ISPPlanet Cache Review Series

Fail-Safe Caching:
InfoLibria DynaCache

by Lisa Phifer VP Core Competence, Inc. [January 17, 2000]

By design, web caches must be placed squarely in harm's way, standing between end users and the World Wide Web. In high-availability networks, measures must be taken to prevent the cache from becoming a traffic bottleneck or single-point-of-failure. In our second installment of this ISP-Planet series [overview], we test-drive InfoLibria's DynaCache 220i. The DynaCache is engineered to provide robust, fail-safe caching for mid-to-large scale ISP and enterprise networks.

DynaCache 220i v2.0.5 $24,995 (as tested) InfoLibria, Inc. Waltham, Mass. 781-398-0288 http://www.infolibria.com

Under the Covers
The DynaCache 220i is capable of supporting 64K concurrent connections with 27 Mbps aggregate throughput, at a list price of $24,995. This model includes 512MB RAM, 36 GB of hot-swappable disk storage, triple 10/100 Ethernets, redundant field-replaceable power supplies, and an electro-mechanical switching device called the DynaLink. An expansion disk array (not evaluated) adds seven 9GB disks for $24,495. The top-of-the-line DynaCache 260i packs 1 GB RAM and 144 GB HDD to transparently push 45 Mbps for $72,995 (mirror disk option available). Looking for something smaller? Entry-level DynaCache 20 proxies 12 Mbps for just $9,995.

The DynaCache can be deployed by itself in proxy mode or combined with your favorite Layer 4 switch from Foundry, F5, Arrowpoint, Alteon, or HydraWEB. All models are also available in an "i" configuration that uses the DynaLink for in-line transparent caching: simply drop this duo between your network and your WAN router. The DynaLink normally diverts all traffic to the DynaCache, where HTTP traffic is serviced and non-HTTP traffic is sent on its way. During periods of high volume, the DynaLink selectively redirects some traffic to the cache, while letting excess load flow directly upstream. If either the cache or the DynaLink become disabled, an electro-mechanical bridge bypasses the cache entirely. The DynaLink makes sure that traffic keeps flowing without interruption, even when power cords or Ethernet cables get disconnected from the cache.

> Installation & Setup	DynaCaching Services
Adding DynaCache to Your Network	Advanced Management Features
Command-Line Administration	Keeping Tabs on the DynaCache
Configuration & Script Files	Product Support/Final Thoughts