From: Bruce Momjian on 8 Feb 2010 08:34 Markus Wanner wrote: > Bruce, > > Bruce Momjian wrote: > > Ah, I now realize it only mentions "warm" standby, not "hot", so I just > > updated the documentation to reflect that; you can see it here: > > Maybe the table below also needs an update, because unlike "Warm Standby > using PITR", a hot standby accepts read-only queries and can be > configured to not loose data on master failure. Ahh, good point. I had not considered the table would change. What I did was to mark "Slaves accept read-only queries" as "Hot only". You can see the result here: http://momjian.us/tmp/pgsql/high-availability.html I did not change "Master failure will never lose data" because the 9.0 streaming implementation is not sychronous (see wal_sender_delay in postgresql.conf), and I don't think even setting that to zero makes the operation synchronous. I think we will have to wait for PG 9.1 for _synchronous_ streaming replication. -- Bruce Momjian <bruce(a)momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Robert Haas on 7 Feb 2010 08:55 On Sun, Feb 7, 2010 at 4:41 AM, Markus Wanner <markus(a)bluegap.ch> wrote: > Bruce Momjian wrote: >> Do we want to call the feature "hot standby"? Is a read-only standby a >> "standby" or a "slave"? > > I think hot standby is pretty much the term, now. See here for the previous iteration of this discussion: http://archives.postgresql.org/pgsql-hackers/2009-08/msg00870.php I've always thought this feature was misnamed and nothing has happened to change my mind, but it's not clear whether I'm in the majority. ....Robert -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: "David E. Wheeler" on 7 Feb 2010 16:25 On Feb 7, 2010, at 12:35 PM, Josh Berkus wrote: >> I've always thought this feature was misnamed and nothing has happened >> to change my mind, but it's not clear whether I'm in the majority. > > I'm afraid force of habit is more powerful than correctness on this one. > It's going to be HS/SR whether that's perfectly correct or not. What would be correct? I thought HS/SR were pretty correct (as long as no one confuses SR with synchronous replication!). Best, David -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Fujii Masao on 8 Feb 2010 19:45 On Mon, Feb 8, 2010 at 10:34 PM, Bruce Momjian <bruce(a)momjian.us> wrote: > Ahh, good point. I had not considered the table would change. What I > did was to mark "Slaves accept read-only queries" as "Hot only". Can the "warm standby" still reside in v9.0? If not, the mark of "Hot only" seems odd for me. > I did not change "Master failure will never lose data" because the 9.0 > streaming implementation is not sychronous (see wal_sender_delay in > postgresql.conf), and I don't think even setting that to zero makes the > operation synchronous. I think we will have to wait for PG 9.1 for > _synchronous_ streaming replication. You are right. Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Bruce Momjian on 8 Feb 2010 23:32
Fujii Masao wrote: > On Mon, Feb 8, 2010 at 10:34 PM, Bruce Momjian <bruce(a)momjian.us> wrote: > > Ahh, good point. ?I had not considered the table would change. ?What I > > did was to mark "Slaves accept read-only queries" as "Hot only". > > Can the "warm standby" still reside in v9.0? If not, the mark of > "Hot only" seems odd for me. Yes, both hot and warm standby is supported in 9.0. -- Bruce Momjian <bruce(a)momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers |