System Load analyze - Mailing list pgsql-general

From Peter Bauer
Subject System Load analyze
Date
Msg-id 47485816.4050702@apus.co.at
Whole thread Raw
Responses Re: System Load analyze  ("Scott Marlowe" <scott.marlowe@gmail.com>)
Re: System Load analyze  (Greg Smith <gsmith@gregsmith.com>)
List pgsql-general
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

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