Hierarchical Rate Limiting in an ODL Orchestrated Virtualized DC. Vishal Thapar, Ericsson Deepthi V V, Ericsson Faseela K, Ericsson

Transcription

1 Hierarchical Rate Limiting in an ODL Orchestrated Virtualized DC Vishal Thapar, Ericsson Deepthi V V, Ericsson Faseela K, Ericsson

2 How to Enforce Rate Limiting at admin specified levels of aggregation in an SDN Controller orchestrated Data Center?

3 Agenda Challenges OpenFlow Meters OF Meter basics Meters based Solution Advantages Proposal Hierarchical Rate Limiter Orchestration Layer Rate Calculator Rate Enforcer Next Steps Demo? Q&A

4 Challenges Distributed VMs Lack of centralized logic to manage bandwidth Dynamic adjustment of rate limits based on traffic conditions Monitoring malicious VMs within the same DC Avoid traffic all the way to gateway only to be dropped

5 OpenFlow Meters

6 OpenFlow Meters OpenFlow 1.3 Defines Per Flow Meters Specified in instruction set Multiple meters for the same packet Controls rate of aggregate of all flows attached to a meter

7 OpenFlow Meters (cntd) Meter Identifier Meter Bands Counters Meter Identifier : unique identifier Meter Bands : rate of the band and way to process the packet Counters : updated when packet processed by the meter

8 OpenFlow Meters - Bands Band Type Rate Burst Counters Type-specific args Band Type: Defines how pkts are processed Drop We use this for Rate Limiter DSCP Remark Rate: Lowest rate at which band can apply Burst: Granularity of meter Counters Type specific arguments: Optional arguments for some band types

9 Meters based Solution Chaining of metered Flows Orchestration layer communicates to SDNc the various bandwidth restrictions of VMs SDNc programs the required METER table entries and flow entries to enforce the rate limiting When new VMs are spawned under the same levels of aggregation, rate limit calculator within SDNc redistributes the rates

10 Meter Table - Example Meter Identifier Meter Bands Counters Tenant A 2Gbps 0 Tenant A : Network 1 1.5Gbps 0 Tenant A : Network 2 0.5Gbps 0 Tenant A : Network 1 : vpn1 0.2Gbps 0 Tenant A : Network 1 : vpn2 0.2Gbps 0 Tenant A : Network 1 : vpn1 : port 1 500Kbps 0

11 Control Flow OpenStack GBP Rate Limiter NSF vswitch1 vswitch2 vswitch3 VM1 VM2 VM3 VM4 VM5 VM6

12 Port Flow Table In_port = 1, apply meter : TenantA:Network1:vpn1:port1, goto network flow table Meter Table Vpn Flow Table Network = 1, vpn = 1, apply meter TenantA:Network1:vpn1, goto tenant flow table Meter1: Tenant A rate : 1Gbps Meter2: Tenant B rate : 2Gbps Meter3: TenantA:Network1:vpn1 -> rate 1Mbps Meter4: TenantA:Network1:vpn1:port1 -> rate 500kbps Tenant Flow Table Tenant = A, apply meter Tenant A

13 Advantages Rate Limiting applied at compute node Avoids multiple calculations for different levels of aggregation

14 Sample Heirarchical Rate Limiter

15 Key Components Orchestration Layer Rate Limit Calculator Rate Limit Enforcer

16 Orchestration Layer Communicates the bandwidth requirements at various levels of aggregation Northbound can be OpenStack, GBP or any other cloud orchestration layer already existing within ODL. Cloud orchestration layer is instructed to setup the datapath for the VM Checks the various rate limiting groups the VM belongs to

17 Rate Calculator Another module of Rate Limiter NSF Gets Rate Limits (policies) to be applied from Orchestration Layer Calculates the distributed rates to be applied at each virtual switch Uses aggregated bandwidth available and the number of virtual instances belonging to this entity. Monitors the statistics of each of the VM meters. If there are overprovisioned VMs on a node under the same aggregation level, re-caculates their rate limits

18 Rate Enforcer Gets rates calculated from Rate Limit Calculator Creates different entries in the Meter Table for each of these rate limiting aggregations based on calculations. Modifies flows/meters as per instructions from Rate Calculator

19 Sample Architecture OpenStack GBP Orchestration Layer Rate Calculator Rate Enforcer Node1 Node1 Node3

20 Next Steps

21 Where do we go from here? Distributed Rate Limit Calculator and Rate Limit Enforcer as ODL NSFs Working PoC of Hierarchical Rate Limiter More OF switches with OF13 Meters support Hierarchical Rate Limiter as ODL Project

22 Q&A