安裝pgpool-II 透過網路上簡易的git repostory去快速的安裝pgpool-2 docker環境 例如：docker-pgpool2 將pgpool conf檔跟執行的shell複製進去docker裡面 執行pgpool 需要在postgres建立pgpool所需要登入的角色，例如使用者：pgpool 利用指令可以查詢現在postgres node status: pcp_node_info [option...] [node_id] pcp_node_info --verbose -h localhost -U postgres 0 問題 出現2018-09-18 05:32:46: pid 6: FATAL: could not open pid file as /var/run/pgpool/pgpool.pid. reason: No such file or directory的錯誤訊息 需要幫process建立/var/run/pgpool的資料夾 pgpool都已經裝好，postgres sever也已經就緒，但是出現無法登入的問題，相同帳號密碼不透過pgpool會登入成功？ 看了一下pgpool2的log檔，出現以下資訊 2018-07-27 06:51:28 DEBUG: pid 30: I am 30 accept fd 5 2018-07-27 06:51:28 LOG: pid 30: connection received: host=192.168.17.178 port=64325 2018-07-27 06:51:28 DEBUG: pid 30: Protocol Major: 1234 Minor: 5679 database: user: 2018-07-27 06:51:28 DEBUG: pid 30: SSLRequest from client 2018-07-27 06:51:28 DEBUG: pid 30: read_startup_packet: application_name: pgAdmin 4 - DB:postgres 2018-07-27 06:51:28 DEBUG: pid 30: Protocol Major: 3 Minor: 0 database: postgres user: postgres 2018-07-27 06:51:28 DEBUG: pid 30: new_connection: connecting 0 backend 2018-07-27 06:51:28 DEBUG: pid 30: new_connection: skipping slot 0 because backend_status = 0 2018-07-27 06:51:28 DEBUG: pid 30: new_connection: connecting 1 backend 2018-07-27 06:51:28 DEBUG: pid 30: pool_read_message_length: slot: 1 length: 12 2018-07-27 06:51:28 DEBUG: pid 30: pool_do_auth: auth kind:5 2018-07-27 06:51:28 DEBUG: pid 30: trying md5 authentication 2018-07-27 06:51:28 ERROR: pid 30: pool_get_passwd: username is NULL 2018-07-27 06:51:28 DEBUG: pid 30: do_md5: (null) does not exist in pool_passwd 2018-07-27 06:51:28 DEBUG: pid 30: do_md5failed in slot 1 正常普通安裝pgpool，設定檔的路徑會出現在/etc/pgpool2，通常會有四個檔案，pcp.