[
https://issues.apache.org/jira/browse/HDFS-16821?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17624183#comment-17624183
]
ASF GitHub Bot commented on HDFS-16821:
---------------------------------------
simbadzina opened a new pull request, #5078:
URL: https://github.com/apache/hadoop/pull/5078
<!--
Thanks for sending a pull request!
1. If this is your first time, please read our contributor guidelines:
https://cwiki.apache.org/confluence/display/HADOOP/How+To+Contribute
2. Make sure your PR title starts with JIRA issue id, e.g.,
'HADOOP-17799. Your PR title ...'.
-->
### Fixes regression in HDFS-13522 that enables observer reads by default
### Refactored existing unit tests and added a new one
**testReadWithoutObserverClientConfigurations** that failing before code change
but not passes with the regression fixed.
### For code changes:
- [ x] Does the title or this PR starts with the corresponding JIRA issue id
(e.g. 'HADOOP-17799. Your PR title ...')?
> Fix regression in HDFS-13522 that enables observer reads by default.
> --------------------------------------------------------------------
>
> Key: HDFS-16821
> URL: https://issues.apache.org/jira/browse/HDFS-16821
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: hdfs
> Reporter: Simbarashe Dzinamarira
> Assignee: Simbarashe Dzinamarira
> Priority: Major
>
> Serving reads consistently from Observer Namenodes is a feature that was
> introduced in HDFS-12943.
> Clients opt-into this feature by configuring the ObserverReadProxyProvider.
> It is important that the opt-in is explicit because for third-party reads to
> remain consistent, these clients then need to perform an msync before reads.
> In HDFS-13522, the ClientGSIContext is implicitly added to the DFSClient thus
> enabling Observer reads for all clients by default. This breaks consistency
> guarantees for clients that haven't opted into observer reads.
> [https://github.com/apache/hadoop/pull/4883/files#diff-a627e2c1f3e68235520d3c28092f4ae8a41aa4557cc530e4e6862c318be7e898R352-R354]
> We need to return to the old behavior of only using the ClientGSIContext when
> users have explicitly opted into Observer reads.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
