th-pg-config=/path/to/pg_config/gems/pg-0.18.1/sample/pg_statistics.rb
#!/usr/bin/env ruby
# vim: set noet nosta sw=4 ts=4 :
#
# PostgreSQL statistic gatherer.
# Mahlon E. Smith <mahlon@martini.nu>
#
# Based on queries by Kenny Gorman.
# http://www.kennygorman.com/wordpress/?page_id=491
#
# An example gnuplot input script is included in the __END__ block
# of this script. Using it, you can feed the output this script
# generates to gnuplot (after removing header lines) to generate
# some nice performance charts.
#
begin
require 'ostruct'
require 'optparse'
require 'etc'
require 'pg'
rescue LoadError # 1.8 support
unless Object.const_defined?( :Gem )
require 'rubygems'
retry
end
raise
end
### PostgreSQL Stats. Fetch information from pg_stat_* tables.
### Optionally run in a continuous loop, displaying deltas.
###
class Stats
VERSION = %q$Id: pg_statistics.rb,v 36ca5b412583 2012/04/17 23:32:25 mahlon $
def initialize( opts )
@opts = opts
@db = PG.connect(
:dbname => opts.database,
:host => opts.host,
:port => opts.port,
:user => opts.user,
:password => opts.pass,
:sslmode => 'prefer'
)
@last = nil
end
######
public
######
### Primary loop. Gather statistics and generate deltas.
###
def run
run_count = 0
loop do
current_stat = self.get_stats
# First run, store and continue
#
if @last.nil?
@last = current_stat
sleep @opts.interval
next
end
# headers
#
if run_count == 0 || run_count % 50 == 0
puts "%-20s%12s%12s%12s%12s%12s%12s%12s%12s%12s%12s%12s%12s%12s%12s" % %w[
time commits rollbks blksrd blkshit bkends seqscan
seqtprd idxscn idxtrd ins upd del locks activeq
]
end
# calculate deltas
#
delta = current_stat.inject({}) do |h, pair|
stat, val = *pair
if %w[ activeq locks bkends ].include?( stat )
h[stat] = current_stat[stat].to_i
else
h[stat] = current_stat[stat].to_i - @last[stat].to_i
end
h
end
delta[ 'time' ] = Time.now.strftime('%F %T')
# new values
#
puts "%-20s%12s%12s%12s%12s%12s%12s%12s%12s%12s%12s%12s%12s%12s%12s" % [
delta['time'], delta['commits'], delta['rollbks'], delta['blksrd'],
delta['blkshit'], delta['bkends'], delta['seqscan'],
delta['seqtprd'], delta['idxscn'], delta['idxtrd'],
delta['ins'], delta['upd'], delta['del'], delta['locks'], delta['activeq']
]
@last = current_stat
run_count += 1
sleep @opts.interval
end
end
### Query the database for performance measurements. Returns a hash.
###
def get_stats
res = @db.exec %Q{
SELECT
MAX(stat_db.xact_commit) AS commits,
MAX(stat_db.xact_rollback) AS rollbks,
MAX(stat_db.blks_read) AS blksrd,
MAX(stat_db.blks_hit) AS blkshit,
MAX(stat_db.numbackends) AS bkends,
SUM(stat_tables.seq_scan) AS seqscan,
SUM(stat_tables.seq_tup_read) AS seqtprd,
SUM(stat_tables.idx_scan) AS idxscn,
SUM(stat_tables.idx_tup_fetch) AS idxtrd,
SUM(stat_tables.n_tup_ins) AS ins,
SUM(stat_tables.n_tup_upd) AS upd,
SUM(stat_tables.n_tup_del) AS del,
MAX(stat_locks.locks) AS locks,
MAX(activity.sess) AS activeq
FROM
pg_stat_database AS stat_db,
pg_stat_user_tables AS stat_tables,
(SELECT COUNT(*) AS locks FROM pg_locks ) AS stat_locks,
(SELECT COUNT(*) AS sess FROM pg_stat_activity WHERE current_query <> '<IDLE>') AS activity
WHERE
stat_db.datname = '%s';
} % [ @opts.database ]
return res[0]
