[DRILL-5804] External Sort times out, may be infinite loop

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.11.0
• Fix Version/s: 1.12.0
• Component/s: Execution - Relational Operators
• Assignee: Paul Rogers
• Reporter: Robert Hou
• Created: 19/Sep/17 20:02
• Updated: 17/Oct/17 23:12
• Resolved: 17/Oct/17 23:12

Description

Query is:

ALTER SESSION SET `exec.sort.disable_managed` = false;
select count(*) from (
  select * from (
    select s1.type type, flatten(s1.rms.rptd) rptds, s1.rms, s1.uid 
    from (
      select d.type type, d.uid uid, flatten(d.map.rm) rms from dfs.`/drill/testdata/resource-manager/nested_large` d order by d.uid
    ) s1
  ) s2
  order by s2.rms.mapid, s2.rptds.a, s2.rptds.do_not_exist
);

Plan is:

| 00-00    Screen
00-01      Project(EXPR$0=[$0])
00-02        StreamAgg(group=[{}], EXPR$0=[$SUM0($0)])
00-03          UnionExchange
01-01            StreamAgg(group=[{}], EXPR$0=[COUNT()])
01-02              Project($f0=[0])
01-03                SingleMergeExchange(sort0=[4 ASC], sort1=[5 ASC], sort2=[6 ASC])
02-01                  SelectionVectorRemover
02-02                    Sort(sort0=[$4], sort1=[$5], sort2=[$6], dir0=[ASC], dir1=[ASC], dir2=[ASC])
02-03                      Project(type=[$0], rptds=[$1], rms=[$2], uid=[$3], EXPR$4=[$4], EXPR$5=[$5], EXPR$6=[$6])
02-04                        HashToRandomExchange(dist0=[[$4]], dist1=[[$5]], dist2=[[$6]])
03-01                          UnorderedMuxExchange
04-01                            Project(type=[$0], rptds=[$1], rms=[$2], uid=[$3], EXPR$4=[$4], EXPR$5=[$5], EXPR$6=[$6], E_X_P_R_H_A_S_H_F_I_E_L_D=[hash32AsDouble($6, hash32AsDouble($5, hash32AsDouble($4, 1301011)))])
04-02                              Project(type=[$0], rptds=[$1], rms=[$2], uid=[$3], EXPR$4=[ITEM($2, 'mapid')], EXPR$5=[ITEM($1, 'a')], EXPR$6=[ITEM($1, 'do_not_exist')])
04-03                                Flatten(flattenField=[$1])
04-04                                  Project(type=[$0], rptds=[ITEM($2, 'rptd')], rms=[$2], uid=[$1])
04-05                                    SingleMergeExchange(sort0=[1 ASC])
05-01                                      SelectionVectorRemover
05-02                                        Sort(sort0=[$1], dir0=[ASC])
05-03                                          Project(type=[$0], uid=[$1], rms=[$2])
05-04                                            HashToRandomExchange(dist0=[[$1]])
06-01                                              UnorderedMuxExchange
07-01                                                Project(type=[$0], uid=[$1], rms=[$2], E_X_P_R_H_A_S_H_F_I_E_L_D=[hash32AsDouble($1, 1301011)])
07-02                                                  Flatten(flattenField=[$2])
07-03                                                    Project(type=[$0], uid=[$1], rms=[ITEM($2, 'rm')])
07-04                                                      Scan(groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=maprfs:///drill/testdata/resource-manager/nested_large]], selectionRoot=maprfs:/drill/testdata/resource-manager/nested_large, numFiles=1, usedMetadataFile=false, columns=[`type`, `uid`, `map`.`rm`]]])

Here is a segment of the drillbit.log, starting at line 55890:

2017-09-19 04:22:56,258 [263f0252-fc60-7f8d-a1b1-c075876d1bd2:frag:2:2] DEBUG o.a.d.e.t.g.SingleBatchSorterGen44 - Took 142 us to sort 1023 records
2017-09-19 04:22:56,265 [263f0252-fc60-7f8d-a1b1-c075876d1bd2:frag:2:4] DEBUG o.a.d.e.t.g.SingleBatchSorterGen44 - Took 105 us to sort 1023 records
2017-09-19 04:22:56,268 [263f0252-fc60-7f8d-a1b1-c075876d1bd2:frag:3:0] DEBUG o.a.d.e.p.i.p.PartitionSenderRootExec - Partitioner.next(): got next record batch with status OK
2017-09-19 04:22:56,275 [263f0252-fc60-7f8d-a1b1-c075876d1bd2:frag:2:7] DEBUG o.a.d.e.t.g.SingleBatchSorterGen44 - Took 145 us to sort 1023 records
2017-09-19 04:22:56,354 [263f0252-fc60-7f8d-a1b1-c075876d1bd2:frag:3:0] DEBUG o.a.d.e.p.i.p.PartitionSenderRootExec - Partitioner.next(): got next record batch with status OK
2017-09-19 04:22:56,357 [263f0252-fc60-7f8d-a1b1-c075876d1bd2:frag:2:2] DEBUG o.a.d.e.t.g.SingleBatchSorterGen44 - Took 143 us to sort 1023 records
2017-09-19 04:22:56,361 [263f0252-fc60-7f8d-a1b1-c075876d1bd2:frag:2:0] DEBUG o.a.d.exec.compile.ClassTransformer - Compiled and merged PriorityQueueCopierGen50: bytecode size = 11.0 KiB, time = 124 ms.
2017-09-19 04:22:56,365 [263f0252-fc60-7f8d-a1b1-c075876d1bd2:frag:2:4] DEBUG o.a.d.e.t.g.SingleBatchSorterGen44 - Took 108 us to sort 1023 records
2017-09-19 04:22:56,367 [263f0252-fc60-7f8d-a1b1-c075876d1bd2:frag:2:0] DEBUG o.a.d.e.p.i.x.m.PriorityQueueCopierWrapper - Copier setup complete
2017-09-19 04:22:56,375 [263f0252-fc60-7f8d-a1b1-c075876d1bd2:frag:2:7] DEBUG o.a.d.e.t.g.SingleBatchSorterGen44 - Took 144 us to sort 1023 records
2017-09-19 04:22:56,396 [263f0252-fc60-7f8d-a1b1-c075876d1bd2:frag:2:0] DEBUG o.a.drill.exec.vector.BigIntVector - Reallocating vector [$data$(BIGINT:REQUIRED)]. # of bytes: [0] -> [0]
2017-09-19 04:22:56,396 [263f0252-fc60-7f8d-a1b1-c075876d1bd2:frag:2:0] DEBUG o.a.drill.exec.vector.BigIntVector - Reallocating vector [$data$(BIGINT:REQUIRED)]. # of bytes: [0] -> [0]
2017-09-19 04:22:56,396 [263f0252-fc60-7f8d-a1b1-c075876d1bd2:frag:2:0] DEBUG o.a.drill.exec.vector.BigIntVector - Reallocating vector [$data$(BIGINT:REQUIRED)]. # of bytes: [0] -> [0]

From here on out, the drillbit.log file is filled with "Reallocating vector" messages. The log seems to be written as fast as Drill can write to disk. The logs are filled within a minute.

sing cln2 q40.q

Issue Links

• Is contained by: DRILL-5758 Rollup of external sort fixes to issues found by QA