Re: Synchronous replication patch v1

On Thu, Nov 6, 2008 at 3:59 PM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> 1) Start postgres in the primary
> 2) Get an online-backup in the primary
> 3) Locate the online-backup in the standby
> 4) Start postgres (with walreceiver) in the standby
> # Configure restore_command, host of the primary and port in recovery.conf
> 5) Manual operation
> # If there are missing files for PITR in the standby, copy them
> from somewhere
> (archive location of the primary, tape backup..etc).
> The missing files might be xlog or history file. Since xlog
> file segment is
> switched when replication starts, the missing xlog files would
> basically exist
> in the archive location of the primary.

More properly, since startup process and walreceiver decide
timeline ID from the history files, all of them need to exist in
the standby (need copy if missing) before 4) starting postgres.

If the database whose timeline is the same as the primary's
exists in the standby, 2)3) getting new online-backup is not
necessary. For example, after the standby falls down, the
database at that time is applicable to restart it.

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center