[ https://issues.apache.org/jira/browse/SPARK-38684?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Apache Spark reassigned SPARK-38684: ------------------------------------ Assignee: (was: Apache Spark) > Stream-stream outer join has a possible correctness issue due to weakly read > consistent on outer iterators > ---------------------------------------------------------------------------------------------------------- > > Key: SPARK-38684 > URL: https://issues.apache.org/jira/browse/SPARK-38684 > Project: Spark > Issue Type: Bug > Components: Structured Streaming > Affects Versions: 3.2.1, 3.3.0 > Reporter: Jungtaek Lim > Priority: Blocker > Labels: correctness > > We figured out stream-stream join has the same issue with SPARK-38320 on the > appended iterators. Since the root cause is same as SPARK-38320, this is only > reproducible with RocksDB state store provider, but even with HDFS backed > state store provider, it is not guaranteed by interface contract hence may > depend on the JVM vendor, version, etc. > I can easily construct the scenario of “data loss” in state store. > Condition follows: > * Use stream-stream time interval outer join > ** left outer join has an issue on left side, right outer join has an issue > on right side, full outer join has an issue on both sides > * At batch N, produce row(s) on the problematic side which are non-late > * At the same batch (batch N), some row(s) on the problematic side should be > evicted by watermark condition > When the condition is fulfilled, out of sync happens with keyToNumValues > between state and the iterator in evict phase. If eviction of the row happens > for the grouping key (updating keyToNumValues), the eviction phase > “overwrites” keyToNumValues in the state as the value it calculates. > Given that the eviction phase “do not know” about the new rows > (keyToNumValues is out of sync), effectively discarding all rows from the > state being added in the batch N. -- This message was sent by Atlassian Jira (v8.20.1#820001) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org