What the heck is tail latency?

Mark May elaborates on the problem of tail latency, as presented on by SNIA at Storage Field Day. According to SNIA, these spikes in latency can be up to ten times as bad as average latency. Mark says that this problem could be fixed by building smarter software that can tag an IO with a retry policy hint, allowing it to favor response time over data recovery. According to SNIA, over 2% of IO may be suffering due to tail latency. Mark knows this is a real problem and hopes it can be fixed in the near future.

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