Automatisation du pcp_promote_node de PGPOOL lors de l'arrêt du serveur primaire

Fermé
vincentmen - Modifié le 20 avril 2021 à 15:13
Bonjour,
Nous souhaitons installer PGPOOLII pour utiliser la fonctionnalité de load balancing.

Nous avons 3 noeuds RHE 7.9 postgres 12 et utilisons PATRONI pour la gestion du cluster et de la réplication. Nous sommes en réplication synchrone.
Nous avons donc un 4eme serveur RHE 7.9 avec PGPOOLII (v4.2.0).

Donc PGPOOLII n'est pas utilisé pour sa fonctionnalité de réplication.

La cible finale est la suivante:
L'application se connecte a PGPOOL, s'il s'agit d'une requête de lecture, la requete sera load balancé sur un des 3 noeuds. S'il s'agit d'une requête d'écriture, la requête sera exécutée sur le noeud primaire.

Si le serveur primaire est stoppé, PATRONI va promouvoir une nouvelle primaire. et PGPOOL identifie automatiquement la nouvelle primaire pour y envoyer les requêtes d'écriture (pcp_promote).

Le problème est que lorsque nous arrêtons notre primaire, le failover fonctionne correctement via PATRONI, nous avons bien une élection et le cluster est de nouveau opérationnel.
Cependant, côté PGPOOLII il ne se passe rien...
La commande show pool_nodes ramène que tous les noeuds sont en standby et DOWN.
-> Si nous restartons PGPOOL (systemctl stop / start) tous les noeuds sont en standby mais UP.
-> Nous devons ensuite manuellement exécuter le "pcp_promote_node" sur la nouvelle primaire définie par PATRONI
-> Nous avons à ce moment là une primaire qui apparait avec le status UP avec la commande show pool_nodes (et les 2 autres standby en DOWN). Le cluster est de nous fonctionnel.

Savez-vous comment automatiser cette promotion de primaire côté PGPOOL ?

Pour info, dans notre log pgpool nous avons en permanence des messages:
FATAL: unable to read data from DB node x

Voici le contenu de notre pgpool.conf:
#------------------------------------------------------------------------------
# BACKEND CLUSTERING MODE
# Choose one of: 'streaming_replication', 'native_replication',
# 'logical_replication', 'slony', 'raw' or 'snapshot_isolation'
# (change requires restart)
#------------------------------------------------------------------------------

backend_clustering_mode = 'streaming_replication'

#------------------------------------------------------------------------------
# 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 = 5432
# Port number
# (change requires restart)
socket_dir = '/var/run/pgpool'
# Unix domain socket path
# The Debian package defaults to
# /var/run/postgresql
# (change requires restart)
reserved_connections = 0
# Number of reserved connections.
# Pgpool-II does not accept connections if over
# num_init_chidlren - reserved_connections.


# - 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 = 9898
# 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)
listen_backlog_multiplier = 2
# Set the backlog parameter of listen(2) 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)

# - Backend Connection Settings -

backend_hostname0 = 'x.x.x.x'
# Host name or IP address to connect to for backend 0
backend_port0 = 5432
# Port number for backend 0
backend_weight0 = 1
# Weight for backend 0 (only in load balancing mode)
backend_data_directory0 = '/data/pgsql_elogbook'
# Data directory for backend 0
backend_flag0 = 'ALLOW_TO_FAILOVER'
# Controls various backend behavior
# ALLOW_TO_FAILOVER, DISALLOW_TO_FAILOVER
# or ALWAYS_PRIMARY
backend_application_name0 = 'node0'
# walsender's application_name, used for "show pool_nodes" command


backend_hostname1 = 'y.y.y.y'
# Host name or IP address to connect to for backend 1
backend_port1 = 5432
# Port number for backend 1
backend_weight1 = 1
# Weight for backend 1 (only in load balancing mode)
backend_data_directory1 = '/data/pgsql_elogbook'
# Data directory for backend 1
backend_flag1 = 'ALLOW_TO_FAILOVER'
# Controls various backend behavior
# ALLOW_TO_FAILOVER, DISALLOW_TO_FAILOVER
# or ALWAYS_PRIMARY
backend_application_name1 = 'node1'
# walsender's application_name, used for "show pool_nodes" command


