Array of Light

The Array TM is a modular system, which means you can purchase only the functionality you require. The base product provides server load-balancing, firewall functionality (WebWall) and clustering. For $6,000 per module, you can also purchase caching, compression and GSLB (global server load-balancing). An additional $8,000 will get you SSL acceleration--not a great deal but nice if you want to manage all your traffic from one spot.

A redundant configuration for high-availability environments is also available, and though an active-active configuration is possible, the KISS principle employed by Array Networks disallows an active-active configuration for the same VIP (Virtual IP address)--and stateful failover is not an option. If you only want to balance a single VIP, the redundant configuration means active-standby mode only.

CLI (command-line interface) jocks will feel right at home with the Cisco IOS-like interface. The device is a breeze to configure and operates in a standard reverse-proxy configuration. Using TCP multiplexing to back-end Web servers enhances the product's performance. SSL re-encryption to back-end secure servers is also available and lets you take advantage of pooling HTTPS (HTTP Secure) sessions on the back end to reduce the latency introduced by establishing secure connections.

Layer 7 functionality is limited compared with that of the competition, including F5 Networks and NetScaler. Only specific HTTP headers are available for routing: host, URL, network and cookie. Plans to support additional headers, such as the SOAPAction header used by Web services, are in the works. URL parsing is rudimentary, offering limited regular expression pattern-matching. When questioned about the limits on content switching, Array Networks' engineers explained that only by limiting the possibilities could they properly optimize their code to reduce performance degradation caused by excessive data parsing.

The Flight Deck, Array Networks' GUI dashboard, is a boon. At a glance, administrators can ascertain the performance both of the device's internal systems and its load-balancing functionality. The rest of the interface design is slick and navigable, but there are usability issues--too many "apply" buttons on a single screen with no apparent grouping of controls makes configuration via the GUI confusing. Array Networks says it is addressing this problem, and though the GUI has been improved dramatically since earlier releases (see our Sneak Preview of the Array 1000), I strongly advise administrators to stick to the CLI except for monitoring. SNMP-, syslog- and CLI-based monitoring options are also available, sans sexy graphics.