Hello great gurus of performance:
Our 'esteemed' Engr group recently informed a customer that in their testing,
upgrading to 8.2.x improved the performance of our J2EE
application "approximately 20%", so of course, the customer then tasked me
with upgrading them. We dumped their db, removed pgsql, installed the 8.2.4
rpms from postgresql.org, did an initdb, and the pg_restored their data. It's
been about a week now, and the customer is complaining that in their testing,
they are seeing a 30% /decrease/ in general performance. Of course, our Engr
group is being less than responsive, and I have a feeling all they're doing
is googling for answers, so I'm turning to this group for actual
assistance :)
I'd like to start by examining the poistgresql.conf file. Under 7.4.x, we had
spent the better part of their 2 years as a customer tuning and tweaking
setting. I've attached the file that was in place at the time of upgrade. I
did some cursory googling of my own, and quickly realized that enough has
changed in v8 that I'm not comfortable making the exact same modification to
their new config file as some options are new, some have gone away, etc. I've
attached the existing v8 conf file as well.
I'd really like it if someone could assist me in determining which of the v8
options need adjusted to be 'functionally equivalent' to the v7 file. Right
now, my goal is to get the customer back to the previous level of
performance, and only then pursue further optimization. I can provide any and
all information needed, but didn't know what to include initially, so I've
opted to include the minimal :)
The DB server in question does nothing else, is running CentOS 4.5, kernel
2.6.9-55.ELsmp. Hyperthreading is disabled in the BIOS and there are 2 Xeon
3.4Ghz cpus. There is 8Gb of RAM in the machine, and another 8Gb of swap.
Thank you in advance for any and all assistance you can provide.
--
Douglas J Hunley (doug at hunley.homeip.net) - Linux User #174778
http://doug.hunley.homeip.net
Handy Guide to Modern Science:
1. If it's green or it wiggles, it's biology.
2. If it stinks, it's chemistry.
3. If it doesn't work, it's physics.
# -----------------------------
# PostgreSQL configuration file
# -----------------------------
#
# This file consists of lines of the form:
#
# name = value
#
# (The '=' is optional.) White space may be used. Comments are introduced
# with '#' anywhere on a line. The complete list of option names and
# allowed values can be found in the PostgreSQL documentation. The
# commented-out settings shown in this file represent the default values.
#
# Any option can also be given as a command line switch to the
# postmaster, e.g. 'postmaster -c log_connections=on'. Some options
# can be changed at run-time with the 'SET' SQL command.
#
# This file is read on postmaster startup and when the postmaster
# receives a SIGHUP. If you edit the file on a running system, you have
# to SIGHUP the postmaster for the changes to take effect, or use
# "pg_ctl reload".
#---------------------------------------------------------------------------
# CONNECTIONS AND AUTHENTICATION
#---------------------------------------------------------------------------
# - Connection Settings -
tcpip_socket = true
max_connections = 220
# note: increasing max_connections costs about 500 bytes of shared
# memory per connection slot, in addition to costs from shared_buffers
# and max_locks_per_transaction.
#superuser_reserved_connections = 2
#port = 5432
#unix_socket_directory = ''
#unix_socket_group = ''
#unix_socket_permissions = 0777 # octal
#virtual_host = '' # what interface to listen on; defaults to any
#rendezvous_name = '' # defaults to the computer name
# - Security & Authentication -
#authentication_timeout = 60 # 1-600, in seconds
#ssl = false
#password_encryption = true
#krb_server_keyfile = ''
