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Dynamic Content Allocation for Cloud- assisted Service of Periodic - - PowerPoint PPT Presentation

Dynamic Content Allocation for Cloud- assisted Service of Periodic Workloads Gyrgy Dn Niklas Carlsson Royal Institute of Technology (KTH) Linkping University @ IEEE INFOCOM 2014 , Toronto, Canada, April/May 2014 Internet Content Delivery


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Dynamic Content Allocation for Cloud- assisted Service of Periodic Workloads

@ IEEE INFOCOM 2014, Toronto, Canada, April/May 2014

György Dán

Royal Institute of Technology (KTH)

Niklas Carlsson

Linköping University

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SLIDE 2

Internet Content Delivery

  • Large amounts of data with varying popularity
  • Multi-billion market ($8B to $20B, 2012-2015)
  • Goal: Minimize content delivery costs
  • Migration to cloud data centers
  • From: Dan and Carlsson, “Power-laws Revisited: A Large Scale

Measurement Study of Peer-to-Peer Content Popularity”, Proc. IPTPS 2010.

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SLIDE 3

Internet Content Delivery

  • Large amounts of data with varying popularity
  • Multi-billion market ($8B to $20B, 2012-2015)
  • Goal: Minimize content delivery costs
  • Migration to cloud data centers
  • From: Dan and Carlsson, “Power-laws Revisited: A Large Scale

Measurement Study of Peer-to-Peer Content Popularity”, Proc. IPTPS 2010.

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SLIDE 4

Internet Content Delivery

  • Large amounts of data with varying popularity
  • Multi-billion market ($8B to $20B, 2012-2015)
  • Goal: Minimize content delivery costs
  • Migration to cloud data centers
  • From: Dan and Carlsson, “Power-laws Revisited: A Large Scale

Measurement Study of Peer-to-Peer Content Popularity”, Proc. IPTPS 2010.

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SLIDE 5

Internet Content Delivery

  • Large amounts of data with varying popularity
  • Multi-billion market ($8B to $20B, 2012-2015)
  • Goal: Minimize content delivery costs
  • Migration to cloud data centers
  • From: Dan and Carlsson, “Power-laws Revisited: A Large Scale

Measurement Study of Peer-to-Peer Content Popularity”, Proc. IPTPS 2010.

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SLIDE 6

Periodic Workloads

  • Characterization of Spotify traces
  • In addition to diurnal traffic volumes …
  • … we found that also the Zipf exponent vary with time-of-day
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SLIDE 7

Content Delivery

  • Cloud-based delivery
  • Dedicated infrastructure

servers cloud

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SLIDE 8

Content Delivery

  • Cloud-based delivery
  • Flexible computation, storage, and bandwidth
  • Pay per volume and access
  • Dedicated infrastructure
  • Limited storage
  • Capped unmetered bandwidth
  • Potentially closer to the user

servers cloud

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SLIDE 9

Content Delivery

  • Cloud-based delivery
  • Flexible computation, storage, and bandwidth
  • Pay per volume and access
  • Dedicated infrastructure
  • Limited storage
  • Capped unmetered bandwidth
  • Potentially closer to the user
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SLIDE 10

Content Delivery

  • Cloud-based delivery
  • Flexible computation, storage, and bandwidth
  • Pay per volume and access
  • Dedicated infrastructure
  • Limited storage
  • Capped unmetered bandwidth
  • Potentially closer to the user
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SLIDE 11

Content Delivery

  • Cloud-based delivery
  • Flexible computation, storage, and bandwidth
  • Pay per volume and access
  • Dedicated infrastructure
  • Limited storage
  • Capped unmetered bandwidth
  • Potentially closer to the user
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SLIDE 12

Content Delivery

  • Cloud-based delivery
  • Flexible computation, storage, and bandwidth
  • Pay per volume and access
  • Dedicated infrastructure
  • Limited storage
  • Capped unmetered bandwidth
  • Potentially closer to the user

Cloud bandwidth elastic; however, flexible comes at premium …

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SLIDE 13

High-level problem

  • Minimize content delivery costs
  • Bandwidth

Cost Cloud-based Elastic/flexible $$$ Dedicated servers Capped $

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SLIDE 14

High-level problem

  • Minimize content delivery costs
  • Bandwidth

Cost Cloud-based Elastic/flexible $$$ Dedicated servers Capped $

How to get the best of two worlds?

