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pgpool-II session failoverPostgreSQL 2019. 10. 11. 14:08
pgpool-II는 자동 session failover가 된다.
테스트 시나리오
- agensgraph의 initdb 명령어로 data1을 생성한다.
- data1/postgresql.conf 파일을 수정하고, ag_ctl 명령어로 data1를 시작한다.
- pg_basebackup 명령어로 data2를 생성하고, ag_ctl 명령어로 data2를 시작한다. 백업대상은 data1이다.
- pgpool-II를 시작한다.
- agens 명령어에 pgpool-II port를 사용하여 질의한다.
- ag_ctl stop명령어로 master인 data1를 죽인다.
- agens 명령어에 pgpool-II port를 사용하여 질의한다.
다음은 위의 테스트 시나리오를 실행한 결과이다.
data1/postgresql.conf 내용
# ----------------------------- # PostgreSQL configuration file # ----------------------------- # # This file consists of lines of the form: # # name = value # # (The "=" is optional.) 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 PostgreSQL documentation. # # The commented-out settings shown in this file represent the default values. # Re-commenting a setting is NOT sufficient to revert it to the default value; # you need to reload the server. # # 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, run "pg_ctl reload", or execute # "SELECT pg_reload_conf()". Some parameters, which are marked below, # require a server shutdown and restart to take effect. # # Any parameter can also be given as a command-line option to the server, e.g., # "postgres -c log_connections=on". Some parameters can be changed at run time # with the "SET" SQL command. # # Memory units: kB = kilobytes Time units: ms = milliseconds # MB = megabytes s = seconds # GB = gigabytes min = minutes # TB = terabytes h = hours # d = days #------------------------------------------------------------------------------ # FILE LOCATIONS #------------------------------------------------------------------------------ # The default values of these variables are driven from the -D command-line # option or PGDATA environment variable, represented here as ConfigDir. #data_directory = 'ConfigDir' # use data in another directory # (change requires restart) #hba_file = 'ConfigDir/pg_hba.conf' # host-based authentication file # (change requires restart) #ident_file = 'ConfigDir/pg_ident.conf' # ident configuration file # (change requires restart) # If external_pid_file is not explicitly set, no extra PID file is written. #external_pid_file = '' # write an extra PID file # (change requires restart) #------------------------------------------------------------------------------ # CONNECTIONS AND AUTHENTICATION #------------------------------------------------------------------------------ # - Connection Settings - #listen_addresses = 'localhost' # what IP address(es) to listen on; # comma-separated list of addresses; # defaults to 'localhost'; use '*' for all # (change requires restart) port = 7432 # (change requires restart) max_connections = 100 # (change requires restart) #superuser_reserved_connections = 3 # (change requires restart) #unix_socket_directories = '/tmp' # comma-separated list of directories # (change requires restart) #unix_socket_group = '' # (change requires restart) #unix_socket_permissions = 0777 # begin with 0 to use octal notation # (change requires restart) #bonjour = off # advertise server via Bonjour # (change requires restart) #bonjour_name = '' # defaults to the computer name # (change requires restart) # - Security and Authentication - #authentication_timeout = 1min # 1s-600s #ssl = off #ssl_ciphers = 'HIGH:MEDIUM:+3DES:!aNULL' # allowed SSL ciphers #ssl_prefer_server_ciphers = on #ssl_ecdh_curve = 'prime256v1' #ssl_dh_params_file = '' #ssl_cert_file = 'server.crt' #ssl_key_file = 'server.key' #ssl_ca_file = '' #ssl_crl_file = '' #password_encryption = md5 # md5 or scram-sha-256 #db_user_namespace = off #row_security = on # GSSAPI using Kerberos #krb_server_keyfile = '' #krb_caseins_users = off # - TCP Keepalives - # see "man 7 tcp" for details #tcp_keepalives_idle = 0 # TCP_KEEPIDLE, in seconds; # 0 selects the system default #tcp_keepalives_interval = 0 # TCP_KEEPINTVL, in seconds; # 0 selects the system default #tcp_keepalives_count = 0 # TCP_KEEPCNT; # 0 selects the system default #------------------------------------------------------------------------------ # RESOURCE USAGE (except WAL) #------------------------------------------------------------------------------ # - Memory - shared_buffers = 128MB # min 128kB # (change requires restart) #huge_pages = try # on, off, or try # (change requires restart) #temp_buffers = 8MB # min 800kB #max_prepared_transactions = 0 # zero disables the feature # (change requires restart) # Caution: it is not advisable to set max_prepared_transactions nonzero unless # you actively intend to use prepared transactions. #work_mem = 4MB # min 64kB #maintenance_work_mem = 64MB # min 1MB #replacement_sort_tuples = 150000 # limits use of replacement selection sort #autovacuum_work_mem = -1 # min 1MB, or -1 to use maintenance_work_mem #max_stack_depth = 2MB # min 100kB #eager_mem = 4MB # min 1MB dynamic_shared_memory_type = posix # the default is the first option # supported by the operating system: # posix # sysv # windows # mmap # use none to disable dynamic shared memory # (change requires restart) # - Disk - #temp_file_limit = -1 # limits per-process temp file space # in kB, or -1 for no limit # - Kernel Resource Usage - #max_files_per_process = 1000 # min 25 # (change requires restart) #shared_preload_libraries = 'pg_stat_statements,pg_statsinfo,pg_hint_plan,hll' # (change requires restart) # - Cost-Based Vacuum Delay - #vacuum_cost_delay = 0 # 0-100 milliseconds #vacuum_cost_page_hit = 1 # 0-10000 credits #vacuum_cost_page_miss = 10 # 0-10000 credits #vacuum_cost_page_dirty = 20 # 0-10000 credits #vacuum_cost_limit = 200 # 1-10000 credits # - Background Writer - #bgwriter_delay = 200ms # 10-10000ms between rounds #bgwriter_lru_maxpages = 100 # 0-1000 max buffers written/round #bgwriter_lru_multiplier = 2.0 # 0-10.0 multiplier on buffers scanned/round #bgwriter_flush_after = 512kB # measured in pages, 0 disables # - Asynchronous Behavior - #effective_io_concurrency = 1 # 1-1000; 0 disables prefetching #max_worker_processes = 8 # (change requires restart) #max_parallel_workers_per_gather = 2 # taken from max_parallel_workers #max_parallel_workers = 8 # maximum number of max_worker_processes that # can be used in parallel queries #old_snapshot_threshold = -1 # 1min-60d; -1 disables; 0 is immediate # (change requires restart) #backend_flush_after = 0 # measured in pages, 0 disables #------------------------------------------------------------------------------ # WRITE AHEAD LOG #------------------------------------------------------------------------------ # - Settings - #wal_level = replica # minimal, replica, or logical # (change requires restart) #fsync = on # flush data to disk for crash safety # (turning this off can cause # unrecoverable data corruption) #synchronous_commit = on # synchronization level; # off, local, remote_write, remote_apply, or on #wal_sync_method = fsync # the default is the first option # supported by the operating system: # open_datasync # fdatasync (default on Linux) # fsync # fsync_writethrough # open_sync #full_page_writes = on # recover from partial page writes #wal_compression = off # enable compression of full-page writes #wal_log_hints = off # also do full page writes of non-critical updates # (change requires restart) #wal_buffers = -1 # min 32kB, -1 sets based on shared_buffers # (change requires restart) #wal_writer_delay = 200ms # 1-10000 milliseconds #wal_writer_flush_after = 1MB # measured in pages, 0 disables #commit_delay = 0 # range 0-100000, in microseconds #commit_siblings = 5 # range 1-1000 # - Checkpoints - #checkpoint_timeout = 5min # range 30s-1d #max_wal_size = 1GB #min_wal_size = 80MB #checkpoint_completion_target = 0.5 # checkpoint target duration, 0.0 - 1.0 #checkpoint_flush_after = 256kB # measured in pages, 0 disables #checkpoint_warning = 30s # 0 disables # - Archiving - #archive_mode = off # enables archiving; off, on, or always # (change requires restart) #archive_command = '' # command to use to archive a logfile segment # placeholders: %p = path of file to archive # %f = file name only # e.g. 'test ! -f /mnt/server/archivedir/%f && cp %p /mnt/server/archivedir/%f' #archive_timeout = 0 # force a logfile segment switch after this # number of seconds; 0 disables #------------------------------------------------------------------------------ # REPLICATION #------------------------------------------------------------------------------ # - Sending Server(s) - # Set these on the master and on any standby that will send replication data. max_wal_senders = 2 # max number of walsender processes # (change requires restart) wal_keep_segments = 32 # in logfile segments, 16MB each; 0 disables #wal_sender_timeout = 60s # in milliseconds; 0 disables #max_replication_slots = 10 # max number of replication slots # (change requires restart) #track_commit_timestamp = off # collect timestamp of transaction commit # (change requires restart) # - Master Server - # These settings are ignored on a standby server. #synchronous_standby_names = '' # standby servers that provide sync rep # method to choose sync standbys, number of sync standbys, # and comma-separated list of application_name # from standby(s); '*' = all #vacuum_defer_cleanup_age = 0 # number of xacts by which cleanup is delayed # - Standby Servers - # These settings are ignored on a master server. hot_standby = on # "off" disallows queries during recovery # (change requires restart) #max_standby_archive_delay = 30s # max delay before canceling queries # when reading WAL from archive; # -1 allows indefinite delay #max_standby_streaming_delay = 30s # max delay before canceling queries # when reading streaming WAL; # -1 allows indefinite delay #wal_receiver_status_interval = 10s # send replies at least this often # 0 disables #hot_standby_feedback = off # send info from standby to prevent # query conflicts #wal_receiver_timeout = 60s # time that receiver waits for # communication from master # in milliseconds; 0 disables #wal_retrieve_retry_interval = 5s # time to wait before retrying to # retrieve WAL after a failed attempt # - Subscribers - # These settings are ignored on a publisher. #max_logical_replication_workers = 4 # taken from max_worker_processes # (change requires restart) #max_sync_workers_per_subscription = 2 # taken from max_logical_replication_workers #------------------------------------------------------------------------------ # QUERY TUNING #------------------------------------------------------------------------------ # - Planner Method Configuration - #enable_bitmapscan = on #enable_hashagg = on #enable_hashjoin = on #enable_indexscan = on #enable_indexonlyscan = on #enable_material = on #enable_mergejoin = on #enable_nestloop = on #enable_seqscan = on #enable_sort = on #enable_tidscan = on #enable_eager = off # - Planner Cost Constants - #seq_page_cost = 1.0 # measured on an arbitrary scale #random_page_cost = 4.0 # same scale as above #cpu_tuple_cost = 0.01 # same scale as above #cpu_index_tuple_cost = 0.005 # same scale as above #cpu_operator_cost = 0.0025 # same scale as above #parallel_tuple_cost = 0.1 # same scale as above #parallel_setup_cost = 1000.0 # same scale as above #min_parallel_table_scan_size = 8MB #min_parallel_index_scan_size = 512kB #effective_cache_size = 4GB # - Genetic Query Optimizer - #geqo = on #geqo_threshold = 12 #geqo_effort = 5 # range 1-10 #geqo_pool_size = 0 # selects default based on effort #geqo_generations = 0 # selects default based on effort #geqo_selection_bias = 2.0 # range 1.5-2.0 #geqo_seed = 0.0 # range 0.0-1.0 # - Other Planner Options - #default_statistics_target = 100 # range 1-10000 #constraint_exclusion = partition # on, off, or partition #cursor_tuple_fraction = 0.1 # range 0.0-1.0 #from_collapse_limit = 8 #join_collapse_limit = 8 # 1 disables collapsing of explicit # JOIN clauses #force_parallel_mode = off #------------------------------------------------------------------------------ # ERROR REPORTING AND LOGGING #------------------------------------------------------------------------------ # - Where to Log - #log_destination = 'stderr' # Valid values are combinations of # stderr, csvlog, syslog, and eventlog, # depending on platform. csvlog # requires logging_collector to be on. # This is used when logging to stderr: #logging_collector = off # Enable capturing of stderr and csvlog # into log files. Required to be on for # csvlogs. # (change requires restart) # These are only used if logging_collector is on: #log_directory = 'log' # directory where log files are written, # can be absolute or relative to PGDATA log_filename = 'postgresql-%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 time. 0 disables. #log_rotation_size = 10MB # Automatic rotation of logfiles will # happen after that much log output. # 0 disables. # These are relevant when logging to syslog: #syslog_facility = 'LOCAL0' #syslog_ident = 'postgres' #syslog_sequence_numbers = on #syslog_split_messages = on # This is only relevant when logging to eventlog (win32): # (change requires restart) #event_source = 'PostgreSQL' # - When to Log - #client_min_messages = notice # values in order of decreasing detail: # debug5 # debug4 # debug3 # debug2 # debug1 # log # notice # warning # error log_min_messages = log # values in order of decreasing