document: Reaching for five nines : ActiveWatch and SiteSeer Every Web admin 's dream is achieving the fabled five nines-99 .999 percent uptime . To attain such availability , your Web site must be down no more than about five minutes per year . Technologies like RAID , clustering , and load balancing make this easier , but to actually track uptime , maintain auditable records , and discover patterns in failures to prevent downtime in the future , you 'll need to set up external monitoring . Because your Internet connection is a key factor in measuring uptime , you must monitor your site from the Internet itself , beyond your firewall . You could monitor with custom software on remote hosts , or you could use one of the two reasonably priced services available : Mercury Interactive 's ActiveWatch and Freshwater Software 's SiteSeer . -LRB- Freshwater Software has been a subsidiary of Mercury Interactive for about a year now . -RRB- The two services offer a slightly different mix of features and target different markets . Both services offer availability and performance monitoring from several remote locations , alerts to email or pager , and periodic reports . They differ in what 's most easily monitored , and in the way you interact with the services
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