pgbouncer-install
前言
每次应用程序和postgres连接，都会克隆出一个服务进程来为应用程序服务，在频繁的创建和销毁进程，会耗费比较多的资源。而pgbouncer会把与后端postgresql数据库的连接缓存住，当有前端请求时，只为分配一个空闲的连接给前端程序使用，这样就降低了资源的消耗。
要求
软件：pgbouncer-1.5.5.tar.gz，libevent-2.0.22-stable.tar.gz
安装
1、上传软件到opt并解压
# tar xvf libevent-2.0.22-stable.tar.gz
# tar xvf pgbouncer-1.5.5.tar.gz
2、安装libevent
# ./configure --prefix=/home/postgres/libevent
# make
# make install
3、安装pgbouncer
# ./configure --prefix=/home/postgres/pgbouncer/ --with-libevent=/home/postgres/libevent/
# make
# make install
4、配置.bash_profile,修改文件权限
# cp /opt/pgbouncer-1.5.5/etc/pgbouncer.ini /home/postgres/pgbouncer/
# chown -R postgres:postgres pgbouncer/
# chown -R postgres:postgres libevent/
# su - postgres
$ vim .bash_profile
export LD_LIBRARY_PATH=/home/postgres/libevent/lib:$LD_LIBRARY_PATH
5、修改配置文件pgbouncer.ini文件并参考该文件要求创建userlist.txt
$ vim pgbouncer.ini
[databases]
postgres = host=localhost port=5432 dbname=postgres user=postgres password=postgres connect_query='SELECT 1'
[pgbouncer]
logfile = /home/postgres/pgbouncer/pgbouncer.log
pidfile = /home/postgres/pgbouncer/pgbouncer.pid
listen_addr = *
listen_port = 6432
auth_type = trust
auth_file = /home/postgres/pgbouncer/userlist.txt
pool_mode = transaction
server_reset_query = DISCARD ALL
max_client_conn = 100
default_pool_size = 20
$ vim userlist.txt
"postgres" "postgres"
6、启动pgbouncer
./pgbouncer -d /home/postgres/pgbouncer/pgbouncer.ini
7、登录
$ psql -p 6432 postgres
8、停止pgbouncer
$ cat /home/postgres/pgbouncer/pgbouncer.pid
$ kill number
9、查看连接池信息
$ psql -p 6432 pgbouncer
=# show help;
NOTICE: Console usage
DETAIL:
SHOW HELP|CONFIG|DATABASES|POOLS|CLIENTS|SERVERS|VERSION
SHOW STATS|FDS|SOCKETS|ACTIVE_SOCKETS|LISTS|MEM
SHOW DNS_HOSTS|DNS_ZONES
SET key = arg
RELOAD
PAUSE [<db>]
RESUME [<db>]
KILL <db>
SUSPEND
SHUTDOWN
SHOW
=# show pools;
报错信息
error 1:
[postgres@postgres93 bin]$ ./pgbouncer -d /home/postgres/pgbouncer/pgbouncer.ini
./pgbouncer: error while loading shared libraries: libevent-2.0.so.5: cannot open shared object file: No such file or directory
[solution]
# su - postgres
$ vim .bash_profile
export LD_LIBRARY_PATH=/home/postgres/libevent/lib:$LD_LIBRARY_PATH
error 2:
[postgres@postgres93 ~]$ psql -p 6432 pgbouncer
psql: ERROR: not allowed
[solution]
$ vim pgbouncer.init
admin_users = postgres
需要重启pgbouncer
$ psql -p 6432 pgbouncer
参考文档：
http://pgbouncer.github.io/downloads/
https://yq.aliyun.com/articles/43328
http://www.bubuko.com/infodetail-1203143.html
http://blog.csdn.net/lk_db/article/details/77939005?locationNum=8&fps=1
