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loeglast Tuesday at 12:35 AM1 replyview on HN

> It smooths out the tail latencies, which are quite high for SSDs.

I'm sorry, tail latencies are high for SSDs? In my experience, the tail latencies are much higher for traditional rotating media (tens of seconds, vs 10s of milliseconds for SSDs).


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johncolanduonilast Tuesday at 1:18 AM

They’re higher relative to median latencies for each. A high end SSD’s P99/median is higher than a high end HDD. That’s the relevant metric for request hedging.

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