Hi all,
i have a system here with 2 2.4GHz Xeon Processors, 2GB RAM, ONE Disk on
a Battery Backed Write Cache SCSI Controller and PostgreSQL 8.1.4
running with the data on a DRBD Device for High Availability. The used
database is also replicated to two similar machines with slony1.
Since the load average is between 1 (most of the time) and 10 (peeks) i
am worried about the load and executed vmstat and iostat which show that
1000-6000 Blocks are writen per second. Please check the attached output
for further details.
top shows that the CPUs are at least 80% idle most of the time so i
think there is an I/O bottleneck. I'm aware that this hardware setup is
probably not sufficient but is would like to investigate how critical
the situation is.
thanks,
Peter
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
0 0 398256 78328 140612 1063556 0 0 0 1472 2029 5081 4 3 92 0
0 2 398256 78268 140612 1063576 0 0 0 2304 1928 4216 0 2 98 0
1 2 398256 78100 140612 1063576 0 0 0 1464 1716 3994 1 3 96 0
0 0 398256 78704 140612 1063592 0 0 0 916 1435 3570 5 3 91 0
0 0 398256 77876 140612 1063616 0 0 0 0 305 1169 3 1 96 0
0 1 398256 79200 140612 1063628 0 0 0 2404 2787 6555 7 6 86 0
0 2 398256 79256 140612 1063660 0 0 0 1564 1640 3577 4 2 94 0
0 0 398256 79324 140612 1063692 0 0 0 1660 2322 5615 5 2 93 0
0 0 398256 78668 140612 1063724 0 0 0 1048 1390 4197 16 13 72 0
1 0 398256 79344 140612 1063748 0 0 0 1896 2416 5675 5 5 89 0
0 0 398256 79336 140612 1063784 0 0 0 1176 1720 4436 5 3 92 0
1 2 398256 79280 140612 1063812 0 0 0 1800 1697 3931 3 3 94 0
0 1 398256 79048 140612 1063832 0 0 0 1384 1733 4137 4 2 93 0
0 1 398256 78792 140612 1063868 0 0 0 1672 2163 5241 3 2 94 0
0 0 398256 77608 140612 1063880 0 0 0 1088 1638 3484 4 2 93 0
0 0 398256 79108 140612 1063884 0 0 0 1568 2103 5382 7 5 88 0
0 0 398256 79100 140612 1063892 0 0 0 1556 1394 3135 2 1 97 0
0 2 398256 79084 140612 1063900 0 0 0 1644 2072 4953 2 0 97 0
0 0 398256 79060 140612 1063932 0 0 0 1240 1714 3888 5 2 92 0
0 2 398256 79032 140612 1063940 0 0 0 1328 1694 4135 4 2 94 0
0 1 398256 78452 140612 1063944 0 0 0 620 925 2824 6 7 87 0
0 0 398256 79036 140612 1063956 0 0 0 1196 1293 2954 6 7 87 0
0 2 398256 79136 140612 1063964 0 0 0 1736 1959 4494 4 2 94 0
0 0 398256 79132 140612 1063964 0 0 0 4 260 1039 1 1 98 0
0 0 398256 79052 140612 1063980 0 0 0 2444 3084 6955 6 5 89 0
0 2 398256 79060 140612 1063988 0 0 0 948 1146 3616 3 1 96 0
0 1 398256 78268 140612 1064056 0 0 0 1908 1809 4086 6 5 88 0
0 1 398256 76728 140612 1064056 0 0 0 6256 6637 15472 5 5 90 0
0 2 398256 77000 140612 1064064 0 0 0 4916 5840 12107 1 4 95 0
0 2 398256 76956 140612 1064068 0 0 0 6468 7432 15211 1 3 96 0
0 6 398256 77388 140612 1064072 0 0 0 8116 7826 18265 1 8 91 0
0 2 398256 74312 140612 1064076 0 0 0 7032 6886 16136 2 7 91 0
0 2 398256 74264 140612 1064076 0 0 0 5680 7143 13411 0 5 95 0
0 2 398256 72980 140612 1064140 0 0 0 5396 6377 13251 6 6 88 0
0 3 398256 76972 140612 1064148 0 0 0 5652 6793 14079 4 9 87 0
0 2 398256 77836 140612 1064148 0 0 0 3968 5321 14187 10 8 82 0
1 0 398256 77280 140612 1064148 0 0 0 1608 3188 8974 21 12 67 0
1 0 398256 77832 140612 1064152 0 0 0 236 834 2625 7 5 87 0
0 0 398256 77464 140612 1064152 0 0 0 244 505 1378 2 4 94 0
1 0 398256 77828 140612 1064164 0 0 0 316 580 1954 7 2 91 0
0 0 398256 77804 140612 1064180 0 0 0 740 673 2248 2 2 96 0
0 0 398256 77000 140612 1064180 0 0 0 304 589 1739 1 3 96 0
0 0 398256 77000 140612 1064184 0 0 0 0 216 886 0 1 99 0
0 0 398256 75452 140612 1064184 0 0 0 432 755 2032 6 1 93 0
0 0 398256 76964 140616 1064200 0 0 0 1980 2722 6452 7 2 91 0