backend_hostname2 = 'z.z.z.z'
# Host name or IP address to connect to for backend 2
backend_port2 = 5432
# Port number for backend 2
backend_weight2 = 1
# Weight for backend 2 (only in load balancing mode)
backend_data_directory2 = '/data/pgsql_elogbook'
# Data directory for backend 2
backend_flag2 = 'ALLOW_TO_FAILOVER'
# Controls various backend behavior
# ALLOW_TO_FAILOVER, DISALLOW_TO_FAILOVER
# or ALWAYS_PRIMARY
backend_application_name2 = 'node2'
# walsender's application_name, used for "show pool_nodes" command


# - Authentication -

enable_pool_hba = off
# 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 = 1min
# Delay in seconds to complete client authentication
# 0 means no timeout.

allow_clear_text_frontend_auth = off
# Allow Pgpool-II to use clear text password authentication
# with clients, when pool_passwd does not
# contain the user password

# - SSL Connections -

ssl = off
# Enable SSL support
# (change requires restart)
#ssl_key = 'server.key'
# SSL private key file
# (change requires restart)
#ssl_cert = 'server.crt'
# SSL public certificate file
# (change requires restart)
#ssl_ca_cert = ''
# 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)
#ssl_crl_file = ''
# SSL certificate revocation list file
# (change requires restart)

ssl_ciphers = 'HIGH:MEDIUM:+3DES:!aNULL'
# Allowed SSL ciphers
# (change requires restart)
ssl_prefer_server_ciphers = off
# Use server's SSL cipher preferences,
# rather than the client's
# (change requires restart)
ssl_ecdh_curve = 'prime256v1'
# Name of the curve to use in ECDH key exchange
ssl_dh_params_file = ''
# Name of the file containing Diffie-Hellman parameters used
# for so-called ephemeral DH family of SSL cipher.
#ssl_passphrase_command=''
# Sets an external command to be invoked when a passphrase
# for decrypting an SSL file needs to be obtained
# (change requires restart)

#------------------------------------------------------------------------------
# POOLS
#------------------------------------------------------------------------------

# - Concurrent session and pool size -

num_init_children = 32
# Number of concurrent sessions allowed
# (change requires restart)
max_pool = 4
# Number of connection pool caches per connection
# (change requires restart)

# - Life time -

child_life_time = 5min
# Pool exits after being idle for this many seconds
child_max_connections = 0
# Pool exits after receiving that many connections
# 0 means no exit
connection_life_time = 240
# Connection to backend closes after being idle for this many seconds
# 0 means no close
client_idle_limit = 120
# Client is disconnected after being idle for that many seconds
# (even inside an explicit transactions!)
# 0 means no disconnection


#------------------------------------------------------------------------------
# LOGS
#------------------------------------------------------------------------------

# - Where to log -
logging_collector = on
log_directory = '/var/log/pgpool'
log_filename = 'pgpool-%Y-%m-%d_%H%M%S.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 = on
# Log connections
log_disconnections = on
# Log disconnections
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_client_messages = off
# Log any client messages
log_standby_delay = 'if_over_threshold'
# 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

# This is used when logging to stderr:
#logging_collector = off # Enable capturing of stderr
# into log files.
# (change requires restart)

# -- Only used if logging_collector is on ---

#log_directory = '/tmp/pgpool_log' # directory where log files are written,
# can be absolute
#log_filename = 'pgpool-%Y-%m-%d_%H%M%S.log'
# log file name pattern,
# can include strftime() escapes

#log_file_mode = 0600 # creation mode for log files,
# begin with 0 to use octal notation

#log_truncate_on_rotation = off # If on, an existing log file with the
# same name as the new log file will be
# truncated rather than appended to.
# But such truncation only occurs on
# time-driven rotation, not on restarts
# or size-driven rotation. Default is
# off, meaning append to existing files
# in all cases.

