pgbouncer [-d][-R][-v][-u user] <pgbouncer.ini>
pgbouncer -V|-h

$ psql -p 6543 pgbouncer

可以通过分别设置环境变量EVENT_NOEPOLL、EVENT_NOKQUEUE、
VENT_NODEVPOLL、EVENT_NOPOLL或EVENT_NOSELECT来禁用对
epoll、kqueue、devpoll、poll或select的支持。

通过设置环境变量EVENT_SHOW_METHOD，libevent显示它使用的内核通知方法。 

;; 数据库名 = 连接串
;;
;; 连接串包括这些参数:
;;   dbname= host= port= user= password=
;;   client_encoding= datestyle= timezone=
;;   pool_size= connect_query=
;;   auth_user=
[databases]

instanceA = host=10.1.1.1 dbname=core
instanceB = host=102.2.2.2 dbname=payment

; 通过Unix套接字的 foodb
;foodb =

; 将bardb在localhost上重定向为bazdb 
;bardb = host=localhost dbname=bazdb

; 使用单个用户访问目标数据库
;forcedb = host=127.0.0.1 port=300 user=baz password=foo client_encoding=UNICODE datestyle=ISO connect_query='SELECT 1'

; 使用定制的连接池大小
;nondefaultdb = pool_size=50 reserve_pool=10

; 如果用户不在认证文件中，替换使用的auth_user; auth_user必须在认证文件中
; foodb = auth_user=bar

; 保底的通配连接串
;* = host=testserver

;; Pgbouncer配置区域
[pgbouncer]

;;;
;;; 管理设置
;;;

logfile = /var/log/pgbouncer/pgbouncer.log
pidfile = /var/run/pgbouncer/pgbouncer.pid

;;;
;;; 监听哪里的客户端
;;;

; 监听IP地址，* 代表所有IP
listen_addr = *
listen_port = 6432

; -R选项也会处理Unix Socket.
; 在Debian上是 /var/run/postgresql
;unix_socket_dir = /tmp
;unix_socket_mode = 0777
;unix_socket_group =

;;;
;;; TLS配置
;;;

;; 选项：disable, allow, require, verify-ca, verify-full
;client_tls_sslmode = disable

;; 信任CA证书的路径
;client_tls_ca_file = <system default>

;; 代表客户端的私钥与证书路径
;; 从客户端接受TLS连接时，这是必须参数
;client_tls_key_file =
;client_tls_cert_file =

;; fast, normal, secure, legacy, <ciphersuite string>
;client_tls_ciphers = fast

;; all, secure, tlsv1.0, tlsv1.1, tlsv1.2
;client_tls_protocols = all

;; none, auto, legacy
;client_tls_dheparams = auto

;; none, auto, <curve name>
;client_tls_ecdhcurve = auto

;;;
;;; 连接到后端数据库时的TLS设置
;;;

;; disable, allow, require, verify-ca, verify-full
;server_tls_sslmode = disable

;; 信任CA证书的路径
;server_tls_ca_file = <system default>

;; 代表后端的私钥与证书
;; 只有当后端服务器需要客户端证书时需要
;server_tls_key_file =
;server_tls_cert_file =

;; all, secure, tlsv1.0, tlsv1.1, tlsv1.2
;server_tls_protocols = all

;; fast, normal, secure, legacy, <ciphersuite string>
;server_tls_ciphers = fast

;;;
;;; 认证设置
;;;

; any, trust, plain, crypt, md5, cert, hba, pam
auth_type = trust
auth_file = /etc/pgbouncer/userlist.txt

;; HBA风格的认证配置文件
# auth_hba_file = /pg/data/pg_hba.conf

;; 从数据库获取密码的查询，结果必须包含两列： 用户名 与 密码哈希值.
;auth_query = SELECT usename, passwd FROM pg_shadow WHERE usename=$1

;;;
;;; 允许访问虚拟数据库'pgbouncer'的用户
;;;

; 允许修改设置，逗号分隔的用户名列表。
admin_users = postgres

; 允许使用SHOW命令，逗号分隔的用户名列表。
stats_users = stats, postgres

;;;
;;; 连接池设置
;;;

; 什么时候服务端连接会被放回到池中？(默认为session)
;   session      - 会话模式，当客户端断开连接时
;   transaction  - 事务模式，当事务结束时
;   statement    - 语句模式，当语句结束时
pool_mode = session

; 客户端释放连接后，用于立刻清理连接的查询。
; 不用把ROLLBACK放在这儿，当事务还没结束时，Pgbouncer是不会重用连接的。
;
; 8.3及更高版本的查询:
;   DISCARD ALL;
;
; 更老的版本:
;   RESET ALL; SET SESSION AUTHORIZATION DEFAULT
;
; 如果启用事务级别的连接池，则为空。
;
server_reset_query = DISCARD ALL


; server_reset_query 是否需要在任何情况下执行。
; 如果关闭(默认)，server_reset_query 只会在会话级连接池中使用。
;server_reset_query_always = 0

