[
https://issues.apache.org/jira/browse/HDFS-17639?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18072876#comment-18072876
]
ASF GitHub Bot commented on HDFS-17639:
---------------------------------------
hadoop-yetus commented on PR #8316:
URL: https://github.com/apache/hadoop/pull/8316#issuecomment-4229819677
:confetti_ball: **+1 overall**
| Vote | Subsystem | Runtime | Logfile | Comment |
|:----:|----------:|--------:|:--------:|:-------:|
| +0 :ok: | reexec | 0m 21s | | Docker mode activated. |
|||| _ Prechecks _ |
| +1 :green_heart: | dupname | 0m 0s | | No case conflicting files
found. |
| +0 :ok: | codespell | 0m 0s | | codespell was not available. |
| +0 :ok: | detsecrets | 0m 0s | | detect-secrets was not available.
|
| +1 :green_heart: | @author | 0m 0s | | The patch does not contain
any @author tags. |
| +1 :green_heart: | test4tests | 0m 0s | | The patch appears to
include 1 new or modified test files. |
|||| _ trunk Compile Tests _ |
| +1 :green_heart: | mvninstall | 27m 2s | | trunk passed |
| +1 :green_heart: | compile | 0m 59s | | trunk passed with JDK
Ubuntu-21.0.10+7-Ubuntu-124.04 |
| +1 :green_heart: | compile | 0m 56s | | trunk passed with JDK
Ubuntu-17.0.18+8-Ubuntu-124.04.1 |
| +1 :green_heart: | checkstyle | 0m 58s | | trunk passed |
| +1 :green_heart: | mvnsite | 1m 3s | | trunk passed |
| +1 :green_heart: | javadoc | 0m 47s | | trunk passed with JDK
Ubuntu-21.0.10+7-Ubuntu-124.04 |
| +1 :green_heart: | javadoc | 0m 51s | | trunk passed with JDK
Ubuntu-17.0.18+8-Ubuntu-124.04.1 |
| +1 :green_heart: | spotbugs | 2m 24s | | trunk passed |
| +1 :green_heart: | shadedclient | 18m 27s | | branch has no errors
when building and testing our client artifacts. |
|||| _ Patch Compile Tests _ |
| +1 :green_heart: | mvninstall | 0m 50s | | the patch passed |
| +1 :green_heart: | compile | 0m 46s | | the patch passed with JDK
Ubuntu-21.0.10+7-Ubuntu-124.04 |
| +1 :green_heart: | javac | 0m 46s | | the patch passed |
| +1 :green_heart: | compile | 0m 53s | | the patch passed with JDK
Ubuntu-17.0.18+8-Ubuntu-124.04.1 |
| +1 :green_heart: | javac | 0m 53s | | the patch passed |
| +1 :green_heart: | blanks | 0m 0s | | The patch has no blanks
issues. |
| +1 :green_heart: | checkstyle | 0m 45s | | the patch passed |
| +1 :green_heart: | mvnsite | 0m 53s | | the patch passed |
| +1 :green_heart: | javadoc | 0m 34s | | the patch passed with JDK
Ubuntu-21.0.10+7-Ubuntu-124.04 |
| +1 :green_heart: | javadoc | 0m 39s | | the patch passed with JDK
Ubuntu-17.0.18+8-Ubuntu-124.04.1 |
| +1 :green_heart: | spotbugs | 2m 25s | | the patch passed |
| +1 :green_heart: | shadedclient | 18m 18s | | patch has no errors
when building and testing our client artifacts. |
|||| _ Other Tests _ |
| +1 :green_heart: | unit | 180m 16s | | hadoop-hdfs in the patch
passed. |
| +1 :green_heart: | asflicense | 0m 30s | | The patch does not
generate ASF License warnings. |
| | | 259m 34s | | |
| Subsystem | Report/Notes |
|----------:|:-------------|
| Docker | ClientAPI=1.54 ServerAPI=1.54 base:
https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8316/4/artifact/out/Dockerfile
|
| GITHUB PR | https://github.com/apache/hadoop/pull/8316 |
| Optional Tests | dupname asflicense compile javac javadoc mvninstall
mvnsite unit shadedclient spotbugs checkstyle codespell detsecrets |
| uname | Linux be7fbfc8235c 5.15.0-171-generic #181-Ubuntu SMP Fri Feb 6
22:44:50 UTC 2026 x86_64 x86_64 x86_64 GNU/Linux |
| Build tool | maven |
| Personality | dev-support/bin/hadoop.sh |
| git revision | trunk / 7c572dfa521d30374c9c29156040eb615f9adca2 |
| Default Java | Ubuntu-17.0.18+8-Ubuntu-124.04.1 |
| Multi-JDK versions |
/usr/lib/jvm/java-21-openjdk-amd64:Ubuntu-21.0.10+7-Ubuntu-124.04
/usr/lib/jvm/java-17-openjdk-amd64:Ubuntu-17.0.18+8-Ubuntu-124.04.1 |
| Test Results |
https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8316/4/testReport/ |
| Max. process+thread count | 4862 (vs. ulimit of 10000) |
| modules | C: hadoop-hdfs-project/hadoop-hdfs U:
hadoop-hdfs-project/hadoop-hdfs |
| Console output |
https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8316/4/console |
| versions | git=2.43.0 maven=3.9.11 spotbugs=4.9.7 |
| Powered by | Apache Yetus 0.14.1 https://yetus.apache.org |
This message was automatically generated.
