Re: DRAFT 9.6 release
Josh Berkus <[email protected]>
| Newsgroups | gmane.comp.db.postgresql.advocacy |
|---|---|
| Message-ID | <[email protected]> |
On 08/30/2016 02:28 PM, Bruce Momjian wrote: > On Tue, Aug 30, 2016 at 09:41:59AM -0700, Josh Berkus wrote: >> On 08/29/2016 06:24 PM, Amit Langote wrote: >>> On 2016/08/30 8:00, Josh Berkus wrote: >>>> Folks, >>>> >>>> Here is a preliminary draft of a 9.6 release announcement. >>>> >>>> Please comment, suggest, edit, make comments on the wiki, whatever. >>>> >>>> https://wiki.postgresql.org/wiki/96releasedraft >>> >>> In the section on scale out, I see quorum commit mentioned but it's not >>> part of what's offered in 9.6. The quorum part is still being worked on: >>> https://commitfest.postgresql.org/10/696/ >> >> Oh, figures the one feature I haven't tested would be the one which >> isn't right. So what DID get added to 9.6? Is it still a significant >> feature? > > We did this (from the 9.6 release notes): > > Allow synchronous replication to support multiple simultaneous > synchronous standby servers, not just one (Masahiko Sawada, > Beena Emerson, Michael Paquier, Fujii Masao, Kyotaro Horiguchi) > > The number of standby servers that must acknowledge a commit > before it is considered complete is now configurable as part of > the synchronous_standby_names parameter. > > You can see the details here, e.g. "3 (s1, s2, s3, s4)" > > https://www.postgresql.org/docs/9.6/static/runtime-config-replication.html#GUC-SYNCHRONOUS-STANDBY-NAMES So that's usually what I mean when I say quorum commit. But apparently our feature does something slightly different? "For example, a setting of 3 (s1, s2, s3, s4) makes transaction commits wait until their WAL records are received by three higher-priority standbys chosen from standby servers s1, s2, s3 and s4" What does that mean exactly? If I do: 3 ( s1, s2, s3, s4, s5 ) And a commit is ack'd by s2, s3, and s5, what happens? -- -- Josh Berkus Red Hat OSAS (any opinions are my own) -- Sent via pgsql-advocacy mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-advocacy