#db_user_namespace = false
#---------------------------------------------------------------------------
# RESOURCE USAGE (except WAL)
#---------------------------------------------------------------------------
# - Memory -
# Needs an actual restart to change!!
shared_buffers = 25000 # min 16, at least max_connections*2, 8KB each
#shared_buffers = 75000 # min 16, at least max_connections*2, 8KB each
#shared_buffers = 200000 # min 16, at least max_connections*2, 8KB each
sort_mem = 15000 # min 64, size in KB
vacuum_mem = 100000 # min 1024, size in KB
#vacuum_mem = 32768 # min 1024, size in KB
# - Free Space Map -
max_fsm_pages = 200000 # min max_fsm_relations*16, 6 bytes each
#max_fsm_pages = 20000 # min max_fsm_relations*16, 6 bytes each
#max_fsm_relations = 1000 # min 100, ~50 bytes each
# - Kernel Resource Usage -
#max_files_per_process = 1000 # min 25
#preload_libraries = ''
#---------------------------------------------------------------------------
# WRITE AHEAD LOG
#---------------------------------------------------------------------------
# - Settings -
fsync = false # turns forced synchronization on or off
#wal_sync_method = fsync # the default varies across platforms:
# fsync, fdatasync, open_sync, or open_datasync
wal_buffers = 4096 # min 4, 8KB each
#wal_buffers = 8 # min 4, 8KB each
# - Checkpoints -
#checkpoint_segments = 3 # in logfile segments, min 1, 16MB each
#checkpoint_timeout = 300 # range 30-3600, in seconds
#checkpoint_warning = 30 # 0 is off, in seconds
commit_delay = 20000 # range 0-100000, in microseconds
commit_siblings = 3 # range 1-1000
#---------------------------------------------------------------------------
# QUERY TUNING
#---------------------------------------------------------------------------
# - Planner Method Enabling -
#enable_hashagg = true
#enable_hashjoin = true
#enable_indexscan = true
enable_mergejoin = false
#enable_nestloop = false
#enable_seqscan = true
#enable_sort = true
#enable_tidscan = true
# - Planner Cost Constants -
# Needs an actual restart to change!!
effective_cache_size = 196608 # typically 8KB each
#effective_cache_size = 68192 # typically 8KB each
#random_page_cost = 4 # units are one sequential page fetch cost
#cpu_tuple_cost = 0.01 # (same)
#cpu_index_tuple_cost = 0.001 # (same)
#cpu_operator_cost = 0.0025 # (same)
# - Genetic Query Optimizer -
geqo = false
#geqo_threshold = 11
#geqo_effort = 1
#geqo_generations = 0
#geqo_pool_size = 0 # default based on tables in statement,
# range 128-1024
#geqo_selection_bias = 2.0 # range 1.5-2.0
# - Other Planner Options -
#default_statistics_target = 10 # range 1-1000
#from_collapse_limit = 8
#join_collapse_limit = 8 # 1 disables collapsing of explicit JOINs
#---------------------------------------------------------------------------
# ERROR REPORTING AND LOGGING
#---------------------------------------------------------------------------
# - Syslog -
#syslog = 2 # range 0-2; 0=stdout; 1=both; 2=syslog
#syslog_facility = 'LOCAL0'
#syslog_ident = 'postgres'
# - When to Log -
#client_min_messages = notice # Values, in order of decreasing detail:
# debug5, debug4, debug3, debug2, debug1,
# log, info, notice, warning, error
#log_min_messages = info # Values, in order of decreasing detail:
# debug5, debug4, debug3, debug2, debug1,
# info, notice, warning, error, log, fatal,
# panic
#log_error_verbosity = default # terse, default, or verbose messages
#log_min_error_statement = panic # Values in order of increasing severity:
# debug5, debug4, debug3, debug2, debug1,
# info, notice, warning, error, panic(off)
#log_min_duration_statement = -1 # Log all statements whose
# execution time exceeds the value, in
# milliseconds. Zero prints all queries.
# Minus-one disables.
#silent_mode = false # DO NOT USE without Syslog!
