[ 
https://issues.apache.org/jira/browse/HDFS-5776?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13877268#comment-13877268
 ] 

Liang Xie commented on HDFS-5776:
---------------------------------

bq. I suppose moving this into finally would be messier than what you have done 
where you add it to the end of the if and the else clauses when exception:
if we hit InvalidEncryptionKeyException or InvalidToken exception, we don't 
want to addToDeadNodes immediately before retry, so we could not move 
addToDeadNodes into a finally block,  FYI, you could refer to HDFS-5766 for the 
reason.

seems i have answered all the above comments, am i missed anyone? :) let me 
upload the new one.



> Support 'hedged' reads in DFSClient
> -----------------------------------
>
>                 Key: HDFS-5776
>                 URL: https://issues.apache.org/jira/browse/HDFS-5776
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: hdfs-client
>    Affects Versions: 3.0.0
>            Reporter: Liang Xie
>            Assignee: Liang Xie
>         Attachments: HDFS-5776-v2.txt, HDFS-5776-v3.txt, HDFS-5776.txt
>
>
> This is a placeholder of hdfs related stuff backport from 
> https://issues.apache.org/jira/browse/HBASE-7509
> The quorum read ability should be helpful especially to optimize read outliers
> we can utilize "dfs.dfsclient.quorum.read.threshold.millis" & 
> "dfs.dfsclient.quorum.read.threadpool.size" to enable/disable the hedged read 
> ability from client side(e.g. HBase), and by using DFSQuorumReadMetrics, we 
> could export the interested metric valus into client system(e.g. HBase's 
> regionserver metric).
> The core logic is in pread code path, we decide to goto the original 
> fetchBlockByteRange or the new introduced fetchBlockByteRangeSpeculative per 
> the above config items.



--
This message was sent by Atlassian JIRA
(v6.1.5#6160)

Reply via email to