From: Ronan Dunklau <ronan.dunklau@aiven.io>
To: pgsql-hackers@lists.postgresql.org
Subject: pg_receivewal starting position
Date: Tue, 27 Jul 2021 07:50:39 +0200
Message-ID: <18708360.4lzOvYHigE@aivenronan> (raw)
Hello,
I've notived that pg_receivewal logic for deciding which LSN to start
streaming at consists of:
- looking up the latest WAL file in our destination folder, and resume from
here
- if there isn't, use the current flush location instead.
This behaviour surprised me when using it with a replication slot: I was
expecting it to start streaming at the last flushed location from the
replication slot instead. If you consider a backup tool which will take
pg_receivewal's output and transfer it somewhere else, using the replication
slot position would be the easiest way to ensure we don't miss WAL files.
Does that make sense ?
I don't know if it should be the default, toggled by a command line flag, or if
we even should let the user provide a LSN.
I'd be happy to implement any of that if we agree.
--
Ronan Dunklau
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To: pgsql-hackers@postgresql.org
Cc: ronan.dunklau@aiven.io, pgsql-hackers@lists.postgresql.org
Subject: Re: pg_receivewal starting position
In-Reply-To: <18708360.4lzOvYHigE@aivenronan>
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