detail: # debug5 # debug4 # debug3 # debug2 # debug1 # info # notice # warning # error # log # fatal # panic #log_min_error_statement = error # values in order of decreasing detail: # debug5 # debug4 # debug3 # debug2 # debug1 # info # notice # warning # error # log # fatal # panic (effectively off) #log_min_duration_statement = -1 # -1 is disabled, 0 logs all statements # and their durations, > 0 logs only # statements running at least this number # of milliseconds # - What to Log - #debug_print_parse = off #debug_print_rewritten = off #debug_print_plan = off #debug_pretty_print = on #log_checkpoints = off #log_connections = off #log_disconnections = off #log_duration = off #log_error_verbosity = default # terse, default, or verbose messages #log_hostname = off #log_line_prefix = '%m [%p] ' # special values: # %a = application name # %u = user name # %d = database name # %r = remote host and port # %h = remote host # %p = process ID # %t = timestamp without milliseconds # %m = timestamp with milliseconds # %n = timestamp with milliseconds (as a Unix epoch) # %i = command tag # %e = SQL state # %c = session ID # %l = session line number # %s = session start timestamp # %v = virtual transaction ID # %x = transaction ID (0 if none) # %q = stop here in non-session # processes # %% = '%' # e.g. '<%u%%%d> ' #log_lock_waits = off # log lock waits >= deadlock_timeout #log_statement = 'none' # none, ddl, mod, all #log_replication_commands = off #log_temp_files = -1 # log temporary files equal or larger # than the specified size in kilobytes; # -1 disables, 0 logs all temp files log_timezone = 'ROK' # - Process Title - #cluster_name = '' # added to process titles if nonempty # (change requires restart) #update_process_title = on #------------------------------------------------------------------------------ # RUNTIME STATISTICS #------------------------------------------------------------------------------ # - Query/Index Statistics Collector - #track_activities = on #track_counts = on #track_io_timing = off #track_functions = none # none, pl, all #track_activity_query_size = 1024 # (change requires restart) #stats_temp_directory = 'pg_stat_tmp' # - Statistics Monitoring - #log_parser_stats = off #log_planner_stats = off #log_executor_stats = off #log_statement_stats = off #------------------------------------------------------------------------------ # AUTOVACUUM PARAMETERS #------------------------------------------------------------------------------ #autovacuum = on # Enable autovacuum subprocess? 'on' # requires track_counts to also be on. log_autovacuum_min_duration = 0 # -1 disables, 0 logs all actions and # their durations, > 0 logs only # actions running at least this number # of milliseconds. #autovacuum_max_workers = 3 # max number of autovacuum subprocesses # (change requires restart) #autovacuum_naptime = 1min # time between autovacuum runs #autovacuum_vacuum_threshold = 50 # min number of row updates before # vacuum #autovacuum_analyze_threshold = 50 # min number of row updates before # analyze #autovacuum_vacuum_scale_factor = 0.2 # fraction of table size before vacuum #autovacuum_analyze_scale_factor = 0.1 # fraction of table size before analyze #autovacuum_freeze_max_age = 200000000 # maximum XID age before forced vacuum # (change requires restart) #autovacuum_multixact_freeze_max_age = 400000000 # maximum multixact age # before forced vacuum # (change requires restart) #autovacuum_vacuum_cost_delay = 20ms # default vacuum cost delay for # autovacuum, in milliseconds; # -1 means use vacuum_cost_delay #autovacuum_vacuum_cost_limit = -1 # default vacuum cost limit for # autovacuum, -1 means use # vacuum_cost_limit #------------------------------------------------------------------------------ # CLIENT CONNECTION DEFAULTS #------------------------------------------------------------------------------ # - Statement Behavior - #search_path = '"$user", public' # schema names #default_tablespace = '' # a tablespace name, '' uses the default #temp_tablespaces = '' # a list of tablespace names, '' uses # only default tablespace #check_function_bodies = on #default_transaction_isolation = 'read committed' #default_transaction_read_only = off #default_transaction_deferrable = off #session_replication_role = 'origin' #statement_timeout = 0 # in milliseconds, 0 is disabled #lock_timeout = 0 # in milliseconds, 0 is disabled #idle_in_transaction_session_timeout = 0 # in