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SLIDE 15

High-level problem

  • Minimize content delivery costs
  • How to get the best out of two worlds?
  • Bandwidth

Cost Cloud-based Elastic/flexible $$$ Dedicated servers Capped $

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SLIDE 16

High-level problem

  • Minimize content delivery costs
  • How to get the best out of two worlds?
  • Improved workload models and prediction enables prefetching …
  • Bandwidth

Cost Cloud-based Elastic/flexible $$$ Dedicated servers Capped $

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SLIDE 17

High-level problem

  • Minimize content delivery costs
  • How to get the best out of two worlds?
  • Improved workload models and predcition enables prefetching …
  • Dynamic content allocation
  • Utilize capped bandwidth (and storage) as much as possible
  • Use elastic cloud-based services to serve “spillover”
  • Bandwidth

Cost Cloud-based Elastic/flexible $$$ Dedicated servers Capped $

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SLIDE 18

Dynamic Content Allocation Problem

18

  • Formulate as a finite horizon dynamic

decision process problem

  • Show discrete time decision process

is good approximation

  • Define exact solution as MILP
  • Provide computationally feasible

approximations (and prove properties about approximation ratios)

  • Validate model and policies using

traces from Spotify

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SLIDE 19

Cost minimization formulation

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SLIDE 20

Cost minimization formulation

Total demand

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SLIDE 21

Cost minimization formulation

Demand of files in capped BW storage

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SLIDE 22

Cost minimization formulation

Capped BW limit (U)

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SLIDE 23

Cost minimization formulation

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SLIDE 24

Cost minimization formulation

Served from capped BW storage

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SLIDE 25

Cost minimization formulation

Served using elastic cloud resources

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SLIDE 26

Cost minimization formulation

Traffic due to allocation

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SLIDE 27

Cost minimization formulation

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SLIDE 28

Cost minimization formulation

  • Traffic of files only in cloud
  • Spillover traffic
  • Traffic due to allocation
  • Total expected cost
  • Optimal policy
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SLIDE 29

Cost minimization formulation

  • Traffic of files only in cloud
  • Spillover traffic
  • Traffic due to allocation
  • Total expected cost
  • Optimal policy
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SLIDE 30

Cost minimization formulation

  • Traffic of files only in cloud
  • Spillover traffic
  • Traffic due to allocation
  • Total expected cost
  • Optimal policy
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SLIDE 31

Cost minimization formulation

  • Traffic of files only in cloud
  • Spillover traffic
  • Traffic due to allocation
  • Total expected cost
  • Optimal policy
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SLIDE 32

Cost minimization formulation

  • Traffic of files only in cloud
  • Spillover traffic
  • Traffic due to allocation
  • Total expected cost
  • Optimal policy
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SLIDE 33

Cost minimization formulation

  • Traffic of files only in cloud
  • Spillover traffic
  • Traffic due to allocation
  • Total expected cost
  • Optimal policy
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SLIDE 34

Cost minimization formulation

  • Traffic of files only in cloud
  • Spillover traffic
  • Traffic due to allocation
  • Total expected cost
  • Optimal policy
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SLIDE 35

Cost minimization formulation

  • Traffic of files only in cloud
  • Spillover traffic
  • Traffic due to allocation
  • Total expected cost
  • Optimal policy
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SLIDE 36

Cost minimization formulation

  • Traffic of files only in cloud
  • Spillover traffic
  • Traffic due to allocation
  • Total expected cost
  • Optimal policy
  • Equivalent formulation