> Lock contention for hasStorageType when the number of storage nodes is large
> ----------------------------------------------------------------------------
>
> Key: HDFS-17639
> URL: https://issues.apache.org/jira/browse/HDFS-17639
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: datanode, server
> Affects Versions: 3.4.0
> Reporter: goaymode
> Priority: Minor
> Labels: pull-request-available
>
> I was looking into methods associated with storages and storageTypes. I found
> [DatanodeDescriptor.hasStorageType|https://github.com/apache/hadoop/blob/2f0dd7c4feb1e482d47786d26d6d32483f39414b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeDescriptor.java#L1138]
> could be a source of bottlenecks. To check whether a specific storage type
> exists among the storage locations associated with a DatanodeDescriptor,
> [hasStorageType|https://github.com/apache/hadoop/blob/2f0dd7c4feb1e482d47786d26d6d32483f39414b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeDescriptor.java#L1138]
> iterates over an array of DatanodeStorageInfos returned by
> [getStorageInfos()|https://github.com/apache/hadoop/blob/2f0dd7c4feb1e482d47786d26d6d32483f39414b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeDescriptor.java#L305].
> This retrieves the storage information from a storageMap and converts it to
> an array while under a lock. As the system scales and the size of storageMap
> grows with more datanodes, the duration spent in the synchronized block will
> increase. This issue could become more significant when hasStorageType is
> called in methods like
> [DatanodeDescriptor.pruneStorageMap|https://github.com/apache/hadoop/blob/49a495803a9451850b8982317e277b605c785587/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeDescriptor.java#L568]
> that could iterate (resulting in a form of nested iteration) over a large
> data structure. The combination of a repeated linear search (within
> hasStorageType) and the iteration within a lock can lead to a significant
> complexity (potentially quadratic) and significant synchronization bottlenecks
>
> [DFSNetworkTopology.chooseRandomWithStorageType|https://github.com/apache/hadoop/blob/2f0dd7c4feb1e482d47786d26d6d32483f39414b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/net/DFSNetworkTopology.java#L180]
> and [DFSNetworkTopology.
> chooseRandomWithStorageTypeTwoTrial|https://github.com/apache/hadoop/blob/2f0dd7c4feb1e482d47786d26d6d32483f39414b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/net/DFSNetworkTopology.java#L107]
> are affected because they both invoke hasStorageType. Additionally,
> [INodeFile.assertAllBlocksComplete|https://github.com/apache/hadoop/blob/2f0dd7c4feb1e482d47786d26d6d32483f39414b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeFile.java#L345]
> and
> [BlockManager.checkRedundancy()|https://github.com/apache/hadoop/blob/6be04633b55bbd67c2875e39977cd9d2308dc1d1/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java#L5018]
> faces a similar issue
> ([FSNamesystem.finalizeINodeFileUnderConstruction|https://github.com/apache/hadoop/blob/2f0dd7c4feb1e482d47786d26d6d32483f39414b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java#L3908]
> invokes both methods under a writeLock)
> This appears to be a similar issue with
> https://issues.apache.org/jira/browse/HDFS-17638 . I’m curious to know if my
> analysis is wrong and if there is anything that can be done to reduce the
> impact of these issues
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
