[
https://issues.apache.org/jira/browse/HDFS-2476?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13145791#comment-13145791
]
jirapos...@reviews.apache.org commented on HDFS-2476:
-----------------------------------------------------
-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/2515/
-----------------------------------------------------------
(Updated 2011-11-07 20:51:43.203090)
Review request for Hairong Kuang.
Changes
-------
Addressed Todd's comments.
Summary
-------
This patch introduces two hash data structures for storing under-replicated,
over-replicated and invalidated blocks.
1. LightWeightHashSet
2. LightWeightLinkedSet
Currently in all these cases we are using java.util.TreeSet which adds
unnecessary overhead.
The main bottlenecks addressed by this patch are:
-cluster instability times, when these queues (especially under-replicated)
tend to grow quite drastically,
-initial cluster startup, when the queues are initialized, after leaving
safemode,
-block reports,
-explicit acks for block addition and deletion
1. The introduced structures are CPU-optimized.
2. They shrink and expand according to current capacity.
3. Add/contains/delete ops are performed in O(1) time (unlike current log n for
TreeSet).
4. The sets are equipped with fast access methods for polling a number of
elements (get+remove), which are used for handling the queues.
This addresses bug HDFS-2476.
https://issues.apache.org/jira/browse/HDFS-2476
Diffs (updated)
-----
trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java
1198921
trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeDescriptor.java
1198921
trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/InvalidateBlocks.java
1198921
trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/UnderReplicatedBlocks.java
1198921
trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
1198921
trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeRpcServer.java
1198921
trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NamenodeFsck.java
1198921
trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSck.java
1198921
trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/util/LightWeightHashSet.java
PRE-CREATION
trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/util/LightWeightLinkedSet.java
PRE-CREATION
trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestListCorruptFileBlocks.java
1198921
trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/util/TestLightWeightHashSet.java
PRE-CREATION
trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/util/TestLightWeightLinkedSet.java
PRE-CREATION
Diff: https://reviews.apache.org/r/2515/diff
Testing
-------
Provided JUnit tests.
Thanks,
Tomasz
> More CPU efficient data structure for
> under-replicated/over-replicated/invalidate blocks
> ----------------------------------------------------------------------------------------
>
> Key: HDFS-2476
> URL: https://issues.apache.org/jira/browse/HDFS-2476
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Components: name-node
> Reporter: Tomasz Nykiel
> Assignee: Tomasz Nykiel
> Attachments: hashStructures.patch, hashStructures.patch-2,
> hashStructures.patch-3, hashStructures.patch-4, hashStructures.patch-5,
> hashStructures.patch-6, hashStructures.patch-7, hashStructures.patch-8
>
>
> This patch introduces two hash data structures for storing under-replicated,
> over-replicated and invalidated blocks.
> 1. LightWeightHashSet
> 2. LightWeightLinkedSet
> Currently in all these cases we are using java.util.TreeSet which adds
> unnecessary overhead.
> The main bottlenecks addressed by this patch are:
> -cluster instability times, when these queues (especially under-replicated)
> tend to grow quite drastically,
> -initial cluster startup, when the queues are initialized, after leaving
> safemode,
> -block reports,
> -explicit acks for block addition and deletion
> 1. The introduced structures are CPU-optimized.
> 2. They shrink and expand according to current capacity.
> 3. Add/contains/delete ops are performed in O(1) time (unlike current log n
> for TreeSet).
> 4. The sets are equipped with fast access methods for polling a number of
> elements (get+remove), which are used for handling the queues.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
