NetworkComputing.co.uk LoadMaster 5500 from Kemp Technologies

NetworkComputing.co.uk

October 24, 2011

Kemp Technologies has previously focused on the SMB application delivery controller market. With its latest product, the LoadMaster 5500 appliance, they indicate a clear shift towards enterprises and service providers. All devices in the LoadMaster range stand out for their excellent value. The 5500 continues this tradition by offering a host of features at a price most of the competition will be hard pressed to match.

The 5500 provides server load balancing, Layer 4/7 content switching, ASIC-based SSL acceleration for up to 10,000 TPS (transactions per second) and it also supports 1,000 physical and 1,000 virtual services out of the box. This 2U appliance provides eighteen Gigabit network ports and its quality hardware specification delivers a 6Gbps traffic throughput, as well as the ability to handle a remarkable 30 million concurrent Layer 4 connections. The appliance supports a range of deployments where a single-arm mode uses one network port with all physical and virtual services on the same subnet. For testing, we used the two-arm mode which kept our physical and virtual services on different subnets. Redundancy is good as the 5500 has dual hot-plug power supplies and it supports high availability through deployment of two appliances for failover.

For installation we connected a local monitor and keyboard to the appliance and followed a quick start wizard to assign IP addresses to the ports. The 5500 adheres to the standard concepts for server load balancing, as you create farms using multiple physical servers and assign these to virtual services. The main web interface is well designed making virtual service creation simple. We provided an IP address, port number and protocol, and then assigned our physical Windows Server 2008 R2 servers to them, using their real IP addresses.

Load balancing schemes are in abundance with the default round robin mode intercepting incoming requests and distributing them to each server in strict rotation. For weighted round robin mode you assign priorities to each server in the farm, to ensure that the better specified systems are kept the busiest. You can base traffic distribution on real servers with the least number of connections and further weightings can be applied to control which servers in the farm are used the most. A new feature is weighted response time scheduling where the weights for each server are automatically adjusted, based on their response times.

Load balancing can also be adapted to server performance using a local agent on each physical server. This presents a web page with a numerical value between 1 and 100 to a LoadMaster query that defines how busy the server is.

The 5500 supports Layer 4 connection persistence which uses the source address to ensure traffic from a particular client is always sent to the same physical server. Extensive Layer 7 connection persistence methods are available and include cookies, session IDs, and URLs, along with rules for inspecting HTTP content. Response times to user requests are improved as the appliance can cache static web content in memory and it can apply GZIP compression to HTTP objects. IPS also comes as standard as the appliance applies SNORT rules to incoming web traffic and blocks malicious content from the server farms.

The 5500 uses a quality Cavium Nitrox card for SSL acceleration. It can decrypt SSL traffic and send it to the internal servers in the clear to improve performance. A new feature allows traffic to be re-encrypted by the card before passing it on.

Compared with the majority of enterprise level application delivery controllers, the LoadMaster 5500 is exceptionally good value. It offers an impressive range of features and it is easy to deploy; it comes with the power to handle very high volumes of web traffic. NC