Re: Configuring synchronous replication
От | Simon Riggs |
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Тема | Re: Configuring synchronous replication |
Дата | |
Msg-id | 1285279903.17321.1221.camel@ebony обсуждение исходный текст |
Ответ на | Re: Configuring synchronous replication (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>) |
Ответы |
Re: Configuring synchronous replication
Re: Configuring synchronous replication Re: Configuring synchronous replication |
Список | pgsql-hackers |
On Thu, 2010-09-23 at 20:42 +0300, Heikki Linnakangas wrote: > If you want the behavior where the master doesn't acknowledge a > commit > to the client until the standby (or all standbys, or one of them > etc.) > acknowledges it, even if the standby is not currently connected, the > master needs to know what standby servers exist. *That's* why > synchronous replication needs a list of standby servers in the master. > > If you're willing to downgrade to a mode where commit waits for > acknowledgment only from servers that are currently connected, then > you don't need any new configuration files. As I keep pointing out, waiting for an acknowledgement from something that isn't there might just take a while. The only guarantee that provides is that you will wait a long time. Is my data more safe? No. To get zero data loss *and* continuous availability, you need two standbys offering sync rep and reply-to-first behaviour. You don't need standby registration to achieve that. > But that's not what I call synchronous replication, it doesn't give > you the guarantees that > textbook synchronous replication does. Which textbook? -- Simon Riggs www.2ndQuadrant.comPostgreSQL Development, 24x7 Support, Training and Services
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