milliseconds, 0 is disabled #vacuum_freeze_min_age = 50000000 #vacuum_freeze_table_age = 150000000 #vacuum_multixact_freeze_min_age = 5000000 #vacuum_multixact_freeze_table_age = 150000000 #bytea_output = 'hex' # hex, escape #xmlbinary = 'base64' #xmloption = 'content' #gin_fuzzy_search_limit = 0 #gin_pending_list_limit = 4MB # - Locale and Formatting - datestyle = 'iso, ymd' #intervalstyle = 'postgres' timezone = 'ROK' #timezone_abbreviations = 'Default' # Select the set of available time zone # abbreviations. Currently, there are # Default # Australia (historical usage) # India # You can create your own file in # share/timezonesets/. #extra_float_digits = 0 # min -15, max 3 #client_encoding = sql_ascii # actually, defaults to database # encoding # These settings are initialized by initdb, but they can be changed. lc_messages = 'ko_KR.UTF-8' # locale for system error message # strings lc_monetary = 'ko_KR.UTF-8' # locale for monetary formatting lc_numeric = 'ko_KR.UTF-8' # locale for number formatting lc_time = 'ko_KR.UTF-8' # locale for time formatting # default configuration for text search default_text_search_config = 'pg_catalog.simple' # - Other Defaults - #dynamic_library_path = '$libdir' #local_preload_libraries = '' #session_preload_libraries = '' #------------------------------------------------------------------------------ # LOCK MANAGEMENT #------------------------------------------------------------------------------ #deadlock_timeout = 1s #max_locks_per_transaction = 64 # min 10 # (change requires restart) #max_pred_locks_per_transaction = 64 # min 10 # (change requires restart) #max_pred_locks_per_relation = -2 # negative values mean # (max_pred_locks_per_transaction # / -max_pred_locks_per_relation) - 1 #max_pred_locks_per_page = 2 # min 0 #------------------------------------------------------------------------------ # VERSION/PLATFORM COMPATIBILITY #------------------------------------------------------------------------------ # - Previous PostgreSQL Versions - #array_nulls = on #backslash_quote = safe_encoding # on, off, or safe_encoding #default_with_oids = off #escape_string_warning = on #lo_compat_privileges = off #operator_precedence_warning = off #quote_all_identifiers = off #standard_conforming_strings = on #synchronize_seqscans = on # - Other Platforms and Clients - #transform_null_equals = off #------------------------------------------------------------------------------ # ERROR HANDLING #------------------------------------------------------------------------------ #exit_on_error = off # terminate session on any error? #restart_after_crash = on # reinitialize after backend crash? #------------------------------------------------------------------------------ # CONFIG FILE INCLUDES #------------------------------------------------------------------------------ # These options allow settings to be loaded from files other than the # default postgresql.conf. #include_dir = 'conf.d' # include files ending in '.conf' from # directory 'conf.d' #include_if_exists = 'exists.conf' # include file only if it exists #include = 'special.conf' # include file #------------------------------------------------------------------------------ # CUSTOMIZED OPTIONS #------------------------------------------------------------------------------ # Add settings for extensions here pg_stat_statements.max = 10000 # Sets the maximum number of statements tracked by # pg_stat_statements. pg_stat_statements.track = all # Selects which statements are tracked by # pg_stat_statements. (none, top, all) #pg_stat_statements.track_utility = on # Selects whether utility commands are tracked by # pg_stat_statements. #pg_stat_statements.save = on # Save pg_stat_statements statistics across server # shutdowns. # - pg_statsinfo settings - # # See http://pgstatsinfo.sourceforge.net/pg_statsinfo.html#configuration # for more detailed information. #pg_statsinfo.adjust_log_level = off # Enables or disables log level altering feature. #pg_statsinfo.adjust_log_log = '' #pg_statsinfo.adjust_log_info = '' #pg_statsinfo.adjust_log_notice = '' #pg_statsinfo.adjust_log_warning = '' #pg_statsinfo.adjust_log_error = '' #pg_statsinfo.adjust_log_fatal = '' # Change loglevel into LOG/INFO/NOTICE/WARNING/ERROR/FATAL # for logged entries with SQLSTATEs listed here. (*5) #pg_statsinfo.controlfile_fsync_interval = 1min # Interval to sync pg_statsinfo's control file. pg_statsinfo.enable_maintenance = 'on' # Enable or disable auto maintenance features. Multiple # items should be comma separated. # 'snapshot': Enables only snapshot maintenance. # 'repolog': Enables only repository log maintenance. # 'log': Enables only log file maintenance. # 'snapshot, log': Enables both snapshot and log file # maintenance. # 'on': Enables all maintenance features. # 'off': Disables everything. #pg_statsinfo.excluded_dbnames = 'template0,template1' # Exclude databases listed here from monitoring. #pg_statsinfo.excluded_schemas = 'pg_catalog,pg_toast,information_schema' # Exclude schemas listed here from monitoring. #pg_statsinfo.log_maintenance_command = 'archive_pglog.sh %l' # Command path to be executed to do log file maintenance. # Default value is a ready-made shell script which archives # old log files into compressed files then removes them. #pg_statsinfo.long_lock_threshold = 30s # Time to wait before record prolonged locks. #pg_statsinfo.long_transaction_max = 10s # Sets the max collection size of long transaction. pg_statsinfo.maintenance_time = '00:02:00' # Time to do automatic maintenance. #pg_statsinfo.repolog_buffer = 10000 # Since repository logs are sent to repository every 10 # seconds by default, pg_statsinfo needs to buffer logs for # the intervals. Additionaly, this buffer is expected to # absorb a transient burst of log entries which might # retard storing them. Log entries which are run over this # buffer are simply dropped off. #pg_statsinfo.repolog_interval = 10s # Repository logs are written at intervals of this value. pg_statsinfo.repolog_keepday = 7 # Repository logs are preserved for this period. #pg_statsinfo.repolog_min_messages = warning # Minimum message levels for repository log. (*1) #pg_statsinfo.repolog_nologging_users = '' # Exclude log lines of these users separated by commas from # repository log. pg_statsinfo.repository_keepday = 7 # Snapshots are preserved for this period. #pg_statsinfo.repository_server = 'dbname=postgres port=5432' # Connection string to connect the repository. (*4) # Password prompt must be avoided. #pg_statsinfo.sampling_interval = 5s # Sampling is a process collecting some additional # informations such like session states several times for # a snapshot interval. This value should be a fraction of # snapshot interval. (*3) pg_statsinfo.snapshot_interval = 30min # snapshot interval (*3) #pg_statsinfo.stat_statements_max = 30 # Maximum number of entries of pg_stat_statements to be # recorded for every snapshot. #pg_statsinfo.stat_statements_exclude_users = '' # Exclude queries of these users separated by commas from # snapshots. pg_statsinfo.syslog_line_prefix = '%t %p %c-%l %x %q(%u, %d, %r, %a) ' # A printf-style string that is output at the beginning of # each syslog line. (*2) Note that timestamp and process ID # in syslog are them of pg_statsinfo daemon, not of # original ones. You need to add %t and %p to preserve the # original values. pg_statsinfo.syslog_min_messages = error # Minimum message level for syslog. (*1) #pg_statsinfo.textlog_filename = 'pg_statsinfo.log' # Textlog filename. Should not be empty. pg_statsinfo.textlog_line_prefix = '%t %p %c-%l %x %q(%u, %d, %r, %a) ' # A printf-style string that is output at the beginning of # each textlog line. (*2) #pg_statsinfo.textlog_min_messages = warning # Minimum message level for textlog. (*1) #pg_statsinfo.textlog_nologging_users = '' # Exclude log lines of these users separated by commas from # text log. #pg_statsinfo.textlog_permission = 0600 # Permission mode for textlog file. #pg_statsinfo.enable_alert = on # Off disables all alerts for this instance. #pg_statsinfo.target_server = '' # Connection string for the observed instance. (*4) #pg_hint_plan.enable_hint = on # Force planner to use plans specified in the hint comment # preceding to the query. #pg_hint_plan.debug_print = off # Logs results of hint parsing. #pg_hint_plan.parse_messages = info # Message level of parse errors. #pg_hint_plan.message_level = info # Message level of debug messages. #pg_hint_plan.enable_hint_table = false # Force planner to not get hint by using table lookups. pgpool.pg_ctl = '/home/bylee/install/agensgraph/bin/agens'data2/recovery.conf 내용
standby_mode = on primary_conninfo = 'host=127.0.0.1 port=7432 user=bylee password=bylee' trigger_file = '/home/bylee/install/pgpool2-4_0_1/data2/trigger'위 내용에서 user=bylee, password=bylee는 replicator에 대한 내용이다. 여기서는 간단히 테스트하기 위해 db root 계정을 사용한다.
pgpool-II의 pgpool.conf 내용
# ---------------------------- # 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 = 'localhost' # Host name or IP address to listen on: # '*' for all, '' for no TCP/IP connections # (change requires restart) port = 9999 # Port number # (change requires restart) socket_dir = '/tmp' # Unix domain socket path # The Debian package defaults to # /var/run/postgresql # (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 = 9898 # Port number for pcp # (change requires restart) pcp_socket_dir = '/tmp' # 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 = 'localhost' # Host name or IP address to connect to for backend 0 backend_port0 = 7432 # Port number for backend 0 backend_weight0 = 1 # Weight for backend 0 (only in load balancing mode) backend_data_directory0 = '/home/bylee/install/pgpool2-4_0_1/data1' # Data directory for backend 0 backend_flag0 = 'ALLOW_TO_FAILOVER' # Controls various backend behavior # ALLOW_TO_FAILOVER, DISALLOW_TO_FAILOVER # or ALWAYS_MASTER backend_hostname1 = 'localhost' backend_port1 = 7433 backend_weight1 = 1 backend_data_directory1 = '/home/bylee/install/pgpool2-4_0_1/data2' backend_flag1 = 'ALLOW_TO_FAILOVER' # - 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 = 60 # 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' # 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 = 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 = 300 # 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 = 0 # Connection to backend closes after being idle for this many seconds # 0 means no close client_idle_limit = 0 # Client is disconnected after being idle for that many seconds # (even inside an explicit transactions!) # 0 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_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 #------------------------------------------------------------------------------ # FILE LOCATIONS #------------------------------------------------------------------------------ pid_file_name = '/home/bylee/install/pgpool2-4_0_1/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 = '/home/bylee/install/pgpool2-4_0_1/tmp' # 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 = on # 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 white_function_list = '' # Comma separated list of function names # that don't write to database # Regexp are accepted black_function_list = 'currval,lastval,nextval,setval' # Comma separated list of function names # that write to database # Regexp are accepted black_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. # Note that any query not in an explicit transaction # is not affected by the parameter. # 'transaction' (the 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. # 'always': if a write query is issued, read queries will # not be load balanced until the session ends. #------------------------------------------------------------------------------ # MASTER/SLAVE MODE #------------------------------------------------------------------------------ master_slave_mode = on # 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 = 0 # Streaming replication check period # Disabled (0) by default sr_check_user = 'bylee' # Streaming replication check user # This is neccessary even if you disable streaming # replication delay check by sr_check_period = 0 sr_check_password = 'bylee' # 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 = 0 # Threshold before not dispatching query to standby node # Unit is in bytes # Disabled (0) 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 = 5 # Health check period # Disabled (0) by default health_check_timeout = 20 # Health check timeout # 0 means no timeout health_check_user = 'bylee' # Health check user health_check_password = 'bylee' # 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 = 'postgres' # 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) #------------------------------------------------------------------------------ #health_check_period0 = 0 #health_check_timeout0 = 20 #health_check_user0 = 'nobody' #health_check_password0 = '' #health_check_database0 = '' #health_check_max_retries0 = 0 #health_check_retry_delay0 = 1 #connect_timeout0 = 10000 #------------------------------------------------------------------------------ # FAILOVER AND FAILBACK #------------------------------------------------------------------------------ failover_command = '/home/bylee/install/pgpool2-4_0_1/failover.sh %d %P %H %R' #failover_command = '' # 