0 0 398256 77040 140616 1064212 0 0 0 1524 1536 3635 5 1 93 0
0 2 398256 77028 140616 1064216 0 0 0 1136 1489 3342 1 2 97 0
0 0 398256 76976 140616 1064236 0 0 0 1392 1831 4468 3 2 94 0
0 0 398256 76944 140616 1064256 0 0 0 932 1374 3318 7 8 85 0
0 0 398256 76856 140616 1064276 0 0 0 1392 1773 3985 5 4 91 0
1 4 398256 76536 140616 1064448 0 0 0 1432 1537 3950 4 2 94 0
0 0 398256 76640 140616 1064308 0 0 0 560 865 2577 6 3 91 0
0 0 398256 76368 140616 1064328 0 0 0 1752 1973 4424 3 3 94 0
0 0 398256 74732 140616 1064340 0 0 0 1244 1807 3758 4 6 90 0
1 2 398256 76244 140616 1064352 0 0 0 876 1189 3579 4 2 94 0
0 0 398256 76192 140616 1064360 0 0 0 1856 1623 3727 5 4 91 0
0 0 398256 76236 140616 1064372 0 0 0 1292 1748 3664 5 4 91 0
0 0 398256 76548 140616 1064392 0 0 0 0 338 1810 11 5 84 0
0 0 398256 76540 140616 1064392 0 0 0 0 278 1055 2 4 93 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 241.00 0.00 6344.00 0 6344
dev8-1 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 39.00 0.00 1240.00 0 1240
dev8-1 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 170.00 0.00 3944.00 0 3944
dev8-1 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 173.00 0.00 3880.00 0 3880
dev8-1 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 73.00 0.00 2656.00 0 2656
dev8-1 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 120.00 0.00 2656.00 0 2656
dev8-1 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 81.00 0.00 2184.00 0 2184
dev8-1 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 133.00 0.00 3144.00 0 3144
dev8-1 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 115.00 0.00 2936.00 0 2936
dev8-1 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 64.00 0.00 2080.00 0 2080
dev8-1 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 176.00 0.00 4384.00 0 4384
dev8-1 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 172.00 0.00 3296.00 0 3296
dev8-1 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 191.00 0.00 3880.00 0 3880
dev8-1 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
dev8-0 144.00 0.00 2464.00 0 2464
dev8-1 0.00 0.00 0.00 0 0
#---------------------------------------------------------------------------
# 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 = '/clstsql/data' # btaf: Data Directory on the drbd device, APUS
#hba_file = 'ConfigDir/pg_hba.conf' # host-based authentication file
#ident_file = 'ConfigDir/pg_ident.conf' # IDENT configuration file
# If external_pid_file is not explicitly set, no extra pid file is written.
#external_pid_file = '(none)' # write an extra pid file
#---------------------------------------------------------------------------
# CONNECTIONS AND AUTHENTICATION
#---------------------------------------------------------------------------
# - Connection Settings -
listen_addresses = '*' # btaf: '*' = Listen to all addresses
port = 5432 # btaf: Use default port for PostgreSQL, APUS
max_connections = 400 # btaf: APUS
# 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 = 2
unix_socket_directory = '/var/run/postgresql'
#unix_socket_group = ''
#unix_socket_permissions = 0777 # octal
#bonjour_name = '' # defaults to the computer name
# - Security & Authentication -
#authentication_timeout = 60 # 1-600, in seconds
ssl = false # btaf: Do not use ssl for connections, APUS
#password_encryption = on
#db_user_namespace = off
# Kerberos
#krb_server_keyfile = ''
#krb_srvname = 'postgres'
#krb_server_hostname = '' # empty string matches any keytab entry
#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 = 40000 # min 16 or max_connections*2, 8KB each, APUS
