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https://issues.apache.org/jira/browse/HADOOP-18521?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17639905#comment-17639905
]
ASF GitHub Bot commented on HADOOP-18521:
-----------------------------------------
pranavsaxena-microsoft commented on code in PR #5117:
URL: https://github.com/apache/hadoop/pull/5117#discussion_r1033198624
##########
hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/ReadBufferManager.java:
##########
@@ -454,31 +597,86 @@ ReadBuffer getNextBlockToRead() throws
InterruptedException {
*/
void doneReading(final ReadBuffer buffer, final ReadBufferStatus result,
final int bytesActuallyRead) {
if (LOGGER.isTraceEnabled()) {
- LOGGER.trace("ReadBufferWorker completed read file {} for offset {}
outcome {} bytes {}",
- buffer.getStream().getPath(), buffer.getOffset(), result,
bytesActuallyRead);
- }
- synchronized (this) {
- // If this buffer has already been purged during
- // close of InputStream then we don't update the lists.
- if (inProgressList.contains(buffer)) {
- inProgressList.remove(buffer);
- if (result == ReadBufferStatus.AVAILABLE && bytesActuallyRead > 0) {
- buffer.setStatus(ReadBufferStatus.AVAILABLE);
- buffer.setLength(bytesActuallyRead);
- } else {
- freeList.push(buffer.getBufferindex());
- // buffer will be deleted as per the eviction policy.
+ LOGGER.trace("ReadBufferWorker completed file {} for offset {} bytes {};
{}",
+ buffer.getStream().getPath(), buffer.getOffset(),
bytesActuallyRead, buffer);
+ }
+ // decrement counter.
+ buffer.prefetchFinished();
+
+ try {
+ synchronized (this) {
+ // remove from the list
+ if (!inProgressList.remove(buffer)) {
+ // this is a sign of inconsistent state, so a major problem, such as
+ // double invocation of this method with the same buffer.
+ String message =
+ String.format("Read completed from an operation not declared as
in progress %s",
+ buffer);
+ LOGGER.warn(message);
+ if (buffer.hasIndexedBuffer()) {
+ // release the buffer (which may raise an exception)
+ placeBufferOnFreeList("read not in progress", buffer);
+ }
+ // report the failure
+ throw new IllegalStateException(message);
}
- // completed list also contains FAILED read buffers
- // for sending exception message to clients.
+
+ // should the read buffer be added to the completed list?
+ boolean addCompleted = true;
+ // flag to indicate buffer should be freed
+ boolean shouldFreeBuffer = false;
+ // and the reason (for logging)
+ String freeBufferReason = "";
+
buffer.setStatus(result);
buffer.setTimeStamp(currentTimeMillis());
- completedReadList.add(buffer);
+ // did the read return any data?
+ if (result == ReadBufferStatus.AVAILABLE
+ && bytesActuallyRead > 0) {
+ // successful read of data; update buffer state.
+ buffer.setLength(bytesActuallyRead);
+ } else {
+ // read failed or there was no data; the buffer can be returned to
the free list.
+ shouldFreeBuffer = true;
+ freeBufferReason = "failed read";
+ // completed list also contains FAILED read buffers
+ // for sending exception message to clients.
+ // NOTE: checks for closed state may update this.
+ addCompleted = result == ReadBufferStatus.READ_FAILED;
Review Comment:
Should we not add the buffer in completedList. Reason being it will always
be removed from the list via oldFailedBuffers removal. Kindly suggest if there
is a reason for adding it. Thanks.
> ABFS ReadBufferManager buffer sharing across concurrent HTTP requests
> ---------------------------------------------------------------------
>
> Key: HADOOP-18521
> URL: https://issues.apache.org/jira/browse/HADOOP-18521
> Project: Hadoop Common
> Issue Type: Bug
> Components: fs/azure
> Affects Versions: 3.3.2, 3.3.3, 3.3.4
> Reporter: Steve Loughran
> Assignee: Steve Loughran
> Priority: Critical
> Labels: pull-request-available
>
> AbfsInputStream.close() can trigger the return of buffers used for active
> prefetch GET requests into the ReadBufferManager free buffer pool.
> A subsequent prefetch by a different stream in the same process may acquire
> this same buffer. This can lead to risk of corruption of its own prefetched
> data, data which may then be returned to that other thread.
> On releases without the fix for this (3.3.2+), the bug can be avoided by
> disabling all prefetching
> {code}
> fs.azure.readaheadqueue.depth = 0
> {code}
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