Re: Logging corruption error codes

On 2019-Jun-20, Andrey Borodin wrote:

> Hi!
>
> We are fine-tuning our data corruption monitoring and found out that many corruption cases do not report proper error code.
> This makes automatic log analyzer way too smart program.
> We think that corruption error codes should be given in cases when B-tree or TOAST do not know how to interpret data.
> PFA patch with cases that we have found in logs and consider evidence of corruption.

This is not totally insane -- other similar messages such as 'corrupted
page pointers' in bufpage.c get the same errcode.

I would like to have a separate marking for messages indicating a
system-level permanent problem rather than user error ("table/column X
does not exist"), retryable condition ("serializability violation"), or
resource exhaustion ("out of memory", "too many clients"), but that's
probably a separate patch: things like "could not open/read/write file"
for a data file, or "xlog flush request XYZ not satisfied", and so on,
which also indicate a kind of corruption. As you say, currently we have
to have much too smart programs to weed out the serious errors that
ought to show up in an alerting system from run-of-the-mill problems.

--
Álvaro Herrera https://www.2ndQuadrant.com/
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