What causes "Problem closing resources for segment[%s]" in apache/druid?

Check the wrapped cause for the root I/O problem (disk errors, fd limits) and fix the underlying storage issue

apache/druid · error · RE

Problem closing resources for segment

Error message

Problem closing resources for segment[%s]

What it means

SegmentToRowsAndColumnsOperator wraps its segment conversion in try/catch to release segment resources on failure (close() may throw IOException). When closing the segment's resources fails, the original error path surfaces as this RE naming the segment id.

Solutions

Check the wrapped cause for the root I/O problem (disk errors, fd limits) and fix the underlying storage issue
Increase file descriptor limits (ulimit) if handles are exhausted on busy historicals
Retry the query; if reproducible, inspect the specific segment's backing files for corruption

Defensive patterns

Strategy: try-catch

Try / catch

try {
  operator.go(receiver, cont);
} catch (RE e) {
  if (e.getMessage() != null && e.getMessage().startsWith("Problem closing resources for segment")) {
    logger.warn(e.getCause(), "Segment cleanup failed for %s", e.getCause());
  } else throw e;
}

Prevention

Raise file descriptor limits on historical nodes running operator queries
Monitor disk I/O health; close failures usually mirror read failures
Ensure queries are cancelled through the normal path so segments close once, not concurrently

When it happens

Trigger: An IOException (or error during close in the finally path) while releasing the segment after pushing rows — typically a failure closing underlying storage used by the segment.

Common situations: Disk I/O errors or exhausted file descriptors when reading from memory-mapped/disk-backed segments, cancelled queries racing with segment cleanup, or storage device problems on historical nodes.

Related errors

AI-assisted analysis of apache/druid@9b90983fd2 (2026-09-07). Data as JSON: /api/errors/37568e24e06bb03e. Report an issue: GitHub.

Appendix: source

Thrown at processing/src/main/java/org/apache/druid/query/operator/SegmentToRowsAndColumnsOperator.java:66

        throw DruidException.defensive("Segment [%s] cannot shapeshift", segment.getDebugString());
      }
      RowsAndColumns rac;
      if (shifty instanceof RowsAndColumns) {
        rac = (RowsAndColumns) shifty;
      } else {
        rac = shifty.as(RowsAndColumns.class);
      }

      if (rac == null) {
        throw new ISE("Cannot work with segment of type[%s]", segment.getClass());
      }

      // After pushing in a single object, we are done, so ignore the signal and call completed()
      receiver.push(rac);
      receiver.completed();
    }
    catch (IOException e) {
      throw new RE(e, "Problem closing resources for segment[%s]", segment.getId());
    }
    return null;
  }
}

View on GitHub (pinned to 9b90983fd2)