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Evaluation Metrics

We identify the following three metrics to evaluate the efficacy of SMFS:


Table 2: Experimental Configuration Parameters
Layered Interleaving r 8
FEC Params[10] c 3
Network-sync Parameters segment size 100 MB
append size 512 kB
block size 4 kB
Experiment Parameters expt duration 3 mins


For effective comparison, we define the following five configurations; all configurations use TCP to communicate between each pair of storage servers.

These five SMFS configurations are evaluated on each of the above metrics, and their comparative performance is presented. The Network-sync, Local-sync+FEC, and Remote-sync+FEC configurations all use the Maelstrom layered interleaving forward error correction codes with parameters $ (r,c)=(8,3)$ , which increases the tolerance to network transmission errors, but reduces the goodput by as much as $ 8/11$ of the maximum throughput without any proactive redundancy. Table 2 lists the configuration parameters used in the experiments described below.


next up previous
Next: Reliability During Disaster Up: Evaluation Previous: Experimental Environment
Hakim Weatherspoon 2009-01-14