centos7 pgpool+postgresql

安装postgresql

CentOS7安装并配置PostgreSQL

安装pgpool

rpm -ivh http://www.pgpool.net/yum/rpms/3.7/redhat/rhel-7-x86_64/pgpool-II-release-3.7-1.noarch.rpm
yum -y install pgpool-II-pg95
yum -y install pgpool-II-pg95-debuginfo
yum -y install pgpool-II-pg95-devel
yum -y install pgpool-II-pg95-extensions
 
开机启动
systemctl enable pgpool

　

添加Pgpool-II运行用户

[root@im110 pgpool-II]# useradd pgpool
[root@im110 pgpool-II]# passwd pgpool
Changing password for user pgpool.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.
[root@im110 pgpool-II]# chown -R pgpool.pgpool /etc/pgpool-II
[root@im110 pgpool-II]# mkdir -p /var/run/pgpool/
[root@im110 pgpool-II]# chown pgpool.pgpool /var/run/pgpool/

修改配置文件

先备份所有配置文件

vi pgpool.conf修改后如下

# ----------------------------
# pgPool-II configuration file
# ----------------------------
#
# This file consists of lines of the form:
#
#   name = value
#
# Whitespace may be used.  Comments are introduced with "#" anywhere on a line.
# The complete list of parameter names and allowed values can be found in the
# pgPool-II documentation.
#
# This file is read on server startup and when the server receives a SIGHUP
# signal.  If you edit the file on a running system, you have to SIGHUP the
# server for the changes to take effect, or use "pgpool reload".  Some
# parameters, which are marked below, require a server shutdown and restart to
# take effect.
#
 
#------------------------------------------------------------------------------
# CONNECTIONS
#------------------------------------------------------------------------------
 
# - pgpool Connection Settings -
 
listen_addresses = '*'
                                   # Host name or IP address to listen on:
                                   # '*' for all, '' for no TCP/IP connections
                                   # (change requires restart)
port =
                                   # Port number
                                   # (change requires restart)
socket_dir = '/var/run/postgresql'
                                   # Unix domain socket path
                                   # The Debian package defaults to
                                   # /var/run/postgresql
                                   # (change requires restart)
listen_backlog_multiplier =
                                   # Set the backlog parameter of listen() to
                                   # num_init_children * listen_backlog_multiplier.
                                   # (change requires restart)
serialize_accept = off
                                   # whether to serialize accept() call to avoid thundering herd problem
                                   # (change requires restart)
 
# - pgpool Communication Manager Connection Settings -
 
pcp_listen_addresses = '*'
                                   # Host name or IP address for pcp process to listen on:
                                   # '*' for all, '' for no TCP/IP connections
                                   # (change requires restart)
pcp_port =
                                   # Port number for pcp
                                   # (change requires restart)
pcp_socket_dir = '/var/run/postgresql'
                                   # Unix domain socket path for pcp
                                   # The Debian package defaults to
                                   # /var/run/postgresql
                                   # (change requires restart)
 
# - Backend Connection Settings -
 
backend_hostname0 = '119.29.218.235'
                                   # Host name or IP address to connect to for backend
backend_port0 =
                                   # Port number for backend
backend_weight0 =
                                   # Weight for backend  (only in load balancing mode)
backend_data_directory0 = '/var/lib/pgsql/data'
                                   # Data directory for backend
backend_flag0 = 'ALLOW_TO_FAILOVER'
                                   # Controls various backend behavior
                                   # ALLOW_TO_FAILOVER, DISALLOW_TO_FAILOVER
                   # or ALWAYS_MASTER
backend_hostname1 = '111.231.195.197'
backend_port1 =
backend_weight1 =
backend_data_directory1 = '/var/lib/pgsql/data'
backend_flag1 = 'ALLOW_TO_FAILOVER'
 
# - Authentication -
 
enable_pool_hba = on
                                   # Use pool_hba.conf for client authentication
pool_passwd = 'pool_passwd'
                                   # File name of pool_passwd for md5 authentication.
                                   # "" disables pool_passwd.
                                   # (change requires restart)
authentication_timeout =
                                   # Delay in seconds to complete client authentication
                                   #  means no timeout.
 
