Transparent SDN Update Scheduling Peter Pereni @ EPFL Maciej - - PowerPoint PPT Presentation

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transparent sdn update scheduling
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Transparent SDN Update Scheduling Peter Pereni @ EPFL Maciej - - PowerPoint PPT Presentation

Mar 30, 2023 218 likes •434 views

ESPRES: Transparent SDN Update Scheduling Peter Pereni @ EPFL Maciej Kuzniar @ EPFL Marco Canini @ UCLouvain Dejan Kosti @ KTH Network events trigger big updates Topology changes Network events trigger big updates Topology changes

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SLIDE 1

ESPRES: Transparent SDN Update Scheduling

Peter Perešíni @ EPFL

Maciej Kuzniar @ EPFL Marco Canini @ UCLouvain Dejan Kostić @ KTH

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SLIDE 2

Network events trigger big updates

Topology changes

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SLIDE 3

Network events trigger big updates

Topology changes

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SLIDE 4

Network events trigger big updates

Topology changes

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SLIDE 5

Network events trigger big updates

Topology changes

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SLIDE 6

Network events trigger big updates

Topology changes Traffic Engineering Policy changes

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SLIDE 7

Network events trigger big updates

Topology changes Traffic Engineering Policy changes

Many rule modifications ⇨ updates take time

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SLIDE 8

What if we reorder installations...

Update touching two (independent) flows

  • blue - 3 changes on a switch
  • red - 2 changes on a switch
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SLIDE 9

What if we reorder installations...

Update touching two (independent) flows

  • blue - 3 changes on a switch
  • red - 2 changes on a switch
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SLIDE 10

What if we reorder installations...

Update touching two (independent) flows

  • blue - 3 changes on a switch
  • red - 2 changes on a switch
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SLIDE 11

What if we reorder installations...

Update touching two (independent) flows

  • blue - 3 changes on a switch
  • red - 2 changes on a switch

vs

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SLIDE 12

What if we reorder installations...

Update touching two (independent) flows

  • blue - 3 changes on a switch
  • red - 2 changes on a switch

vs

total time same but different ordering of rule installation matters

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SLIDE 13

Some challenges

Scheduling sounds easy but

  • multiple switches affected
  • and switch-speeds are different over time
  • rule dependencies
  • e.g. update ingress only after core installed
  • control channel is FIFO
  • no reordering
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SLIDE 14

ESPRES overview

(See paper for more details)

  • Keep backlog of rule installations in

ESPRES

  • enables re-ordering on control channel
  • Schedule rules to be installed next
  • react on-the-fly to current switch conditions
  • needs to be fast
  • support flexible goals
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SLIDE 15

Possible scheduling goals

Already illustrated:

  • install majority of flows sooner

See paper:

  • decrease mid-update rule overhead
  • decrease transient instabilities
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SLIDE 16

1000 new flows; 18 switches

A taste of results

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SLIDE 17

1000 new flows; 18 switches

A taste of results

➢ No scheduling (send rule when dependencies are met)

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SLIDE 18

1000 new flows; 18 switches

A taste of results

➢ Espres A ➢ Espres B ➢ Optimal (Offline) ➢ No scheduling (send rule when dependencies are met)

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SLIDE 19

1000 new flows; 18 switches

A taste of results

➢ Espres A ➢ Espres B ➢ Optimal (Offline)

We reduce completion time by ≥40% for half of flows

➢ No scheduling (send rule when dependencies are met)

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SLIDE 20

Summary

  • Updates touch many flows
  • Changing rule installation order helps

achieve different goals ESPRES ➢Maintain backlog of rule installations at the controller ➢Schedule their order on-the-fly