[ https://issues.apache.org/jira/browse/SPARK-22163?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Michael N reopened SPARK-22163: ------------------------------- It is obvious that you don't understand the differences between design flaws vs coding bugs, particularly you have not been able to provide the answers the the questions of 1. In the first place, why does Spark serialize the application objects *asynchronously* while the streaming application is running continuously from batch to batch ? 2. If Spark needs to do this type of serialization at all, why does it not do at the end of the batch *synchronously* ? Instead of blindly closing tickets, you need to either either find their answers and post them here or let someone else who is capable to address them. > Design Issue of Spark Streaming that Causes Random Run-time Exception > --------------------------------------------------------------------- > > Key: SPARK-22163 > URL: https://issues.apache.org/jira/browse/SPARK-22163 > Project: Spark > Issue Type: Bug > Components: DStreams, Structured Streaming > Affects Versions: 2.2.0 > Environment: Spark Streaming > Kafka > Linux > Reporter: Michael N > Priority: Critical > > The application objects can contain List and can be modified dynamically as > well. However, Spark Streaming framework asynchronously serializes the > application's objects as the application runs. Therefore, it causes random > run-time exception on the List when Spark Streaming framework happens to > serializes the application's objects while the application modifies a List in > its own object. > In fact, there are multiple bugs reported about > Caused by: java.util.ConcurrentModificationException > at java.util.ArrayList.writeObject > that are permutation of the same root cause. So the design issue of Spark > streaming framework is that it should do this serialization asynchronously. > Instead, it should either > 1. do this serialization synchronously. This is preferred to eliminate the > issue completely. Or > 2. Allow it to be configured per application whether to do this serialization > synchronously or asynchronously, depending on the nature of each application. > Also, Spark documentation should describe the conditions that trigger Spark > to do this type of serialization asynchronously, so the applications can work > around them until the fix is provided. -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org