# - SSL Connections -
 
ssl = off
                                   # Enable SSL support
                                   # (change requires restart)
#ssl_key = './server.key'
                                   # Path to the SSL private key file
                                   # (change requires restart)
#ssl_cert = './server.cert'
                                   # Path to the SSL public certificate file
                                   # (change requires restart)
#ssl_ca_cert = ''
                                   # Path to a single PEM format file
                                   # containing CA root certificate(s)
                                   # (change requires restart)
#ssl_ca_cert_dir = ''
                                   # Directory containing CA root certificate(s)
                                   # (change requires restart)
 
#------------------------------------------------------------------------------
# POOLS
#------------------------------------------------------------------------------
 
# - Concurrent session and pool size -
 
num_init_children =
                                   # Number of concurrent sessions allowed
                                   # (change requires restart)
max_pool =
                                   # Number of connection pool caches per connection
                                   # (change requires restart)
 
# - Life time -
 
child_life_time =
                                   # Pool exits after being idle for this many seconds
child_max_connections =
                                   # Pool exits after receiving that many connections
                                   #  means no exit
connection_life_time =
                                   # Connection to backend closes after being idle for this many seconds
                                   #  means no close
client_idle_limit =
                                   # Client is disconnected after being idle for that many seconds
                                   # (even inside an explicit transactions!)
                                   #  means no disconnection
 
#------------------------------------------------------------------------------
# LOGS
#------------------------------------------------------------------------------
 
# - Where to log -
 
log_destination = 'stderr'
                                   # Where to log
                                   # Valid values are combinations of stderr,
                                   # and syslog. Default to stderr.
 
# - What to log -
 
log_line_prefix = '%t: pid %p: '   # printf-style string to output at beginning of each log line.
 
log_connections = off
                                   # Log connections
log_hostname = off
                                   # Hostname will be shown in ps status
                                   # and in logs if connections are logged
log_statement = off
                                   # Log all statements
log_per_node_statement = off
                                   # Log all statements
                                   # with node and backend informations
log_standby_delay = 'none'
                                   # Log standby delay
                                   # Valid values are combinations of always,
                                   # if_over_threshold, none
 
# - Syslog specific -
 
syslog_facility = 'LOCAL0'
                                   # Syslog local facility. Default to LOCAL0
syslog_ident = 'pgpool'
                                   # Syslog program identification string
                                   # Default to 'pgpool'
 
# - Debug -
 
#log_error_verbosity = default          # terse, default, or verbose messages
 
#client_min_messages = notice           # values in order of decreasing detail:
                                        #   debug5
                                        #   debug4
                                        #   debug3
                                        #   debug2
                                        #   debug1
                                        #   log
                                        #   notice
                                        #   warning
                                        #   error
 
#log_min_messages = warning             # values in order of decreasing detail:
                                        #   debug5
                                        #   debug4
                                        #   debug3
                                        #   debug2
                                        #   debug1
                                        #   info
                                        #   notice
                                        #   warning
                                        #   error
                                        #   log
                                        #   fatal
                                        #   panic
 
#------------------------------------------------------------------------------
# FILE LOCATIONS
#------------------------------------------------------------------------------
 
pid_file_name = '/var/run/pgpool/pgpool.pid'
                                   # PID file name
                                   # Can be specified as relative to the"
                                   # location of pgpool.conf file or
                                   # as an absolute path
                                   # (change requires restart)
logdir = '/var/log/pgpool'
                                   # Directory of pgPool status file
                                   # (change requires restart)
 
#------------------------------------------------------------------------------
# CONNECTION POOLING
#------------------------------------------------------------------------------
 
connection_cache = on
                                   # Activate connection pools
                                   # (change requires restart)
 
                                   # Semicolon separated list of queries
                                   # to be issued at the end of a session
                                   # The default is for 8.3 and later
reset_query_list = 'ABORT; DISCARD ALL'
                                   # The following one is for 8.2 and before
#reset_query_list = 'ABORT; RESET ALL; SET SESSION AUTHORIZATION DEFAULT'
 
