Frequently Answered Questions on Cloud Load Balancers

What is a cloud load balancer?

Load balancing distributes workloads across two or more servers, network links, and other resources to maximize throughput, minimise response time and avoid overload. This type of functionality is required to maintain high availability for mission-critical web-based applications and workloads. Rackspace cloud load balancers allow you to quickly load balance multiple Cloud Servers™ or Dedicated Servers for optimal resource utilisation.

How much does a Rackspace Cloud Load Balancer cost?

Pricing starts from 1p per hour, however please see the pricing page for details. Standard charges for Cloud Files™ will apply if you have elected to enable log delivery to your Cloud Files account. Standard charges will apply for additional (unique) virtual IP addresses per load balancer.

How does Rackspace charge for bandwidth (public and private traffic)?

• Standard bandwidth rates apply for outbound transfers over the public network. There is no charge for inbound transfers.
• No charges for in/out bandwidth transfers over Rackspace's internal network.

Can I manage my cloud load balancer using the API and Rackspace Cloud Control Panel?

Yes, implementation and management of our cloud load balancer solution is currently available through our Rackspace Cloud Control Panel and the API. In order to use our API, customers should have a general understanding of the load balancing service and be familiar with:

• RESTful Web Services
• HTTP/1.1 Conventions
• JSON and/or Serialization Formats
• Atom Syndication Format

Can I use cloud load balancers in conjunction with RackConnect™?

Yes, customers are able to utilise the RackConnect Cisco ASA solution to connect dedicated and cloud servers, while leveraging cloud load balancers to load balance between cloud servers. Customers utilising RackConnect will be billed for outgoing bandwidth through their dedicated environment, as well as outbound traffic for their cloud load balancer.

If customers need to include dedicated and cloud servers in the same resource pools (to load balance between both platforms), they should leverage the RackConnect F5® BIG-IP® Local Traffic Manager™Solution.

Do cloud load balancers work with dedicated servers?

Yes; however, we recommend using this service via RackConnect if you wish to include dedicated servers.

We do not currently recommend leveraging cloud load balancers with dedicated servers without RackConnect, except in low traffic scenarios (due to potential for significant bandwidth charges). Without RackConnect, you would be metered or billed for bandwidth charges for the request outbound from the cloud load balancer, the response outbound from their dedicated firewall and the response outbound again from the cloud load balancer returning to the user.

How many concurrent connections can the service handle?

A single customer load balancer can handle 150,000 connections and 10Gb/sec throughput. A cloud load balancer cluster as currently built now can handle 1.2 million concurrent connections and can be expanded easily to 2.4 million.

How will you manage and distribute IPs?

Each load balancer comes with one (1) public IPv4 address. Additional IPv4 addresses can be purchased for an additional $2 each per month, with proper justification. The scenarios where additional IPv4 addresses will be approved are: High Availability configurations and SSL Certificates (no self-signed certificates). Please submit a ticket requesting an additional IPv4 address.

Will customers be able to perform SSL termination?

Yes. SSL allows users to have their traffic terminate at the load balancer with easier centralized certificate management, SSL acceleration for improved throughput, reduced CPU load at the application server for better performance and HTTP/HTTPS session persistence.

Who should not be using the SSL Termination on Cloud Load Balancers?

Customers who have Personally Identifiable Information (PII) in their data. Examples of PII are HIPAA protected health information, Gramm-Leach-Bliley financial information, credit card information and any personal data. Generally any information which when disclosed could result in the theft of a person's identity.

How long will it take to provision a customer load balancer?

In most cases, it should take less than one minute for a load balancer to be provisioned once the API request is submitted. During periods of extreme system load, we anticipate no more than a few minutes for complete provisioning.

What is the max throughput of each load balancer?

A single cloud load balancer is connected via 10Gb/second network to both public and Rackspace's internal network, which we have tested to achieve about 9Gb/second of actual throughput. There are some limiting factors which may influence the actual throughput at any given time.

How can a customer raise the API limits?

Customers who wish to modify their imposed API rate limits will need to contact Support.