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https://issues.apache.org/jira/browse/HBASE-24625?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17156579#comment-17156579
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chenglei edited comment on HBASE-24625 at 7/13/20, 9:09 AM:
------------------------------------------------------------
Open an addendum [PR#2055|https://github.com/apache/hbase/pull/2055] to
incorporate [~ndimiduk] 's suggestions in
[PR#2034|https://github.com/apache/hbase/pull/2034] and other minor changes.
I did not use the {{AtomicLong.getAndAccumulate}} to replace
{{AtomicUtils.updateMax}} because
https://issues.apache.org/jira/browse/HBASE-24625?focusedCommentId=17155993&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-17155993
was (Author: comnetwork):
Open an addendum [PR#2055|https://github.com/apache/hbase/pull/2055] to
incorporate [~ndimiduk] 's suggestions in [link
PR#2034|https://github.com/apache/hbase/pull/2034] and other minor changes.
I did not use the {{AtomicLong.getAndAccumulate}} to replace
{{AtomicUtils.updateMax}} because
https://issues.apache.org/jira/browse/HBASE-24625?focusedCommentId=17155993&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-17155993
> AsyncFSWAL.getLogFileSizeIfBeingWritten does not return the expected synced
> file length.
> ----------------------------------------------------------------------------------------
>
> Key: HBASE-24625
> URL: https://issues.apache.org/jira/browse/HBASE-24625
> Project: HBase
> Issue Type: Bug
> Components: Replication, wal
> Affects Versions: 2.1.0, 2.0.0, 2.2.0, 2.3.0
> Reporter: chenglei
> Assignee: chenglei
> Priority: Critical
> Fix For: 3.0.0-alpha-1, 2.3.1, 2.4.0, 2.2.6
>
>
> By HBASE-14004, we introduce {{WALFileLengthProvider}} interface to keep the
> current writing wal file length by ourselves, {{WALEntryStream}} used by
> {{ReplicationSourceWALReader}} could only read WAL file byte size <=
> {{WALFileLengthProvider.getLogFileSizeIfBeingWritten}} if the WAL file is
> current been writing on the same RegionServer .
> {{AsyncFSWAL}} implements {{WALFileLengthProvider}} by
> {{AbstractFSWAL.getLogFileSizeIfBeingWritten}}, just as folllows :
> {code:java}
> public OptionalLong getLogFileSizeIfBeingWritten(Path path) {
> rollWriterLock.lock();
> try {
> Path currentPath = getOldPath();
> if (path.equals(currentPath)) {
> W writer = this.writer;
> return writer != null ? OptionalLong.of(writer.getLength()) :
> OptionalLong.empty();
> } else {
> return OptionalLong.empty();
> }
> } finally {
> rollWriterLock.unlock();
> }
> }
> {code}
> For {{AsyncFSWAL}}, above {{AsyncFSWAL.writer}} is
> {{AsyncProtobufLogWriter}} ，and {{AsyncProtobufLogWriter.getLength}} is as
> follows:
> {code:java}
> public long getLength() {
> return length.get();
> }
> {code}
> But for {{AsyncProtobufLogWriter}}, any append method may increase the above
> {{AsyncProtobufLogWriter.length}}, especially for following
> {{AsyncFSWAL.append}}
> method just appending the {{WALEntry}} to
> {{FanOutOneBlockAsyncDFSOutput.buf}}:
> {code:java}
> public void append(Entry entry) {
> int buffered = output.buffered();
> try {
> entry.getKey().
>
> getBuilder(compressor).setFollowingKvCount(entry.getEdit().size()).build()
> .writeDelimitedTo(asyncOutputWrapper);
> } catch (IOException e) {
> throw new AssertionError("should not happen", e);
> }
>
> try {
> for (Cell cell : entry.getEdit().getCells()) {
> cellEncoder.write(cell);
> }
> } catch (IOException e) {
> throw new AssertionError("should not happen", e);
> }
> length.addAndGet(output.buffered() - buffered);
> }
> {code}
> That is to say, {{AsyncFSWAL.getLogFileSizeIfBeingWritten}} could not reflect
> the file length which successfully synced to underlying HDFS, which is not
> as expected.
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