[ 
https://issues.apache.org/jira/browse/SENTRY-1888?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16139420#comment-16139420
 ] 

Alexander Kolbasov commented on SENTRY-1888:
--------------------------------------------

[~lina.li] In the current Hive implementation the following things may happen:

1. Multiple events may have the same ID.
2. Earlier ID may appear later then more recent ID. Smaller ID values may 
appear after larger ID values.
3. No ordering assumptions can be made about events with the  same ID

> Sentry might not fetch all HMS duplicated events IDs when requested
> -------------------------------------------------------------------
>
>                 Key: SENTRY-1888
>                 URL: https://issues.apache.org/jira/browse/SENTRY-1888
>             Project: Sentry
>          Issue Type: Bug
>          Components: Sentry
>    Affects Versions: 2.0.0
>            Reporter: Sergio Peña
>            Assignee: Sergio Peña
>
> HMS does not guarantee that each notification has unique IDs. SENTRY-1803 
> solved the issue with Sentry to handle those duplicated events IDs. However, 
> HMS notifications with duplicated events IDs could appear late on the HMS 
> side due to delay issues on the DB (especially on HMS HA mode). These events 
> could not be fetched by Sentry if we already processed a duplicated event ID 
> before.
> Example:
> 1. HMS 1 attempts to persist event ID = 1
> 2. HMS 2 attempts to persist event ID = 1
> 3. HMS 1 commits event ID = 1
> 4. Sentry fetches notifications >= 1 (bringing the event from HMS 1)
> 5. HMS 2 commits event ID = 1
> 6. Sentry fetches notifications >= 2 (no events are fetched)    
> HMS 2 event ID = 1 is never fetched nor processed by Sentry.
> The above scenario could cause Sentry to be out-of-sync because of these 
> events that were not committed on time.



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

Reply via email to