Synchronous P2P Request Latency Too Large

[andrei3131]

Please find below the latencies measured for the synchronous case of P2P Model Request and Store update. This is the current bottleneck of the system which needs to be resolved in order to improve the throughput of the system.

[127.0.0.1/02/02-of-04::stdout] Model store update took 16.012414ms
[127.0.0.1/03/03-of-04::stdout] Model store update took 276.625µs
[127.0.0.1/02/02-of-04::stdout] Model store update took 176.388µs
[127.0.0.1/02/02-of-04::stdout] Request took 673.288µs
[127.0.0.1/03/03-of-04::stdout] Request took 15.947665ms
[127.0.0.1/00/00-of-04::stdout] Model store update took 3.733306ms
[127.0.0.1/01/01-of-04::stdout] Model store update took 175.905µs
[127.0.0.1/00/00-of-04::stdout] Request took 14.822951ms
[127.0.0.1/03/03-of-04::stdout] Model store update took 195.484µs
[127.0.0.1/01/01-of-04::stdout] Request took 20.67839ms
[127.0.0.1/02/02-of-04::stdout] Model store update took 216.966µs
[127.0.0.1/00/00-of-04::stdout] Model store update took 235.257µs
[127.0.0.1/01/01-of-04::stdout] Request took 833.436µs

[luomai]

We benchmark the requesting model latency on playtpus2. The peer actually requests a local peer (though through domain socket). The latency is high.

The requested model size is 2MB. In the worst case if using a 10 Gbps link, the actual data transmission should not take more than 2ms.

Could you look into this if you have time? @lgarithm

[lgarithm]

Commit id for benchmarks: e97969d

[lgarithm]

The latency varies from t to 2t (#83), I think it is stable, considering the memory bandwidth is shared.