On Fri, Mar 11, 2011 at 10:18 PM, Robert Haas <robertmh...@gmail.com> wrote: >> I added this replication timeout patch into next CF. >> >> I explain why this feature is required for the future review; >> >> Without this feature, walsender might unexpectedly remain for a while when >> the standby crashes or the network outage happens. TCP keepalive can >> improve this situation to a certain extent, but it's not perfect. Remaining >> walsender can cause some problems. >> >> For example, when hot_standby_feedback is enabled, such a remaining >> walsender would prevent oldest xmin from advancing and interfere with >> vacuuming on the master. For example, when you use synchronous >> replication and walsender in SYNC mode gets stuck, any synchronous >> standby candidate cannot switch to SYNC mode until that walsender exits, >> and all the transactions would pause. >> >> This feature causes walsender to exit when there is no reply from the >> standby before the replication timeout expires. Then we can avoid the >> above problems. > > I think we should consider making this change for 9.1. This is a real > wart, and it's going to become even more of a problem with sync rep, I > think.
Yeah, that's a welcome! Please feel free to review the patch. 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
