We could never be absolutely sure, due to the true Heisenbug nature of the behavior, but after tons of code audits and the observation after reverse proxy traffic analysis that it only occurred on processing by the non-ECC hosts, and never on the ECC hosts, that it was the most likely culprit.
The fact that the errors were single bit errors also strongly pointed in that direction.
Comments
We could never be absolutely sure, due to the true Heisenbug nature of the behavior, but after tons of code audits and the observation after reverse proxy traffic analysis that it only occurred on processing by the non-ECC hosts, and never on the ECC hosts, that it was the most likely culprit.
The fact that the errors were single bit errors also strongly pointed in that direction.