[
https://issues.apache.org/jira/browse/CHUKWA-330?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12723813#action_12723813
]
Ari Rabkin commented on CHUKWA-330:
-----------------------------------
Yes. The parseArgs() method returns exactly the part of the argument used for
duplicate detection; this was intended to carry out your suggestion. I noticed
that isDuplicate would basically have to reproduce all the parsing logic from
start(), and it occurred to me that that should be factored out-- duplicating
the code would be a significant maintainance burden.
The point about "optional parts" is a good one. I think this is a
documentation-only fix -- instead of talking about optional parts, the comment
should be more explicit that the string returned is used for duplicate
detection.
As to not keeping a registry -- object creation in Java is really efficient, as
is garbage-collecting short-lived objects so I think the overhead of creating
an object, and throwing it away if that adaptor already exists, is OK.
(Particularly since it avoids a hash lookup) Adding more shared datastructures
is unappealing -- each new datastructure needs a synchronization scheme, and
introduces the posibility of subtle bugs.
> controller should not create duplicates for adaptors with offsets
> -----------------------------------------------------------------
>
> Key: CHUKWA-330
> URL: https://issues.apache.org/jira/browse/CHUKWA-330
> Project: Hadoop Chukwa
> Issue Type: Bug
> Components: input tools
> Reporter: Ari Rabkin
> Assignee: Ari Rabkin
> Priority: Blocker
> Fix For: 0.2.0, 0.3.0
>
> Attachments: CHUKWA-330-big.patch, CHUKWA-330.patch
>
> Original Estimate: 1.5h
> Remaining Estimate: 1.5h
>
> The offset-of-first-byte param to FileTailingAdaptor is hashed into the
> default adaptor name. This changes the semantics of adaptor uniqueness, and
> broke metrics and the log4jappender.
> Proposed fix:
> Add a new "addByName()" method to ChukwaAgentController that lets callers
> specify names.
> Use this new method whenever finer control of adaptor uniqueness is needed.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
