[TEZ-2544] Incorrect dag result due to wrong TaskSpec in recovering

• Type: Sub-task
• Status: Resolved
• Priority: Critical
• Resolution: Won't Fix
• Labels: Recovery
• Target Version/s: 0.8.6
• Assignee: Jeff Zhang
• Reporter: Jeff Zhang
• Created: 09/Jun/15 12:01
• Updated: 23/Apr/21 21:18
• Resolved: 23/Apr/21 21:18

Description

Expected TaskSpec

DAGName : OrderedWordCount, VertexName: Summation, VertexParallelism: 1, TaskAttemptID:attempt_1433850314856_0019_1_01_000000_0, processorName=org.apache.tez.examples.OrderedWordCount$SumProcessor, inputSpecListSize=1, 
outputSpecListSize=1, inputSpecList=[{{ sourceVertexName=Tokenizer, physicalEdgeCount=2, inputClassName=org.apache.tez.runtime.library.input.OrderedGroupedKVInput }}, ], outputSpecList=[{{ destinationVertexName=Sorter, physicalEdgeCount=1, outputClassName=org.apache.tez.runtime.library.output.OrderedPartitionedKVOutput }}

The actual TaskSpec

DAGName : OrderedWordCount, VertexName: Summation, VertexParallelism: 1, TaskAttemptID:attempt_1433850314856_0019_1_01_000000_0, processorName=org.apache.tez.examples.OrderedWordCount$SumProcessor, inputSpecListSize=1, 
outputSpecListSize=1, inputSpecList=[{{ sourceVertexName=Tokenizer, physicalEdgeCount=1, inputClassName=org.apache.tez.runtime.library.input.OrderedGroupedKVInput }}, ], outputSpecList=[{{ destinationVertexName=Sorter, physicalEdgeCount=1, outputClassName=org.apache.tez.runtime.library.output.OrderedPartitionedKVOutput }}

The expected physicalEdgeCount is 2 but actually it is 1, it happens when dynamic parallelism estimation is enabled.

The cause is that Task is recovering but its vertex's source edge manager has not been updated from ScatterGatherEdgeManager to CustomShuffleEdgeManager, so will result in different physicalEdgeCount for InputSpec

Issue Links

• is related to: TEZ-2107 Recovery failure in the case of Auto-reduce parallelism