> Suppose that, i have a limit of 100 connections on postgres, no more no > less, now my question are: > > if i set a num_init_children to 100 , have i set max_pool to 1 > only??? > or > if i set num_init_children to 50, have i set max_pool to 2 only?????? > or > if i set num_init_children to 25, have i set max_pool to 4 only??? > > i mean: > > num_init_children * max_pool = postgres's connections ??
All are correct. Plus, you need to consider superuser_reserved_connections (see postgresql.conf). Also you need to consider query cancelation, which requires one more connection per concurrent query cancel operations. In summary, you need to satisfy one of them: 1) max_pool*num_init_children <= (max_connections - superuser_reserved_connections) 2) max_pool*num_init_children*2 <= (max_connections - superuser_reserved_connections) #2 includes query cancelation worst case. For example, default setting of max_pool = 4 and num_init_children = 32 requires max_connections = 131 at least(assuming superuser_reserved_connections = 3) for #1, 259 for #2. -- Tatsuo Ishii SRA OSS, Inc. Japan English: http://www.sraoss.co.jp/index_en.php Japanese: http://www.sraoss.co.jp _______________________________________________ Pgpool-general mailing list [email protected] http://pgfoundry.org/mailman/listinfo/pgpool-general
