We also compare behavior of the Anypoint switch with an alternative service structure using a redirecting proxy that terminates incoming client connections and relay traffic over connections maintained between the proxy and the servers. Our proxies are implemented at the application level for TCP or UDP. The TCP proxy uses a blocking select to relay data between the peer and ensemble.
The Anypoint testbed consists of Dell PowerEdge 4400s with 733 MHz Pentium-III CPUs and 256 MB RAM, running FreeBSD 4.4. Each node has an Alteon Gigabit Ethernet NIC with hardware checkum offloading, connected to an Extreme Summit 7i switch. Unless stated otherwise, our microbenchmark tests use 4KB transport frames, 128 KB socket buffers, 9KB (Jumbo) segment/MTU sizes, and delayed acks. The Anypoint switch uses a frame window w of 384 entries. Each Slite NFS server is fitted with eight 18 GB 10,000 RPM Seagate Cheetah drives over two dual-channel Ultra-160 SCSI controllers.