On 26.06.2013 17:15, Tom Lane wrote:
> Heikki Linnakangas<hlinnakangas@vmware.com> writes:
>> We've discussed retrying short writes before, and IIRC Tom has argued
>> that it shouldn't be necessary when writing to disk. Nevertheless, I
>> think we should retry in XLogWrite(). It can write much bigger chunks
>> than most write() calls, so there's more room for a short write to
>> happen there if it can happen at all. Secondly, it PANICs on failure, so
>> it would be nice to try a bit harder to avoid that.
>
> Seems reasonable. My concern about the idea in general was the
> impossibility of being sure we'd protected every single write() call.
> But if we can identify specific call sites that seem at more risk than
> most, I'm okay with adding extra logic there.
Committed a patch to add retry loop to XLogWrite().
I noticed that FileWrite() has some additional Windows-specific code to
also retry on an ERROR_NO_SYSTEM_RESOURCES error. That's a bit scary,
because we don't check for that in any other write() calls in the
backend. If we really need to be prepared for that on Windows, I think
that would need to be in a wrapper function in src/port or src/backend/port.
Would a Windows-person like to comment on that?
- Heikki