[
https://issues.apache.org/jira/browse/HADOOP-17028?focusedWorklogId=479301&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-479301
]
ASF GitHub Bot logged work on HADOOP-17028:
-------------------------------------------
Author: ASF GitHub Bot
Created on: 05/Sep/20 06:18
Start Date: 05/Sep/20 06:18
Worklog Time Spent: 10m
Work Description: umamaheswararao edited a comment on pull request #2260:
URL: https://github.com/apache/hadoop/pull/2260#issuecomment-687277527
Thanks @steveloughran for review!
In addition to his comments, I have the following question/comment.
In practice, I am thinking this lazy initialization will not give us real
benefit in the following case with MR/YARN.
In DelegationTokenIssuer#collectDelegationTokens, it will try to get tokens
from all children.
```
// Now collect the tokens from the children.
final DelegationTokenIssuer[] ancillary =
issuer.getAdditionalTokenIssuers();
if (ancillary != null) {
for (DelegationTokenIssuer subIssuer : ancillary) {
collectDelegationTokens(subIssuer, renewer, credentials, tokens);
}
}
```
I am wondering this call will make all fs to be initialized. That means we
are not getting this lazy initialization benefit fully.
Did you consider this case?
Is there a way to avoid this ? MR/YARN team can suggest something if we have
alternative way to load tokens.
CC: @wangdatan @sunilgovind @rohithsharmaks
CC: @xiaoyuyao
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
Issue Time Tracking
-------------------
Worklog Id: (was: 479301)
Time Spent: 2h 10m (was: 2h)
> ViewFS should initialize target filesystems lazily
> --------------------------------------------------
>
> Key: HADOOP-17028
> URL: https://issues.apache.org/jira/browse/HADOOP-17028
> Project: Hadoop Common
> Issue Type: Bug
> Components: client-mounts, fs, viewfs
> Affects Versions: 3.2.1
> Reporter: Uma Maheswara Rao G
> Assignee: Abhishek Das
> Priority: Major
> Labels: pull-request-available
> Time Spent: 2h 10m
> Remaining Estimate: 0h
>
> Currently viewFS initialize all configured target filesystems when
> viewfs#init itself.
> Some target file system initialization involve creating heavy objects and
> proxy connections. Ex: DistributedFileSystem#initialize will create DFSClient
> object which will create proxy connections to NN etc.
> For example: if ViewFS configured with 10 target fs with hdfs uri and 2
> targets with s3a.
> If one of the client only work with s3a target, But ViewFS will initialize
> all targets irrespective of what clients interested to work with. That means,
> here client will create 10 DFS initializations and 2 s3a initializations. Its
> unnecessary to have DFS initialization here. So, it will be a good idea to
> initialize the target fs only when first time usage call come to particular
> target fs scheme.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
