For your information, I would like to explain a little bit more about pgpool-II own replication (we call it "native replication mode" to separate from streaming replication or slony replication). In the pgpool-II's native replication mode, for a start pgpool-II sends the query to "master" PostgreSQL node, which is the first one in the configuration file. After the PostgreSQL returns response, pgpool-II sends the query to the second PostgreSQL node. This is to avoid deadlock between DB nodes. If you have third or fourth DB node, pgpool-II sends the query concurrently with the second node. So in theory pgpool-II's performance in DML/DDL is no less than 50% comparing with single PostgreSQL regardless number of DB nodes. There's one optimization however. If there's only one concurrent sessions (i.e. the number pgpool-II preforked child process is 1), then pgpool-II sends DML/DDL to all the DB nodes at once because there's no possibilty of deadlock. In this case the DML/DDL performance is equivalent to single PostgreSQL in theory. I remember a user deployed inter continental pgpool-II configuration. If my memory serves, the continentals were Australia and North America. Best regards, -- Tatsuo Ishii SRA OSS, Inc. Japan English: http://www.sraoss.co.jp/index_en.php Japanese:http://www.sraoss.co.jp > The question is specifically about the replication feature mentioned here > http://www.pgpool.net/mediawiki/index.php/Main_Page for the purposes of > failing over minimizing downtime. > > On Thu, Aug 13, 2015 at 12:28 PM, Joshua D. Drake <jd@xxxxxxxxxxxxxxxxx> > wrote: > >> >> On 08/13/2015 08:52 AM, Wayne E. Seguin wrote: >> >> "BDR is only one in Beta compare to stable options: >>> >>> https://wiki.postgresql.org/wiki/Replication,_Clustering,_and_Connection_Pooling >>> . >>> Not sure why this solution would be chosen. Experience with pgpool is >>> that you only needed to change a port and no SQL changes required on an >>> application side." >>> >>> I appreciate any input as to pros/cons of BDR vs PGPool-II v3 in this >>> >> >> BDR is async multi master. PGPool is largely just a connection pooler with >> load balancing (although it has other features). They play different sports. >> >> JD >> >> >> -- >> Command Prompt, Inc. - http://www.commandprompt.com/ 503-667-4564 >> PostgreSQL Centered full stack support, consulting and development. >> Announcing "I'm offended" is basically telling the world you can't >> control your own emotions, so everyone else should do it for you. >> > > > > -- > ~Wayne > > Wayne E. Seguin > wayneeseguin@xxxxxxxxx > wayneeseguin on irc.freenode.net > http://twitter.com/wayneeseguin/ > https://github.com/wayneeseguin/ -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
