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https://issues.apache.org/jira/browse/HDFS-17737?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17930847#comment-17930847
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ASF GitHub Bot commented on HDFS-17737:
---------------------------------------
hadoop-yetus commented on PR #7427:
URL: https://github.com/apache/hadoop/pull/7427#issuecomment-2686189332
:broken_heart: **-1 overall**
| Vote | Subsystem | Runtime | Logfile | Comment |
|:----:|----------:|--------:|:--------:|:-------:|
| +0 :ok: | reexec | 0m 31s | | Docker mode activated. |
|||| _ Prechecks _ |
| +1 :green_heart: | dupname | 0m 1s | | No case conflicting files
found. |
| +0 :ok: | codespell | 0m 0s | | codespell was not available. |
| +0 :ok: | detsecrets | 0m 0s | | detect-secrets was not available.
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| +0 :ok: | xmllint | 0m 0s | | xmllint was not available. |
| +1 :green_heart: | @author | 0m 0s | | The patch does not contain
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| +1 :green_heart: | test4tests | 0m 0s | | The patch appears to
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|||| _ trunk Compile Tests _ |
| +0 :ok: | mvndep | 7m 23s | | Maven dependency ordering for branch |
| +1 :green_heart: | mvninstall | 31m 3s | | trunk passed |
| +1 :green_heart: | compile | 5m 42s | | trunk passed with JDK
Ubuntu-11.0.26+4-post-Ubuntu-1ubuntu120.04 |
| +1 :green_heart: | compile | 5m 5s | | trunk passed with JDK
Private Build-1.8.0_442-8u442-b06~us1-0ubuntu1~20.04-b06 |
| +1 :green_heart: | checkstyle | 1m 24s | | trunk passed |
| +1 :green_heart: | mvnsite | 2m 14s | | trunk passed |
| +1 :green_heart: | javadoc | 1m 57s | | trunk passed with JDK
Ubuntu-11.0.26+4-post-Ubuntu-1ubuntu120.04 |
| +1 :green_heart: | javadoc | 2m 25s | | trunk passed with JDK
Private Build-1.8.0_442-8u442-b06~us1-0ubuntu1~20.04-b06 |
| +1 :green_heart: | spotbugs | 5m 33s | | trunk passed |
| +1 :green_heart: | shadedclient | 35m 52s | | branch has no errors
when building and testing our client artifacts. |
|||| _ Patch Compile Tests _ |
| +0 :ok: | mvndep | 0m 34s | | Maven dependency ordering for patch |
| +1 :green_heart: | mvninstall | 1m 50s | | the patch passed |
| +1 :green_heart: | compile | 5m 55s | | the patch passed with JDK
Ubuntu-11.0.26+4-post-Ubuntu-1ubuntu120.04 |
| +1 :green_heart: | javac | 5m 55s | | the patch passed |
| +1 :green_heart: | compile | 5m 14s | | the patch passed with JDK
Private Build-1.8.0_442-8u442-b06~us1-0ubuntu1~20.04-b06 |
| +1 :green_heart: | javac | 5m 14s | | the patch passed |
| +1 :green_heart: | blanks | 0m 0s | | The patch has no blanks
issues. |
| +1 :green_heart: | checkstyle | 1m 14s | | hadoop-hdfs-project: The
patch generated 0 new + 110 unchanged - 4 fixed = 110 total (was 114) |
| +1 :green_heart: | mvnsite | 2m 1s | | the patch passed |
| -1 :x: | javadoc | 0m 38s |
[/patch-javadoc-hadoop-hdfs-project_hadoop-hdfs-client-jdkUbuntu-11.0.26+4-post-Ubuntu-1ubuntu120.04.txt](https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-7427/4/artifact/out/patch-javadoc-hadoop-hdfs-project_hadoop-hdfs-client-jdkUbuntu-11.0.26+4-post-Ubuntu-1ubuntu120.04.txt)
| hadoop-hdfs-client in the patch failed with JDK
Ubuntu-11.0.26+4-post-Ubuntu-1ubuntu120.04. |
| +1 :green_heart: | javadoc | 2m 8s | | the patch passed with JDK
Private Build-1.8.0_442-8u442-b06~us1-0ubuntu1~20.04-b06 |
| +1 :green_heart: | spotbugs | 5m 39s | | the patch passed |
| +1 :green_heart: | shadedclient | 35m 58s | | patch has no errors
when building and testing our client artifacts. |
|||| _ Other Tests _ |
| +1 :green_heart: | unit | 2m 30s | | hadoop-hdfs-client in the patch
passed. |
| +1 :green_heart: | unit | 1m 31s | | hadoop-hdfs in the patch
passed. |
| +1 :green_heart: | asflicense | 0m 37s | | The patch does not
generate ASF License warnings. |
| | | 164m 38s | | |
