[
https://issues.apache.org/jira/browse/HDFS-16439?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Work on HDFS-16439 started by JiangHua Zhu.
-------------------------------------------
> Makes calculating maxNodesPerRack simpler
> -----------------------------------------
>
> Key: HDFS-16439
> URL: https://issues.apache.org/jira/browse/HDFS-16439
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: namenode
> Affects Versions: 3.4.0
> Reporter: JiangHua Zhu
> Assignee: JiangHua Zhu
> Priority: Major
> Labels: pull-request-available
> Time Spent: 10m
> Remaining Estimate: 0h
>
> When creating a new file, it is usually necessary to communicate with the
> namenode first to obtain the location of some DataNodes as the target
> location of Blockd. At this time, when
> BlockPlacementPolicyDefault#getMaxNodesPerRack() is executed, if the number
> of replicas is very large, once it exceeds the number of all nodes in the
> cluster. The following piece of code will be executed:
> int clusterSize = clusterMap.getNumOfLeaves();
> int totalNumOfReplicas = numOfChosen + numOfReplicas;
> if (totalNumOfReplicas > clusterSize) {
> numOfReplicas -= (totalNumOfReplicas-clusterSize);
> totalNumOfReplicas = clusterSize;
> }
> Here, the calculation for numOfReplicas gets a little more complicated. It
> can be simplified like:
> numOfReplicas = clusterSize - numOfChosen
> It would be more helpful to understand it this way, while also freeing up a
> little cpu (though not a lot).
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
