elb 3.3 spec

Table of Contents Overview Requirements Considerations ELB Spikes Load Balancers Software Load Balancers Other Questions

Overview

• In-Region Load Balancing Service
• Distributes traffic across multiple Availability Zones
  • HTTP/S, TCP/S
• Built-in Health Check
• Fully fault-tolerant
• Can span multiple AZs

Requirements

• SSL termination
• Runtime reconfiguration of the service (i.e., no restarting allowed)
• Multi-tenancy (i.e., possible to configure multiple load balancing inbounds with seperate pools of outbound endpoints)
• Arbitrary TCP load balancing
• HTTP/HTTPs Session stickiness (both application level and load balancer level)
• DNS vhosting
• Endpoint health monitoring
• Metric collection
  • Latency
  • RequestCount
  • HTTP Response code counts (e.g., 400, 404, 500, etc.)

Considerations

• ELB is a service but runs on EC2
• The IP Addresses will change over time
• Use CNAME records in DNS or Route 53 “Alias” records
• SSL is supported
• Client SSL Termination
• Backend ELB-to-Server mutual SSL
• Sticky sessions

ELB Spikes

The purpose of this investigation is to evaluate viable software based load balancers and vet their conformance to fundamental requirements for ELB. These are:

• Fundamental ELB requirements
  • SSL termination
  • Runtime reconfiguration of the service (i.e., no restarting allowed)
  • Multi-tenancy (i.e., possible to configure multiple load balancing inbounds with seperate pools of outbound endpoints)
  • Arbitrary TCP load balancing
  • HTTP/HTTPs Session stickiness (both application level and load balancer level)
  • DNS vhosting
  • Endpoint health monitoring
  • Metric collection
    • Latency
    • RequestCount
    • HTTP Response code counts (e.g., 400, 404, 500, etc.)

Load Balancers

For each of the below listed load balancers:

1. Evaluate and report on
   1. The support for functionality in the above listed requirements.
   2. The availability in distributions.
   3. A simple performance experiment comparing native execution vs. execution in a virtual machine.

Software Load Balancers

1. nginx - http://wiki.nginx.org/Main
2. HA proxy - http://haproxy.1wt.eu/
3. Zen - http://sourceforge.net/projects/zenloadbalancer/
4. pound - http://www.apsis.ch/pound/

Other

• software f5; software big ip
• impl details related to zone coverage
  • e.g., zone goes down elb can cross zones to continue service
• identification of things we need (to change) in existing APIs
  • list needed to consider scheduling
• versions of protocols we support HTTP,HTTPS,TLSv?,SSLv?
• types of session management wrt load balancing
  • affinities, stickinesses,
  • ssl termination (at lb?)
• ipv6 - out of scope? guessing yes.
• initially a eucalyptus component
  • software reference implementation
  • support for hardware future requirement
• configuration, esp. compared to what can be configured in AWS (e.g., http connections time outs)
• candidates for reference software implementation
  • ha proxy
  • nginx
  • glassfish plugin: probably doesn't work for us
  • squid
  • linux virtual server
  • momentum si?
• future hardware support expected:
  • big ip f5
• preconfigured load balancing rules

Questions

• what is the functional spec/use cases
  • implications on deployment (e.g., backup power, network hardware/topology)
• survey of customer load balancing use cases, infrastructure?
• hybrid use case/story? importance?
• tightly coupled with autoscaling? is that use case central?
• use cases are satisfied by elb?
  • is there any case which is not satisfiable by ELB?

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tag:rls-3.3