selective redundancy in network-as-a-service: differentiated qos in multi-tenant clouds

Selective Redundancy in Network-as-a-Service:Differentiated QoS in Multi-Tenant Clouds

Pradeeban Kathiravelu, Luıs Veiga

INESC-ID LisboaInstituto Superior Tecnico, Universidade de Lisboa

Lisbon, Portugal

11 th International Workshop onEnterprise Integration, Interoperability and Networking (EI2N 2016)

26 th October 2016, Rhodes, Greece.

Pradeeban Kathiravelu SMART 1 / 28

Introduction

Introduction

I Cloud data centers consist of various tenants with multiple roles.I Differentiated Quality of Service (QoS) in multi-tenant clouds.

I Service Level Agreements (SLA).I Different priorities among tenant processes.

I Network is shared among the tenants.I End-to-end delivery guarantee despite congestion for critical flows.


Introduction

Software-Defined Networking (SDN) for Clouds

I Cross-layer optimization of clouds with SDN.I Centralized control plane of the network-as-a-service.


Introduction

Middleboxes in the cloud networks

I Middleboxes - hardware and software.I Device that manipulates network traffic, other than packet forwarding.


Introduction

Motivation

I How to offer differentiated QoS and SLA in multi-tenant networks?I Application-level user preferences and system policies.I Performance guarantees at the network-level.


Introduction

Motivation

I How to offer differentiated QoS and SLA in multi-tenant networks?I Application-level user preferences and system policies.I Performance guarantees at the network-level.

I More potential in having them both!I SDN, Middleboxes, . . .


Introduction

Goals

I How to offer differentiated QoS and SLA in multi-tenant networks?I Leverage SDN to offer a selective partial redundancy in network flows.I FlowTags - Software middlebox to tag the flows with contextual

information.

I Application-level preferences to the network control plane as tags.I Dynamic flow routing modifications based on the tags.


Solution Architecture

SMART

I An SDN Middlebox Architecture for Reliable Transfers.

I An architectural enhancement for network flows allocation, routing,and control.

I Timely delivery of priority flows by dynamically diverting them to aless congested path.

I Cloning subflows of higher priority flows.

I An adaptive approach in cloning and diverting of the flows.



Contributions

I A cross-layer architecture ensuring differentiated QoS.I A context-aware appraoch in load balancing the network.

I servers supporting multihoming, connected topologies, . . .



SMART Approach

I Divert and clone subflows by setting breakpoints in the flows in theirroute to avert congestion.

I Trade-off of minimal redundancy to ensure the SLA of priority flows.I Adaptive execution with contextual information on the network.

I Leverage FlowTags middleboxI to pass application-level system and user preferences to the network.



SMART Enhancements

I When to break and when to merge?I Clone destination.



SMART Deployment


SMART Workflow

SMART Workflow


SMART Workflow

I: Tag Generation for Priority Flows

I Tag generation query and response.I between the hosts and the FlowTags

controller.

I A centralized controller forFlowTags.

I Tag the flows at the origin.

I FlowTagger software middlebox.

I A generator of the tags.I Invoked by the host application layer.I Similar to the FlowTags-capable

middleboxes for NATs.


SMART Workflow

II: Regular routing till the tags are violated


SMART Workflow

III: When a threshold is met

I Controller is triggered through OpenFlow API.


SMART Workflow

III: When a threshold is met

I Controller is triggered through OpenFlow API.

I A series of control flows inside the control plane.

I Modify flow entries in the relevant switches.


SMART Workflow

SMART Control Flows: Rules Manager

I A software middlebox in the control plane.I Consumes the tags from the packet.

I Similar to FlowTags-capable firewalls.


SMART Workflow

Rules Manager Tags Consumption

I Interprets the tagsI as input to the SMART Enhancer


SMART Workflow

SMART Enhancer

I Core of the SMART architecture.I Gets the input to the enhancement algorithms.I Decides the flow modifications.

I Breakpoint node.I Brekpoint packet.I Clone/divert decisions.


Implementation

Prototype Implementation

I Developed in Oracle Java 1.8.0.

I OpenDaylight Beryllium as the core SDN controller.I Enhancer and the Rules Manager middlebox as controller extensions.

I Developed as OSGi bundles.I Deployed into Apache Karaf runtime of OpenDaylight.

I FlowTags middlebox controller deployed along the SDN controller.I Originally a POX extension.

I Network nodes and flows emulated with Mininet.I Larger scale cloud deployments simulated.


Evaluation

Evaluation Strategy

I Data center network with 1024 nodes and leaf-spine topology.I Path lengths of more than two-hops.I Up to 100,000 of short flows.

I Flow completion time < 1 s.I A few non-priority elephant flows.

I SLA → maximum permitted flow completion time for priority flowsI Uniformly randomized congestion.

I hitting a few uplinks of nodes concurrently.I overwhelming amount of flows through the same nodes and links.

I Benchmark: SMART enhancements over base routing algorithms.I Performance (SLA awareness), redundancy, and overhead.


Evaluation

SMART Adaptive Clone/Replicate with Shortest-Path

I Replicate the subsequent flows once a previous flow was cloned.


Evaluation

SMART Adaptive Clone/Replicate with ECMP

I Repeat the experiment with Equal-cost multi-path routing.


Conclusion

Related Work

I Multipath TCP (MPTCP) uses the available multiple paths betweenthe nodes concurrently to route the flows across the nodes.

I Performance, bandwidth utilization, and congestion controlI through a distributed load balancing.

I ProgNET leverages WS-Agreement and SDN for SLA-aware cloud.

I pFabric for deadline-constrained data flows with minimal completiontime.

I QJump linux traffic control module for latency-sensitive applications.


Conclusion

Conclusion

I ConclusionsI SMART leverages redundancy in the flows as a mean to improve the

SLA of the priority flows.I Opens an interesting research question leveraging SDN, middleboxes,

and redundancy.I Cross-layer optimizations through tagging the flows.I For differentiated QoS.

I Future WorkI Implementation of SMART on a real data center network.I Evaluate against the identified related work quantitatively.


Conclusion

Conclusion

I ConclusionsI SMART leverages redundancy in the flows as a mean to improve the

SLA of the priority flows.I Opens an interesting research question leveraging SDN, middleboxes,

and redundancy.I Cross-layer optimizations through tagging the flows.I For differentiated QoS.

I Future WorkI Implementation of SMART on a real data center network.I Evaluate against the identified related work quantitatively.

Thank you!Questions?


selective redundancy in network-as-a-service: differentiated qos in multi-tenant clouds

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