#------------------------------------------------------------------------------
# REPLICATION MODE
#------------------------------------------------------------------------------
 
replication_mode = off
                                   # Activate replication mode
                                   # (change requires restart)
replicate_select = off
                                   # Replicate SELECT statements
                                   # when in replication mode
                                   # replicate_select is higher priority than
                                   # load_balance_mode.
 
insert_lock = on
                                   # Automatically locks a dummy row or a table
                                   # with INSERT statements to keep SERIAL data
                                   # consistency
                                   # Without SERIAL, no lock will be issued
lobj_lock_table = ''
                                   # When rewriting lo_creat command in
                                   # replication mode, specify table name to
                                   # lock
 
# - Degenerate handling -
 
replication_stop_on_mismatch = off
                                   # On disagreement with the packet kind
                                   # sent from backend, degenerate the node
                                   # which is most likely "minority"
                                   # If off, just force to exit this session
 
failover_if_affected_tuples_mismatch = off
                                   # On disagreement with the number of affected
                                   # tuples in UPDATE/DELETE queries, then
                                   # degenerate the node which is most likely
                                   # "minority".
                                   # If off, just abort the transaction to
                                   # keep the consistency
 
#------------------------------------------------------------------------------
# LOAD BALANCING MODE
#------------------------------------------------------------------------------
 
load_balance_mode = off
                                   # Activate load balancing mode
                                   # (change requires restart)
ignore_leading_white_space = on
                                   # Ignore leading white spaces of each query
white_function_list = ''
                                   # Comma separated list of function names
                                   # that don't write to database
                                   # Regexp are accepted
black_function_list = 'nextval,setval,nextval,setval'
                                   # Comma separated list of function names
                                   # that write to database
                                   # Regexp are accepted
 
database_redirect_preference_list = ''
                                   # comma separated list of pairs of database and node id.
                                   # example: postgres:primary,mydb[-]:,mydb[-]:'
                                   # valid for streaming replicaton mode only.
 
app_name_redirect_preference_list = ''
                                   # comma separated list of pairs of app name and node id.
                                   # example: 'psql:primary,myapp[0-4]:1,myapp[5-9]:standby'
                                   # valid for streaming replicaton mode only.
allow_sql_comments = off
                                   # if on, ignore SQL comments when judging if load balance or
                                   # query cache is possible.
                                   # If off, SQL comments effectively prevent the judgment
                                   # (pre 3.4 behavior).
 
#------------------------------------------------------------------------------
# MASTER/SLAVE MODE
#------------------------------------------------------------------------------
 
master_slave_mode = off
                                   # Activate master/slave mode
                                   # (change requires restart)
master_slave_sub_mode = 'stream'
                                   # Master/slave sub mode
                                   # Valid values are combinations stream, slony
                                   # or logical. Default is stream.
                                   # (change requires restart)
 
# - Streaming -
 
sr_check_period =
                                   # Streaming replication check period
                                   # Disabled () by default
sr_check_user = 'postgres'
                                   # Streaming replication check user
                                   # This is necessary even if you disable
                                   # streaming replication delay check with
                                   # sr_check_period =
sr_check_password = 'your pass word'
                                   # Password for streaming replication check user
sr_check_database = 'postgres'
                                   # Database name for streaming replication check
delay_threshold =
                                   # Threshold before not dispatching query to standby node
                                   # Unit is in bytes
                                   # Disabled () by default
 
# - Special commands -
 
follow_master_command = ''
                                   # Executes this command after master failover
                                   # Special values:
                                   #   %d = node id
                                   #   %h = host name
                                   #   %p = port number
                                   #   %D = database cluster path
                                   #   %m = new master node id
                                   #   %H = hostname of the new master node
                                   #   %M = old master node id
                                   #   %P = old primary node id
                                   #   %r = new master port number
                                   #   %R = new master database cluster path
                                   #   %% = '%' character
 
