Hi Josh, Glad I could help. The CursorUtil class it seems has not changed since it was first created as part of PHOENIX-3572 - and is still the same in master (I checked a bit earlier).
Sure - will have a go at creating a JIRA for this. Regards, On Tue, 21 Aug 2018 at 16:23, Josh Elser <els...@apache.org> wrote: > > Hi Jack, > > Given your assessment, it sounds like you've stumbled onto a race > condition! Thanks for bringing it to our attention. > > A few questions: > > * Have you checked if the same code exist in the latest > branches/releases (4.x-HBase-1.{2,3,4} or master)? > * Want to create a Jira issue to track this? Else, I can do this for ya. > > On 8/21/18 9:48 AM, Jack Steenkamp wrote: > > Hi All, > > > > In my application I make heavy use of Apache Phoenix's Cursors > > (https://phoenix.apache.org/cursors.html) - and for the majority of > > cases it works great and makes my life a lot easier (thanks for > > implementing them). However, in very rare cases (fiendishly rare > > cases), I get NullpointerExceptions such as the following: > > > > java.lang.NullPointerException: null > > at org.apache.phoenix.util.CursorUtil.updateCursor(CursorUtil.java:179) > > at > > org.apache.phoenix.iterate.CursorResultIterator.next(CursorResultIterator.java:46) > > at org.apache.phoenix.jdbc.PhoenixResultSet.next(PhoenixResultSet.java:779) > > > > (This is for 4.13.1 - but seems that > > org.apache.phoenix.util.CursorUtil has not changed much since it was > > first created). > > > > Upon closer inspection it would seem that on line 124 of CursorUtil, a > > HashMap is used to keep state which is then exposed via a number > > static methods, which, one has to assume, can be accessed by many > > different threads. Using a plain old HashMap in cases like these have > > (at least in my experience) been to blame for rare issues such as > > these. > > > > Would you perhaps consider changing the implementation of > > mapCursorIDQuery to a ConcurrentHashMap instead? That should hopefully > > tighten up the class and prevent any potential inconsistencies. > > > > Regards, > > > > Jack Steenkamp > >