Is it reasonable to expect decent performance from a SQL server connected via fiber private WAN – 5000 km's away. The carrier is telling us that this network is the 'best' possible, and will introduce less than 50ms latency guaranteed.
Our database is currently connected via gigabit ethernet to our other machines within the same datacenter. Getting a 5000km 'LAN Extension' between the two DC's is appealing to us. But when we connect via the Internet and VPN, we find the performance very slow doing large volumes of small transactions. We don't have any WAN experience, so not sure what most companies do in these cases. Can we simulate 5000kms of 'latency'?
Best Answer
5000Kms at the speed of light would be ~17ms latency. Down optical fibre, more like 25ms. And that's a best case server-to-server fibre with no delays for media conversion, switching, routing, server response, etc.
Minimum is 25ms, guaranteed maximum 50ms...
yes there are tools to simulate a slow link, e.g.
http://jagt.github.io/clumsy/ - a Windows program for network traffic changing
http://wanem.sourceforge.net/ - a Linux LiveCD for WAN emulation
and lots of suggestions https://stackoverflow.com/questions/130354/how-do-i-simulate-a-low-bandwidth-high-latency-environment and https://stackoverflow.com/questions/1094760/network-tools-that-simulate-slow-network-connection