squito commented on a change in pull request #25304:
[SPARK-28570][CORE][SHUFFLE] Make UnsafeShuffleWriter use the new API.
URL: https://github.com/apache/spark/pull/25304#discussion_r309011967
##########
File path:
core/src/main/java/org/apache/spark/shuffle/sort/UnsafeShuffleWriter.java
##########
@@ -316,102 +304,100 @@ void forceSorterToSpill() throws IOException {
// that doesn't need to interpret the spilled bytes.
if (transferToEnabled && !encryptionEnabled) {
logger.debug("Using transferTo-based fast merge");
- partitionLengths = mergeSpillsWithTransferTo(spills, outputFile);
+ partitionLengths = mergeSpillsWithTransferTo(spills, mapWriter);
} else {
logger.debug("Using fileStream-based fast merge");
- partitionLengths = mergeSpillsWithFileStream(spills, outputFile,
null);
+ partitionLengths = mergeSpillsWithFileStream(spills, mapWriter,
null);
}
} else {
logger.debug("Using slow merge");
- partitionLengths = mergeSpillsWithFileStream(spills, outputFile,
compressionCodec);
+ partitionLengths = mergeSpillsWithFileStream(spills, mapWriter,
compressionCodec);
}
// When closing an UnsafeShuffleExternalSorter that has already
spilled once but also has
// in-memory records, we write out the in-memory records to a file but
do not count that
// final write as bytes spilled (instead, it's accounted as shuffle
write). The merge needs
// to be counted as shuffle write, but this will lead to
double-counting of the final
// SpillInfo's bytes.
writeMetrics.decBytesWritten(spills[spills.length - 1].file.length());
- writeMetrics.incBytesWritten(outputFile.length());
return partitionLengths;
}
} catch (IOException e) {
- if (outputFile.exists() && !outputFile.delete()) {
- logger.error("Unable to delete output file {}", outputFile.getPath());
- }
throw e;
}
}
/**
* Merges spill files using Java FileStreams. This code path is typically
slower than
* the NIO-based merge, {@link
UnsafeShuffleWriter#mergeSpillsWithTransferTo(SpillInfo[],
- * File)}, and it's mostly used in cases where the IO compression codec does
not support
- * concatenation of compressed data, when encryption is enabled, or when
users have
- * explicitly disabled use of {@code transferTo} in order to work around
kernel bugs.
+ * ShuffleMapOutputWriter)}, and it's mostly used in cases where the IO
compression codec
+ * does not support concatenation of compressed data, when encryption is
enabled, or when
+ * users have explicitly disabled use of {@code transferTo} in order to work
around kernel bugs.
* This code path might also be faster in cases where individual partition
size in a spill
* is small and UnsafeShuffleWriter#mergeSpillsWithTransferTo method
performs many small
* disk ios which is inefficient. In those case, Using large buffers for
input and output
* files helps reducing the number of disk ios, making the file merging
faster.
*
* @param spills the spills to merge.
- * @param outputFile the file to write the merged data to.
+ * @param mapWriter the map output writer to use for output.
* @param compressionCodec the IO compression codec, or null if shuffle
compression is disabled.
* @return the partition lengths in the merged file.
*/
private long[] mergeSpillsWithFileStream(
SpillInfo[] spills,
- File outputFile,
+ ShuffleMapOutputWriter mapWriter,
@Nullable CompressionCodec compressionCodec) throws IOException {
- assert (spills.length >= 2);
final int numPartitions = partitioner.numPartitions();
final long[] partitionLengths = new long[numPartitions];
final InputStream[] spillInputStreams = new InputStream[spills.length];
- final OutputStream bos = new BufferedOutputStream(
- new FileOutputStream(outputFile),
- outputBufferSizeInBytes);
- // Use a counting output stream to avoid having to close the underlying
file and ask
- // the file system for its size after each partition is written.
- final CountingOutputStream mergedFileOutputStream = new
CountingOutputStream(bos);
-
boolean threwException = true;
try {
for (int i = 0; i < spills.length; i++) {
spillInputStreams[i] = new NioBufferedFileInputStream(
- spills[i].file,
- inputBufferSizeInBytes);
+ spills[i].file,
+ inputBufferSizeInBytes);
}
for (int partition = 0; partition < numPartitions; partition++) {
- final long initialFileLength = mergedFileOutputStream.getByteCount();
- // Shield the underlying output stream from close() and flush() calls,
so that we can close
- // the higher level streams to make sure all data is really flushed
and internal state is
- // cleaned.
- OutputStream partitionOutput = new CloseAndFlushShieldOutputStream(
- new TimeTrackingOutputStream(writeMetrics, mergedFileOutputStream));
- partitionOutput =
blockManager.serializerManager().wrapForEncryption(partitionOutput);
- if (compressionCodec != null) {
- partitionOutput =
compressionCodec.compressedOutputStream(partitionOutput);
- }
- for (int i = 0; i < spills.length; i++) {
- final long partitionLengthInSpill =
spills[i].partitionLengths[partition];
- if (partitionLengthInSpill > 0) {
- InputStream partitionInputStream = new
LimitedInputStream(spillInputStreams[i],
- partitionLengthInSpill, false);
- try {
- partitionInputStream =
blockManager.serializerManager().wrapForEncryption(
- partitionInputStream);
- if (compressionCodec != null) {
- partitionInputStream =
compressionCodec.compressedInputStream(partitionInputStream);
+ boolean copyThrewExecption = true;
+ ShufflePartitionWriter writer =
mapWriter.getPartitionWriter(partition);
+ OutputStream partitionOutput = writer.openStream();
+ try {
+ // Shield the underlying output stream from close() calls, so that
we can close the
+ // higher level streams to make sure all data is really flushed and
internal state
+ // is cleaned
Review comment:
comment doesn't belong here anymore -- you're not doing any shielding here,
its left to individual implementations to to do (as you do in
LocalDiskShuffleMapOutputWriter)
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