#log_rotation_age = 1d # Automatic rotation of logfiles will
# happen after that (minutes)time.
# 0 disables time based rotation.
#log_rotation_size = 10MB # Automatic rotation of logfiles will
# happen after that much (KB) log output.
# 0 disables size based rotation.
#------------------------------------------------------------------------------
# FILE LOCATIONS
#------------------------------------------------------------------------------

pid_file_name = '/var/run/postgresql/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
#------------------------------------------------------------------------------

replicate_select = off
# Replicate SELECT statements
# when in replication mode
# replicate_select is higher priority than
# load_balance_mode.

insert_lock = off
# 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 = on
# Activate load balancing mode
# (change requires restart)
ignore_leading_white_space = on
# Ignore leading white spaces of each query
read_only_function_list = ''
# Comma separated list of function names
# that don't write to database
# Regexp are accepted
write_function_list = ''
# Comma separated list of function names
# that write to database
# Regexp are accepted
# If both read_only_function_list and write_function_list
# is empty, function's volatile property is checked.
# If it's volatile, the function is regarded as a
# writing function.

primary_routing_query_pattern_list = ''
# Semicolon separated list of query patterns
# that should be sent to primary node
# Regexp are accepted
# valid for streaming replicaton mode only.

database_redirect_preference_list = ''
# comma separated list of pairs of database and node id.
# example: postgres:primary,mydb[0-4]:1,mydb[5-9]:2'
# 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).

disable_load_balance_on_write = 'transaction'
# Load balance behavior when write query is issued
# in an explicit transaction.
#
# Valid values:
#
# 'transaction' (default):
# if a write query is issued, subsequent
# read queries will not be load balanced
# until the transaction ends.
#
# 'trans_transaction':
# if a write query is issued, subsequent
# read queries in an explicit transaction
# will not be load balanced until the session ends.
#
# 'dml_adaptive':
# Queries on the tables that have already been
# modified within the current explicit transaction will
# not be load balanced until the end of the transaction.
#
# 'always':
# if a write query is issued, read queries will
# not be load balanced until the session ends.
#
# Note that any query not in an explicit transaction
# is not affected by the parameter.

dml_adaptive_object_relationship_list= ''
# comma separated list of object pairs
# [object]:[dependent-object], to disable load balancing
# of dependent objects within the explicit transaction
# after WRITE statement is issued on (depending-on) object.
#
# example: 'tb_t1:tb_t2,insert_tb_f_func():tb_f,tb_v:my_view'
# Note: function name in this list must also be present in
# the write_function_list
# only valid for disable_load_balance_on_write = 'dml_adaptive'.

statement_level_load_balance = off
# Enables statement level load balancing

#------------------------------------------------------------------------------
# NATIVE REPLICATION MODE
#------------------------------------------------------------------------------

# - Streaming -

sr_check_period = 10
# Streaming replication check period
# Disabled (0) by default
sr_check_user = 'nobody'
# Streaming replication check user
# This is neccessary even if you disable streaming
# replication delay check by sr_check_period = 0
sr_check_password = ''
# Password for streaming replication check user
# Leaving it empty will make Pgpool-II to first look for the
# Password in pool_passwd file before using the empty password

sr_check_database = 'postgres'
# Database name for streaming replication check
delay_threshold = 10000000
# Threshold before not dispatching query to standby node
# Unit is in bytes
# Disabled (0) by default

# - Special commands -

follow_primary_command = ''
# Executes this command after main node failover
# Special values:
# %d = failed node id
# %h = failed node host name
# %p = failed node port number
# %D = failed node database cluster path
# %m = new main node id
# %H = new main node hostname
# %M = old main node id
# %P = old primary node id
# %r = new main port number
# %R = new main database cluster path
# %N = old primary node hostname
# %S = old primary node port number
# %% = '%' character

#------------------------------------------------------------------------------
# HEALTH CHECK GLOBAL PARAMETERS
#------------------------------------------------------------------------------

health_check_period = 0
# Health check period
# Disabled (0) by default
health_check_timeout = 20
# Health check timeout
# 0 means no timeout
health_check_user = 'nobody'
# Health check user
health_check_password = ''
# Password for health check user
# Leaving it empty will make Pgpool-II to first look for the
# Password in pool_passwd file before using the empty password

health_check_database = ''
# Database name for health check. If '', tries 'postgres' frist,
health_check_max_retries = 0
# Maximum number of times to retry a failed health check before giving up.
health_check_retry_delay = 1
# Amount of time to wait (in seconds) between retries.
connect_timeout = 10000
# Timeout value in milliseconds before giving up to connect to backend.
# Default is 10000 ms (10 second). Flaky network user may want to increase
# the value. 0 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)
#------------------------------------------------------------------------------

#------------------------------------------------------------------------------
# FAILOVER AND FAILBACK
#------------------------------------------------------------------------------

failover_command = ''
# Executes this command at failover
# Special values:
# %d = failed node id
# %h = failed node host name
# %p = failed node port number
# %D = failed node database cluster path
# %m = new main node id
# %H = new main node hostname
# %M = old main node id
# %P = old primary node id
# %r = new main port number
# %R = new main database cluster path
# %N = old primary node hostname
# %S = old primary node port number
# %% = '%' character
failback_command = ''
# Executes this command at failback.
# Special values:
# %d = failed node id
# %h = failed node host name
# %p = failed node port number
# %D = failed node database cluster path
# %m = new main node id
# %H = new main node hostname
# %M = old main node id
# %P = old primary node id
# %r = new main port number
# %R = new main database cluster path
# %N = old primary node hostname
# %S = old primary node port number
# %% = '%' character

failover_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.
detach_false_primary = off
# Detach false primary if on. Only
# valid in streaming replicaton
# mode and with PostgreSQL 9.6 or
# after.

search_primary_node_timeout = 5min
# Timeout in seconds to search for the
# primary node when a failover occurs.
# 0 means no timeout, keep searching
# for a primary node forever.

#------------------------------------------------------------------------------
# ONLINE RECOVERY
#------------------------------------------------------------------------------

recovery_user = 'nobody'
# Online recovery user
recovery_password = ''
# Online recovery password
# Leaving it empty will make Pgpool-II to first look for the
# Password in pool_passwd file before using the empty password

recovery_1st_stage_command = ''
# Executes a command in first stage
recovery_2nd_stage_command = ''
# Executes a command in second stage
recovery_timeout = 90
# Timeout in seconds to wait for the
# recovering node's postmaster to start up
# 0 means no wait
client_idle_limit_in_recovery = 0
# Client is disconnected after being idle
# for that many seconds in the second stage
# of online recovery
# 0 means no disconnection
# -1 means immediate disconnection

auto_failback = off
# Dettached backend node reattach automatically
# if replication_state is 'streaming'.
auto_failback_interval = 1min
# Min interval of executing auto_failback in
# seconds.

#------------------------------------------------------------------------------
# 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 -

hostname0 = ''
# Host name or IP address of pgpool node
# for watchdog connection
# (change requires restart)
wd_port0 = 9000
# Port number for watchdog service
# (change requires restart)
pgpool_port0 = 9999
# Port number for pgpool
# (change requires restart)

#hostname1 = ''
#wd_port1 = 9000
#pgpool_port1 = 9999

#hostname2 = ''
#wd_port2 = 9000
#pgpool_port2 = 9999

wd_priority = 1
# 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
# If if_up/down_cmd starts with "/", if_cmd_path will be ignored.
# (change requires restart)
if_up_cmd = '/usr/bin/sudo /sbin/ip addr add $_IP_$/24 dev eth0 label eth0:0'
# startup delegate IP command
# (change requires restart)
if_down_cmd = '/usr/bin/sudo /sbin/ip addr del $_IP_$/24 dev eth0'
# shutdown delegate IP command
# (change requires restart)
arping_path = '/usr/sbin'
# arping command path
# If arping_cmd starts with "/", if_cmd_path will be ignored.
# (change requires restart)
arping_cmd = '/usr/bin/sudo /usr/sbin/arping -U $_IP_$ -w 1 -I eth0'
# 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 leader pgpool resigns from being leader.
# (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)


enable_consensus_with_half_votes = off
# apply majority rule for consensus and quorum computation
# at 50% of votes in a cluster with even number of nodes.
# when enabled the existence of quorum and consensus
# on failover is resolved after receiving half of the
# total votes in the cluster, otherwise both these
# decisions require at least one more vote than
# half of the total votes.
# (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 = 10
# lifecheck interval (sec) > 0
# (change requires restart)

