alt Hacker NewsThe difference in throughput for local versus distributed orchestration would mainly come from serdes, networking, switching. Serdes can be substantial. Networking and switching has been aggressively offloaded from CPU through better hardware support.
Individual tasks would definitely have better latency, but I'd suspect the impact on throughput/CPU usage might be muted. Of course at the extremes (very small jobs, very large/complex objects being passed) you'd see big gains.
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mtremsal • 10/12/2024
Would you mind expanding on how SerDes become a bottleneck? I’m not familiar and reading the Wikipedia article wasn’t enough to connect the dots.
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By way of a single example, we've been migrating recently from spark to duckdb. Our jobs are not huge, but too big for a single 'normal' machine. We've gone from a 2.5 hour runtime on a cluster of 10 machines (40,vCPU total) to a 15 minute runtime on a 32vCPU single machine. I don't know for sure, but I think this is largely because it eliminates expensive shuffles and serde. Obviously results vary hugely depending on workload, and some jobs are simply too big even for a 192 core machine. But I suspect a high proportion of workloads would be better run on single large machines nowadays