[ 
https://issues.apache.org/jira/browse/HADOOP-18528?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Steve Loughran resolved HADOOP-18528.
-------------------------------------
    Fix Version/s: 3.4.0
                   3.3.5
     Release Note: 
ABFS block prefetching has been disabled to avoid HADOOP-18521 and buffer 
sharing on multithreaded processes (Hive, Spark etc). This will have little/no 
performance impact on queries against Parquet or ORC data, but can slow down 
sequential stream processing, including CSV files -however, the read data will 
be correct.
It may slow down distcp downloads, where the race condition does not arise. For 
maximum distcp performance re-enable the readahead by setting 
fs.abfs.enable.readahead to true.

       Resolution: Fixed

> ABFS: Disable readAhead/prefetching by default
> ----------------------------------------------
>
>                 Key: HADOOP-18528
>                 URL: https://issues.apache.org/jira/browse/HADOOP-18528
>             Project: Hadoop Common
>          Issue Type: Bug
>          Components: fs/azure
>    Affects Versions: 3.3.4
>            Reporter: Mehakmeet Singh
>            Assignee: Mehakmeet Singh
>            Priority: Major
>              Labels: pull-request-available
>             Fix For: 3.4.0, 3.3.5
>
>
> After the addition of HADOOP-18517, we should disable readAhead by default to 
> mitigate inconsistent read results caused by ABFS prefetching, HADOOP-18521.
> As an urgent fix: Disable readAhead/prefetch, tracked for 3.3.5.
> Long-term fix: HADOOP-18521, tracked for 3.3.6.



--
This message was sent by Atlassian Jira
(v8.20.10#820010)

---------------------------------------------------------------------
To unsubscribe, e-mail: common-dev-unsubscr...@hadoop.apache.org
For additional commands, e-mail: common-dev-h...@hadoop.apache.org

Reply via email to