What's All The Cluster About

I see more and more hosts popping up (and older hosts switching to) offering what they call clustered load balanced plans. These plans are mostly on the low end price wise (sub $10/month), and the marketing speak tells of zero downtime, intelligent clustered, load balanced, failover, will wash your clothes approaches to keeping websites up 110% of the time.

I guess what I fail to grasp is are these plans really, truly load balanced clustered approaches, or is it more of a case of we have 1 DNS server, 1 mail server, 1 web server, 1 mysql server, and a backup server that in an emergency has rsyncs each hour to "failover" to and screw up your dynamic data?

If the webservers are load balanced, what about accounts that use SQLite db's, or berkeley db's, are these maintained 100% in synch, and if so, how? If one server goes down, and the other picks up the slack, won't the db's be out of synch and data contention will occur? Are sessions including SSL truly handled correctly?

Same for MySQL. Is this true two way replication with fault tolerant switchovers between master and slave to preclude data loss and corruption on hot switch overs when a server fails?

I guess I just see everyone slapping a "clustered" label on things, and speaking of load balancers, etc... all for the cup of coffee a month. But I am highly suspect if these plans are truly load balanced, or is it a band-aid approach to load balancing?

Just the ranting of a an older hosting owner who's just not sure what many companies are truly offering when they speak of clustered, load balanced, more uptime than Viagra type of solutions...