James Taylor commented on OMID-102:

[~ohads] - Jenkins build is failing for an unrelated reason. See 
[https://builds.apache.org/job/Phoenix-omid2/77/console.] Not sure if something 
is down in maven land or there's a problem. You can try manually running the 
Phoenix unit tests locally and report back.

> Implement visibility filter as pure HBase Filter
> ------------------------------------------------
>                 Key: OMID-102
>                 URL: https://issues.apache.org/jira/browse/OMID-102
>             Project: Apache Omid
>          Issue Type: Sub-task
>            Reporter: James Taylor
>            Assignee: Yonatan Gottesman
>            Priority: Major
> The way Omid currently filters through it's own RegionScanner won't work the 
> way it's implemented (i.e. the way the filtering is done *after* the next 
> call). The reason is that the state of HBase filters get messed up since 
> these filters will start to see cells that it shouldn't (i.e. cells that 
> would be filtered based on snapshot isolation). It cannot be worked around by 
> manually running filters afterwards because filters may issue seek calls 
> which are handled during the running of scans by HBase.
> Instead, the filtering needs to be implemented as a pure HBase filter and 
> that filter needs to delegate to the other, delegate filter once it's 
> determined that the cell is visible. See Tephra's TransactionVisibilityFilter 
> and they way it calls the delegate filter (cellFilters) only after it's 
> determined that the cell is visible. You may run into TEPHRA-169 without 
> including the CellSkipFilter too. 
> Because it'll be easier if you see shadow cells *before* their corresponding 
> real cells you can prefix instead of suffix the column qualifiers to 
> guarantee that you'd see the shadow cells prior to the actual cells. Or you 
> could buffer cells in your filter prior to omitting them. Another issue would 
> be if the shadow cells aren't found and you need to consult the commit table 
> - I suppose if the shadow cells are first, this logic would be easier to know 
> when it needs to be called.
> To reproduce, see the Phoenix unit tests 
> FlappingTransactionIT.testInflightUpdateNotSeen() and 
> testInflightDeleteNotSeen().

This message was sent by Atlassian JIRA

Reply via email to