[STRATOS-625] Error in scale down logic

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 4.0.0 Alpha
• Fix Version/s: 4.0.0
• Component/s: Autoscaler
• Assignee: Nirmal Fernando
• Reporter: Nirmal Fernando
• Created: 23/Apr/14 04:07
• Updated: 23/Apr/14 04:20
• Resolved: 23/Apr/14 04:20

Description

Seems like following current scale down rule is not accurate.

scaleDown : Boolean() from ((rifReset && (rifPredictedValue < rifAverageLimit * 0.1)) || (mcReset && (mcPredictedValue < mcAverageLimit * 0.1)) || (laReset && (laPredictedValue < laAverageLimit * 0.1)))

Note the 'OR' conditions. If you read this, it'll mean that system would scale down if any of the factors resulted to drop down than its threshold, despite higher requests in one of the factors.

IMO we should use 'AND's instead of 'OR's.

Proposed fix:

scaleDown : Boolean() from ((rifReset && (rifPredictedValue < rifAverageLimit * 0.1)) && (mcReset && (mcPredictedValue < mcAverageLimit * 0.1)) && (laReset && (laPredictedValue < laAverageLimit * 0.1)))