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Hive QA commented on HIVE-21028: -------------------------------- | (/) *{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:green}+1{color} | {color:green} mvninstall {color} | {color:green} 7m 54s{color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 0m 24s{color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 0m 7s{color} | {color:green} master passed {color} | | {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue} 1m 5s{color} | {color:blue} standalone-metastore/metastore-server in master has 188 extant Findbugs warnings. {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 0m 17s{color} | {color:green} master passed {color} | || || || || {color:brown} Patch Compile Tests {color} || | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 0m 26s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 0m 25s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} javac {color} | {color:green} 0m 25s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 0m 7s{color} | {color:green} the patch passed {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} 1m 6s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 0m 18s{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} 12m 42s{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-15292/dev-support/hive-personality.sh | | git revision | master / a43581b | | Default Java | 1.8.0_111 | | findbugs | v3.0.0 | | modules | C: standalone-metastore/metastore-server U: standalone-metastore/metastore-server | | Console output | http://104.198.109.242/logs//PreCommit-HIVE-Build-15292/yetus.txt | | Powered by | Apache Yetus http://yetus.apache.org | This message was automatically generated. > get_table_meta should use a fetch plan to avoid race conditions ending up in > NucleusObjectNotFoundException > ----------------------------------------------------------------------------------------------------------- > > Key: HIVE-21028 > URL: https://issues.apache.org/jira/browse/HIVE-21028 > Project: Hive > Issue Type: Bug > Reporter: Karthik Manamcheri > Assignee: Karthik Manamcheri > Priority: Major > Attachments: HIVE-21028.1.patch > > > The {{getTableMeta}} call retrieves the tables, loops through the tables and > during this loop it retrieves the database object to get the containing > database name. DataNuclues does a lazy retrieval and so, when the first call > to get all the tables is done, it does not retrieve the database objects. > When this query is executed > {code}query = pm.newQuery(MTable.class, filterBuilder.toString()); > {code} > it loads all the tables, and when you do > {code} > table.getDatabase().getName() > {code} > it then goes and retrieves the database object. > *However*, there could be another thread which actually has deleted the > database!! If this happens, we end up with exceptions such as > {code} > 2018-12-04 22:25:06,525 INFO DataNucleus.Datastore.Retrieve: > [pool-7-thread-191]: Object with id > "6930391[OID]org.apache.hadoop.hive.metastore.model.MTable" not found ! > 2018-12-04 22:25:06,527 WARN DataNucleus.Persistence: [pool-7-thread-191]: > Exception thrown by StateManager.isLoaded > No such database row > org.datanucleus.exceptions.NucleusObjectNotFoundException: No such database > row > {code} > We see this happen especially with calls which retrieve all the tables in all > the databases (basically a call to get_table_meta with dbNames="\*" and > tableNames="\*"). > To avoid this, we can define a custom fetch plan and activate it only for the > get_table_meta query. This fetch plan would fetch the database object along > with the MTable object. > We would first create a fetch plan on the pmf > {code} > pmf.getFetchGroup(MTable.class, > "mtable_db_fetch_group").addMember("database"); > {code} > Then we use it just before calling the query > {code} > pm.getFetchPlan().addGroup("mtable_db_fetch_group"); > query = pm.newQuery(MTable.class, filterBuilder.toString()); > Collection<MTable> tables = (Collection<MTable>) query.executeWithArray(...); > ... > {code} > Before the API call ends, we can remove the fetch plan by > {code} > pm.getFetchPlan().removeGroup("mtable_db_fetch_group"); > {code} -- This message was sent by Atlassian JIRA (v7.6.3#76005)