[AMBARI-23270] Stack Advisor and LLAP. Update Stack Advisor's capacity-scheduler walk through to ignore YARN Node labelling string "accessible-node-labels" for queues.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Invalid
• Fix Version/s: trunk, 2.7.0
• Component/s: ambari-server
• Assignee: Swapan Shridhar
• Reporter: Swapan Shridhar
• Due: 16/Mar/18
• Created: 16/Mar/18 19:28
• Updated: 16/Mar/18 19:57
• Resolved: 16/Mar/18 19:57

Description

Issue: Stack Advisor(SA) call returns 500 error (breaks) during LLAP calculations if YARN Node labelling is enabled, which makes it way to capacity-scheduler. SA does a capacity-scheduler walkthrough to figure out the capacity of the queue used by LLAP, to do the LLAP calculations.

When YARN Node labelling enabled, the capacity-scheduler looks like this: (Note the presence of string "accessible-node-labels")

capacity-scheduler with YARN Node Labelling enabled

yarn.scheduler.capacity.maximum-am-resource-percent=0.4
yarn.scheduler.capacity.maximum-applications=10000
yarn.scheduler.capacity.node-locality-delay=40
yarn.scheduler.capacity.root.accessible-node-labels=nonllap,lowmem,llap
yarn.scheduler.capacity.root.acl_administer_queue=*
yarn.scheduler.capacity.root.capacity=100
yarn.scheduler.capacity.root.default.acl_submit_applications=*
yarn.scheduler.capacity.root.default.capacity=5
yarn.scheduler.capacity.root.default.maximum-capacity=10
yarn.scheduler.capacity.root.default.state=RUNNING
yarn.scheduler.capacity.root.default.user-limit-factor=1
yarn.scheduler.capacity.root.queues=default,llap,users
yarn.scheduler.capacity.queue-mappings-override.enable=false
yarn.scheduler.capacity.root.accessible-node-labels.llap.capacity=100
yarn.scheduler.capacity.root.accessible-node-labels.llap.maximum-capacity=100
yarn.scheduler.capacity.root.accessible-node-labels.lowmem.capacity=100
yarn.scheduler.capacity.root.accessible-node-labels.lowmem.maximum-capacity=100
yarn.scheduler.capacity.root.accessible-node-labels.nonllap.capacity=100
yarn.scheduler.capacity.root.accessible-node-labels.nonllap.maximum-capacity=100
yarn.scheduler.capacity.root.default.accessible-node-labels=nonllap,lowmem
yarn.scheduler.capacity.root.default.accessible-node-labels.lowmem.capacity=20
yarn.scheduler.capacity.root.default.accessible-node-labels.lowmem.maximum-capacity=20
yarn.scheduler.capacity.root.default.accessible-node-labels.nonllap.capacity=20
yarn.scheduler.capacity.root.default.accessible-node-labels.nonllap.maximum-capacity=20
yarn.scheduler.capacity.root.default.default-node-label-expression=nonllap
yarn.scheduler.capacity.root.default.priority=0
yarn.scheduler.capacity.root.llap.accessible-node-labels=llap
yarn.scheduler.capacity.root.llap.accessible-node-labels.llap.capacity=100
yarn.scheduler.capacity.root.llap.accessible-node-labels.llap.maximum-capacity=100
yarn.scheduler.capacity.root.llap.acl_administer_queue=*
yarn.scheduler.capacity.root.llap.acl_submit_applications=*
yarn.scheduler.capacity.root.llap.capacity=90
yarn.scheduler.capacity.root.llap.default-node-label-expression=llap
yarn.scheduler.capacity.root.llap.maximum-capacity=90
yarn.scheduler.capacity.root.llap.minimum-user-limit-percent=100
yarn.scheduler.capacity.root.llap.ordering-policy=fifo
yarn.scheduler.capacity.root.llap.priority=0
yarn.scheduler.capacity.root.llap.state=RUNNING
yarn.scheduler.capacity.root.llap.user-limit-factor=1
yarn.scheduler.capacity.root.maximum-capacity=100
yarn.scheduler.capacity.root.priority=0
yarn.scheduler.capacity.root.users.accessible-node-labels=nonllap,lowmem
yarn.scheduler.capacity.root.users.accessible-node-labels.lowmem.capacity=80
