Thread: expose confirmed_flush for replication slots

Hi,

I had some trouble today with a misbehaving logical replication client
which had confirmed a flush of an LSN far into the future.  Debugging it
was a bit of a pain for a number of reasons, but I think the most
important one was that confirmed_flush isn't exposed in
pg_stat_replication_slots.  Attached patch exposes it, as
confirmed_flush_lsn (to make it look like restart_lsn; not sure whether
we should just keep the internal name or not).

Adding this one to the next commit fest, but any feedback welcome in the
meanwhile.


.m

On 2015-07-08 14:57, I wrote:
> Adding this one to the next commit fest, but any feedback welcome in the
> meanwhile.

Forgot to change PG_GET_REPLICATION_SLOTS_COLS; fixed in the attached patch.


.m

On 2015-07-08 15:01:15 +0300, Marko Tiikkaja wrote:
> +        if (confirmed_flush_lsn != InvalidTransactionId)
> +            values[i++] = LSNGetDatum(confirmed_flush_lsn);
> +        else
> +            nulls[i++] = true;
> +

Hm. That comparison is using the wrong datatype, but it appears you only
copied my earlier mistake... Fixed back to 9.4 and in your patch.

Other notes:

* you missed to touch test_decoding's regression test output files.
* None of the docs were touched. catalogs.sgml definitely needs docs about the new columns, and I see no reason to
leavethe examples elsewhere stale.
 

Fixed those and committed it. Thanks for the patch!

- Andres

On 8/10/15 1:29 PM, Andres Freund wrote:
> On 2015-07-08 15:01:15 +0300, Marko Tiikkaja wrote:
>> +        if (confirmed_flush_lsn != InvalidTransactionId)
>> +            values[i++] = LSNGetDatum(confirmed_flush_lsn);
>> +        else
>> +            nulls[i++] = true;
>> +
>
> Hm. That comparison is using the wrong datatype, but it appears you only
> copied my earlier mistake... Fixed back to 9.4 and in your patch.
>
> Other notes:
>
> * you missed to touch test_decoding's regression test output files.
> * None of the docs were touched. catalogs.sgml definitely needs docs
>    about the new columns, and I see no reason to leave the examples
>    elsewhere stale.

Yeah.  I should've grepped around a bit more.  Sorry about that.

> Fixed those and committed it. Thanks for the patch!

Thank you very much!


.m