Class: Stats

Inherits:
Object show all
Defined in:
lib/rubypitaya/app-template/vendor/bundle/ruby/3.1.0/gems/pg-1.4.5/sample/pg_statistics.rb

Overview

PostgreSQL Stats. Fetch information from pg_stat_* tables. Optionally run in a continuous loop, displaying deltas.

Constant Summary collapse

VERSION = 
%q$Id$

Instance Method Summary collapse

Constructor Details

#initialize(opts) ⇒ Stats

Returns a new instance of Stats.



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# File 'lib/rubypitaya/app-template/vendor/bundle/ruby/3.1.0/gems/pg-1.4.5/sample/pg_statistics.rb', line 28

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

Instance Method Details

#get_stats ⇒ Object

Query the database for performance measurements. Returns a hash.



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# File 'lib/rubypitaya/app-template/vendor/bundle/ruby/3.1.0/gems/pg-1.4.5/sample/pg_statistics.rb', line 103

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

#run ⇒ Object

Primary loop. Gather statistics and generate deltas.



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# File 'lib/rubypitaya/app-template/vendor/bundle/ruby/3.1.0/gems/pg-1.4.5/sample/pg_statistics.rb', line 47

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