Обсуждение: Synchronous standbys?
Reading documents coming with Simon's patches, I'm a little bit confused by the idea of "synchronous standbys". In the sgmls doc, "The commit wait will last until the first reply from any standby. Multiple standby servers allow increased availability and possibly increase performance as well." So in my understanding there could be one or more synchronous standbys. However in his mail: "If the current synchronous standby dies then one of the other standbys will take over." It seems there's only one synchronous standby allowed at the same time. Does anybody know which one is correct? -- Tatsuo Ishii SRA OSS, Inc. Japan English: http://www.sraoss.co.jp/index_en.php Japanese: http://www.sraoss.co.jp
On Wed, Feb 23, 2011 at 3:42 AM, Tatsuo Ishii <ishii@postgresql.org> wrote: > > It seems there's only one synchronous standby allowed at the same > time. > > Does anybody know which one is correct? there could be only one standby at the same time... in the original patch there could be several synchronous standby servers and the primary was going to wait until the first one of them to answer, but that was removed and replaced by a list of possible synch standby servers and the first that connects is the one the primary will wait for. because right now it's a simple list the first one will always be the synch standby until it's removed from the list or phisically. the other comment in the doc should be removed -- Jaime Casanova www.2ndQuadrant.com Professional PostgreSQL: Soporte y capacitación de PostgreSQL
> there could be only one standby at the same time... > in the original patch there could be several synchronous standby > servers and the primary was going to wait until the first one of them > to answer, but that was removed and replaced by a list of possible > synch standby servers and the first that connects is the one the > primary will wait for. because right now it's a simple list the first > one will always be the synch standby until it's removed from the list > or phisically. > > the other comment in the doc should be removed Thanks for the info! -- Tatsuo Ishii SRA OSS, Inc. Japan English: http://www.sraoss.co.jp/index_en.php Japanese: http://www.sraoss.co.jp