Re: Inconsistent error handling in START_REPLICATION command

On 1/21/16 9:53 AM, Shulgin, Oleksandr wrote:
> On Thu, Jan 21, 2016 at 3:25 PM, Robert Haas <robertmhaas(at)gmail(dot)com
> <mailto:robertmhaas(at)gmail(dot)com>> wrote:
>
>
> So it's true that the client can't unilaterally terminate COPY BOTH
> mode; it can only send CopyDone. But an error on the server side
> should do so.
>
>
> Hm, you're right. Even though the server sends COPY_BOTH message
> before the plugin startup, an attempt by the client to actually read
> the data messages results in ErrorResponse handled on the client, then
> the client can re-submit the corrected START_REPLICATION command and
> continue without the need to reconnect. This cannot be actually
> tested in psql, but I can verify the behavior with my python scripts.
>
> Then I don't have a preference for the early error reporting in this
> case. If the current behavior potentially allows for more flexible
> error reporting, I'm for keeping it.

It looks like a decision needs to be made here whether to apply this
patch, send it back to the author, or reject it so I'm marking it "Ready
for Committer".

Robert, since you were participating in this conversation can you have a
look?

--
-David
david(at)pgmasters(dot)net