#------------------------------------------------------------------------------
# HEALTH CHECK GLOBAL PARAMETERS
#------------------------------------------------------------------------------
 
health_check_period =
                                   # Health check period
                                   # Disabled () by default
health_check_timeout =
                                   # Health check timeout
                                   #  means no timeout
health_check_user = 'nobody'
                                   # Health check user
health_check_password = ''
                                   # Password for health check user
health_check_database = ''
                                   # Database name for health check. If '', tries 'postgres' frist, then 'template1'
 
health_check_max_retries =
                                   # Maximum number of times to retry a failed health check before giving up.
health_check_retry_delay =
                                   # Amount of time to wait (in seconds) between retries.
connect_timeout =
                                   # Timeout value in milliseconds before giving up to connect to backend.
                                   # Default is  ms ( second). Flaky network user may want to increase
                                   # the value.  means no timeout.
                                   # Note that this value is not only used for health check,
                                   # but also for ordinary conection to backend.
 
#------------------------------------------------------------------------------
# HEALTH CHECK PER NODE PARAMETERS (OPTIONAL)
#------------------------------------------------------------------------------
#health_check_period0 =
#health_check_timeout0 =
#health_check_user0 = 'nobody'
#health_check_password0 = ''
#health_check_database0 = ''
#health_check_max_retries0 =
#health_check_retry_delay0 =
#connect_timeout0 = 
 
#------------------------------------------------------------------------------
# FAILOVER AND FAILBACK
#------------------------------------------------------------------------------
 
failover_command = '/usr/local/bin/failover_stream.sh %d %H /tmp/trigger_file0'
                                   # Executes this command at failover
                                   # Special values:
                                   #   %d = node id
                                   #   %h = host name
                                   #   %p = port number
                                   #   %D = database cluster path
                                   #   %m = new master node id
                                   #   %H = hostname of the new master node
                                   #   %M = old master node id
                                   #   %P = old primary node id
                                   #   %r = new master port number
                                   #   %R = new master database cluster path
                                   #   %% = '%' character
failback_command = ''
                                   # Executes this command at failback.
                                   # Special values:
                                   #   %d = node id
                                   #   %h = host name
                                   #   %p = port number
                                   #   %D = database cluster path
                                   #   %m = new master node id
                                   #   %H = hostname of the new master node
                                   #   %M = old master node id
                                   #   %P = old primary node id
                                   #   %r = new master port number
                                   #   %R = new master database cluster path
                                   #   %% = '%' character
 
fail_over_on_backend_error = on
                                   # Initiates failover when reading/writing to the
                                   # backend communication socket fails
                                   # If set to off, pgpool will report an
                                   # error and disconnect the session.
 
search_primary_node_timeout =
                                   # Timeout in seconds to search for the
                                   # primary node when a failover occurs.
                                   #  means no timeout, keep searching
                                   # for a primary node forever.
 
#------------------------------------------------------------------------------
# ONLINE RECOVERY
#------------------------------------------------------------------------------
 
recovery_user = 'nobody'
                                   # Online recovery user
recovery_password = ''
                                   # Online recovery password
recovery_1st_stage_command = ''
                                   # Executes a command in first stage
recovery_2nd_stage_command = ''
                                   # Executes a command in second stage
recovery_timeout =
                                   # Timeout in seconds to wait for the
                                   # recovering node's postmaster to start up
                                   #  means no wait
client_idle_limit_in_recovery =
                                   # Client is disconnected after being idle
                                   # for that many seconds in the second stage
                                   # of online recovery
                                   #  means no disconnection
                                   # - means immediate disconnection
 
#------------------------------------------------------------------------------
# WATCHDOG
#------------------------------------------------------------------------------
 
# - Enabling -
 
use_watchdog = off
                                    # Activates watchdog
                                    # (change requires restart)
 
# -Connection to up stream servers -
 
trusted_servers = ''
                                    # trusted server list which are used
                                    # to confirm network connection
                                    # (hostA,hostB,hostC,...)
                                    # (change requires restart)
ping_path = '/bin'
                                    # ping command path
                                    # (change requires restart)
 
