Hi Anupam, The obvious cause is that you are running out of memory. We won’t be able to debug this unless you share your configuration and the query. Also, what version of Drill are you using? Best, — C
> On Dec 16, 2025, at 05:34, Anupam Gupta <[email protected]> > wrote: > > Hello Apache Drill Support Team, > We are currently working with Apache Drill to fetch millions to billions of > records. To support this workload, we have configured multiple Drill nodes > and are executing queries in distributed mode. > However, we are observing that only a single fragment appears to be in use at > a time, and the query does not execute as expected. During execution, the > Drill UI becomes unresponsive and breaks intermittently. > Our setup is running Apache Drill using Docker on a Windows machine. While > executing the queries, we encounter the following error in the Drillbit logs: > > Exception in thread "I/O dispatcher 6" java.lang.OutOfMemoryError: Java heap > space > > 07:07:32.552 [Curator-ConnectionStateManager-0] ERROR > o.apache.curator.utils.ThreadUtils - Unexpected exception in thread: > Thread[Curator-ConnectionStateManager-0,5,main] > > > We would appreciate your guidance on how to properly configure Apache Drill > for large-scale distributed queries and resolve the memory and execution > issues we are facing. > Thank you for your support. >
