[
https://issues.apache.org/jira/browse/HDFS-13880?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16599427#comment-16599427
]
Chen Liang commented on HDFS-13880:
-----------------------------------
Thanks for the comments [~xkrogen], [~shv]
{quote}{{@ReadOnly(isMasync = true)}}. This won't help with preventing ...
{quote}
Makes sense, this can be done by setting masync to true by default, will update
in next patch.
{quote}Also, right now it is only checking the name of the method....
{quote}
Not a big fan of checking by method name personally either. But it seems this
is already what's being used on server side RPC. It is included in RPC header
and server side ProtobufRPCEngine is actually based on method name to find the
right call. So I tend to believe that it should be okay to use here. Different
protocols having same method is neither an issue because rpc header also has
{{getDeclaringClassProtocolName()}} which gives the protocol name. With this,
we can look up annotations of method in pretty much any protocol. Will leverage
this in next patch as well.
I would say the approach being taken in current patch is fine, but I'm totally
open to see how HDFS-13872 goes.
> Add mechanism to allow certain RPC calls to bypass sync
> -------------------------------------------------------
>
> Key: HDFS-13880
> URL: https://issues.apache.org/jira/browse/HDFS-13880
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Components: namenode
> Reporter: Chen Liang
> Assignee: Chen Liang
> Priority: Major
> Attachments: HDFS-13880-HDFS-12943.001.patch,
> HDFS-13880-HDFS-12943.002.patch
>
>
> Currently, every single call to NameNode will be synced, in the sense that
> NameNode will not process it until state id catches up. But in certain cases,
> we would like to bypass this check and allow the call to return immediately,
> even when the server id is not up to date. One case could be the to-be-added
> new API in HDFS-13749 that request for current state id. Others may include
> calls that do not promise real time responses such as {{getContentSummary}}.
> This Jira is to add the mechanism to allow certain calls to bypass sync.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
