Received query error with Postgres VG

There was 1 query running on Stardog and it was loaded onto a 64G memory VM!

WARN  2020-07-18 06:02:58,757 [stardog-user-8] com.complexible.stardog.protocols.http.server.StardogUndertowErrorHandler:accept(64): Unexpected exception was handled by the server
org.postgresql.util.PSQLException: ERROR: could not resize shared memory segment "/PostgreSQL.649798421" to 8388608 bytes: No space left on device
  Where: parallel worker
        at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2533) ~[postgresql-42.2.12.jar:42.2.12]
        at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2268) ~[postgresql-42.2.12.jar:42.2.12]
        at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:313) ~[postgresql-42.2.12.jar:42.2.12]
        at org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:448) ~[postgresql-42.2.12.jar:42.2.12]
        at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:369) ~[postgresql-42.2.12.jar:42.2.12]
        at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:310) ~[postgresql-42.2.12.jar:42.2.12]
        at org.postgresql.jdbc.PgStatement.executeCachedSql(PgStatement.java:296) ~[postgresql-42.2.12.jar:42.2.12]
        at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:273) ~[postgresql-42.2.12.jar:42.2.12]
        at org.postgresql.jdbc.PgStatement.executeQuery(PgStatement.java:226) ~[postgresql-42.2.12.jar:42.2.12]
        at sun.reflect.GeneratedMethodAccessor12.invoke(Unknown Source) ~[?:?]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_252]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_252]
        at org.apache.tomcat.jdbc.pool.StatementFacade$StatementProxy.invoke(StatementFacade.java:114) ~[tomcat-jdbc-9.0.24.jar:?]
        at com.sun.proxy.$Proxy81.executeQuery(Unknown Source) ~[?:?]
        at com.complexible.stardog.virtual.vega.rdbms.RdbmsRelExecutor.execute(RdbmsRelExecutor.java:54) ~[stardog-virtual-core-7.3.2.jar:?]
        at com.complexible.stardog.virtual.vega.VirtualServiceQuery.execute(VirtualServiceQuery.java:187) ~[stardog-virtual-core-7.3.2.jar:?]
        at com.complexible.stardog.virtual.vega.VirtualServiceQuery.evaluate(VirtualServiceQuery.java:200) ~[stardog-virtual-core-7.3.2.jar:?]
        at com.complexible.stardog.plan.eval.operator.impl.ServiceOperatorImpl.computeNext(ServiceOperatorImpl.java:93) ~[stardog-7.3.2.jar:?]
        at com.complexible.stardog.plan.eval.operator.impl.ServiceOperatorImpl.computeNext(ServiceOperatorImpl.java:29) ~[stardog-7.3.2.jar:?]
        at com.complexible.common.collect.AbstractSkippingIterator.tryToComputeNext(AbstractSkippingIterator.java:147) ~[stardog-utils-common-7.3.2.jar:?]
        at com.complexible.common.collect.AbstractSkippingIterator.hasNext(AbstractSkippingIterator.java:134) ~[stardog-utils-common-7.3.2.jar:?]
        at com.complexible.stardog.plan.eval.operator.impl.ProjectionOp.computeNext(ProjectionOp.java:125) ~[stardog-7.3.2.jar:?]
        at com.complexible.stardog.plan.eval.operator.impl.ProjectionOp.computeNext(ProjectionOp.java:32) ~[stardog-7.3.2.jar:?]
        at com.complexible.common.collect.AbstractSkippingIterator.tryToComputeNext(AbstractSkippingIterator.java:147) ~[stardog-utils-common-7.3.2.jar:?]
        at com.complexible.common.collect.AbstractSkippingIterator.hasNext(AbstractSkippingIterator.java:134) ~[stardog-utils-common-7.3.2.jar:?]
        at com.complexible.stardog.plan.eval.operator.impl.DistinctOp.computeNext(DistinctOp.java:58) ~[stardog-7.3.2.jar:?]
        at com.complexible.stardog.plan.eval.operator.impl.DistinctOp.computeNext(DistinctOp.java:21) ~[stardog-7.3.2.jar:?]

This happens after 1 query!

Andrea

Never mind ... I think that the team providing data to us dockerized Postgres last night during a maintenance period and didn't resize shared memory.

I have been seeing terrible perf ... a query that times out from Stardog VG ... versus took 55 seconds on PSQL. This may all be related.

BUT ... when the VG queries time out, they stay in Stardog's operational environment and require a server stop/start to clean out.

Andrea