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Rahul Challapalli commented on DRILL-4831: ------------------------------------------ Related Issue : On random occasions we do not read from the metadata cache even when the cache file is supposedly there (since I just ran the refresh metadata command). This points to a question whether updating the metadata cache file is atomic or not? > Running refresh table metadata concurrently randomly fails with > JsonParseException > ---------------------------------------------------------------------------------- > > Key: DRILL-4831 > URL: https://issues.apache.org/jira/browse/DRILL-4831 > Project: Apache Drill > Issue Type: Bug > Components: Metadata > Affects Versions: 1.8.0 > Reporter: Rahul Challapalli > Attachments: error.log, l_3level.tgz > > > git.commit.id.abbrev=f476eb5 > Just run the below command concurrently from 10 different JDBC connections. > There is a likelihood that you might encounter the below error > Extracts from the log > {code} > Caused By (java.lang.AssertionError) Internal error: Error while applying > rule DrillPushProjIntoScan, args > [rel#189411:LogicalProject.NONE.ANY([]).[](input=rel#189289:Subset#3.ENUMERABLE.ANY([]).[],l_orderkey=$1,dir0=$2,dir1=$3,dir2=$4,l_shipdate=$5,l_extendedprice=$6,l_discount=$7), > rel#189233:EnumerableTableScan.ENUMERABLE.ANY([]).[](table=[dfs, > metadata_caching_pp, l_3level])] > org.apache.calcite.util.Util.newInternal():792 > org.apache.calcite.plan.volcano.VolcanoRuleCall.onMatch():251 > ..... > ..... > java.lang.Thread.run():745 > Caused By (org.apache.drill.common.exceptions.DrillRuntimeException) > com.fasterxml.jackson.core.JsonParseException: Illegal character ((CTRL-CHAR, > code 0)): only regular white space (\r, \n, \t) is allowed between tokens > at [Source: com.mapr.fs.MapRFsDataInputStream@57a574a8; line: 1, column: 2] > org.apache.drill.exec.planner.logical.DrillPushProjIntoScan.onMatch():95 > {code} > Attached the complete log message and the data set -- This message was sent by Atlassian JIRA (v6.3.4#6332)