In a satisfying confirmation of my envelope-back debugging, one of our
network boffins confirmed to me that our long-distance link from
Gainesville, Florida to Atlanta, Georgia was detoured through Chicago,
Illinois for several weeks.

This added up to latency going up by more than a factor of three,
nicely contributing to my collapse in throughput.

In the odd way of such things, the introduction and resolution of this
problem has actually made me feel more confident in my infrastructure,
because oddities in it are susceptible to investigation.  Now I need
to get some monitoring in place for the latency over that link.

But to conclude: fast tapes at the end of a well tuned fast pipe
totally rock.


- Allen S. Rout