I'm planning to buy new server for memcache/couchbase.
Would you recommend using ECC memory for a memcache server, why/why not?
SnapOverflow
If you want to have high availability its always recommended to buy ECC, no matter what service you run on it.
It depends on your strategy. Either have many cheap boxes which replicate the data between each other and use HA solutions to make sure the cluster stays available, or pay more money for better hardware and put more importance on the uptime of single boxes.
ECC is helpful to keep to uptime of a single box up. but depending on the architecture of the whole environment thats either more or less important, depending on your case.