Grid-enabled particle physics event analysis: experiences using a 10 Gb, high-latency network for a high-energy physics application

This paper examines issues encountered attempting to exploit a high-bandwidth, high-latency link in support of a high-energy physics (HEP) analysis application. The primary issue was that the TCP additive increase/multiplicative decrease (AIMD) algorithm is not suitable for "long fat networks". While this is a known problem, the magnitude of the impact on application performance was much greater than anticipated. We were able to overcome much of the impact, by altering the AIMD coefficients. Such an approach, of course, is non-TCP compliant, and there was insufficient time to test the network friendliness of these modifications.