| Subsystem | Report/Notes |
|----------:|:-------------|
| Docker | ClientAPI=1.48 ServerAPI=1.48 base:
https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-7427/4/artifact/out/Dockerfile
|
| GITHUB PR | https://github.com/apache/hadoop/pull/7427 |
| Optional Tests | dupname asflicense compile javac javadoc mvninstall
mvnsite unit shadedclient codespell detsecrets xmllint spotbugs checkstyle |
| uname | Linux dccdc7ce188b 5.15.0-131-generic #141-Ubuntu SMP Fri Jan 10
21:18:28 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux |
| Build tool | maven |
| Personality | dev-support/bin/hadoop.sh |
| git revision | trunk / e8339b09243598378bcc3611d8057c0e15069214 |
| Default Java | Private Build-1.8.0_442-8u442-b06~us1-0ubuntu1~20.04-b06 |
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/usr/lib/jvm/java-8-openjdk-amd64:Private
Build-1.8.0_442-8u442-b06~us1-0ubuntu1~20.04-b06 |
| Test Results |
https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-7427/4/testReport/ |
| Max. process+thread count | 700 (vs. ulimit of 5500) |
| modules | C: hadoop-hdfs-project/hadoop-hdfs-client
hadoop-hdfs-project/hadoop-hdfs U: hadoop-hdfs-project |
| Console output |
https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-7427/4/console |
| versions | git=2.25.1 maven=3.6.3 spotbugs=4.2.2 |
| Powered by | Apache Yetus 0.14.0 https://yetus.apache.org |
This message was automatically generated.
> Implement Backoff Retry for ErasureCoding reads
> -----------------------------------------------
>
> Key: HDFS-17737
> URL: https://issues.apache.org/jira/browse/HDFS-17737
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: dfsclient, ec, erasure-coding
> Affects Versions: 3.3.4
> Reporter: Danny Becker
> Assignee: Danny Becker
> Priority: Major
> Labels: pull-request-available
>
> #Why
> Currently EC Reads are less stable than replication reads because if 4 out of
> 9 datanodes in the block group are unable to connect, then the whole read
> fails. Erasure Coding reads need to be able to handle connection failures
> from DataNodes and retry after a backoff duration to avoid overloading the
> DataNodes while increasing the stability of the read.
> Throttling on server side was another proposed solution, but we prefer this
> client side backoff for a few main reasons:
> 1. Throttling on the server would use up thread connections which have a
> maximum limit.
> 2. Throttling was originally added only for cohosting scenario to reduce
> impact on other services
> 3. Throttling would use up resources on the DataNode which could already be
> in a bad state.
> #What
> The previous implementation followed a 4 phase algorithm to read.
> 1. Attempt to read chunks from the data blocks
> 2. Check for missing data chunks. Fail if there are more missing than the
> number of parity blocks, otherwise read parity blocks and null data blocks
> 3. Wait for data to be read into the buffers and handle any read errors by
> reading from more parity blocks
> 4. Check for missing blocks and either decode or fail.
> The new implementation now merges phase 1-3 into a single loop:
> 1. Loop until we have enough blocks for read or decode, or we have too many
> missing blocks to succeed
> - Determine the number of chunks we need to fetch. ALLZERO chunks count
> towards this total. null data chunks also count towards this total unless
> there are MISSING or SLEEPING data chunks.
> - Read chunks until we have enough pending or fetched to be able to decode
> or normal read.
> faster.
> - Get results from reads and handle exceptions by preparing more reads for
> decoding the missing data
> - Check if we should sleep before retrying any reads.
> 2. Check for missing blocks and either decode or fail.
> #Tests
> Add unit test to `TestWriteReadStripedFile`
> - Covers RS(3,2) with 1 chunk busy, 2 chunks busy, and 3 chunks busy.
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