底层环境：
OS:CentOS 6
DB:Postgres 9.1.2
Pool:pgbouncer 1.5.4
pgbouncer的配置脚本：
[root@kenyon config]# more pgbouncer.ini [databases] db_kenyon = host=172.65.20.35 port=2949 dbname=db_kenyon openfire = host=172.65.20.35 port=2949 dbname=openfire [pgbouncer] listen_port = 5432 listen_addr = 172.65.20.35 auth_type = md5 auth_file = /home/postgres/pgbouncer/config/user.txt logfile = /home/postgres/pgbouncer/pgbouncer.log pidfile = /home/postgres/pgbouncer/pgbouncer.pid admin_users = u_kenyon pool_mode = Transaction max_client_conn = 1500user.txt的配置脚本
[root@kenyon config]# more user.txt "u_test" "md53173bce1d3101d6659vceb49d7eb3f2d" "u_kenyon" "md53173bce1d3101d6659vceb49d7eb3f2d"启动连接时是正常的，但是程序压测开始后数据并没有生成，查看日志，有异常内容如下：
2012-12-11 19:36:14.870 19072 WARNING C-0x3620a20: (nodb)/(nouser)@172.65.20.35:55418 unsupported startup parameter: extra_float_digits=2 2012-12-11 19:36:14.870 19072 LOG C-0x3620a20: (nodb)/(nouser)@172.65.20.35:55418 closing because: Unsupported startup parameter: extra_float_digits (age=0) 2012-12-11 19:36:14.870 19072 WARNING C-0x3620a20: (nodb)/(nouser)@172.65.20.35:55418 Pooler Error: Unsupported startup parameter: extra_float_digits 2012-12-11 19:36:44.881 19072 WARNING C-0x3620a20: (nodb)/(nouser)@172.65.20.35:55419 unsupported startup parameter: extra_float_digits=2 2012-12-11 19:36:44.881 19072 LOG C-0x3620a20: (nodb)/(nouser)@172.65.20.35:55419 closing because: Unsupported startup parameter: extra_float_digits (age=0) 2012-12-11 19:36:44.881 19072 WARNING C-0x3620a20: (nodb)/(nouser)@172.65.20.35:55419 Pooler Error: Unsupported startup parameter: extra_float_digits报错很明显，有一个参数不支持， unsupported startup parameter extra_float_digits ，pgbouncer中有一个参数是可以忽略启动参数的，叫ignore_startup_parameters
处理办法：
修改配置文件pgbouncer.ini，在[pgbouncer]下面新增一行
ignore_startup_parameters = extra_float_digits
重启pgbouncer，再次查看日志，该参数已被忽略，测试数据正常。
其他：
程序有可能也有其他参数会导致pgbpuncer异常，比如geqo等，忽略多个参数时，以逗号分隔即可，比如： ignore_startup_parameters = extra_float_digits,geqo
源码中的定义：char *cf_ignore_startup_params = "";
参考：http://archives.postgresql.org/pgsql-committers/2008-04/msg00101.php
顺带说一句，用了pgbouncer，实际连到DB的进程数大大减少，平均下来有20个左右。没有启用pgbouncer做压测的时候，默认的100个最大连接数是不够用的。
原文链接：https://www.f2er.com/postgresql/196335.html