end
end
### Parse command line arguments. Return a struct of global options.
###
def parse_args( args )
options = OpenStruct.new
options.database = Etc.getpwuid( Process.uid ).name
options.host = '127.0.0.1'
options.port = 5432
options.user = Etc.getpwuid( Process.uid ).name
options.sslmode = 'disable'
options.interval = 5
opts = OptionParser.new do |opts|
opts.banner = "Usage: #{$0} [options]"
opts.separator ''
opts.separator 'Connection options:'
opts.on( '-d', '--database DBNAME',
"specify the database to connect to (default: \"#{options.database}\")" ) do |db|
options.database = db
end
opts.on( '-h', '--host HOSTNAME', 'database server host' ) do |host|
options.host = host
end
opts.on( '-p', '--port PORT', Integer,
"database server port (default: \"#{options.port}\")" ) do |port|
options.port = port
end
opts.on( '-U', '--user NAME',
"database user name (default: \"#{options.user}\")" ) do |user|
options.user = user
end
opts.on( '-W', 'force password prompt' ) do |pw|
print 'Password: '
begin
system 'stty -echo'
options.pass = gets.chomp
ensure
system 'stty echo'
puts
end
end
opts.separator ''
opts.separator 'Other options:'
opts.on( '-i', '--interval SECONDS', Integer,
"refresh interval in seconds (default: \"#{options.interval}\")") do |seconds|
options.interval = seconds
end
opts.on_tail( '--help', 'show this help, then exit' ) do
$stderr.puts opts
exit
end
opts.on_tail( '--version', 'output version information, then exit' ) do
puts Stats::VERSION
exit
end
end
opts.parse!( args )
return options
end
### Go!
###
if __FILE__ == $0
$stdout.sync = true
Stats.new( parse_args( ARGV ) ).run
end
__END__
######################################################################
### T E R M I N A L O P T I O N S
######################################################################
#set terminal png nocrop enhanced font arial 8 size '800x600' x000000 xffffff x444444
#set output 'graph.png'
set terminal pdf linewidth 4 size 11,8
set output 'graph.pdf'
#set terminal aqua
######################################################################
### O P T I O N S F O R A L L G R A P H S
######################################################################
set multiplot layout 2,1 title "PostgreSQL Statistics\n5 second sample rate (smoothed)"
set grid x y
set key right vertical outside
set key nobox
set xdata time
set timefmt "%Y-%m-%d.%H:%M:%S"
set format x "%l%p"
set xtic rotate by -45
input_file = "database_stats.txt"
# edit to taste!
set xrange ["2012-04-16.00:00:00":"2012-04-17.00:00:00"]
######################################################################
### G R A P H 1
######################################################################
set title "Database Operations and Connection Totals"
set yrange [0:200]
plot \
input_file using 1:2 title "Commits" with lines smooth bezier, \
input_file using 1:3 title "Rollbacks" with lines smooth bezier, \
input_file using 1:11 title "Inserts" with lines smooth bezier, \
input_file using 1:12 title "Updates" with lines smooth bezier, \
input_file using 1:13 title "Deletes" with lines smooth bezier, \
input_file using 1:6 title "Backends (total)" with lines, \
input_file using 1:15 title "Active queries (total)" with lines smooth bezier
######################################################################
### G R A P H 2
######################################################################
set title "Backend Performance"
set yrange [0:10000]
plot \
input_file using 1:4 title "Block (cache) reads" with lines smooth bezier, \
input_file using 1:5 title "Block (cache) hits" with lines smooth bezier, \
input_file using 1:7 title "Sequence scans" with lines smooth bezier, \
input_file using 1:8 title "Sequence tuple reads" with lines smooth bezier, \
input_file using 1:9 title "Index scans" with lines smooth bezier, \
input_file using 1:10 title "Index tuple reads" with lines smooth bezier
######################################################################
### C L E A N U P
######################################################################
unset multiplot
reset