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https://issues.apache.org/jira/browse/HDFS-17974?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18112107#comment-18112107
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ASF GitHub Bot commented on HDFS-17974:
---------------------------------------
hadoop-yetus commented on PR #8715:
URL: https://github.com/apache/hadoop/pull/8715#issuecomment-5562109001
:confetti_ball: **+1 overall**
| Vote | Subsystem | Runtime | Logfile | Comment |
|:----:|----------:|--------:|:--------:|:-------:|
| +0 :ok: | reexec | 0m 57s | | Docker mode activated. |
|||| _ Prechecks _ |
| +1 :green_heart: | dupname | 0m 0s | | No case conflicting files
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| +0 :ok: | xmllint | 0m 1s | | 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
include 1 new or modified test files. |
|||| _ trunk Compile Tests _ |
| +1 :green_heart: | mvninstall | 47m 14s | | trunk passed |
| +1 :green_heart: | compile | 1m 43s | | trunk passed with JDK
Ubuntu-21.0.12+8-1-24.04-Ubuntu |
| +1 :green_heart: | compile | 1m 47s | | trunk passed with JDK
Ubuntu-17.0.20+8-1-24.04-Ubuntu |
| +1 :green_heart: | checkstyle | 1m 53s | | trunk passed |
| +1 :green_heart: | mvnsite | 1m 57s | | trunk passed |
| +1 :green_heart: | javadoc | 1m 30s | | trunk passed with JDK
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| +1 :green_heart: | javadoc | 1m 30s | | trunk passed with JDK
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| +1 :green_heart: | spotbugs | 4m 22s | | trunk passed |
| +1 :green_heart: | shadedclient | 37m 34s | | branch has no errors
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|||| _ Patch Compile Tests _ |
| +1 :green_heart: | mvninstall | 1m 24s | | the patch passed |
| +1 :green_heart: | compile | 1m 17s | | the patch passed with JDK
Ubuntu-21.0.12+8-1-24.04-Ubuntu |
| +1 :green_heart: | javac | 1m 17s | | the patch passed |
| +1 :green_heart: | compile | 1m 23s | | the patch passed with JDK
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| +1 :green_heart: | javac | 1m 23s | | the patch passed |
| +1 :green_heart: | blanks | 0m 0s | | The patch has no blanks
issues. |
| -0 :warning: | checkstyle | 1m 22s |
[/results-checkstyle-hadoop-hdfs-project_hadoop-hdfs.txt](https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8715/6/artifact/out/results-checkstyle-hadoop-hdfs-project_hadoop-hdfs.txt)
| hadoop-hdfs-project/hadoop-hdfs: The patch generated 27 new + 382 unchanged
- 0 fixed = 409 total (was 382) |
| +1 :green_heart: | mvnsite | 1m 28s | | the patch passed |
| +1 :green_heart: | javadoc | 0m 58s | | the patch passed with JDK
Ubuntu-21.0.12+8-1-24.04-Ubuntu |
| +1 :green_heart: | javadoc | 1m 3s | | the patch passed with JDK
Ubuntu-17.0.20+8-1-24.04-Ubuntu |
| +1 :green_heart: | spotbugs | 4m 4s | | the patch passed |
| +1 :green_heart: | shadedclient | 36m 45s | | patch has no errors
when building and testing our client artifacts. |
|||| _ Other Tests _ |
| +1 :green_heart: | unit | 267m 39s | | hadoop-hdfs in the patch
passed. |
| +1 :green_heart: | asflicense | 0m 53s | | The patch does not
generate ASF License warnings. |
| | | 416m 47s | | |
| Subsystem | Report/Notes |
|----------:|:-------------|
| Docker | ClientAPI=1.56 ServerAPI=1.56 base:
https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8715/6/artifact/out/Dockerfile
|
| GITHUB PR | https://github.com/apache/hadoop/pull/8715 |
| Optional Tests | dupname asflicense compile javac javadoc mvninstall
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| uname | Linux fd090cc4226b 5.15.0-185-generic #195-Ubuntu SMP Fri Jun 19
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| Build tool | maven |
| Personality | dev-support/bin/hadoop.sh |
| git revision | trunk / 095387b0daafe844d8744b5ad3ab247a06e15906 |
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/usr/lib/jvm/java-17-openjdk-amd64:Ubuntu-17.0.20+8-1-24.04-Ubuntu |
| Test Results |
https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8715/6/testReport/ |
| Max. process+thread count | 3343 (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-8715/6/console |
| versions | git=2.43.0 maven=3.9.15 spotbugs=4.9.7 |
| Powered by | Apache Yetus 0.14.1 https://yetus.apache.org |
This message was automatically generated.
> HDFS DataNode Affinity for Tenant Isolation
> -------------------------------------------
>
> Key: HDFS-17974
> URL: https://issues.apache.org/jira/browse/HDFS-17974
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: hdfs
> Reporter: Rajan Dhabalia
> Priority: Major
> Labels: pull-request-available
>
> h2. Summary
> Introduce a pluggable, regex-based DataNode affinity mechanism that maps HDFS
> paths to dedicated DataNode pools.
