hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Steve Loughran (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-12263) Revise StreamCapacities doc to describe the API usage and the requirements for customized OutputStream implemetation
Date Mon, 21 Aug 2017 11:44:00 GMT

    [ https://issues.apache.org/jira/browse/HDFS-12263?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16135063#comment-16135063
] 

Steve Loughran commented on HDFS-12263:
---------------------------------------

I'm doing this in HADOOP-13327, with some tests.

It says

# you MUST NOT declare a capability unless you really do implement the hsync/hflush operations
# you SHOULD NOT implement Syncable unless you implement the operations
# If you implement Syncable but not the operations (e.g. through subclassing). you MUST make
them no-ops (don't throw any exception), and MUST override {{hasCapability()}} to declare
that capability is not supported.
# If you implement Syncable, you MUST implement {{hasCapability()}}. (patch adds that to Azure
and ADL where appropriate)

Callers SHOULD use hasCapability() to check for behavior, and assume if a stream says it does
hsync/hflush, it is being honest. If it does not declare that it does so, assume that it doesn't
do them.




> Revise StreamCapacities doc to describe the API usage and the requirements for customized
OutputStream implemetation
> --------------------------------------------------------------------------------------------------------------------
>
>                 Key: HDFS-12263
>                 URL: https://issues.apache.org/jira/browse/HDFS-12263
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>    Affects Versions: 3.0.0-alpha4
>            Reporter: Lei (Eddy) Xu
>            Assignee: Lei (Eddy) Xu
>
> [~busbey] raised the concerns to call out what is the expected way to call {{StreamCapabilities}}
from the client side.   And this doc should also describe the rules for any {{FSOutputStream}}
implementation to follow.



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscribe@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-help@hadoop.apache.org


Mime
View raw message