> I hava a db server (mysql) in my web application, it include 550 > tables and about 100000 rows in each table. Now, I want to change the > db server to postgresql and construct a HA environment. > > I have two 2U servers to build postgresql server (one is master, the > other is slave), and two 1U servers for any purpose about the ha > environment. And I expect to use the FreeBSD as the operation system. > > My request is, when a server fail (no matter the master or slave), the > web server can still access (read/write) the database correctly. > > I have three ideas about the HA environment, does anyone give me some advices? > Or guide me to learn more advanced ideas. Thanks. :) > > First idea: > I install the pgpool on each web server (the web server farm include > 16 web servers), and configure the pgpool as replication mode. The web > application (written by php) access to the db server through the local > pgpool daemon. > The idea sounds a little unusual, dose it seems workable? > I just use very simple sql statment in the web application, no any > complex statment. This is not unusual and actualy I think it's a good idea. Also you could enjoy the advantage of the load-balance capability of pgpool in this case. > Second idea: > I install the pgpool and linux-ha on the two 1U server, and configure > the pgpool as replication mode. The web application access to the db > server through the pgpool daemon. I'm not familiar with linux-ha so have no idea if this works or not. > Third idea: > I install the Slony-I, linux-ha and postgresql on the same server of > the two 2U servers. The web application access to the db server > directly and without pgpool. I'm not sure what would happen with this configuration. -- Tatsuo Ishii SRA OSS, Inc. Japan
