The libraries we maintain (1) are responsible for a non-trivial part of Facebook's overall compute footprint, (2) should basically never fail of their own accord, and (3) have pretty good error monitoring. So my team is operating what is effectively (among other things) a very sensitive detector for hardware failure.
And indeed we see examples all the time of blobs that fail to decompress, and usually when we dig in we find that the blob is only a single bit-flip away from a blob that decompresses successfully into a syntactically correct message. I can't share numbers, but, off the top of my head, I think it's the largest source of failures we see. It happens frequently enough that I wrote a tool to automate checking [0].
So yes. It happens. Pretty frequently, in the sense that if you're doing xillions of operations a day, a one-in-a-xillion failure happens all the time.
The libraries we maintain (1) are responsible for a non-trivial part of Facebook's overall compute footprint, (2) should basically never fail of their own accord, and (3) have pretty good error monitoring. So my team is operating what is effectively (among other things) a very sensitive detector for hardware failure.
And indeed we see examples all the time of blobs that fail to decompress, and usually when we dig in we find that the blob is only a single bit-flip away from a blob that decompresses successfully into a syntactically correct message. I can't share numbers, but, off the top of my head, I think it's the largest source of failures we see. It happens frequently enough that I wrote a tool to automate checking [0].
So yes. It happens. Pretty frequently, in the sense that if you're doing xillions of operations a day, a one-in-a-xillion failure happens all the time.
[0] https://github.com/facebook/zstd/tree/dev/contrib/diagnose_c...