Horton

Re: warning to publication created and wal_level is not set to logical

Andres Freund <andres@anarazel.de>

View thread View on postgr.es
From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Haas <robertmhaas@gmail.com>, David Fetter <david@fetter.org>, Lucas Viecelli <lviecelli199@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2019-03-25T18:06:13Z
Lists: pgsql-hackers 
Hi,

On 2019-03-25 13:53:32 -0400, Tom Lane wrote:
> One idea that might be useful is to have walsenders refuse to transmit
> any logical-replication data if they see wal_level is too low.  That
> would get users' attention pretty quickly.

They do:


/*
 * Load previously initiated logical slot and prepare for sending data (via
 * WalSndLoop).
 */
static void
StartLogicalReplication(StartReplicationCmd *cmd)
{
	StringInfoData buf;

	/* make sure that our requirements are still fulfilled */
	CheckLogicalDecodingRequirements();

and CheckLogicalDecodingReqs contains:

	if (wal_level < WAL_LEVEL_LOGICAL)
		ereport(ERROR,
				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
				 errmsg("logical decoding requires wal_level >= logical")));


Greetings,

Andres Freund

Commits

  1. Warn if wal_level is too low when creating a publication.