;
; Comma-separated list of parameters to ignore when given
; in startup packet.  Newer JDBC versions require the
; extra_float_digits here.
;
;ignore_startup_parameters = extra_float_digits

;
; When taking idle server into use, this query is ran first.
;   SELECT 1
;
;server_check_query = select 1

; If server was used more recently that this many seconds ago,
; skip the check query.  Value 0 may or may not run in immediately.
;server_check_delay = 30

; Close servers in session pooling mode after a RECONNECT, RELOAD,
; etc. when they are idle instead of at the end of the session.
;server_fast_close = 0

;; Use <appname - host> as application_name on server.
;application_name_add_host = 0

;;;
;;; 连接限制
;;;

; 最大允许的连接数
max_client_conn = 100

; 默认的连接池尺寸，当使用事务连接池时，20是一个合适的值。对于会话级连接池而言
; 该值是你想在同一时刻处理的最大连接数。
default_pool_size = 20

;; 连接池中最少的保留连接数
;min_pool_size = 0

; 出现问题时，最多允许多少条额外连接
;reserve_pool_size = 0

; 如果客户端等待超过这么多秒，使用备用连接池
;reserve_pool_timeout = 5

; 单个数据库/用户最多允许多少条连接
;max_db_connections = 0
;max_user_connections = 0

; If off, then server connections are reused in LIFO manner
;server_round_robin = 0

;;;
;;; Logging
;;;

;; Syslog settings
;syslog = 0
;syslog_facility = daemon
;syslog_ident = pgbouncer

; log if client connects or server connection is made
;log_connections = 1

; log if and why connection was closed
;log_disconnections = 1

; log error messages pooler sends to clients
;log_pooler_errors = 1

;; Period for writing aggregated stats into log.
;stats_period = 60

;; Logging verbosity.  Same as -v switch on command line.
;verbose = 0

;;;
;;; Timeouts
;;;

;; Close server connection if its been connected longer.
;server_lifetime = 3600

;; Close server connection if its not been used in this time.
;; Allows to clean unnecessary connections from pool after peak.
;server_idle_timeout = 600

;; Cancel connection attempt if server does not answer takes longer.
;server_connect_timeout = 15

;; If server login failed (server_connect_timeout or auth failure)
;; then wait this many second.
;server_login_retry = 15

;; Dangerous.  Server connection is closed if query does not return
;; in this time.  Should be used to survive network problems,
;; _not_ as statement_timeout. (default: 0)
;query_timeout = 0

;; Dangerous.  Client connection is closed if the query is not assigned
;; to a server in this time.  Should be used to limit the number of queued
;; queries in case of a database or network failure. (default: 120)
;query_wait_timeout = 120

;; Dangerous.  Client connection is closed if no activity in this time.
;; Should be used to survive network problems. (default: 0)
;client_idle_timeout = 0

;; Disconnect clients who have not managed to log in after connecting
;; in this many seconds.
;client_login_timeout = 60

;; Clean automatically created database entries (via "*") if they
;; stay unused in this many seconds.
; autodb_idle_timeout = 3600

;; How long SUSPEND/-R waits for buffer flush before closing connection.
;suspend_timeout = 10

;; Close connections which are in "IDLE in transaction" state longer than
;; this many seconds.
;idle_transaction_timeout = 0

;;;
;;; Low-level tuning options
;;;

;; buffer for streaming packets
;pkt_buf = 4096

;; man 2 listen
;listen_backlog = 128

;; Max number pkt_buf to process in one event loop.
;sbuf_loopcnt = 5

;; Maximum PostgreSQL protocol packet size.
;max_packet_size = 2147483647

;; networking options, for info: man 7 tcp

;; Linux: notify program about new connection only if there
;; is also data received.  (Seconds to wait.)
;; On Linux the default is 45, on other OS'es 0.
;tcp_defer_accept = 0

;; In-kernel buffer size (Linux default: 4096)
;tcp_socket_buffer = 0

;; whether tcp keepalive should be turned on (0/1)
;tcp_keepalive = 1

;; The following options are Linux-specific.
;; They also require tcp_keepalive=1.

;; count of keepalive packets
;tcp_keepcnt = 0

;; how long the connection can be idle,
;; before sending keepalive packets
;tcp_keepidle = 0

;; The time between individual keepalive probes.
;tcp_keepintvl = 0

;; DNS lookup caching time
;dns_max_ttl = 15

;; DNS zone SOA lookup period
;dns_zone_check_period = 0

;; DNS negative result caching time
;dns_nxdomain_ttl = 15

;;;
;;; Random stuff
;;;

;; Hackish security feature.  Helps against SQL-injection - when PQexec is disabled,
;; multi-statement cannot be made.
;disable_pqexec = 0

;; Config file to use for next RELOAD/SIGHUP.
;; By default contains config file from command line.
;conffile

;; Win32 service name to register as.  job_name is alias for service_name,
;; used by some Skytools scripts.
;service_name = pgbouncer
;job_name = pgbouncer

;; Read additional config from the /etc/pgbouncer/pgbouncer-other.ini file
;%include /etc/pgbouncer/pgbouncer-other.ini