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 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 = 300 # 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 #------------------------------------------------------------------------------ # 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 = 9000 # port number for watchdog service # (change requires restart) 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 = '/tmp' # 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 = 10 # lifecheck interval (sec) > 0 # (change requires restart) # -- heartbeat mode -- wd_heartbeat_port = 9694 # Port number for receiving heartbeat signal # (change requires restart) 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) heartbeat_destination0 = 'localhost' # Host name or IP address of destination 0 # for sending heartbeat signal. # (change requires restart) heartbeat_destination_port0 = 9694 # Port number of destination 0 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 0. # This works only when this is not empty # and pgpool has root privilege. # (change requires restart) #heartbeat_destination1 = 'host0_ip2' #heartbeat_destination_port1 = 9694 #heartbeat_device1 = '' # -- 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) # - Other pgpool Connection Settings - other_pgpool_hostname0 = 'localhost' # Host name or IP address to connect to for other pgpool 0 # (change requires restart) other_pgpool_port0 = 9999 # Port number for other pgpool 0 # (change requires restart) other_wd_port0 = 9000 # Port number for other watchdog 0 # (change requires restart) #other_pgpool_hostname1 = 'host1' #other_pgpool_port1 = 5432 #other_wd_port1 = 9000 #------------------------------------------------------------------------------ # 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 = 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 = 11211 # Memcached port number. Mondatory if memqcache_method = 'memcached'. # Defaults to 11211. # (change requires restart) memqcache_total_size = 67108864 # 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 = 409600 # Maximum SELECT result size in bytes. # Must be smaller than memqcache_cache_block_size. Defaults to 400KB. # (change requires restart) memqcache_cache_block_size = 1048576 # 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 accepted위 내용에서 failover_command에는 failover.sh 파일의 경로를 지정한다.
failover.sh 파일 내용
#! /bin/sh -x # Execute command by failover. # special values: %d = node id # %h = host name # %p = port number # %D = database cluster path # %m = new master node id # %M = old master node id # %H = new master node host name # %P = old primary node id # %R = new master database cluster path # %r = new master port number # %% = '%' character falling_node=$1 # %d old_primary=$2 # %P new_primary=$3 # %H pgdata=$4 # %R pghome=/home/bylee/install/agensgraph log=failover.log date >> $log echo "failed_node_id=$falling_node new_primary=$new_primary" >> $log if [ $falling_node = $old_primary ]; then $pghome/bin/ag_ctl promote -D $pgdata exit 0; fi; exit 0;pgpool-II 구성 확인
[bylee@bylee5 pgpool2-4_0_1]$ agens -p 9999 -d postgres agens (AgensGraph 1.4devel, based on PostgreSQL 10.3) Type "help" for help. postgres=# show pool_nodes; node_id | hostname | port | status | lb_weight | role | select_cnt | load_balance_node | replication_delay | last_status_change ---------+-----------+------+--------+-----------+---------+------------+-------------------+-------------------+--------------------- 0 | localhost | 7432 | up | 0.500000 | primary | 0 | true | 0 | 2018-11-21 13:48:28 1 | localhost | 7433 | up | 0.500000 | standby | 0 | false | 0 | 2018-11-21 13:48:28 (2 rows)data1 stop
[bylee@bylee5 pgpool2-4_0_1]$ ag_ctl -D data1 stop waiting for server to shut down.... done server stoppedfailover 확인
[bylee@bylee5 pgpool2-4_0_1]$ agens -p 9999 -d postgres agens (AgensGraph 1.4devel, based on PostgreSQL 10.3) Type "help" for help. postgres=# show pool_nodes; node_id | hostname | port | status | lb_weight | role | select_cnt | load_balance_node | replication_delay | last_status_change ---------+-----------+------+--------+-----------+---------+------------+-------------------+-------------------+--------------------- 0 | localhost | 7432 | down | 0.500000 | standby | 0 | false | 0 | 2018-11-22 09:36:11 1 | localhost | 7433 | up | 0.500000 | primary | 0 | true | 0 | 2018-11-22 09:36:11 (2 rows)위에서 보는 바와 같이 failover가 발생해도 -p 9999 옵션으로 전과 동일하게 접속이 가능하다.
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