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Posted to dev@drill.apache.org by GitBox <gi...@apache.org> on 2022/02/17 15:03:50 UTC
[GitHub] [drill] vdiravka commented on a change in pull request #2463: DRILL-8139: Data corruption and occasional segfaults querying Parquet/gzip under the async column reader and sync page reader
vdiravka commented on a change in pull request #2463:
URL: https://github.com/apache/drill/pull/2463#discussion_r809090421
##########
File path: exec/java-exec/src/main/java/org/apache/drill/exec/store/parquet/compression/AirliftBytesInputCompressor.java
##########
@@ -159,13 +160,13 @@ public void decompress(ByteBuffer input, int compressedSize, ByteBuffer output,
@Override
public void release() {
- logger.debug(
- "will release {} allocated buffers.",
- this.allocatedBuffers.size()
- );
+ int bufCount = allocatedBuffers.size();
- while (!this.allocatedBuffers.isEmpty()) {
- this.allocator.release(allocatedBuffers.pop());
+ // LIFO release order to try to reduce memory fragmentation.
+ while (!allocatedBuffers.isEmpty()) {
+ allocator.release(allocatedBuffers.pop());
}
+
+ logger.debug("released {} allocated buffers", bufCount);
Review comment:
We possibly can assert or log the actual `allocatedBuffers.size()` to make sure allocated buffers are released
##########
File path: exec/java-exec/src/main/java/org/apache/drill/exec/store/parquet/compression/DrillCompressionCodecFactory.java
##########
@@ -50,17 +52,31 @@
// The set of codecs to be handled by aircompressor
private static final Set<CompressionCodecName> AIRCOMPRESSOR_CODECS = new HashSet<>(
- Arrays.asList(CompressionCodecName.LZ4, CompressionCodecName.LZO,
- CompressionCodecName.SNAPPY, CompressionCodecName.ZSTD));
+ Arrays.asList(
+ CompressionCodecName.LZ4,
+ CompressionCodecName.LZO,
+ CompressionCodecName.SNAPPY,
+ CompressionCodecName.ZSTD
+ )
+ );
- // pool of reused aircompressor compressors (parquet-mr's factory has its own)
+ // pool of reusable thread-safe aircompressor compressors (parquet-mr's factory
Review comment:
```suggestion
// pool of reusable thread-safe aircompressor compressors (parquet-mr's factory has its own)
```
##########
File path: exec/java-exec/src/main/java/org/apache/drill/exec/store/parquet/compression/DrillCompressionCodecFactory.java
##########
@@ -50,17 +52,31 @@
// The set of codecs to be handled by aircompressor
private static final Set<CompressionCodecName> AIRCOMPRESSOR_CODECS = new HashSet<>(
- Arrays.asList(CompressionCodecName.LZ4, CompressionCodecName.LZO,
- CompressionCodecName.SNAPPY, CompressionCodecName.ZSTD));
+ Arrays.asList(
+ CompressionCodecName.LZ4,
+ CompressionCodecName.LZO,
+ CompressionCodecName.SNAPPY,
+ CompressionCodecName.ZSTD
+ )
+ );
- // pool of reused aircompressor compressors (parquet-mr's factory has its own)
+ // pool of reusable thread-safe aircompressor compressors (parquet-mr's factory
+ // has its own)
private final Map<CompressionCodecName, AirliftBytesInputCompressor> airCompressors = new HashMap<>();
// fallback parquet-mr compression codec factory
- private CompressionCodecFactory parqCodecFactory;
+ private final CompressionCodecFactory parqCodecFactory;
// direct memory allocator to be used during (de)compression
- private ByteBufferAllocator allocator;
+ private final ByteBufferAllocator allocator;
+
+ // Start: members for working around a gzip concurrency bug c.f. DRILL-8139
+ private final Deque<CompressionCodecFactory> singleUseFactories;
+
Review comment:
```suggestion
```
##########
File path: exec/java-exec/src/main/java/org/apache/drill/exec/store/parquet/compression/DrillCompressionCodecFactory.java
##########
@@ -80,38 +99,56 @@ public DrillCompressionCodecFactory(Configuration config, ByteBufferAllocator al
}
@Override
- public BytesInputCompressor getCompressor(CompressionCodecName codecName) {
+ public synchronized BytesInputCompressor getCompressor(CompressionCodecName codecName) {
if (AIRCOMPRESSOR_CODECS.contains(codecName)) {
return airCompressors.computeIfAbsent(
codecName,
c -> new AirliftBytesInputCompressor(codecName, allocator)
);
+ } else if (codecName != CompressionCodecName.SNAPPY) {
+ // Work around PARQUET-2126: construct a new codec factory every time to
+ // avoid a concurrrency bug c.f. DRILL-8139. Remove once PARQUET-2126 is
+ // fixed. Snappy is immune because of the thread safety in the Xerial lib.
