Nagaura-san, The client-side tcp_user_timeout patch looks good.
The server-side tcp_user_timeout patch needs fixing the following: (1) + GUC_UNIT_MS | GUC_NOT_IN_SAMPLE + 12000, 0, INT_MAX, GUC_NOT_IN_SAMPLE should be removed because the parameter appears in postgresql.conf.sample. The default value should be 0, not 12000. (2) Now that you've changed show_tcp_usertimeout() to use pq_gettcpusertimeout(), you need to modify pq_settcpusertimeout(); just immitate pq_setkeepalivesidle(). Otherwise, SHOW would display a wrong value. Regards Takayuki Tsunakawa
