Re: Outdated replication protocol error?
Fujii Masao <masao.fujii@oss.nttdata.com>
From: Fujii Masao <masao.fujii@oss.nttdata.com>
To: Jeff Davis <pgsql@j-davis.com>, pgsql-hackers@postgresql.org
Cc: Simon Riggs <simon@2ndQuadrant.com>,
Craig Ringer <craig.ringer@enterprisedb.com>
Date: 2021-01-14T07:40:26Z
Lists: pgsql-hackers
On 2021/01/12 9:06, Jeff Davis wrote: > Commit 5ee2197767 (about 4 years old) introduced the error: > > "IDENTIFY_SYSTEM has not been run before START_REPLICATION" > > But it seems like running START_REPLICATION first works (at least in > the simple case). > > We should either: > > 1. Document that IDENTIFY_SYSTEM must always be run before > START_REPLICATION, and always issue a WARNING if that's not done (an > ERROR might break existing applications); or > > 2. If the commit is out of date and no longer needed, or if it's easy > enough to fix, just remove the error (and Assert a valid > ThisTimeLineID). +1 to remove the error if START_REPLICATION can always work fine without IDENTIFY_SYSTEM. I found that the error happens when we connect to the standby and just run START_REPLICATION without IDENTIFY_SYSTEM. But I'm not sure if IDENTIFY_SYSTEM is actually necessary even in that case. Regards, -- Fujii Masao Advanced Computing Technology Center Research and Development Headquarters NTT DATA CORPORATION
Commits
-
Eliminate replication protocol error related to IDENTIFY_SYSTEM.
- 8e7811e952b4 15.0 landed
-
Ensure ThisTimeLineID is valid before START_REPLICATION
- 5ee2197767f6 10.0 cited