yarn.scheduler.capacity.root.users.accessible-node-labels.lowmem.maximum-capacity=80
yarn.scheduler.capacity.root.users.accessible-node-labels.nonllap.capacity=80
yarn.scheduler.capacity.root.users.accessible-node-labels.nonllap.maximum-capacity=80
yarn.scheduler.capacity.root.users.acl_administer_queue=*
yarn.scheduler.capacity.root.users.acl_submit_applications=*
yarn.scheduler.capacity.root.users.analyst.accessible-node-labels=nonllap,lowmem
yarn.scheduler.capacity.root.users.analyst.accessible-node-labels.lowmem.capacity=50
yarn.scheduler.capacity.root.users.analyst.accessible-node-labels.lowmem.maximum-capacity=50
yarn.scheduler.capacity.root.users.analyst.accessible-node-labels.nonllap.capacity=50
yarn.scheduler.capacity.root.users.analyst.accessible-node-labels.nonllap.maximum-capacity=50
yarn.scheduler.capacity.root.users.analyst.acl_administer_queue=*
yarn.scheduler.capacity.root.users.analyst.acl_submit_applications=*
yarn.scheduler.capacity.root.users.analyst.capacity=50
yarn.scheduler.capacity.root.users.analyst.maximum-capacity=80
yarn.scheduler.capacity.root.users.analyst.minimum-user-limit-percent=100
yarn.scheduler.capacity.root.users.analyst.ordering-policy=fifo
yarn.scheduler.capacity.root.users.analyst.priority=0
yarn.scheduler.capacity.root.users.analyst.state=RUNNING
yarn.scheduler.capacity.root.users.analyst.user-limit-factor=1
yarn.scheduler.capacity.root.users.capacity=5
yarn.scheduler.capacity.root.users.default-node-label-expression=nonllap
yarn.scheduler.capacity.root.users.engineering.accessible-node-labels=nonllap,lowmem
yarn.scheduler.capacity.root.users.engineering.accessible-node-labels.lowmem.capacity=50
yarn.scheduler.capacity.root.users.engineering.accessible-node-labels.lowmem.maximum-capacity=50
yarn.scheduler.capacity.root.users.engineering.accessible-node-labels.nonllap.capacity=50
yarn.scheduler.capacity.root.users.engineering.accessible-node-labels.nonllap.maximum-capacity=50
yarn.scheduler.capacity.root.users.engineering.acl_administer_queue=*
yarn.scheduler.capacity.root.users.engineering.acl_submit_applications=*
yarn.scheduler.capacity.root.users.engineering.capacity=50
yarn.scheduler.capacity.root.users.engineering.maximum-capacity=80
yarn.scheduler.capacity.root.users.engineering.minimum-user-limit-percent=100
yarn.scheduler.capacity.root.users.engineering.ordering-policy=fifo
yarn.scheduler.capacity.root.users.engineering.priority=0
yarn.scheduler.capacity.root.users.engineering.state=RUNNING
yarn.scheduler.capacity.root.users.engineering.user-limit-factor=1
yarn.scheduler.capacity.root.users.maximum-capacity=80
yarn.scheduler.capacity.root.users.minimum-user-limit-percent=100
yarn.scheduler.capacity.root.users.priority=0
yarn.scheduler.capacity.root.users.queues=analyst,engineering
yarn.scheduler.capacity.root.users.state=RUNNING
yarn.scheduler.capacity.root.users.user-limit-factor=1

Reason on why it breaks: SA code is not aware of Node labelling in general. Thus, when it tries to calculate the capacity of the LLAP selected queue (for example: : 'llap' queue), it does the following:

Looks for the line showing capacity for 'llap' queue and fetches the line :

yarn.scheduler.capacity.root.llap.accessible-node-labels.llap.capacity=100

• It then looks for memory percentage for queues : [root, accessible-node-labels, llap]
• But there is no .capacity associated with accessible-node-labels.
• Thus walkthrough fails.

Fix:

Added a skip code when we detect accessible-node-labels / YARN Node Labelling enabled.

Issue Links

• duplicates: AMBARI-23145 Stack Advisor Should not Use 'accessible-node-labels' as a Queue Name