Re: [HACKERS] How to debug the wire protocol?

On 9 Feb 2017, at 20:15, Tom Lane <tgl@sss.pgh.pa.us> wrote:

Rui Pacheco <rui.pacheco@gmail.com> writes:

I’ve sent a similar email to the general mailing list but got no reply.

Uh, multiple people answered you, see
https://www.postgresql.org/message-id/flat/22DB2E08-6329-4EF8-B3E5-C0A7728A067B%40gmail.com

Is there a way to see how Postgres parses the message? I’ve set logging to DEBUG5 but the only thing I can see in the logs is, among other things, the message

ERROR:  invalid string in message
FATAL:  invalid frontend message type 63

That seems to comport with the theory I suggested before, that you were
sending an incorrect message length word --- although this additional
evidence indicates that the sent length is too short, not too long
which is what I'd been thinking.  Or possibly you left out required
field(s) of the message.  Anyway it's expecting a null-terminated string
and not finding one in the remaining message data.

regards, tom lane