# - What to Log -
#debug_print_parse = false
#debug_print_rewritten = false
#debug_print_plan = false
#debug_pretty_print = false
#log_connections = false
#log_duration = false
#log_pid = false
#log_statement = false
#log_timestamp = true
#log_hostname = false
#log_source_port = false
#---------------------------------------------------------------------------
# RUNTIME STATISTICS
#---------------------------------------------------------------------------
# - Statistics Monitoring -
#log_parser_stats = false
#log_planner_stats = false
#log_executor_stats = false
#log_statement_stats = false
# - Query/Index Statistics Collector -
#stats_start_collector = true
#stats_command_string = false
#stats_block_level = false
#stats_row_level = false
#stats_reset_on_server_start = true
#---------------------------------------------------------------------------
# CLIENT CONNECTION DEFAULTS
#---------------------------------------------------------------------------
# - Statement Behavior -
#search_path = '$user,public' # schema names
#check_function_bodies = true
#default_transaction_isolation = 'read committed'
#default_transaction_read_only = false
statement_timeout = 300000 # 0 is disabled, in milliseconds
# - Locale and Formatting -
#datestyle = 'iso, mdy'
#timezone = unknown # actually, defaults to TZ environment setting
#australian_timezones = false
#extra_float_digits = 0 # min -15, max 2
#client_encoding = sql_ascii # actually, defaults to database encoding
# These settings are initialized by initdb -- they may be changed
lc_messages = 'en_US.UTF-8' # locale for system error message strings
lc_monetary = 'en_US.UTF-8' # locale for monetary formatting
lc_numeric = 'en_US.UTF-8' # locale for number formatting
lc_time = 'en_US.UTF-8' # locale for time formatting
# - Other Defaults -
#explain_pretty_print = true
#dynamic_library_path = '$libdir'
#max_expr_depth = 10000 # min 10
#---------------------------------------------------------------------------
# LOCK MANAGEMENT
#---------------------------------------------------------------------------
#deadlock_timeout = 1000 # in milliseconds
#max_locks_per_transaction = 64 # min 10, ~260*max_connections bytes each
#---------------------------------------------------------------------------
# VERSION/PLATFORM COMPATIBILITY
#---------------------------------------------------------------------------
# - Previous Postgres Versions -
#add_missing_from = true
#regex_flavor = advanced # advanced, extended, or basic
#sql_inheritance = true
# - Other Platforms & Clients -
#transform_null_equals = false
# -----------------------------
# PostgreSQL configuration file
# -----------------------------
#
# This file consists of lines of the form:
#
# name = value
#
# (The '=' is optional.) White space may be used. Comments are introduced
# with '#' anywhere on a line. The complete list of option names and
# allowed values can be found in the PostgreSQL documentation. The
# commented-out settings shown in this file represent the default values.
#
# Please note that re-commenting a setting is NOT sufficient to revert it
# to the default value, unless you restart the server.
#
# Any option can also be given as a command line switch to the server,
# e.g., 'postgres -c log_connections=on'. Some options can be changed at
# run-time with the 'SET' SQL command.
#
# This file is read on server startup and when the server receives a
# SIGHUP. If you edit the file on a running system, you have to SIGHUP the
# server for the changes to take effect, or use "pg_ctl reload". Some
# settings, which are marked below, require a server shutdown and restart
# to take effect.
#
# Memory units: kB = kilobytes MB = megabytes GB = gigabytes
# Time units: ms = milliseconds s = seconds min = minutes h = hours d = days
#---------------------------------------------------------------------------
# FILE LOCATIONS
#---------------------------------------------------------------------------
# The default values of these variables are driven from the -D command line
# switch 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 = '(none)' # write an extra PID file
# (change requires restart)
#---------------------------------------------------------------------------
# CONNECTIONS AND AUTHENTICATION
#---------------------------------------------------------------------------
# - Connection Settings -
listen_addresses = '*' # what IP address(es) to listen on;
# comma-separated list of addresses;
# defaults to 'localhost', '*' = all
# (change requires restart)
#port = 5432 # (change requires restart)
max_connections = 200 # (change requires restart)
# Note: increasing max_connections costs ~400 bytes of shared memory per
# connection slot, plus lock space (see max_locks_per_transaction). You
# might also need to raise shared_buffers to support more connections.
#superuser_reserved_connections = 3 # (change requires restart)
#unix_socket_directory = '' # (change requires restart)
#unix_socket_group = '' # (change requires restart)
#unix_socket_permissions = 0777 # octal
# (change requires restart)
#bonjour_name = '' # defaults to the computer name
# (change requires restart)
# - Security & Authentication -
#authentication_timeout = 1min # 1s-600s
#ssl = off # (change requires restart)
#password_encryption = on
#db_user_namespace = off
# Kerberos
#krb_server_keyfile = '' # (change requires restart)
#krb_srvname = 'postgres' # (change requires restart)
#krb_server_hostname = '' # empty string matches any keytab entry
# (change requires restart)
#krb_caseins_users = off # (change requires restart)
