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ql/src/java/org/apache/hadoop/hive/ql/Driver.java (line 193)
<https://reviews.apache.org/r/52559/#comment221144>

    comments for closed, destroyed, error and interrupt states would be useful



ql/src/java/org/apache/hadoop/hive/ql/Driver.java (line 379)
<https://reviews.apache.org/r/52559/#comment221130>

    nit: here and elsewhere, lock should be outside of the try, since we don't 
want to call unlock if the lock call itself fails



ql/src/java/org/apache/hadoop/hive/ql/Driver.java (line 611)
<https://reviews.apache.org/r/52559/#comment221138>

    this will overwrite the previous error (this being finally) without logging 
it (other than to console). In fact the original error if any is probably more 
useful to the user...



ql/src/java/org/apache/hadoop/hive/ql/Driver.java (line 629)
<https://reviews.apache.org/r/52559/#comment221139>

    this ignores downstreamError. By design? Same for similar code below. The 
existing code with this pattern returns immediately in the catch that sets 
downstreamError, but here the execution can continue from the above catch



ql/src/java/org/apache/hadoop/hive/ql/Driver.java (line 1399)
<https://reviews.apache.org/r/52559/#comment221133>

    nit: typo
    
    also is it really true for every other possible state?



ql/src/java/org/apache/hadoop/hive/ql/Driver.java (line 1557)
<https://reviews.apache.org/r/52559/#comment221135>

    some interrupt-related return paths in the try above will result in 
isFinishedWithError being true here... it seems like that's by design right now 
because error and interrupt conditions are not distinguished here. It might be 
helpful to adcd a comment



ql/src/java/org/apache/hadoop/hive/ql/Driver.java (line 1989)
<https://reviews.apache.org/r/52559/#comment221141>

    same as above - should we return here? seems like the below ignores 
downstreamError on some paths



ql/src/java/org/apache/hadoop/hive/ql/Driver.java (line 2245)
<https://reviews.apache.org/r/52559/#comment221142>

    does it have to throw here or can it just exit? the old code seems to only 
do stuff when in the right state, and nothing in the wrong state



ql/src/java/org/apache/hadoop/hive/ql/Driver.java (line 2390)
<https://reviews.apache.org/r/52559/#comment221143>

    I don't see an explicit check for this state anywhere in the code, except 
for some error paths. What is setting driver state to destroyed supposed to 
trigger?


- Sergey Shelukhin


On Oct. 11, 2016, 10:12 p.m., Chaoyu Tang wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/52559/
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> 
> (Updated Oct. 11, 2016, 10:12 p.m.)
> 
> 
> Review request for hive, Sergey Shelukhin, Thejas Nair, Vaibhav Gumashta, and 
> Yongzhi Chen.
> 
> 
> Bugs: HIVE-14799
>     https://issues.apache.org/jira/browse/HIVE-14799
> 
> 
> Repository: hive-git
> 
> 
> Description
> -------
> 
> This patch is going to fix a couple of Driver issues related to the close 
> request from a thread other than the one running the query (e.g. from 
> SQLOperation cancel via Timeout or Ctrl-C):
> 1. Driver is not thread safe and usually supports only one thread at time 
> since it has variables like ctx, plan which are not thread protected. But 
> certain special use cases need access the Driver objects from multiply 
> threads. For example, when a query runs in a background thread, driver.close 
> is invoked in another thread by the query timeout (see HIVE-4924). The close 
> process could nullify the shared variables like ctx which could cause NPE in 
> the other query thread which is using them. This runtime exception is 
> unpredictable and not well handled in the code. Some resources (e.g. locks, 
> files) are left behind and not be cleaned because there are no more available 
> = references to them. In this patch, I use the waiting in the close which 
> makes sure only one thread uses these variables and the resource cleaning 
> happens after the query finished (or interrupted).
> 2. SQLOperation.cancel sends the interrupt signal to the background thread 
> running the query (via backgroundHandle.cancel(true)) but it could not stop 
> that process since there is no code to capture the signal in the process. In 
> another word, current timeout code could not gracefully and promptly stop the 
> query process, though it could eventually stop the process by killing the 
> running tasks (e.g. MapRedTask) via driverContext.shutdown (see HIVE-5901). 
> So in the patch, I added a couple of checkpoints to intercept the interrupt 
> signal either set by close method (a volatile variable) or thread.interrupt. 
> They should be helpful to capture these signals earlier , though not 
> intermediately.
> 
> 
> Diffs
> -----
> 
>   ql/src/java/org/apache/hadoop/hive/ql/Driver.java dd55434 
> 
> Diff: https://reviews.apache.org/r/52559/diff/
> 
> 
> Testing
> -------
> 
> Manually tests
> Precommit tests
> 
> 
> Thanks,
> 
> Chaoyu Tang
> 
>

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