Oops. At Tue, 17 Nov 2015 19:40:10 +0900 (Tokyo Standard Time), Kyotaro HORIGUCHI <horiguchi.kyot...@lab.ntt.co.jp> wrote in <20151117.194010.17198448.horiguchi.kyot...@lab.ntt.co.jp> > Hello, > > At Tue, 17 Nov 2015 18:13:11 +0900, Masahiko Sawada <sawada.m...@gmail.com> > wrote in <CAD21AoC=an+dkynwsjp6coz-6qmhxxuenxvpisxgpxcuxmp...@mail.gmail.com> > > >> One question is that what is different between the leading "n" in > > >> s_s_names and the leading "n" of "n-priority"? > > > > > > Ah. Sorry for the ambiguous description. 'n' in s_s_names > > > representing an arbitrary integer number and that in "n-priority" > > > is literally an "n", meaning "a format with any number of > > > priority hosts" as a whole. As an instance, > > > > > > synchronous_replication_method = "n-priority" > > > synchronous_standby_names = "2, mercury, venus, earth, mars, jupiter" > > > > > > I added "n-" of "n-priority" to distinguish with "1-priority" so > > > if we won't provide "1-priority" for backward compatibility, > > > "priority" would be enough to represent the type. > > > > > > By the way, s_r_method is not essentially necessary but it would > > > be important to avoid complexity of autodetection of formats > > > including currently undefined ones. > > > > Than you for your explanation, I understood that. > > > > It means that the format of s_s_names will be changed, which would be not > > good. > > I believe that the format of definition of "replication set"(?) > is not fixed and it would be more complex format to support > nested definition. This should be in very different format from > the current simple list of names. This is a selection among three > or possiblly more disigns in order to be tolerable for future > changes, I suppose. > > 1. Additional formats of definition in future will be stored in > elsewhere of s_s_names. > > 2. Additional format will be stored in s_s_names, the format will > be automatically detected. > > 3. (ditto), the format is designated by s_r_method. > > 4. Any other way? > > I choosed the third way. What do you think about future expansion > of the format? > > > So, how about the adding just s_r_method parameter and the number of > > required ACK is represented in the leading of s_r_method? > > For example, the following setting is same as above. > > > > synchronous_replication_method = "2-priority" > > synchronous_standby_names = "mercury, venus, earth, mars, jupiter" > > I *feel* it is the same or worse as having the third parameter > s_s_num as your previous design.
I feel it is the same or worse *than* having the third parameter s_s_num as your previous design. > > In quorum method, we can set; > > synchronous_replication_method = "2-quorum" > > synchronous_standby_names = "mercury, venus, earth, mars, jupiter" > > > > Thought? > > > regards, -- Kyotaro Horiguchi NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers