[ Thanks to Robert
Pupazzoni for this link. ]
“EBay’s persistent site failures stem from a lack of coordinated
IT planning and a centralized database and storage structure that
creates a single point of failure, insiders and experts say. …
The series of mishaps that led to eBay’s 11-hour site crash on Jan.
3 was reminiscent of 15 similar outages between August 1998 and
November 1999, including one in June 1999 that made the popular
auction site unreachable for 22 hours.”
“EBay uses Sun Enterprise Servers in tightly integrated
clusters, which group servers using special software and hardware
interconnects so that they appear to be a single system to the
user, application and systems manager. That approach is easier to
administer, but it’s also more prone to breakdowns because servers
tend to share central resources, such as an operating system and
storage system, Kusnetzky said.”
“Other high-traffic sites use more loosely integrated server
farms, in which a large number of small, low-end servers perform
identical functions in a redundant configuration. Search engine
Google, for instance, uses 4,000 Linux servers that do searches and
serve up Web pages in parallel, while Yahoo uses clusters of BSD
Unix servers. If one server goes down, the rest pick up the
load. The downside is that management is more labor-intensive,
because each server must be administered individually.”