Re: postgres 7.4 at 100% - Mailing list pgsql-performance

Hi Richard,
Thanks so much for replying.  Pls see below.
Thanks in advance for any advice,
Chris

> People are going to need more information. Are you talking about
> CPU/disk IO/memory?

## CPU is at 100%.

>
> > My settings are default on both boxes I think.
>
> Doubtful - PG crawls with the default settings. Check your old
> postgresql.conf file and compare. Also, read the tuning article at:
>   http://www.varlena.com/varlena/GeneralBits/Tidbits/index.php
>
> > There are only about 20 inserts per second, which is really low.
> > Anyone have any ideas as to something I have to do to Postgres 7.4 to
> > change it from the default so that it's not eating up all my CPU?  I
> > have no clue how to debug this...
>
> What does top/vmstat/iostat show during heavy usage?
>
TOP:

137 processes: 135 sleeping, 2 running, 0 zombie, 0 stopped
CPU states:  81.4% user  17.9% system   0.0% nice   0.0% iowait   0.5% idle
Mem:   507036k av,  500244k used,    6792k free,       0k shrd,   68024k buff
       133072k active,             277368k inactive
Swap:  787176k av,   98924k used,  688252k free                  232500k cached

  PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME CPU COMMAND
20734 postgres  15   0  4028 4028  3244 R    83.6  0.7 348:03   0 postmaster
21249 numnet     9   0 78060  76M  8440 S     7.5 15.3  32:51   0 myapp
18478 user     12   0  1224 1224   884 S     5.7  0.2  57:01   0 top

[root@live root]# vmstat
   procs                      memory      swap          io     system      cpu
 r  b  w   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy id
 1  0  0  98924   5980  68024 233528    4    3     6    22   28    10 13  6 24

iostat:
Time: 03:18:18 AM
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
dev3-0           11.00         0.80       142.40          4        712

Time: 03:18:23 AM
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
dev3-0           10.60         0.00       143.20          0        716

or blocks:

Time: 03:20:58 AM
Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
dev3-0           25.40         3.20       756.80         16       3784

Time: 03:21:03 AM
Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
dev3-0           30.20         3.20       841.60         16       4208

extended:

Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s
avgrq-sz avgqu-sz   await  svctm  %util
/dev/hda3    0.00  79.20  0.60 30.60    4.80  878.40     2.40   439.20
   28.31     0.36    1.15   0.45   1.40

avg-cpu:  %user   %nice    %sys   %idle
          31.00    0.00   18.20   50.80

Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s
avgrq-sz avgqu-sz   await  svctm  %util
/dev/hda3    0.00  45.80  0.00 10.80    0.00  452.80     0.00   226.40
   41.93     0.08    0.74   0.37   0.40

avg-cpu:  %user   %nice    %sys   %idle
          83.20    0.00   16.60    0.20

Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s
avgrq-sz avgqu-sz   await  svctm  %util
/dev/hda     0.00  28.20  0.00 10.10    0.00  315.20     0.00   157.60
   31.21 4294917.33    0.30  99.01 100.00
/dev/hda1    0.00   0.00  0.00  0.00    0.00    0.00     0.00     0.00
    0.00     0.00    0.00   0.00   0.00
/dev/hda2    0.00   0.00  0.00  0.00    0.00    0.00     0.00     0.00
    0.00     0.00    0.00   0.00   0.00
/dev/hda3    0.00  28.20  0.00 10.10    0.00  315.20     0.00   157.60
   31.21     0.03    0.30   0.20   0.20

My conf file:

[root@live setup]# cat /var/lib/pgsql/data/postgresql.conf
# -----------------------------
# 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 = 20
        # 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 -

shared_buffers = 40             # min 16, at least max_connections*2, 8KB each
#sort_mem = 1024                # min 64, size in KB
#vacuum_mem = 8192              # min 1024, size in KB

# - Free Space Map -

#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 = true                   # turns forced synchronization on or off
#wal_sync_method = fsync        # the default varies across platforms:
                                # fsync, fdatasync, open_sync, or open_datasync
#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 = 0               # range 0-100000, in microseconds
#commit_siblings = 5            # range 1-1000


#---------------------------------------------------------------------------
# QUERY TUNING
#---------------------------------------------------------------------------

# - Planner Method Enabling -

#enable_hashagg = true
#enable_hashjoin = true
#enable_indexscan = true
#enable_mergejoin = true
#enable_nestloop = true
#enable_seqscan = true
#enable_sort = true
#enable_tidscan = true

# - Planner Cost Constants -

#effective_cache_size = 1000    # 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 = true
#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 = 0                      # range 0-2; 0=stdout; 1=both; 2=syslog
syslog_facility = 'LOCAL0'
syslog_ident = 'postgres'

# - When to Log -

client_min_messages = warning   # Values, in order of decreasing detail:
                                #   debug5, debug4, debug3, debug2, debug1,
                                #   log, info, 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_error_verbosity = default   # terse, default, or verbose messages

log_min_error_statement = warning # 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 = false
#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 = 0          # 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