[YARN-1902] Allocation of too many containers when a second request is done with the same resource capability

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.2.0, 2.3.0, 2.4.0
• Component/s: client
• Labels: client
• Assignee: Sietse T. Au
• Reporter: Sietse T. Au
• Created: 04/Apr/14 14:51
• Updated: 30/Apr/20 11:03

Description

Regarding AMRMClientImpl

Scenario 1:
Given a ContainerRequest x with Resource y, when addContainerRequest is called z times with x, allocate is called and at least one of the z allocated containers is started, then if another addContainerRequest call is done and subsequently an allocate call to the RM, (z+1) containers will be allocated, where 1 container is expected.

Scenario 2:
No containers are started between the allocate calls.

Analyzing debug logs of the AMRMClientImpl, I have found that indeed a (z+1) are requested in both scenarios, but that only in the second scenario, the correct behavior is observed.

Looking at the implementation I have found that this (z+1) request is caused by the structure of the remoteRequestsTable. The consequence of Map<Resource, ResourceRequestInfo> is that ResourceRequestInfo does not hold any information about whether a request has been sent to the RM yet or not.

There are workarounds for this, such as releasing the excess containers received.

The solution implemented is to initialize a new ResourceRequest in ResourceRequestInfo when a request has been successfully sent to the RM.

The patch includes a test in which scenario one is tested.

Issue Links

• causes: YARN-9877 Intermittent TIME_OUT of LogAggregationReport
• is related to: SLIDER-829 when containers are allocated, explicitly cancel the request
• relates to: YARN-110 AM releases too many containers due to the protocol