[
https://issues.apache.org/jira/browse/HDFS-16076?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17367256#comment-17367256
]
tomscut commented on HDFS-16076:
--------------------------------
The main code changes are as follows：
org.apache.hadoop.hdfs.DFSUtil#StaleAndSlowComparator#compare()
{code:java}
@Override
public int compare(DatanodeInfo a, DatanodeInfo b) {
int ret = super.compare(a, b);
if (ret != 0) {
return ret;
}
// Stale nodes will be moved behind the normal nodes
if (avoidStaleDataNodesForRead) {
boolean aStale = a.isStale(staleInterval);
boolean bStale = b.isStale(staleInterval);
ret = aStale == bStale ? 0 : (aStale ? 1 : -1);
if (ret != 0) {
return ret;
}
}
// Slow nodes will be moved behind the normal nodes
if (avoidSlowDataNodesForRead) {
boolean aSlow = slowNodesUuidSet.contains(a.getDatanodeUuid());
boolean bSlow = slowNodesUuidSet.contains(b.getDatanodeUuid());
ret = aSlow == bSlow ? 0 : (aSlow ? 1 : -1);
}
return ret;
}
{code}
> Avoid using slow DataNodes for reading by sorting locations
> -----------------------------------------------------------
>
> Key: HDFS-16076
> URL: https://issues.apache.org/jira/browse/HDFS-16076
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: hdfs
> Reporter: tomscut
> Assignee: tomscut
> Priority: Major
> Labels: pull-request-available
> Time Spent: 1h 10m
> Remaining Estimate: 0h
>
> After sorting the expected location list will be: live -> slow -> stale ->
> staleAndSlow -> entering_maintenance -> decommissioned. This reduces the
> probability that slow nodes will be used for reading.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