+ CompressionCodecFactory ccf = CodecFactory.createDirectCodecFactory(config, allocator, pageSize);
+ // hold onto a reference for later release()
+ singleUseFactories.add(ccf);
+ return ccf.getCompressor(codecName);
} else {
return parqCodecFactory.getCompressor(codecName);
}
}
@Override
- public BytesInputDecompressor getDecompressor(CompressionCodecName codecName) {
+ public synchronized BytesInputDecompressor getDecompressor(CompressionCodecName codecName) {
if (AIRCOMPRESSOR_CODECS.contains(codecName)) {
return airCompressors.computeIfAbsent(
codecName,
c -> new AirliftBytesInputCompressor(codecName, allocator)
);
+ } else if (codecName != CompressionCodecName.SNAPPY) {
Review comment:
Looks like existed `else` block starts to be never reached:
When `codecName` is SNAPPY or other from `AIRCOMPRESSOR_CODECS` we will pass through the first condition
and for all other cases we will pass through the new `else if` block. If that by design the logic can be simplified: `else if` -> `else`. `return parqCodecFactory.getDecompressor(codecName);` possibly can be commented.
The same for `#getCompressor` method
##########
File path: exec/java-exec/src/main/java/org/apache/drill/exec/store/parquet/compression/DrillCompressionCodecFactory.java
##########
@@ -80,38 +99,56 @@ public DrillCompressionCodecFactory(Configuration config, ByteBufferAllocator al
}
@Override
- public BytesInputCompressor getCompressor(CompressionCodecName codecName) {
+ public synchronized BytesInputCompressor getCompressor(CompressionCodecName codecName) {
if (AIRCOMPRESSOR_CODECS.contains(codecName)) {
return airCompressors.computeIfAbsent(
codecName,
c -> new AirliftBytesInputCompressor(codecName, allocator)
);
+ } else if (codecName != CompressionCodecName.SNAPPY) {
+ // Work around PARQUET-2126: construct a new codec factory every time to
+ // avoid a concurrrency bug c.f. DRILL-8139. Remove once PARQUET-2126 is
Review comment:
```suggestion
// avoid a concurrrency bug c.f. DRILL-8139. TODO: Remove once PARQUET-2126 is
Write Preview
```
##########
File path: exec/java-exec/src/main/java/org/apache/drill/exec/store/parquet/compression/DrillCompressionCodecFactory.java
##########
@@ -50,17 +52,31 @@
// The set of codecs to be handled by aircompressor
private static final Set<CompressionCodecName> AIRCOMPRESSOR_CODECS = new HashSet<>(
- Arrays.asList(CompressionCodecName.LZ4, CompressionCodecName.LZO,
- CompressionCodecName.SNAPPY, CompressionCodecName.ZSTD));
+ Arrays.asList(
+ CompressionCodecName.LZ4,
+ CompressionCodecName.LZO,
+ CompressionCodecName.SNAPPY,
+ CompressionCodecName.ZSTD
+ )
+ );
- // pool of reused aircompressor compressors (parquet-mr's factory has its own)
+ // pool of reusable thread-safe aircompressor compressors (parquet-mr's factory
+ // has its own)
private final Map<CompressionCodecName, AirliftBytesInputCompressor> airCompressors = new HashMap<>();
// fallback parquet-mr compression codec factory
- private CompressionCodecFactory parqCodecFactory;
+ private final CompressionCodecFactory parqCodecFactory;
// direct memory allocator to be used during (de)compression
- private ByteBufferAllocator allocator;
+ private final ByteBufferAllocator allocator;
+
+ // Start: members for working around a gzip concurrency bug c.f. DRILL-8139
+ private final Deque<CompressionCodecFactory> singleUseFactories;
+
+ private final Configuration config;
+
Review comment:
```suggestion
```
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