Utilization maximization

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SLIDE 37

Cost minimization formulation

  • Traffic of files only in cloud
  • Spillover traffic
  • Traffic due to allocation
  • Total expected cost
  • Optimal policy
  • Equivalent formulation

Utilization maximization

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SLIDE 38

Cost minimization formulation

  • Equivalent formulation

Utilization maximization

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SLIDE 39

Cost minimization formulation

  • Equivalent formulation

Utilization maximization

Two file example

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SLIDE 40

Cost minimization formulation

  • Equivalent formulation

Utilization maximization

Two file example

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SLIDE 41

Cost minimization formulation

  • Equivalent formulation

Utilization maximization

Two file example

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SLIDE 42

Cost minimization formulation

  • Equivalent formulation

Utilization maximization

Two file example

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SLIDE 43

Cost minimization formulation

  • Equivalent formulation

Utilization maximization

Two file example

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SLIDE 44
  • Equivalent formulation

Cost minimization formulation Utilization maximization

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SLIDE 45

Discrete-time Decision Problem

  • Equivalent formulation
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SLIDE 46
  • Approximation
  • Finite horizon decision

problem

Discrete-time Decision Problem

decrease exponentially

  • Equivalent formulation
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SLIDE 47
  • Approximation
  • Finite horizon decision

problem

Discrete-time Decision Problem

decrease exponentially

  • Equivalent formulation
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SLIDE 48
  • Approximation
  • Finite horizon decision

problem

Discrete-time Decision Problem

decrease exponentially

  • Equivalent formulation
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SLIDE 49
  • Approximation
  • Finite horizon decision

problem

Discrete-time Decision Problem

decrease exponentially

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SLIDE 50
  • Approximation
  • Finite horizon decision

problem

Discrete-time Decision Problem

Theorem: Exact solution as a MILP

decrease exponentially

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SLIDE 51
  • Consider next interval only

Policy: No Download Cost (NDC)

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SLIDE 52
  • Proposition 1: Unbounded approximation ratio
  • Proposition 2: Approximation bound
  • Consider next interval only

Policy: No Download Cost (NDC)

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SLIDE 53
  • Proposition 1: Unbounded approximation ratio
  • Proposition 2: Approximation bound
  • Consider next interval only

Policy: No Download Cost (NDC)

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SLIDE 54
  • Proposition 1: Unbounded approximation ratio
  • Proposition 2: Approximation bound
  • Consider next interval only

Policy: No Download Cost (NDC)

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SLIDE 55
  • Proposition 1: Unbounded approximation ratio
  • Proposition 2: Approximation bound
  • Consider next interval only

Policy: No Download Cost (NDC)

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SLIDE 56
  • Consider k next intervals

Policy: k-Step Look Ahead (k-SLA)

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  • Proposition 3: Unbounded approximation ratio
  • Proposition 4: Approximation bound
  • Consider k next intervals

Policy: k-Step Look Ahead (k-SLA)

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  • Proposition 3: Unbounded approximation ratio
  • Proposition 4: Approximation bound
  • Consider k next intervals

Policy: k-Step Look Ahead (k-SLA)

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SLIDE 59
  • Proposition 3: Unbounded approximation ratio
  • Proposition 4: Approximation bound
  • Consider k next intervals

Policy: k-Step Look Ahead (k-SLA)

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SLIDE 60
  • Proposition 3: Unbounded approximation ratio
  • Proposition 4: Approximation bound
  • Consider k next intervals

Policy: k-Step Look Ahead (k-SLA)

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SLIDE 61

Trace-based analysis (Synthetic)

  • Normalized traffic savings
  • Workload: 3 groups of 1000 files; peaks N(0,2) offset by 8h for

each group; sinusoid with 24h period; min/max ratio N(0.075,0.075), file sizes U(L/2,3L/2), bandwidth demand Bounded Pareto (Bmin, Bmax, )

Based on Spotify trace characterization

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Trace-based analysis (Synthetic)

Normalize against policy that stores the most popular files

  • Normalized traffic savings
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SLIDE 63

