I am looking at implementing SSD based hardware RAID and have been unable to find anything about how it behaves in a situation where the data isn't readable from the queried device.
Spinning metal will retry until the time limit is set by the drive firmware's error recovery control (ERC) feature (called time-limited error recovery -TLER- by Western Digital and command completion time limit -CCTL- by Samsung/Hitachi). Unless the time limit is set to something reasonable, this can be a long time. I have experienced what happens when the first drive in a mirrored set of drives (without ERC) is the one having the issue.
Is there ERC on SSD?