attempt_id
+                base_dir, self.partition_id, attempt_id
             )
         } else {
-            format!("{}/part-{:05}.parquet", work_dir, self.partition_id)
+            format!("{}/part-{:05}.parquet", base_dir, self.partition_id)
         };
 
         // Configure writer properties
@@ -824,6 +842,7 @@ mod tests {
             work_dir,
             None,      // job_id
             Some(123), // task_attempt_id
+            None,      // staging_file_path
             CompressionCodec::None,
             0, // partition_id
             column_names,

native/core/src/execution/planner.rs

@@ -1573,13 +1573,10 @@ impl PhysicalPlanner {
                 let parquet_writer = Arc::new(ParquetWriterExec::try_new(
                     Arc::clone(&child.native_plan),
                     writer.output_path.clone(),
-                    writer
-                        .work_dir
-                        .as_ref()
-                        .expect("work_dir is provided")
-                        .clone(),
+                    writer.work_dir.clone().unwrap_or_default(),
                     writer.job_id.clone(),
                     writer.task_attempt_id,
+                    writer.staging_file_path.clone(),
                     codec,
                     self.partition,
                     writer.column_names.clone(),

native/proto/src/proto/operator.proto

@@ -328,7 +328,7 @@ message ParquetWriter {
   CompressionCodec compression = 2;
   repeated string column_names = 4;
   // Working directory for temporary files (used by FileCommitProtocol)
-  // If not set, files are written directly to output_path
+  // DEPRECATED: Use staging_file_path instead for proper 2PC support
   optional string work_dir = 5;
   // Job ID for tracking this write operation
   optional string job_id = 6;
@@ -341,6 +341,9 @@ message ParquetWriter {
   // configuration value "spark.hadoop.fs.s3a.access.key" will be stored as "fs.s3a.access.key" in
   // the map.
   map<string, string> object_store_options = 8;
+  // Complete staging file path from FileCommitProtocol.newTaskTempFile()
+  // When set, native writer writes directly to this path for proper 2PC
+  optional string staging_file_path = 9;
 }
 
 enum AggregateMode {

spark/src/main/scala/org/apache/comet/serde/operator/CometDataWritingCommand.scala

@@ -24,7 +24,6 @@ import java.util.Locale
 
 import scala.jdk.CollectionConverters._
 
-import org.apache.spark.SparkException
 import org.apache.spark.sql.comet.{CometNativeExec, CometNativeWriteExec}
 import org.apache.spark.sql.execution.command.DataWritingCommandExec
 import org.apache.spark.sql.execution.datasources.{InsertIntoHadoopFsRelationCommand, WriteFilesExec}
@@ -179,29 +178,13 @@ object CometDataWritingCommand extends CometOperatorSerde[DataWritingCommandExec
         other
     }
 
-    // Create FileCommitProtocol for atomic writes
-    val jobId = java.util.UUID.randomUUID().toString
-    val committer =
-      try {
-        // Use Spark's SQLHadoopMapReduceCommitProtocol
-        val committerClass =
-          classOf[org.apache.spark.sql.execution.datasources.SQLHadoopMapReduceCommitProtocol]
-        val constructor =
-          committerClass.getConstructor(classOf[String], classOf[String], classOf[Boolean])
-        Some(
-          constructor
-            .newInstance(
-              jobId,
-              outputPath,
-              java.lang.Boolean.FALSE // dynamicPartitionOverwrite = false for now
-            )
-            .asInstanceOf[org.apache.spark.internal.io.FileCommitProtocol])
-      } catch {
-        case e: Exception =>
-          throw new SparkException(s"Could not instantiate FileCommitProtocol: ${e.getMessage}")
-      }
-
-    CometNativeWriteExec(nativeOp, childPlan, outputPath, committer, jobId)
+    // Note: We don't create our own FileCommitProtocol here because:
+    // 1. InsertIntoHadoopFsRelationCommand creates and manages its own committer
+    // 2. That committer is passed to FileFormatWriter which handles the commit flow
+    // 3. Our CometNativeWriteExec child is only used for data, not commit protocol
+    // The native writer writes directly to the output path, relying on Spark's
+    // existing commit protocol for atomicity.
+    CometNativeWriteExec(nativeOp, childPlan, outputPath)
   }
 
   private def parseCompressionCodec(cmd: InsertIntoHadoopFsRelationCommand) = {