On Thu, May 27, 2010 at 6:30 PM, Simon Riggs <si...@2ndquadrant.com> wrote: > Who sends the ack message?
walreceiver > Who receives it? walsender > Would it be easier to have > this happen in a second pair of processes WALSynchroniser (on primary) > and WAL Acknowledger (on standby). WALAcknowledger would send back a > stream of ack messages with latest xlog positions. WALSynchroniser would > receive these messages and wake up sleeping backends. If we did that > then there'd be almost no change at all to existing code, just > additional code and processes for the sync case. Code would be separate > and there would be no performance concerns either. No, this seems to be bad idea. We should not establish extra connection between servers. That would be a source of trouble. > If you do choose to make #3 important, then I'd say you need to work out > how to make WALWriter active as well, so it can perform regular fsyncs, > rather than having WALReceiver wait across that I/O. Yeah, this might be an option for optimization though I'm not sure how it has good effect. Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers