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Hive QA commented on HIVE-20682: -------------------------------- | (x) *{color:red}-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 29s{color} | {color:blue} Maven dependency ordering for branch {color} | | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 7m 45s{color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 2m 4s{color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 1m 10s{color} | {color:green} master passed {color} | | {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue} 0m 38s{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 40s{color} | {color:blue} ql in master has 2315 extant Findbugs warnings. {color} | | {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue} 0m 36s{color} | {color:blue} service in master has 48 extant Findbugs warnings. {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 1m 31s{color} | {color:green} master passed {color} | || || || || {color:brown} Patch Compile Tests {color} || | {color:blue}0{color} | {color:blue} mvndep {color} | {color:blue} 0m 9s{color} | {color:blue} Maven dependency ordering for patch {color} | | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 2m 21s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 1m 59s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} javac {color} | {color:green} 1m 59s{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 12s{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:red}-1{color} | {color:red} findbugs {color} | {color:red} 3m 49s{color} | {color:red} ql generated 1 new + 2315 unchanged - 0 fixed = 2316 total (was 2315) {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 1m 31s{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 14s{color} | {color:black} {color} | \\ \\ || Reason || Tests || | FindBugs | module:ql | | | org.apache.hadoop.hive.ql.metadata.Hive.finalize() is public; should be protected At Hive.java:protected At Hive.java:[lines 419-421] | \\ \\ || 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-14703/dev-support/hive-personality.sh | | git revision | master / f3fab45 | | Default Java | 1.8.0_111 | | findbugs | v3.0.0 | | findbugs | http://104.198.109.242/logs//PreCommit-HIVE-Build-14703/yetus/new-findbugs-ql.html | | modules | C: itests/hive-unit ql service U: . | | Console output | http://104.198.109.242/logs//PreCommit-HIVE-Build-14703/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 > > > *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)