Re: [PATCH] Verify Checksums during Basebackups

Hi,

On Sun, Mar 04, 2018 at 06:19:00PM +0100, Magnus Hagander wrote:
> So sure, if we go with WARNING + exit with an errorcode, that is perhaps
> the best combination of the two.

I had a look at how to go about this, but it appears to be a bit
complicated; the first problem is that sendFile() and sendDir() don't
have status return codes that could be set on checksum verifcation
failure. So I added a global variable and threw an ereport(ERROR) at the
end of perform_base_backup(), but then I realized that `pg_basebackup'
the client program purges the datadir it created if it gets an error:

|pg_basebackup: final receive failed: ERROR: Checksum mismatch during
|basebackup
|
|pg_basebackup: removing data directory "data2"

So I guess this would have to be sent back via the replication protocol,
but I don't see an off-hand way to do this easily?

Another option would be to see whether it is possible to verify the
checksum on the client side, but then only pg_basebackup (and no other
possible external tools using BASE_BACKUP) would profit.

Michael

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