# - 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 = 32MB # min 128kB or max_connections*16kB
# (change requires restart)
#temp_buffers = 8MB # min 800kB
#max_prepared_transactions = 5 # can be 0 or more
# (change requires restart)
# Note: increasing max_prepared_transactions costs ~600 bytes of shared memory
# per transaction slot, plus lock space (see max_locks_per_transaction).
#work_mem = 1MB # min 64kB
#maintenance_work_mem = 16MB # min 1MB
#max_stack_depth = 2MB # min 100kB
# - Free Space Map -
#max_fsm_pages = 1638400 # min max_fsm_relations*16, 6 bytes each
# (change requires restart)
#max_fsm_relations = 1000 # min 100, ~70 bytes each
# (change requires restart)
# - Kernel Resource Usage -
#max_files_per_process = 1000 # min 25
# (change requires restart)
#shared_preload_libraries = '' # (change requires restart)
# - Cost-Based Vacuum Delay -
#vacuum_cost_delay = 0 # 0-1000 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 # 0-10000 credits
# - Background writer -
#bgwriter_delay = 200ms # 10-10000ms between rounds
#bgwriter_lru_percent = 1.0 # 0-100% of LRU buffers scanned/round
#bgwriter_lru_maxpages = 5 # 0-1000 buffers max written/round
#bgwriter_all_percent = 0.333 # 0-100% of all buffers scanned/round
#bgwriter_all_maxpages = 5 # 0-1000 buffers max written/round
#---------------------------------------------------------------------------
# WRITE AHEAD LOG
#---------------------------------------------------------------------------
# - Settings -
fsync = off # turns forced synchronization on or off
#wal_sync_method = fsync # the default is the first option
# supported by the operating system:
# open_datasync
# fdatasync
# fsync
# fsync_writethrough
# open_sync
#full_page_writes = on # recover from partial page writes
#wal_buffers = 64kB # min 32kB
# (change requires restart)
commit_delay = 20000 # range 0-100000, in microseconds
commit_siblings = 3 # range 1-1000
# - Checkpoints -
#checkpoint_segments = 3 # in logfile segments, min 1, 16MB each
#checkpoint_timeout = 5min # range 30s-1h
#checkpoint_warning = 30s # 0 is off
# - Archiving -
#archive_command = '' # command to use to archive a logfile segment
#archive_timeout = 0 # force a logfile segment switch after this
# many seconds; 0 is off
#---------------------------------------------------------------------------
# QUERY TUNING
#---------------------------------------------------------------------------
# - Planner Method Configuration -
#enable_bitmapscan = on
#enable_hashagg = on
#enable_hashjoin = on
#enable_indexscan = on
enable_mergejoin = off
#enable_nestloop = off
#enable_seqscan = on
#enable_sort = on
#enable_tidscan = on
# - 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
#effective_cache_size = 128MB
# - Genetic Query Optimizer -
geqo = off
#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
# - Other Planner Options -
#default_statistics_target = 10 # range 1-1000
#constraint_exclusion = off
#from_collapse_limit = 8
#join_collapse_limit = 8 # 1 disables collapsing of explicit
# JOINs
#---------------------------------------------------------------------------
# ERROR REPORTING AND LOGGING
#---------------------------------------------------------------------------
# - Where to Log -
#log_destination = 'stderr' # Valid values are combinations of
# stderr, syslog and eventlog,
# depending on platform.
# This is used when logging to stderr:
#redirect_stderr = off # Enable capturing of stderr into log
# files
# (change requires restart)
# These are only used if redirect_stderr is on:
#log_directory = 'pg_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_truncate_on_rotation = off # If on, any existing log file of 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 to
# disable.
#log_rotation_size = 10MB # Automatic rotation of logfiles will
# happen after that much log
# output. 0 to disable.
# These are relevant when logging to syslog:
#syslog_facility = 'LOCAL0'
#syslog_ident = 'postgres'
# - 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 = notice # Values, in order of decreasing detail:
# debug5
# debug4
# debug3
# debug2
# debug1
# info
# notice
# warning
# error
# log
# fatal
# panic
#log_error_verbosity = default # terse, default, or verbose messages
#log_min_error_statement = error # Values in order of increasing severity:
# debug5
# debug4
# debug3
# debug2
# debug1
# info
# notice
# warning
# error
# fatal
# panic (effectively off)
#log_min_duration_statement = -1 # -1 is disabled, 0 logs all statements
# and their durations.
#silent_mode = off # DO NOT USE without syslog or
# redirect_stderr
# (change requires restart)
# - What to Log -
#debug_print_parse = off
#debug_print_rewritten = off
#debug_print_plan = off
#debug_pretty_print = off
#log_connections = off
#log_disconnections = off
#log_duration = off
#log_line_prefix = '' # Special values:
# %u = user name
# %d = database name
# %r = remote host and port
# %h = remote host
# %p = PID
# %t = timestamp (no milliseconds)
# %m = timestamp with milliseconds
# %i = command tag
# %c = session id
# %l = session line number
# %s = session start timestamp
# %x = transaction id
# %q = stop here in non-session
# processes
# %% = '%'
# e.g. '<%u%%%d> '
#log_statement = 'none' # none, ddl, mod, all
#log_hostname = off
#---------------------------------------------------------------------------
# RUNTIME STATISTICS
#---------------------------------------------------------------------------
# - Query/Index Statistics Collector -
#stats_command_string = on
#update_process_title = on
#stats_start_collector = on # needed for block or row stats
# (change requires restart)
#stats_block_level = off
#stats_row_level = off
#stats_reset_on_server_start = off # (change requires restart)
# - Statistics Monitoring -
#log_parser_stats = off
#log_planner_stats = off
#log_executor_stats = off
#log_statement_stats = off
#---------------------------------------------------------------------------
# AUTOVACUUM PARAMETERS
#---------------------------------------------------------------------------
#autovacuum = off # enable autovacuum subprocess?
# 'on' requires stats_start_collector
# and stats_row_level to also be on
#autovacuum_naptime = 1min # time between autovacuum runs
#autovacuum_vacuum_threshold = 500 # min # of tuple updates before
# vacuum
#autovacuum_analyze_threshold = 250 # min # of tuple updates before
# analyze
#autovacuum_vacuum_scale_factor = 0.2 # fraction of rel size before
# vacuum
#autovacuum_analyze_scale_factor = 0.1 # fraction of rel size before
# analyze
#autovacuum_freeze_max_age = 200000000 # maximum XID age before forced vacuum
# (change requires restart)
#autovacuum_vacuum_cost_delay = -1 # default vacuum cost delay for
# autovacuum, -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 = '"$user",public' # schema names
#default_tablespace = '' # a tablespace name, '' uses
# the default
#check_function_bodies = on
#default_transaction_isolation = 'read committed'
#default_transaction_read_only = off
statement_timeout = 300000 # 0 is disabled
#vacuum_freeze_min_age = 100000000
# - Locale and Formatting -
#datestyle = 'iso, mdy'
#timezone = unknown # actually, defaults to TZ
# environment setting
#timezone_abbreviations = 'Default' # select the set of available timezone
# abbreviations. Currently, there are
# Default
# Australia
# India
# However you can also create your own
# file in share/timezonesets/.
#extra_float_digits = 0 # min -15, max 2
#client_encoding = sql_ascii # actually, defaults to database
# encoding
# These settings are initialized by initdb -- they might be changed
#lc_messages = 'C' # locale for system error message
# strings
#lc_monetary = 'C' # locale for monetary formatting
#lc_numeric = 'C' # locale for number formatting
#lc_time = 'C' # locale for time formatting
# - Other Defaults -
#explain_pretty_print = on
#dynamic_library_path = '$libdir'
#local_preload_libraries = ''
#---------------------------------------------------------------------------
# LOCK MANAGEMENT
#---------------------------------------------------------------------------
#deadlock_timeout = 1s
#max_locks_per_transaction = 64 # min 10
# (change requires restart)
# Note: each lock table slot uses ~270 bytes of shared memory, and there are
# max_locks_per_transaction * (max_connections + max_prepared_transactions)
# lock table slots.
#---------------------------------------------------------------------------
# VERSION/PLATFORM COMPATIBILITY
#---------------------------------------------------------------------------
# - Previous Postgres Versions -
#add_missing_from = off
#array_nulls = on
#backslash_quote = safe_encoding # on, off, or safe_encoding
#default_with_oids = off
#escape_string_warning = on
#standard_conforming_strings = off
#regex_flavor = advanced # advanced, extended, or basic
#sql_inheritance = on
# - Other Platforms & Clients -
#transform_null_equals = off
#---------------------------------------------------------------------------
# CUSTOMIZED OPTIONS
#---------------------------------------------------------------------------
#custom_variable_classes = '' # list of custom variable class names
