[DRILL-1752] Drill cluster returns error when querying Mongo shards on an unsharded collection

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.6.0, 0.7.0
• Fix Version/s: 1.3.0
• Component/s: Storage - MongoDB

Environment

Drill cluster on nodes with Mongo Shards

• Assignee: Unassigned
• Reporter: Andries Engelbrecht
• Created: 19/Nov/14 22:27
• Updated: 02/Nov/15 02:59
• Resolved: 02/Nov/15 02:57

Description

Query fails on a large unsharded collection in MongoDB sharded cluster with drillbits on each node with Mongo shards.

Error message:
0: jdbc:drill:se0:5181> select * from unshard limit 2;
Query failed: Failure while setting up query. Incoming endpoints 1 is greater than number of chunks 0 [cb2121f7-eb3e-48cd-8530-474ca76c598d]

Error: exception while executing query: Failure while trying to get next result batch. (state=,code=0)

0: jdbc:drill:se0:5181> explain plan for select * from unshard limit 2;
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text

json

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00-00 Screen 00-01 SelectionVectorRemover 00-02 Limit(fetch=[2]) 00-03 Scan(groupscan=[MongoGroupScan [MongoScanSpec=MongoScanSpec [dbName=review_syn, collectionName=unshard, filters=null], columns=[SchemaPath [`*`]]]])

{ "head" : Unknown macro: { "version" } , "graph" : [ Unknown macro: { "pop" } , { "pop" : "limit", "@id" : 2, "child" : 3, "first" : 0, "last" : 2, "initialAllocation" : 1000000, "maxAllocation" : 10000000000, "cost" : 625000.0 } , { "pop" : "selection-vector-remover", "@id" : 1, "child" : 2, "initialAllocation" : 1000000, "maxAllocation" : 10000000000, "cost" : 625000.0 } , { "pop" : "screen", "@id" : 0, "child" : 1, "initialAllocation" : 1000000, "maxAllocation" : 10000000000, "cost" : 625000.0 } ] }

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