[DRILL-6107] NullPointerException while querying MongoDB collection

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.11.0, 1.12.0
• Component/s: Server

Environment

Drill specific

export DRILL_HEAP=${DRILL_HEAP:-"1G"}
export DRILL_MAX_DIRECT_MEMORY=${DRILL_MAX_DIRECT_MEMORY:-"2G"}

Other

Memory: 8 GiB
Processor: 2 VCPU (Intel i7)
Disk: 19 GiB (13 GiB free)
OS: Ubuntu 16.06
Java: OpenJDK 1.8.0_151

• Assignee: Unassigned
• Reporter: Duarte Silva
• Created: 25/Jan/18 12:38
• Updated: 10/Jun/18 14:37

Description

I have installed Drill and configured it to connect to a MongoDB instance. That instance as a collection with a single document. When I query that collection using:

select ports from mongo.ivre.hosts;

It fails with a NullPointerException. I'm able to query that collection as long as I don't select the "ports" property. Looking at the exception stack trace and respective Drill code it is clear that the "map" variable isn't suppose to be "null".

public MapOrListWriter list(final String name) {
  assert map != null;
  return new MapOrListWriterImpl(map.list(name));
}

I couldn't figure out why it wasn't being initialized. I have attached the log and the collection BSON file. Thanks in advance.