Major Description
Local properties set via sparkContext are not available as TaskContext properties when executing jobs and threadpools have idle threads which are reused
Explanation:
When SubqueryExec, the relationFuture is evaluated via a separate thread. The threads inherit the localProperties from sparkContext as they are the child threads.
These threads are controlled via the executionContext (thread pools). Each Thread pool has a default keepAliveSeconds of 60 seconds for idle threads.
Scenarios where the thread pool has threads which are idle and reused for a subsequent new query, the thread local properties will not be inherited from spark context (thread properties are inherited only on thread creation) hence end up having old or no properties set. This will cause taskset properties to be missing when properties are transferred by child thread via sparkContext.runJob/submitJob