temp_buffers = 8000 # min 100, 8KB each, APUS
#max_prepared_transactions = 5 # can be 0 or more
# note: increasing max_prepared_transactions costs ~600 bytes of shared memory
# per transaction slot, plus lock space (see max_locks_per_transaction).
work_mem = 20480 # min 64, size in KB, APUS
maintenance_work_mem = 51200 # min 1024, size in KB, APUS
#max_stack_depth = 2048 # min 100, size in KB
# - Free Space Map -
max_fsm_pages = 40000 # min max_fsm_relations*16, 6 bytes each, APUS
#max_fsm_relations = 1000 # min 100, ~70 bytes each
# - Kernel Resource Usage -
#max_files_per_process = 1000 # min 25
#preload_libraries = ''
# - 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 = 100 # 10-10000 milliseconds between rounds, APUS
bgwriter_lru_percent = 2.0 # 0-100% of LRU buffers scanned/round, APUS
bgwriter_lru_maxpages = 10 # 0-1000 buffers max written/round, APUS
bgwriter_all_percent = 1 # 0-100% of all buffers scanned/round, APUS
bgwriter_all_maxpages = 10 # 0-1000 buffers max written/round, APUS
#---------------------------------------------------------------------------
# WRITE AHEAD LOG
#---------------------------------------------------------------------------
# - Settings -
#fsync = on # 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 = 8 # min 4, 8KB each
#commit_delay = 0 # range 0-100000, in microseconds
#commit_siblings = 5 # range 1-1000
# - Checkpoints -
checkpoint_segments = 32 # in logfile segments, min 1, 16MB each, APUS
#checkpoint_timeout = 300 # range 30-3600, in seconds
checkpoint_warning = 100 # in seconds, 0 is off, APUS
# - Archiving -
#archive_command = '' # command to use to archive a logfile
# segment
#---------------------------------------------------------------------------
# QUERY TUNING
#---------------------------------------------------------------------------
# - Planner Method Configuration -
#enable_bitmapscan = on
#enable_hashagg = on
#enable_hashjoin = on
#enable_indexscan = on
#enable_mergejoin = on
#enable_nestloop = on
#enable_seqscan = on
#enable_sort = on
#enable_tidscan = on
# - Planner Cost Constants -
effective_cache_size = 89600 # typically 8KB each, APUS
#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 = 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
# - 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
# 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 = 1440 # Automatic rotation of logfiles will
# happen after so many minutes. 0 to
# disable.
#log_rotation_size = 10240 # Automatic rotation of logfiles will
# happen after so many kilobytes of 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 = panic # Values in order of increasing severity:
# debug5
# debug4
# debug3
# debug2
# debug1
# info
# notice
# warning
# error
# panic(off)
log_min_duration_statement = 1000 # -1 is disabled, 0 logs all statements
# and their durations, in milliseconds.
#silent_mode = off # DO NOT USE without syslog or
# redirect_stderr
# - 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 = '[%d %m]' # 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, mod, ddl, all
#log_hostname = off
#---------------------------------------------------------------------------
# RUNTIME STATISTICS
#---------------------------------------------------------------------------
# - Statistics Monitoring -
#log_parser_stats = off
#log_planner_stats = off
#log_executor_stats = off
#log_statement_stats = off
# - Query/Index Statistics Collector -
#stats_start_collector = on
stats_command_string = on
#stats_block_level = off
stats_row_level = on
#stats_reset_on_server_start = off
#---------------------------------------------------------------------------
# AUTOVACUUM PARAMETERS
#---------------------------------------------------------------------------
autovacuum = on # enable autovacuum subprocess?
autovacuum_naptime = 30 # time between autovacuum runs, in secs, APUS
autovacuum_vacuum_threshold = 500 # min # of tuple updates before, APUS
# vacuum
autovacuum_analyze_threshold = 250 # min # of tuple updates before, APUS
# analyze
autovacuum_vacuum_scale_factor = 0.2 # fraction of rel size before, APUS
# vacuum
autovacuum_analyze_scale_factor = 0.1 # fraction of rel size before, APUS
# analyze
#autovacuum_vacuum_cost_delay = -1 # default vacuum cost delay for
# autovac, -1 means use
# vacuum_cost_delay
#autovacuum_vacuum_cost_limit = -1 # default vacuum cost limit for
# autovac, -1 means use
# vacuum_cost_limit
#---------------------------------------------------------------------------
# CLIENT CONNECTION DEFAULTS
#---------------------------------------------------------------------------
# - Statement Behavior -
#search_path = '$user,public' # schema names
#default_tablespace = '' # a tablespace name, '' uses
# the default
#check_function_bodies = on
#default_transaction_isolation = 'read committed'
#default_transaction_read_only = off
statement_timeout = 60000 # 0 is disabled, in milliseconds, APUS
# - Locale and Formatting -
#datestyle = 'iso, mdy'
#timezone = unknown # actually, defaults to TZ
# environment setting
#australian_timezones = off
#extra_float_digits = 0 # min -15, max 2
#client_encoding = sql_ascii # actually, defaults to database
# encoding
# These settings are initialized by initdb -- they might be changed
lc_messages = 'C' # locale for system error message
# strings
lc_monetary = 'C' # locale for monetary formatting
lc_numeric = 'C' # locale for number formatting
lc_time = 'C' # locale for time formatting
# - Other Defaults -
#explain_pretty_print = on
#dynamic_library_path = '$libdir'
#---------------------------------------------------------------------------
# LOCK MANAGEMENT
#---------------------------------------------------------------------------
#deadlock_timeout = 1000 # in milliseconds
#max_locks_per_transaction = 64 # min 10
# note: each lock table slot uses ~220 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 = on # btaf: Add missing FROM clauses to improve compatibility with 7.4.x versions
#backslash_quote = safe_encoding # on, off, or safe_encoding
#default_with_oids = off
#escape_string_warning = 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
---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
