[ https://issues.apache.org/jira/browse/HDFS-15759 ]
ruiliang deleted comment on HDFS-15759:
---------------------------------
was (Author: ruilaing):
When I validate a block that has been corrupted many times, does it appear
normal?
ByteBuffer hb show [0......]
{code:java}
buffers = {ByteBuffer[5]@3270}
0 = {HeapByteBuffer@3430} "java.nio.HeapByteBuffer[pos=65536 lim=65536
cap=65536]"
1 = {HeapByteBuffer@3434} "java.nio.HeapByteBuffer[pos=65536 lim=65536
cap=65536]"
2 = {HeapByteBuffer@3438} "java.nio.HeapByteBuffer[pos=65536 lim=65536
cap=65536]"
3 = {HeapByteBuffer@3504} "java.nio.HeapByteBuffer[pos=0 lim=65536 cap=65536]"
hb = {byte[65536]@3511} [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, +65,436 more]
buffers[this.dataBlkNum + ixx].equals(outputs[ixx] =true ?
outputs = {ByteBuffer[2]@3271}
0 = {HeapByteBuffer@3455} "java.nio.HeapByteBuffer[pos=0 lim=65536 cap=65536]"
hb = {byte[65536]@3459} [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, +65,436 more]{code}
Can this situation be judged as an anomaly?
{code:java}
hdfs debug verifyEC -file /file.orc
24/06/07 15:40:29 WARN erasurecode.ErasureCodeNative: ISA-L support is not
available in your platform... using builtin-java codec where applicable
Checking EC block group: blk_-9223372036492703744
Status: OK
{code}
check orc file
{code:java}
Structure for skip_ip/_skip_file File Version: 0.12 with ORC_517 by ORC Java
Exception in thread "main" java.io.IOException: Problem opening stripe 0 footer
in skip_ip/_skip_file. at
org.apache.orc.impl.RecordReaderImpl.<init>(RecordReaderImpl.java:360)
at org.apache.orc.impl.ReaderImpl.rows(ReaderImpl.java:879) at
org.apache.orc.impl.ReaderImpl.rows(ReaderImpl.java:873) at
org.apache.orc.tools.FileDump.printMetaDataImpl(FileDump.java:345) at
org.apache.orc.tools.FileDump.printMetaData(FileDump.java:276) at
org.apache.orc.tools.FileDump.main(FileDump.java:137) at
org.apache.orc.tools.Driver.main(Driver.java:124) Caused by:
java.lang.IllegalArgumentException: Buffer size too small. size = 131072 needed
= 7752508 in column 3 kind LENGTH at
org.apache.orc.impl.InStream$CompressedStream.readHeader(InStream.java:481)
at
org.apache.orc.impl.InStream$CompressedStream.ensureUncompressed(InStream.java:528)
at
org.apache.orc.impl.InStream$CompressedStream.read(InStream.java:507)
at
org.apache.orc.impl.RunLengthIntegerReaderV2.readValues(RunLengthIntegerReaderV2.java:59)
at
org.apache.orc.impl.RunLengthIntegerReaderV2.next(RunLengthIntegerReaderV2.java:333)
at
org.apache.orc.impl.TreeReaderFactory$StringDictionaryTreeReader.readDictionaryLengthStream(TreeReaderFactory.java:2221)
at
org.apache.orc.impl.TreeReaderFactory$StringDictionaryTreeReader.startStripe(TreeReaderFactory.java:2201)
at
org.apache.orc.impl.TreeReaderFactory$StringTreeReader.startStripe(TreeReaderFactory.java:1943)
at
org.apache.orc.impl.reader.tree.StructBatchReader.startStripe(StructBatchReader.java:112)
at
org.apache.orc.impl.RecordReaderImpl.readStripe(RecordReaderImpl.java:1251)
at
org.apache.orc.impl.RecordReaderImpl.advanceStripe(RecordReaderImpl.java:1290)
at
org.apache.orc.impl.RecordReaderImpl.advanceToNextRow(RecordReaderImpl.java:1333)
at
org.apache.orc.impl.RecordReaderImpl.<init>(RecordReaderImpl.java:355)
... 6 more
{code}
> EC: Verify EC reconstruction correctness on DataNode
> ----------------------------------------------------
>
> Key: HDFS-15759
> URL: https://issues.apache.org/jira/browse/HDFS-15759
> Project: Hadoop HDFS
> Issue Type: New Feature
> Components: datanode, ec, erasure-coding
> Affects Versions: 3.4.0
> Reporter: Toshihiko Uchida
> Assignee: Toshihiko Uchida
> Priority: Major
> Labels: pull-request-available
> Fix For: 3.3.1, 3.4.0, 3.2.3
>
> Time Spent: 10h 20m
> Remaining Estimate: 0h
>
> EC reconstruction on DataNode has caused data corruption: HDFS-14768,
> HDFS-15186 and HDFS-15240. Those issues occur under specific conditions and
> the corruption is neither detected nor auto-healed by HDFS. It is obviously
> hard for users to monitor data integrity by themselves, and even if they find
> corrupted data, it is difficult or sometimes impossible to recover them.
> To prevent further data corruption issues, this feature proposes a simple and
> effective way to verify EC reconstruction correctness on DataNode at each
> reconstruction process.
> It verifies correctness of outputs decoded from inputs as follows:
> 1. Decoding an input with the outputs;
> 2. Compare the decoded input with the original input.
> For instance, in RS-6-3, assume that outputs [d1, p1] are decoded from inputs
> [d0, d2, d3, d4, d5, p0]. Then the verification is done by decoding d0 from
> [d1, d2, d3, d4, d5, p1], and comparing the original and decoded data of d0.
> When an EC reconstruction task goes wrong, the comparison will fail with high
> probability.
> Then the task will also fail and be retried by NameNode.
> The next reconstruction will succeed if the condition triggered the failure
> is gone.
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