# - Watchdog communication Settings -
 
wd_hostname = ''
                                    # Host name or IP address of this watchdog
                                    # (change requires restart)
wd_port =
                                    # port number for watchdog service
                                    # (change requires restart)
wd_priority =
                                    # priority of this watchdog in leader election
                                    # (change requires restart)
 
wd_authkey = ''
                                    # Authentication key for watchdog communication
                                    # (change requires restart)
 
wd_ipc_socket_dir = '/var/run/postgresql'
                                    # Unix domain socket path for watchdog IPC socket
                                    # The Debian package defaults to
                                    # /var/run/postgresql
                                    # (change requires restart)
 
# - Virtual IP control Setting -
 
delegate_IP = ''
                                    # delegate IP address
                                    # If this is empty, virtual IP never bring up.
                                    # (change requires restart)
if_cmd_path = '/sbin'
                                    # path to the directory where if_up/down_cmd exists
                                    # (change requires restart)
if_up_cmd = 'ip addr add $_IP_$/24 dev eth0 label eth0:0'
                                    # startup delegate IP command
                                    # (change requires restart)
if_down_cmd = 'ip addr del $_IP_$/24 dev eth0'
                                    # shutdown delegate IP command
                                    # (change requires restart)
arping_path = '/usr/sbin'
                                    # arping command path
                                    # (change requires restart)
arping_cmd = 'arping -U $_IP_$ -w 1'
                                    # arping command
                                    # (change requires restart)
 
# - Behaivor on escalation Setting -
 
clear_memqcache_on_escalation = on
                                    # Clear all the query cache on shared memory
                                    # when standby pgpool escalate to active pgpool
                                    # (= virtual IP holder).
                                    # This should be off if client connects to pgpool
                                    # not using virtual IP.
                                    # (change requires restart)
wd_escalation_command = ''
                                    # Executes this command at escalation on new active pgpool.
                                    # (change requires restart)
wd_de_escalation_command = ''
                                    # Executes this command when master pgpool resigns from being master.
                                    # (change requires restart)
 
# - Watchdog consensus settings for failover -
 
failover_when_quorum_exists = on
                                    # Only perform backend node failover
                                    # when the watchdog cluster holds the quorum
                                    # (change requires restart)
 
failover_require_consensus = on
                                    # Perform failover when majority of Pgpool-II nodes
                                    # aggrees on the backend node status change
                                    # (change requires restart)
 
allow_multiple_failover_requests_from_node = off
                                    # A Pgpool-II node can cast multiple votes
                                    # for building the consensus on failover
                                    # (change requires restart)
 
# - Lifecheck Setting -
 
# -- common --
 
wd_monitoring_interfaces_list = ''  # Comma separated list of interfaces names to monitor.
                                    # if any interface from the list is active the watchdog will
                                    # consider the network is fine
                                    # 'any' to enable monitoring on all interfaces except loopback
                                    # '' to disable monitoring
                                    # (change requires restart)
 
wd_lifecheck_method = 'heartbeat'
                                    # Method of watchdog lifecheck ('heartbeat' or 'query' or 'external')
                                    # (change requires restart)
wd_interval =
                                    # lifecheck interval (sec) >
                                    # (change requires restart)
 
# -- heartbeat mode --
 
wd_heartbeat_port =
                                    # Port number for receiving heartbeat signal
                                    # (change requires restart)
wd_heartbeat_keepalive =
                                    # Interval time of sending heartbeat signal (sec)
                                    # (change requires restart)
wd_heartbeat_deadtime =
                                    # Deadtime interval for heartbeat signal (sec)
                                    # (change requires restart)
heartbeat_destination0 = 'host0_ip1'
                                    # Host name or IP address of destination
                                    # for sending heartbeat signal.
                                    # (change requires restart)
heartbeat_destination_port0 =
                                    # Port number of destination  for sending
                                    # heartbeat signal. Usually this is the
                                    # same as wd_heartbeat_port.
                                    # (change requires restart)
heartbeat_device0 = ''
                                    # Name of NIC device (such like 'eth0')
                                    # used for sending/receiving heartbeat
                                    # signal to/from destination .
                                    # This works only when this is not empty
                                    # and pgpool has root privilege.
                                    # (change requires restart)
 
#heartbeat_destination1 = 'host0_ip2'
#heartbeat_destination_port1 =
#heartbeat_device1 = ''
 
# -- query mode --
 
wd_life_point =
                                    # lifecheck retry times
                                    # (change requires restart)
wd_lifecheck_query = 'SELECT 1'
                                    # lifecheck query to pgpool from watchdog
                                    # (change requires restart)
wd_lifecheck_dbname = 'template1'
                                    # Database name connected for lifecheck
                                    # (change requires restart)
wd_lifecheck_user = 'nobody'
                                    # watchdog user monitoring pgpools in lifecheck
                                    # (change requires restart)
wd_lifecheck_password = ''
                                    # Password for watchdog user in lifecheck
                                    # (change requires restart)
 
# - Other pgpool Connection Settings -
 
#other_pgpool_hostname0 = 'host0'
                                    # Host name or IP address to connect to for other pgpool
                                    # (change requires restart)
#other_pgpool_port0 =
                                    # Port number for other pgpool
                                    # (change requires restart)
#other_wd_port0 =
                                    # Port number for other watchdog
                                    # (change requires restart)
#other_pgpool_hostname1 = 'host1'
#other_pgpool_port1 =
#other_wd_port1 = 
 
#------------------------------------------------------------------------------
# OTHERS
#------------------------------------------------------------------------------
relcache_expire =
                                   # Life time of relation cache in seconds.
                                   #  means no cache expiration(the default).
                                   # The relation cache is used for cache the
                                   # query result against PostgreSQL system
                                   # catalog to obtain various information
                                   # including table structures or if it's a
                                   # temporary table or not. The cache is
                                   # maintained in a pgpool child local memory
                                   # and being kept as long as it survives.
                                   # If someone modify the table by using
                                   # ALTER TABLE or some such, the relcache is
                                   # not consistent anymore.
                                   # For this purpose, cache_expiration
                                   # controls the life time of the cache.
 
relcache_size =
                                   # Number of relation cache
                                   # entry. If you see frequently:
                                   # "pool_search_relcache: cache replacement happend"
                                   # in the pgpool log, you might want to increate this number.
 
check_temp_table = on
                                   # If on, enable temporary table check in SELECT statements.
                                   # This initiates queries against system catalog of primary/master
                                   # thus increases load of master.
                                   # If you are absolutely sure that your system never uses temporary tables
                                   # and you want to save access to primary/master, you could turn this off.
                                   # Default is on.
 
check_unlogged_table = on
                                   # If on, enable unlogged table check in SELECT statements.
                                   # This initiates queries against system catalog of primary/master
                                   # thus increases load of master.
                                   # If you are absolutely sure that your system never uses unlogged tables
                                   # and you want to save access to primary/master, you could turn this off.
                                   # Default is on.
 
#------------------------------------------------------------------------------
# IN MEMORY QUERY MEMORY CACHE
#------------------------------------------------------------------------------
memory_cache_enabled = off
                                   # If on, use the memory cache functionality, off by default
memqcache_method = 'shmem'
                                   # Cache storage method. either 'shmem'(shared memory) or
                                   # 'memcached'. 'shmem' by default
                                   # (change requires restart)
memqcache_memcached_host = 'localhost'
                                   # Memcached host name or IP address. Mandatory if
                                   # memqcache_method = 'memcached'.
                                   # Defaults to localhost.
                                   # (change requires restart)
memqcache_memcached_port =
                                   # Memcached port number. Mondatory if memqcache_method = 'memcached'.
                                   # Defaults to .
                                   # (change requires restart)
memqcache_total_size =
                                   # Total memory size in bytes for storing memory cache.
                                   # Mandatory if memqcache_method = 'shmem'.
                                   # Defaults to 64MB.
                                   # (change requires restart)
memqcache_max_num_cache =
                                   # Total number of cache entries. Mandatory
                                   # if memqcache_method = 'shmem'.
                                   # Each cache entry consumes  bytes on shared memory.
                                   # Defaults to ,,(.8MB).
                                   # (change requires restart)
memqcache_expire =
                                   # Memory cache entry life time specified in seconds.
                                   #  means infinite life time.  by default.
                                   # (change requires restart)
memqcache_auto_cache_invalidation = on
                                   # If on, invalidation of query cache is triggered by corresponding
                                   # DDL/DML/DCL(and memqcache_expire).  If off, it is only triggered
                                   # by memqcache_expire.  on by default.
                                   # (change requires restart)
memqcache_maxcache =
                                   # Maximum SELECT result size in bytes.
                                   # Must be smaller than memqcache_cache_block_size. Defaults to 400KB.
                                   # (change requires restart)
memqcache_cache_block_size =
                                   # Cache block size in bytes. Mandatory if memqcache_method = 'shmem'.
                                   # Defaults to 1MB.
                                   # (change requires restart)
memqcache_oiddir = '/var/log/pgpool/oiddir'
                                      # Temporary work directory to record table oids
                                   # (change requires restart)
white_memqcache_table_list = ''
                                   # Comma separated list of table names to memcache
                                   # that don't write to database
                                   # Regexp are accepted
black_memqcache_table_list = ''
                                   # Comma separated list of table names not to memcache
                                   # that don't write to database
                                   # Regexp are accepted

vi pool_hba.conf修改后如下

# pgpool Client Authentication Configuration File
# ===============================================
#
# The format rule in this file follows the rules in the PostgreSQL
# Administrator's Guide. Refer to chapter "Client Authentication" for a
# complete description.  A short synopsis follows.
#
# This file controls: which hosts are allowed to connect, how clients
# are authenticated, which user names they can use, which databases they
# can access.  Records take one of these forms:
#
# local      DATABASE  USER  METHOD  [OPTION]
# host       DATABASE  USER  CIDR-ADDRESS  METHOD  [OPTION]
#
# (The uppercase items must be replaced by actual values.)
#
# The first field is the connection type: "local" is a Unix-domain
# socket, "host" is either a plain or SSL-encrypted TCP/IP socket.
#
# DATABASE can be "all", "sameuser", a database name, or a comma-separated
# list thereof. Note that "samegroup" like in PostgreSQL's pg_hba.conf
# file is not supported, since pgpool does not know which group a user
# belongs to. Also note that the database specified here may not exist in
# the backend PostgreSQL. pgpool will authenticate based on the database's
# name, not based on whether it exists or not.
#
# USER can be "all", a user name, or a comma-separated list thereof.  In
# both the DATABASE and USER fields you can also write a file name prefixed
# with "@" to include names from a separate file. Note that a group name
# prefixed with "+" like in PostgreSQL's pg_hba.conf file is not supported
# because of the same reason as "samegroup" token. Also note that a user
# name specified here may not exist in the backend PostgreSQL. pgpool will
# authenticate based on the user's name, not based on whether he/she exists.
#
# CIDR-ADDRESS specifies the set of hosts the record matches.
# It is made up of an IP address and a CIDR mask that is an integer
# (between  and  (IPv4) that specifies the number of significant bits in
# the mask.  Alternatively, you can write an IP address and netmask in
# separate columns to specify the set of hosts.
#
# METHOD can be "trust", "reject", "md5" or "pam".  Note that "pam" sends passwords
# in clear text.
#
# OPTION is the name of the PAM service. Default service name is "pgpool"
#
# Database and user names containing spaces, commas, quotes and other special
# characters must be quoted. Quoting one of the keywords "all" or "sameuser"
# makes the name lose its special character, and just match a database or
# username with that name.
#
# This file is read on pgpool startup.  If you edit the file on a running
# system, you have to restart the pgpool  for the changes to take effect.
 
# Put your actual configuration here
# ----------------------------------
#
# If you want to allow non-local connections, you need to add more
# "host" records. In that case you will also need to make pgpool listen
# on a non-local interface via the listen_addresses configuration parameter.
#
 
# TYPE  DATABASE    USER        CIDR-ADDRESS          METHOD
 
# "local" is for Unix domain socket connections only
local   all         all                               trust
# IPv4 local connections:
host    all         all         0.0.0.0/   md5
#host    all         all         127.0.0.1/          trust
host    all         all         ::/               trust

启用配置文件pool_passwd

[root@pgpool etc]# pg_md5 -m -p -u postgres pool_passwd
password:

创建主从切换脚本

[root@pgpool bin]# vi /usr/local/bin/failover_stream.sh
# Failover command for streaming replication.
# This script assumes that DB node  is primary, and  is standby.
#
# If standby goes down, do nothing. If primary goes down, create a
# trigger file so that standby takes over primary node.
#
# Arguments: $: failed node id. $: new master hostname. $: path to
# trigger file.
 
failed_node=$
new_master=$
trigger_file=$
 
# Do nothing if standby goes down.
if [ $failed_node =  ]; then
        exit ;
fi
 
# Create the trigger file.
/usr/bin/ssh -T $new_master /bin/touch $trigger_file
 
exit ;
 
[root@pgpool bin]# chmod  failover_stream.sh

启动pgpool

[root@VM_176_134_centos pgpool-II]# pgpool -n -d > /tmp/pgpool.log >& &
[]
[root@VM_176_134_centos pgpool-II]# ps -aux|grep pgpool
root         0.0  0.0    pts/    S    :   : su pgpool
pgpool       0.0  0.0    pts/    S    :   : bash
root        0.0  0.0    pts/    S+   :   : vi /var/log/pgpool/pgpool_status
root        0.0  0.1     pts/    S    :   : pgpool -n -d
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: PCP: wait for connection request
root        0.0  0.0     pts/    S    :   : pgpool: worker process
root        0.0  0.0     pts/    S    :   : pgpool: health check process()
root        0.0  0.0     pts/    R+   :   : grep --color=auto pgpool
[root@VM_176_134_centos pgpool-II]# 

启动两台服务器数据库

[root@VM_176_134_centos pgpool-II]# systemctl start postgresql
[root@VM_176_134_centos pgpool-II]# ps -aux|grep postgresql
root        0.0  0.0     pts/    S+   :   : grep --color=auto postgresql
[root@VM_176_134_centos pgpool-II]# ps -aux|grep postgres
postgres    0.0  0.2    ?        S    :   : /usr/bin/postgres -D /var/lib/pgsql/data -p
postgres    0.0  0.0    ?        Ss   :   : postgres: logger process
postgres    0.0  0.0    ?        Ss   :   : postgres: checkpointer process
postgres    0.0  0.0    ?        Ss   :   : postgres: writer process
postgres    0.0  0.0    ?        Ss   :   : postgres: wal writer process
postgres    0.0  0.0    ?        Ss   :   : postgres: autovacuum launcher process
postgres    0.0  0.0    ?        Ss   :   : postgres: stats collector process
root        0.0  0.0     pts/    S+   :   : grep --color=auto postgres
[root@VM_176_134_centos pgpool-II]# 

连接测试

1.连接pgpool，能看到235的数据

2.在pgpool新建test_pgpool表，235的数据库也可以看到表，但备机197上似乎没有看到test_pgpool

 

3.修改配置文件

vi pgpool.conf
 
改下面两个属性
replication_mode = true
load_balance_mode = true
 
然后关闭客户端的连接
235上停止pgpool: pgpool stop
235上启动pgpool: pgpool

4.通过主节点建表test_pgpool2，可以看到主、备节点均有test_pgpool2

 

5.关掉235上的postgresql,看看能否切换到197

[root@VM_176_134_centos pgpool-II]# systemctl stop postgresql
[root@VM_176_134_centos pgpool-II]# ps -aux|grep postgres
root        0.0  0.0     ?        S    :   : pgpool: postgres postgres 113.116.51.86() idle
root        0.0  0.0     pts/    R+   :   : grep --color=auto postgres
[root@VM_176_134_centos pgpool-II]# 

可以看到已经切换到197了，表明在运行中，如果235挂掉了，还有197可用。

但是发现再启动235后的数据库后，pgpool不会自动切回来，可能切换脚本有问题，这个不弄了，等专业的来

参考

官方文档：pgpool-II 入门教程

PostgreSQL+pgpool-II复制方案

pgpool-II主备流复制的架设