host   all             all             0.0.0.0/0            trust
host   replication     all             0.0.0.0/0            trust

listen_addresses = '*'
max_wal_senders = 5
wal_level = hot_standby
pg_ctl -D mnt/40g/pgdata/pgpool start

mkdir pgpool
chown postgres:postgres  pgpool
chown postgres:postgres mnt/40g/software/pgpool-II-4.1.2.tar.gz

cd mnt/40g/software/
tar -xzvf pgpool-II-4.1.2.tar.gz
cd pgpool-II-4.1.2
./configure --prefix='/pgpool'  
--with-pgsql-libdir="/usr/local/hg_dist/lib"  
--with-pgsql="/usr/local/hg_dist/"
make
make install

cd mnt/40g/software/pgpool-II-4.1.2/src/sql/pgpool-regclass/
make
make install

scppgpool-regclass.so postgres@maggie2:/usr/local/hg_dist/lib/postgresqlpsql -f 
pgpool-regclass.sql -h maggie2 -p 5432 template1

pg_basebackup -h 192.168.31.102 -p 5432 -U postgres -Fp -Xs -Pv -R -D /mnt/40g/pgdata/pgpool
pg_ctl start

[root@maggie1 etc]# pg_md5 -p postgres
password:
e8a48653851e28c69d0506508fb27fc5

cd usr/local/etc  #pgpool的默认安装路径
cp pgpool.conf.sample pgpool.conf
listen_addresses='*'   #接受所有的链接
socket_dir='/var/run'  #建立接受 UNIX 域套接字连接的目录，修改要重启pgpool
pcp_listen_addresses = '*'
pcp_socket_dir = '/var/run'
backend_hostname0 = 'maggie1'
backend_port0 = 5432
backend_weight0 = 1   #负载均衡的权限，两台backend权限相同时，做平均分配
backend_data_directory0 = '/mnt/40g/pgdata/pgpool'
backend_hostname1 = 'maggie2'
backend_port1 = 5432
backend_weight1 = 1
backend_data_directory1 = '/mnt/40g/pgdata/pgpool'
load_balance_mode = on
master_slave_mode = on
master_slave_sub_mode = 'stream'
sr_check_period = 2
sr_check_user = 'postgres'
sr_check_database = 'postgres'
delay_threshold = 10
replication_mode = off
replicate_select = off
num_init_children = 150 // 从客户端发起的最大并发连接数
max_pool = 4  //到PG的连接数为num_init_children * max_pool

pgpool -n  > /tmp/pgpool.log 2>&1 &
pgpool stop

[postgres@maggie1 ~]$ pgbench -c 300 -j 300 -M prepared -n -P 2 -S -T 200 -r -h maggie1 -p 9999
transaction type: <builtin: select only>
scaling factor: 100
query mode: prepare
dnumber of clients: 300
number of threads: 300
duration: 200 s
number of transactions actually processed: 2898267
latency average = 10.293 ms
latency stddev = 5.346 ms
tps = 14445.955582 (including connections establishing)
tps = 25308.963441 (excluding connections establishing) 

    0.005  \set aid random(1,100000 * :scale)    
    10.290  SELECT abalance FROM pgbench_accounts WHERE aid = :aid;

[postgres@maggie1 ~]$ pgbench -c 300 -j 300 -M prepared -n -P 2 -S -T 200 -r -h maggie2 -p 5432
transaction type: <builtin: select only>
scaling factor: 100
query mode: prepared
number of clients: 300
number of threads: 300
duration: 200 s
number of transactions actually processed: 4662318
latency average = 12.758 ms
latency stddev = 3.460 ms
tps = 23281.878597 (including connections establishing)
tps = 23473.435897 (excluding connections establishing)

   0.003  \set aid random(1, 100000 * :scale)    
   12.762  SELECT abalance FROM pgbench_accounts WHERE aid = :aid;

[postgres@maggie1 ~]$ pgbench -c 400 -j 300 -M prepared -n -P 2 -S -T 200 -r -h maggie1 -p 9999
transaction type: <builtin: select only>
scaling factor: 100
query mode: prepared
number of clients: 400
number of threads: 300
duration: 200 s
number of transactions actually processed: 2879549
latency average = 6.795 ms
latency stddev = 3.551 ms
tps = 14357.998016 (including connections establishing)
tps = 20360.802379 (excluding connections establishing)

  0.004  \set aid random(1, 100000 * :scale)   
  6.792  SELECT abalance FROM pgbench_accounts WHERE aid = :aid;

[postgres@maggie1 ~]$ pgbench -c 400 -j 400 -M prepared -n -P 2 -S -T 200 -r -h maggie2 -p 5432
transaction type: <builtin: select only>
scaling factor: 100
query mode: prepared
number of clients: 400
number of threads: 400
duration: 200 s
number of transactions actually processed: 4523310
latency average = 17.420 ms
latency stddev = 4.249 ms
tps = 22587.966748 (including connections establishing)
tps = 22910.531557 (excluding connections establishing)

    0.004  \set aid random(1, 100000 * :scale)   
    17.424  SELECT abalance FROM pgbench_accounts WHERE aid = :aid;