VMworld 2017: Predictive DRS Best Practices

Session: SER2849BU

Case 1: VMs performance can suffer due to resource constraints/surges

Case 2: Inefficient usage of resources due to reserving capacity for peak loads.

-Move VMs after contention occurs

-Statically reserve more resource
-Learn workload pattern, and move before VMs spike

What is the best solution? Predictive DRS

What is Predictive DRS?
-DRS enabled with predictions
-DRS scheduling + vROPs analytics

How does it work?
-Resource usage from vCenter
-vROPs consumes the data
-Predictions are made
-DRS invoked to perform optimizations

vROps Dynamic Thresholds (DT)
-Sophisticated analytics – 10 algorithms
-Learns normal behavior
-Detects hourly, daily, monthly patterns
-Generates upper and lower dynamic thresholds
-Predictions are then sent to vCenter

Software Requirements
-vSphere 6.5 Enterprise Plus
-vROps 6.4 or 6.5
-Time sync between vCenter and vROps needs to be less than 5 minutes

Speaker shows a demo of  a ‘follow the sun’ scenario with workloads spiking at different times on a regular pattern. pDRS learned the pattern, and vMotioned VMs to make sure VMs had enough resources. He shows a performance graph, where pDRS headed off performance issues and it resulted in consistent VM performance.

DPM with Predictions
Speaker asks audience to raise hands if anyone is using DPM. Two people raise their hands.
-Predictions can proactively power up ESXi hosts to absorb the workload demand

-Workloads it can predict: Periodic usage pattern
-Short spikes of a few minutes will not be predicted
-The more consistent the workload, the more accurate it will be

Learning Period
-Set to 14 days by default
-The longer the period, the better the accuracy
-Predictions only happen after 14 days

-Compute dynamic thresholds – Calculated once a day, or push a button to force a new calculation.
-Lookahead interval – Amount of time DRS looks ahead while accounting for predictions – default is 1 hour

Identify vMotions due to Preditions
-Not a clear answer as there can be a mix of VMs with predictions and those without
-pDRS moves are only in logs


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