Pervasive Load-Balancing

1. Samar Sharma
ssharma@cisco.com
PLB: Pervasive Load-Balancing

2. Agenda
• Problem statement
• PLB Concept
• Benefits
• Deployment scenarios
• Packet flows
• Management

3. Problem statement
• There is no load-balancer today that scales for the East-West
traffic
• There is no telemetry/analytics solution which is integrated
within the Fabric.
• There is no load-balancer integrated within the Fabric.
Customers have to buy an external load-balancer.
• There is no solution to provide recommendations, when to
expand/shrink the data center resources

4. PLB
• Entire fabric acts as a massive load-balancer
• Entire fabric acts as a massive telemetry/analytics engine
• Clients, servers, L4-L7 appliances can be connected anywhere
in the fabric
• Fabric could be VXLAN/EVPN/BGP, FabricPath, DFA.
• PLB availability
– Nexus 7k: Already shipping in NX-OS 8.01 (Atherton)
– Nexus 9k: Available for EFT

5. Load-balancing Everywhere
Clients
Servers
L4-L7 Appliances
Switching
Fabric
Each entry point acts as
load-balancer and
telemetry engine

6. Elastic Data Center
Clients
Servers
L4-L7 Appliances
Switching
Fabric
PLB Analytics allow to expand/shrink the services and VMs based on need

7. PLB Deployment
MAN/WAN
FW1 FW2 FW3
Loadbalance the
traffic to devices,
such as Firewalls

8. Benefits : Slide 1
• Very low CAPEX and OPEX
• Analytics & Telemetry: Massive data from all switches across the
fabric
• Build an Elastic Data Center
• Wire-speed performance
• Health monitoring and automatic failure handling
• Bidirectional coherency
– Irrespective of different hardware
– Even in failure scenarios
• Apply PLB on VXLAN interfaces

9. Benefits : Slide 2
• Platform agnostic, eg, Nexus 9k/7k
• Works in VXLAN/EVPN/BGP, FabricPath, DFA fabrics
• Synchronization of LB across multiple switches in fabric
• Auto-synchronization of failure information
• Recommendation system
• Seemless addition/removal of servers, appliances.
• Works with Virtual and physical devices: VMs, Containers, etc.

10. Analytics and Telemetry
• PLB sits on the path between clients, servers, L4-L7 services.
This is very valuable.
– There are a number of clients (local and across border leaf), DB
servers, app servers, web servers, firewalls, WAAS, IPS, IDS, video
caches, etc.
• How much traffic is going to each FW, WAAS, IPS, IDS, server,
etc from each device in the fabric.
• When does each traffic go high and low.

11. Elastic Data Center
• Build a truly Elastic Data Center
• Based on the Analytics and telemetry, provide details about
when/how to grow/shrink the capacity of servers, Firewalls,
IPS, WAF, WAAS etc.

12. Recommendation System
• Based on the Analytics and telemetry, provide
recommendations
• Provide information about the bottlenecks.
• Provide information about when is good time to do system
maintenance, eg, upgrade software.
• When to charge more money to the tenants.

13. Deployment scenarios
• Non-DSR SLB
• WAAS/WCCP Insertion
• Firewall Cluster LB
• DSR SLB
– Client and server/FW on different subnet
– Client and server/FW on same subnet
• Firewall Non-Cluster LB

14. PLB Configuration CLI
Command Description
plb Creates a PLB service instance and parameters for it.
plb l3-device-group Creates a PLB device group for balancing server or
appliance loads.
plb statistics Enables PLB statistics function.

15. Show commands
• show running-config plb-services
– Displays the running configuration of all PLB services on a VDC or
ToR/leaf switch.
• show tech-support plb [detail]
– Displays technical support information for PLB.
• show plb service
– Displays current state of the specified PLB service.
• show plb plb-service-name analytics [brief]
– Displays detailed analytics of the specified service.

16. Management
• Puppet/Chef
• REST APIs
• NX-API
• CLI on each switch
• DCNM
• Others..

17. References and more info
Config guide
http://www.cisco.com/c/en/us/td/docs/switches/datacenter/pf/configuratio
n/guide/b-pf-configuration/Forwarding-Configurations.html
Command reference guide
http://www.cisco.com/c/en/us/td/docs/switches/datacenter/pf/command/re
ference/pf-cr-book/Programmable-Fabric-Commands-N-to-
Z.html#wp2066246057
Mailer
nxos-plb@cisco.com