> This enables *tenant/dataset-level storage and I/O isolation* without
> requiring separate HDFS clusters or rack-based workarounds.
> h2. Motivation
> The current HDFS block placement policy has no native path-based mechanism to
> restrict data to a specific DataNode pool. This can cause noisy-neighbor
> interference for isolation-sensitive workloads.
> The feature provides:
> * Path-to-DataNode-pool mapping
> * Tenant/dataset I/O isolation
> * More predictable performance
> * Independent capacity planning
> * Runtime configuration updates without NameNode restart
> h2. Design
> Introduce a pluggable `DatanodeAffinityManager` configured through:
> {code:java}
> dfs.datanode.affinity.manager.classname
> {code}
> An affinity rule maps:
> {code:java}
> HDFS path regex -> DataNode hostname regex
> {code}
> Example:
> {code:java}
> /data/tenantA/.* -> dn-tenantA-.*
> /data/tenantB/.* -> dn-tenantB-.*
> {code}
> The manager resolves the hostname regex against registered DataNodes and
> builds a restricted `NetworkTopology` containing only eligible DataNodes for
> each affinity group.
> h2. NameNode Integration
> *DatanodeManager*
> * Identifies DataNodes belonging to affinity pools during registration.
> * Removes affinity-only DataNodes from the default placement topology.
> * Prevents non-affinity workloads from using dedicated DataNodes.
> * Refreshes affinity state through `hdfs dfsadmin -refreshNodes`.
> *BlockManager*
> For each block placement request:
> # Match the source path against configured affinity groups.
> # Use the group's `BlockPlacementPolicy` if matched.
> # Select targets from the group's restricted topology.
> # Fall back to the default placement policy when no group matches.
> This avoids large exclusion lists on the placement hot path.
> h2. Pluggable Implementation
> `DatanodeAffinityManager` is an abstraction that allows different affinity
> sources without changing block-placement logic.
> Built-in implementation:
> {code:java}
> FileDatanodeAffinityManager
> {code}
> It loads affinity rules from a JSON configuration file and reloads them
> through `dfsadmin -refreshNodes`.
> h2. Configuration
> ||Property||Default||Description||
> |`dfs.datanode.affinity.manager.classname`|Empty|`DatanodeAffinityManager`
> implementation. Empty disables the feature.|
> |`dfs.datanode.affinity.file.path`|Empty|JSON affinity configuration used by
> `FileDatanodeAffinityManager`.|
> Example:
> {code:java}
> /data/tenantA/.* -> dn-tenantA-.*
> /data/tenantB/.* -> dn-tenantB-.*
> {code}
> h2. Operational Visibility
> Add:
> {code:java}
> hdfs fsck <path> -favored-nodes
> {code}
> to display the DataNodes resolved for a path.
> Example:
> {code:java}
> hdfs fsck /data/tenantA -favored-nodes
> {code}
> This provides a dry-run mechanism to validate affinity configuration before
> enabling it.
> h2. Runtime Refresh
> Affinity configuration and DataNode membership can be updated using:
> {code:java}
> hdfs dfsadmin -refreshNodes
> {code}
> No NameNode restart is required.
> Supported changes include:
> * Adding/removing DataNodes from an affinity pool
> * Updating path-to-pool mappings
> * Changing hostname matching rules
> h2. Benefits
> * *Tenant Isolation:* Affinity-enabled data is placed only on its dedicated
> DataNode pool.
> * *Predictable Performance:* Reduces noisy-neighbor impact and isolates I/O
> capacity.
> * *Default Pool Protection:* Dedicated DataNodes are excluded from normal
> placement.
> * *Efficient Placement:* Restricted topology limits placement to the
> relevant pool.
> * *Runtime Configuration:* Changes take effect without NameNode restart.
> h2. Expected Impact
> ||Dimension||Expected Impact||
> |Cross-tenant interference|Eliminated within the isolated DataNode pool|
> |Tail latency|Reduced when contention exists|
> |Placement scope|Limited to affinity pool|
> |Default-pool throughput|No expected regression|
> |Configuration changes|Runtime refresh|
> The primary goal is {*}isolation and performance predictability{*}, not raw
> throughput improvement.
> h2. Implementation
> Key changes:
> * `DatanodeAffinityManager` abstraction
> * `FileDatanodeAffinityManager`
> * Path-regex to DataNode-hostname-regex mapping
> * Per-group restricted `NetworkTopology`
> * `DatanodeManager` topology integration
> * Per-group `BlockPlacementPolicy` in `BlockManager`
> * Affinity-aware `chooseTarget4NewBlock`
> * Runtime refresh via `dfsadmin -refreshNodes`
> * `hdfs fsck -favored-nodes` validation
> h2. Backward Compatibility
> * Disabled by default.
> * Existing block placement behavior is unchanged when affinity is not
> configured.
> * Non-matching paths continue to use the default placement policy.
> * No HDFS client changes are required.
> * Can be enabled selectively for specific tenants or datasets.
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