Trace-based analysis (Synthetic)

  • Normalized traffic savings
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SLIDE 64

Trace-based analysis (Synthetic)

  • Normalized traffic savings
  • Good
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SLIDE 65

Trace-based analysis (Synthetic)

  • Normalized traffic savings
  • Modest gains when Zipf-like (1) rank popularity
  • Significant gains when more uniform (10)
  • NDC fails for larges sizes (6-SLA still works well)
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SLIDE 66

Trace-based analysis (Synthetic)

  • Normalized traffic savings
  • Modest gains when Zipf-like (1) rank popularity
  • Significant gains when more uniform (10)
  • NDC fails for larges sizes (6-SLA still works well)
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SLIDE 67

Trace-based analysis (Synthetic)

  • Normalized traffic savings
  • Modest gains when Zipf-like (1) rank popularity
  • Significant gains when more uniform (10)
  • NDC fails for larges sizes (6-SLA still works well)
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SLIDE 68

Trace-based analysis (Synthetic)

  • Normalized traffic savings
  • Modest gains when Zipf-like (1) rank popularity
  • Significant gains when more uniform (10)
  • NDC fails for larges sizes (6-SLA still works well)
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SLIDE 69

Trace-based analysis (Synthetic)

  • Normalized traffic savings
  • Modest gains when Zipf-like (1) rank popularity
  • Significant gains when more uniform (10)
  • NDC fails for larges sizes (6-SLA still works well)
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SLIDE 70

Trace-based Analysis

  • Spotify traces (all requests for 1M random tracks; 1 week)
  • Prediction policies: (i) “oracle”, (ii) 24h, (iii) interval average
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SLIDE 71

Trace-based Analysis

  • Spotify traces (all requests for 1M random tracks; 1 week)
  • Prediction policies: (i) “oracle”, (ii) 24h, (iii) interval average
  • NDC fails; 3-SLA works reasonably well
  • Dynamic allocation with k-SLA outperform LRU by far
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SLIDE 72

Trace-based Analysis

  • Spotify traces (all requests for 1M random tracks; 1 week)
  • Prediction policies: (i) “oracle”, (ii) 24h, (iii) interval average
  • NDC fails; 3-SLA works reasonably well
  • Dynamic allocation with k-SLA outperform LRU by far

Normalize against offline “global knowledge” policy that stores most popular files

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SLIDE 73

Trace-based Analysis

  • Spotify traces (all requests for 1M random tracks; 1 week)
  • Prediction policies: (i) “oracle”, (ii) 24h, (iii) interval average
  • NDC fails; 3-SLA works reasonably well
  • Dynamic allocation with k-SLA outperform LRU by far

Good Bad

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SLIDE 74

Trace-based Analysis

  • Spotify traces (all requests for 1M random tracks; 1 week)
  • Prediction policies: (i) “oracle”, (ii) 24h, (iii) interval average
  • NDC fails; 3-SLA works reasonably well
  • Dynamic allocation with k-SLA outperform LRU by far
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SLIDE 75

Trace-based Analysis

  • Spotify traces (all requests for 1M random tracks; 1 week)
  • Prediction policies: (i) “oracle”, (ii) 24h, (iii) interval average
  • NDC fails; 3-SLA works reasonably well
  • Dynamic allocation with k-SLA outperform LRU by far
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SLIDE 76

Dynamic Content Allocation Problem

76

  • Finite horizon dynamic decision problem
  • Discrete mean-value approximation
  • Exact solution as MILP
  • Computationally feasible approximations

(e.g., k-SLA) with performance bounds

  • Validate model and policies using traces

from Spotify

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SLIDE 77

Thank you!

Niklas Carlsson (niklas.carlsson@liu.se)

www.ida.liu.se/~nikca/papers/infocom14.pdf

Dynamic Content Allocation for Cloud- assisted Service of Periodic Workloads

György Dan (KTH) and Niklas Carlsson (LiU)