[ 
https://issues.apache.org/jira/browse/HIVE-20682?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16679358#comment-16679358
 ] 

Hive QA commented on HIVE-20682:
--------------------------------

| (/) *{color:green}+1 overall{color}* |
\\
\\
|| Vote || Subsystem || Runtime || Comment ||
|| || || || {color:brown} Prechecks {color} ||
| {color:green}+1{color} | {color:green} @author {color} | {color:green}  0m  
0s{color} | {color:green} The patch does not contain any @author tags. {color} |
|| || || || {color:brown} master Compile Tests {color} ||
| {color:blue}0{color} | {color:blue} mvndep {color} | {color:blue}  0m 
27s{color} | {color:blue} Maven dependency ordering for branch {color} |
| {color:green}+1{color} | {color:green} mvninstall {color} | {color:green}  8m 
 4s{color} | {color:green} master passed {color} |
| {color:green}+1{color} | {color:green} compile {color} | {color:green}  1m 
58s{color} | {color:green} master passed {color} |
| {color:green}+1{color} | {color:green} checkstyle {color} | {color:green}  1m 
 9s{color} | {color:green} master passed {color} |
| {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue}  0m 
35s{color} | {color:blue} itests/hive-unit in master has 2 extant Findbugs 
warnings. {color} |
| {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue}  3m 
41s{color} | {color:blue} ql in master has 2315 extant Findbugs warnings. 
{color} |
| {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue}  0m 
35s{color} | {color:blue} service in master has 48 extant Findbugs warnings. 
{color} |
| {color:green}+1{color} | {color:green} javadoc {color} | {color:green}  1m 
33s{color} | {color:green} master passed {color} |
|| || || || {color:brown} Patch Compile Tests {color} ||
| {color:blue}0{color} | {color:blue} mvndep {color} | {color:blue}  0m 
10s{color} | {color:blue} Maven dependency ordering for patch {color} |
| {color:green}+1{color} | {color:green} mvninstall {color} | {color:green}  2m 
22s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} compile {color} | {color:green}  1m 
58s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} javac {color} | {color:green}  1m 
58s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} checkstyle {color} | {color:green}  0m 
19s{color} | {color:green} The patch hive-unit passed checkstyle {color} |
| {color:green}+1{color} | {color:green} checkstyle {color} | {color:green}  0m 
38s{color} | {color:green} ql: The patch generated 0 new + 218 unchanged - 2 
fixed = 218 total (was 220) {color} |
| {color:green}+1{color} | {color:green} checkstyle {color} | {color:green}  0m 
13s{color} | {color:green} The patch service passed checkstyle {color} |
| {color:green}+1{color} | {color:green} whitespace {color} | {color:green}  0m 
 0s{color} | {color:green} The patch has no whitespace issues. {color} |
| {color:green}+1{color} | {color:green} findbugs {color} | {color:green}  5m 
10s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} javadoc {color} | {color:green}  1m 
33s{color} | {color:green} the patch passed {color} |
|| || || || {color:brown} Other Tests {color} ||
| {color:green}+1{color} | {color:green} asflicense {color} | {color:green}  0m 
12s{color} | {color:green} The patch does not generate ASF License warnings. 
{color} |
| {color:black}{color} | {color:black} {color} | {color:black} 31m 20s{color} | 
{color:black} {color} |
\\
\\
|| Subsystem || Report/Notes ||
| Optional Tests |  asflicense  javac  javadoc  findbugs  checkstyle  compile  |
| uname | Linux hiveptest-server-upstream 3.16.0-4-amd64 #1 SMP Debian 
3.16.36-1+deb8u1 (2016-09-03) x86_64 GNU/Linux |
| Build tool | maven |
| Personality | 
/data/hiveptest/working/yetus_PreCommit-HIVE-Build-14804/dev-support/hive-personality.sh
 |
| git revision | master / 840dd43 |
| Default Java | 1.8.0_111 |
| findbugs | v3.0.0 |
| modules | C: itests/hive-unit ql service U: . |
| Console output | 
http://104.198.109.242/logs//PreCommit-HIVE-Build-14804/yetus.txt |
| Powered by | Apache Yetus    http://yetus.apache.org |


This message was automatically generated.



> Async query execution can potentially fail if shared sessionHive is closed by 
> master thread.
> --------------------------------------------------------------------------------------------
>
>                 Key: HIVE-20682
>                 URL: https://issues.apache.org/jira/browse/HIVE-20682
>             Project: Hive
>          Issue Type: Bug
>          Components: HiveServer2
>    Affects Versions: 3.1.0, 4.0.0
>            Reporter: Sankar Hariappan
>            Assignee: Sankar Hariappan
>            Priority: Major
>              Labels: pull-request-available
>         Attachments: HIVE-20682.01.patch, HIVE-20682.02.patch, 
> HIVE-20682.03.patch, HIVE-20682.04.patch, HIVE-20682.05.patch, 
> HIVE-20682.06.patch
>
>
> *Problem description:*
> The master thread initializes the *sessionHive* object in *HiveSessionImpl* 
> class when we open a new session for a client connection and by default all 
> queries from this connection shares the same sessionHive object. 
> If the master thread executes a *synchronous* query, it closes the 
> sessionHive object (referred via thread local hiveDb) if  
> {{Hive.isCompatible}} returns false and sets new Hive object in thread local 
> HiveDb but doesn't change the sessionHive object in the session. Whereas, 
> *asynchronous* query execution via async threads never closes the sessionHive 
> object and it just creates a new one if needed and sets it as their thread 
> local hiveDb.
> So, the problem can happen in the case where an *asynchronous* query is being 
> executed by async threads refers to sessionHive object and the master thread 
> receives a *synchronous* query that closes the same sessionHive object. 
> Also, each query execution overwrites the thread local hiveDb object to 
> sessionHive object which potentially leaks a metastore connection if the 
> previous synchronous query execution re-created the Hive object.
> *Possible Fix:*
> The *sessionHive* object could be shared my multiple threads and so it 
> shouldn't be allowed to be closed by any query execution threads when they 
> re-create the Hive object due to changes in Hive configurations. But the Hive 
> objects created by query execution threads should be closed when the thread 
> exits.
> So, it is proposed to have an *isAllowClose* flag (default: *true*) in Hive 
> object which should be set to *false* for *sessionHive* and would be 
> forcefully closed when the session is closed or released.
> Also, when we reset *sessionHive* object with new one due to changes in 
> *sessionConf*, the old one should be closed when no async thread is referring 
> to it. This can be done using "*finalize*" method of Hive object where we can 
> close HMS connection when Hive object is garbage collected.
> cc [~pvary]



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

Reply via email to