This concept is not new. MPLS/BGP/VPNs has long been a “carrier technology” used for isolating customer traffic A from customer traffic B. As typical hardware in the distribution layers of campus networks such as Cisco 6880, Brocade MLX and Juniper MX switches have had or added MPLS support more have begun adopting the strategy. The Cloud Connectiv team has subject matter experts that can help you with any type of MPLS and/or WAN deployment whether you need a basic BGP peering for your provider managed MPLS network or you very own VPN V4/ LDP deployment.

Modern high-traffic websites must serve hundreds of thousands, if not millions, of concurrent requests from users or clients and return the correct text, images, video, or application data, all in a fast and reliable manner. To cost-effectively scale to meet these high volumes, modern computing best practice generally requires adding more servers.

A load balancer acts as the “traffic cop” sitting in front of your servers and routing client requests across all servers capable of fulfilling those requests in a manner that maximizes speed and capacity utilization and ensures that no one server is overworked, which could degrade performance. If a single server goes down, the load balancer redirects traffic to the remaining online servers. When a new server is added to the server group, the load balancer automatically starts to send requests to it.

In this manner, a load balancer performs the following functions:
• Distributes client requests or network load efficiently across multiple servers
• Ensures high availability and reliability by sending requests only to servers that are online
• Provides the flexibility to add or subtract servers as demand dictates

Different load balancing algorithms provide different benefits; the choice of load balancing method depends on your needs:

• Round Robin – Requests are distributed across the group of servers sequentially.
• Least Connections – A new request is sent to the server with the fewest current connections to clients. The relative computing capacity of each server is factored into determining which one has the least connections.
• IP Hash – The IP address of the client is used to determine which server receives the request.

Information about a user’s session is often stored locally in the browser. For example, in a shopping cart application the items in a user’s cart might be stored at the browser level until the user is ready to purchase them. Changing which server receives requests from that client in the middle of the shopping session can cause performance issues or outright transaction failure. In such cases, it is essential that all requests from a client are sent to the same server for the duration of the session. This is known as session persistence.

The best load balancers can handle session persistence as needed. Another use case for session persistence is when an upstream server stores information requested by a user in its cache to boost performance. Switching servers would cause that information to be fetched for the second time, creating performance inefficiencies.

Dynamic Configuration of Server Groups

Many fast-changing applications require new servers to be added or taken down on a constant basis. This is common in environments such as the Amazon Elastic Compute Cloud (EC2), which enables users to pay only for the computing capacity they actually use, while at the same time ensuring that capacity scales up in response traffic spikes. In such environments it greatly helps if the load balancer can dynamically add or remove servers from the group without interrupting existing connections.

Hardware vs. Software Load Balancing

Load balancers typically come in two flavors: hardware-based and software-based. Vendors of hardware-based solutions load proprietary software onto the machine they provide, which often uses specialized processors. To cope with increasing traffic at your website, you have to buy more or bigger machines from the vendor. Software solutions generally run on commodity hardware, making them less expensive and more flexible. You can install the software on the hardware of your choice or in cloud environments like AWS EC2.

Cisco takes this technology several leaps and bounds forward with their innovative UCS platform and accompanying unified fabric. This allows for the consolidation of IP, Storage and Management networks using a “wire-once” philosophy. The resource allocation for things such as bandwidth and I/O configurations are then administered dynamically via the system’s integrated administration interface. This allows for all servers to host the same workloads by simply adjusting configurations via embedded software. The approach of leveraging a single network technology for IP, Storage and Management not only reduces acquisition CAPEX and TCO

but also dramatically increases performance by eliminating reliance on external network architectures as well as reducing the number of interfaces, cables and switches required to support the infrastructure.

1 Scalability
Did your computing needs shoot up overnight? Or did they drop drastically during your slow season? Instead of having to hire — or fire — new staff or purchase more equipment to handle it yourself, you can just make a call to your colocation provider and scale your service up or down as needed.

2 Connectivity
Colocation providers keep your servers in climate-controlled data centers, with high bandwidth speeds, and excellent redundancy for network connections. You won’t have to pay the costs to purchase and maintain this kind of IT infrastructure in your own offices, and your internal IT staff can focus on other business operations.

3 Security
Quality colocation providers house your servers in secure data centers, with security measures that include biometric scanners, closed circuit cameras, on-site security, coded access, alarm systems, and more. And with colocation, you

don’t have to hire or purchase any of these security measures yourself — it’s all included in your service plan.

4 Stability
If you have to move offices, or are hit with a power outage, or suffer a natural disaster, you won’t have to worry about your data or services going down. A colocation provider will have multiple backup generators and contingencies in place to ensure that there is never an interruption in service, for you, or for your customers.

5 Predictability
Not only does using a colocation provider often save money, but it also turns unpredictable capital outlays into predictable monthly expenses.  You only pay for your own equipment, not a whole datacenter.  Your company will be able to budget for IT needs and allocate existing resources more efficiently.