On Tue, Jun 25, 2013 at 12:19 PM, Pavan Deolasee <pavan.deola...@gmail.com> wrote: > > > > On Mon, Jun 24, 2013 at 7:17 PM, Sawada Masahiko <sawada.m...@gmail.com> > wrote: >> >> >> >> -------------------- >> [Server] >> standby_name = 'slave1' >> synchronous_transfer = commit >> wal_sender_timeout = 30 >> [Server] >> standby_name = 'slave2' >> synchronous_transfer = all >> wal_sender_timeout = 50 >> ------------------- > > > What different values/modes you are thinking for synchronous_transfer ? IMHO > only "commit" and "all" may not be enough. As I suggested upthread, we may > need an additional mode, say "data", which will ensure synchronous WAL > transfer before making any file system changes. We need this separate mode > because the failback safe (or whatever we call it) standby need not wait on > the commits and it's important to avoid that wait since it comes in a direct > path of client transactions. > > If we are doing it, I wonder if an additional mode "none" also makes sense > so that users can also control asynchronous standbys via the same mechanism.
I made mistake how to use name of parameter between synchronous_transfer and failback_safe_standby_mode. it means that we control file system changes using failback_safe_standby_mode. if failback_safe_standby_mode is set 'remote_flush', master server wait for flushing all data page in standby server (e.g., CLOG, pg_control). right? for example: ------ [server] standby_name = 'slave1' failback_safe_standby_mode = remote_flush wal_sender_timeout = 50 ------ in this case, we should also set synchronous_commit and synchronous_level to each standby server. that is, do we need to set following 3 parameters for supporting case 3,4 as I said? -synchronous_commit = on/off/local/remote_write -failback_safe_standby_mode = off/remote_write/remote_flush -synchronous_level = sync/async (this parameter means that standby server is connected using which mode (sync/async) .) please give me your feedback. Regards, ------- Sawada Masahiko -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
