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| require "bundler/inline" | |
| gemfile(true) do | |
| source "https://rubygems.org" | |
| gem "rails", "~> 7.2" | |
| gem "pg" | |
| end | |
| require "active_record" | |
| require "logger" | |
| class ActiveRecord::ConnectionAdapters::ConnectionPool::ConnectionLeasingQueue | |
| private | |
| def internal_poll(timeout) | |
| result = super | |
| result | |
| rescue ActiveRecord::ConnectionTimeoutError => e | |
| puts "\n=== Connection Pool Timeout ===" | |
| puts "\nPool size: #{ActiveRecord::Base.connection_pool.size}" | |
| puts "Checked out connections: #{ActiveRecord::Base.connection_pool.connections.count}" | |
| connection_owners = ActiveRecord::Base.connection_pool.connections.map(&:owner) | |
| puts "\nThread list:" | |
| Thread.list.each_with_index do |t, i| | |
| connection_mark = connection_owners.include?(t) ? "[HAS CONNECTION]" : "[NO CONNECTION]" | |
| connection_mark += "[CURRENT]" if t == Thread.current | |
| connection_mark += "[MAIN]" if t == Thread.main | |
| puts "---- #{connection_mark} : Thread #{i}, status: #{t.status.inspect}, thread_info: #{t.inspect.split(' ', 2)[1].chop}" | |
| end | |
| puts "\nCurrent thread: #{Thread.current.inspect}" | |
| puts "\n=== End Debug Info ===\n" | |
| raise e | |
| end | |
| end | |
| # Configure a very small connection pool | |
| ActiveRecord::Base.establish_connection( | |
| adapter: "postgresql", | |
| database: "playground", # create a database named "playground" in your local PostgreSQL | |
| pool: 2, | |
| checkout_timeout: 2 | |
| ) | |
| ActiveRecord::Base.logger = Logger.new(STDOUT) | |
| # Create a simple table | |
| ActiveRecord::Schema.define do | |
| create_table :shipments, force: true do |t| | |
| t.string :status | |
| end | |
| end | |
| class Shipment < ActiveRecord::Base | |
| end | |
| def dangerous_threads | |
| threads = [] | |
| # We duplicate code to report different lines in the stack trace | |
| threads << Thread.new do | |
| puts "Thread 1 starting..." | |
| ActiveRecord::Base.connection.execute("select pg_sleep(5)") | |
| end | |
| threads << Thread.new do | |
| puts "Thread 2 starting..." | |
| ActiveRecord::Base.connection.execute("select pg_sleep(5)") | |
| end | |
| threads << Thread.new do | |
| puts "Thread 2 starting..." | |
| ActiveRecord::Base.connection.execute("select pg_sleep(5)") | |
| end | |
| threads.each(&:join) | |
| end | |
| puts "Connection pool size: #{ActiveRecord::Base.connection_pool.size}" | |
| puts "Starting threads..." | |
| dangerous_threads |
Author
benoittgt
commented
Feb 26, 2025
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