hive-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "william zhu (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (HIVE-6831) The job schedule in condition task could not be correct with skewed join optimization
Date Thu, 03 Apr 2014 10:09:18 GMT

     [ https://issues.apache.org/jira/browse/HIVE-6831?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

william zhu updated HIVE-6831:
------------------------------

    Attachment: 6831.patch

> The job schedule in condition task could not be correct with skewed join optimization
> -------------------------------------------------------------------------------------
>
>                 Key: HIVE-6831
>                 URL: https://issues.apache.org/jira/browse/HIVE-6831
>             Project: Hive
>          Issue Type: Bug
>          Components: Query Processor
>    Affects Versions: 0.11.0
>         Environment: Hive 0.11.0
>            Reporter: william zhu
>         Attachments: 6831.patch
>
>
> Code isnippet in ConditionalTask.java we can see : 
>     // resolved task
>         if (driverContext.addToRunnable(tsk)) {
>           console.printInfo(tsk.getId() + " is selected by condition resolver.");
>     }
> The selected task be added into the runnable queue immediately without any dependency
checking. If the selected task is original task ,and its parent task is not being executed,
then the result will be incorrect.
> Like this:
> 1. Before skew join optimization:
> Step1 ,Step 2 <-- step 3   ( Step1 and Step2 is Step 3's parent)
> 2. after skew join optimization:
> Step1 <- Step4 (ConditionTask)<- consists of [Step3,Step10]    
> Step2 <- Step5 (ConditionTask)<- consists of [Step3,Step11]
> 3. Runing
> Step3 is selected in Step4 and Step5
> Step3 will be execute immediately after Step4 , its not correct.
> Step3 will be execute after Step5 again, its not correct either.
> 4. The correct scheduler is that step3 will be execute after step4 and step5.
> 5. So, I add a checking operate in the snippet  as bellow:
>         if (!driverContext.getRunnable().contains(tsk)) {
>           console.printInfo(tsk.getId() + " is selected by condition resolver.");
>           if(DriverContext.isLaunchable(tsk)){
>         	 // run the original task now
>         	  driverContext.addToRunnable(tsk);
>           }
>         }
> So , that is work right for me in my enviroment. I am not sure whether it will has some
problems  in someother condition. 



--
This message was sent by Atlassian JIRA
(v6.2#6252)

Mime
View raw message