# -- heartbeat mode --

heartbeat_hostname0 = ''
# Host name or IP address used
# for sending heartbeat signal.
# (change requires restart)
heartbeat_port0 = 9694
# Port number used for receiving/sending heartbeat signal
# Usually this is the same as heartbeat_portX.
# (change requires restart)
heartbeat_device0 = ''
# Name of NIC device (such like 'eth0')
# used for sending/receiving heartbeat
# signal to/from destination 0.
# This works only when this is not empty
# and pgpool has root privilege.
# (change requires restart)

#heartbeat_hostname1 = ''
#heartbeat_port1 = 9694
#heartbeat_device1 = ''
#heartbeat_hostname2 = ''
#heartbeat_port2 = 9694
#heartbeat_device2 = ''

wd_heartbeat_keepalive = 2
# Interval time of sending heartbeat signal (sec)
# (change requires restart)
wd_heartbeat_deadtime = 30
# Deadtime interval for heartbeat signal (sec)
# (change requires restart)

# -- query mode --

wd_life_point = 3
# 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
# Leaving it empty will make Pgpool-II to first look for the
# Password in pool_passwd file before using the empty password
# (change requires restart)

#------------------------------------------------------------------------------
# OTHERS
#------------------------------------------------------------------------------
relcache_expire = 0
# Life time of relation cache in seconds.
# 0 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 = 256
# 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 = catalog
# Temporary table check method. catalog, trace or none.
# Default is catalog.

check_unlogged_table = on
# If on, enable unlogged table check in SELECT statements.
# This initiates queries against system catalog of primary/main
# thus increases load of primary.
# If you are absolutely sure that your system never uses unlogged tables
# and you want to save access to primary/main, you could turn this off.
# Default is on.
enable_shared_relcache = on
# If on, relation cache stored in memory cache,
# the cache is shared among child process.
# Default is on.
# (change requires restart)

relcache_query_target = primary # Target node to send relcache queries. Default is primary node.
# If load_balance_node is specified, queries will be sent to load balance node.
#------------------------------------------------------------------------------
# IN MEMORY QUERY MEMORY CACHE
#------------------------------------------------------------------------------
memory_cache_enabled = off
# If on, use the memory cache functionality, off by default
# (change requires restart)
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 = 11211
# Memcached port number. Mondatory if memqcache_method = 'memcached'.
# Defaults to 11211.
# (change requires restart)
memqcache_total_size = 64MB
# Total memory size in bytes for storing memory cache.
# Mandatory if memqcache_method = 'shmem'.
# Defaults to 64MB.
# (change requires restart)
memqcache_max_num_cache = 1000000
# Total number of cache entries. Mandatory
# if memqcache_method = 'shmem'.
# Each cache entry consumes 48 bytes on shared memory.
# Defaults to 1,000,000(45.8MB).
# (change requires restart)
memqcache_expire = 0
# Memory cache entry life time specified in seconds.
# 0 means infinite life time. 0 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 = 400kB
# Maximum SELECT result size in bytes.
# Must be smaller than memqcache_cache_block_size. Defaults to 400KB.
# (change requires restart)
memqcache_cache_block_size = 1MB
# 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)
cache_safe_memqcache_table_list = ''
# Comma separated list of table names to memcache
# that don't write to database
# Regexp are accepted
cache_unsafe_memqcache_table_list = ''
# Comma separated list of table names not to memcache
# that don't write to database
# Regexp are accepted


Par avance merci pour votre aide!


Cordialemet,
VME