[YARN-7600] Yarn NODE_LOCAL request downgraded to RACK_LOCAL didn't cancel the original NODE_LOCAL request

• Type: Task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.7.3
• Target Version/s: 2.7.3
• Assignee: Unassigned Assign to me
• Reporter: wuchang
• Created: 02/Dec/17 13:37
• Updated: 11/Dec/17 21:17

Description

I know, when AM making container request, if the request container is NODE_LOCAL, then AM will also send out RACK_LOCAL and OFF_SWITCH requests. On the ResourceManager side, if RM successfully assigned a NODE_LOCAL container, I saw that RM canceled RACK_LOCAL and OFF_SWITCH requests because it was a duplicated request and did not need to be allocated any more.
However, my problem is that if the *allowRelaxity* for RACK_LOCAL and OFF_SWITCH is true, NODE_LOCAL request is downgraded to RACK_LOCAL , thus NODE_LOCAL's request is allocated with RACK_LOCAL locality, then OFF_SWITCH's duplicated request will be canceled of cource, however I did not see RM cancel the duplicated NODE_LOCAL request, so, won't it lead to NODE_LOCAL request still exist and then be scheduled in the next-round scheduling?