[
https://issues.apache.org/jira/browse/KYLIN-1883?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Zhong Yanghong resolved KYLIN-1883.
-----------------------------------
Resolution: Fixed
> Consensus Problem when running the tool, MetadataCleanupJob
> -----------------------------------------------------------
>
> Key: KYLIN-1883
> URL: https://issues.apache.org/jira/browse/KYLIN-1883
> Project: Kylin
> Issue Type: Bug
> Reporter: Zhong Yanghong
> Assignee: Zhong Yanghong
> Attachments:
> better_solution_for_consensus_issue_of_MetadataCleanupJob.patch
>
>
> When do the cleanup, current strategy is as follows:
> 1. firstly create an referenceSet
> 2. then add items not belonging to the referenceSet to the toDeleteSet
> 3. finally delete those items in the toDeleteSet
> Consensus issue will occur since we cannot make sure that all of the items in
> toDeleteSet are not referenced in case that referenceSet changes during the
> process.
> For example, before the cleanup, SEGMENT_A is deleted and leave a DICT_A
> created at the building step. Then the referenceSet will not include DICT_A.
> After creating the reference set, SEGMENT_B is starting to build. Since
> DICT_A still exists, it can still be referenced by SEGMENT_B. Then DICT_A
> will still be included in the toDeleteSet and will be deleted later. Finally
> SEGMENT_B only owns a reference with no data.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
