This is simple patch, would that impact badly if patched to prior versions or some other constraints forced to not do that. I am just trying to understand this a bit.
On AWS RDS we have primary and secondary hosts known in advance in most cases. So if a primary instance fails over it will be other host and hence we have to update the active nodes in targets using lamda function. AWS RDS fails over very quickly under 3 seconds mostly and hence we have set that health checks to 3seconds. I'll go back to AWS folks and see if they can do this in prior releases.
Regards,
Virendra Kumar
On Wednesday, March 11, 2020, 5:29:38 PM PDT, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Can you please back port patch where if a 0 byte packet sent to PG instance (Health Checks), it starts complaining about invalid startup packet and flood the log which increases log size considerably if the health checks are every 3 seconds or something like that. > Patch Requested - https://git.postgresql.org/gitweb/?p=postgresql.git;a=patch;h=342cb650e
We generally don't like to change behavior of back branches without ironclad agreement that the existing behavior is a bug ... which this surely isn't. Also, the discussion leading up to that patch specifically considered and rejected back-patching; so I'm disinclined to overrule that decision now.
I would suggest that an every-three-second health check is not appropriate, especially one that is so minimal that it only detects whether the postmaster is alive.