VM Interference and Placement for Server Consolidation

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VM Interference and Placement for Server
Consolidation

• Umesh Bellur
• IIT Bombay

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App Lifecycle in a VM Env.
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Some Problems

• Translating application QoS into VM
  configurations
• Quantifying the effects of interference and
  affinity
• Placement strategies

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Generating VM Configs

• Input
• Application performance characterization leading
  to
• Building and solving predictive performance
  models for the application
• QoS operating ranges and estimated load patterns
• Output
• A set of VM configurations along with a mapping
  of application components to VMs.

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• Challenges
• Automating characterizing appl perf. For
  virtualized env.
• Extending standard performance prediction
  techniques (Queuing) to include the effects of
  virtualization

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Interference/Affinity

• VMs dont provide performance isolation
• VMM takes up some percentage of resources.
• Given an application components performance on a
  single VM, can we estimate the effect the
  colocating other VMs running different types of
  workloads (CPU intensive, I/O intensive etc.).
  Further, can we characterize this effect with
  changing parameters of the interfering component?

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Results of interference
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Results - 2

• Ping latency of a VM doubled when when it was
  deployed with a mixture of CPU-intensive and I/O
  bandwidth intensive VMs, as compared to when it
  was deployed with only I/O bandwidth intensive
  VMs.

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VM Placement

• Given a current deployment and the set of VMs
  that need to be deployed in a data center, output
  a plan of placing the VMs on the existing
  physical machines to optimize number of physical
  servers used and other application specified
  constraints (for fault tolerance etc.)
• Migration costs
• A multi dimensional bin packing problem subject
  to various constraints
• Interference conflicts
• App driven conflicts