pgcat/tests/ruby/misc_spec.rb

# frozen_string_literal: true
require_relative 'spec_helper'

describe "Miscellaneous" do
  let(:processes) { Helpers::Pgcat.single_shard_setup("sharded_db", 5) }
  after do
    processes.all_databases.map(&:reset)
    processes.pgcat.shutdown
  end

  context "when adding then removing instance using RELOAD" do
    it "works correctly" do
      admin_conn = PG::connect(processes.pgcat.admin_connection_string)

      current_configs = processes.pgcat.current_config
      correct_count = current_configs["pools"]["sharded_db"]["shards"]["0"]["servers"].count
      expect(admin_conn.async_exec("SHOW DATABASES").count).to eq(correct_count)

      extra_replica = current_configs["pools"]["sharded_db"]["shards"]["0"]["servers"].last.clone
      extra_replica[0] = "127.0.0.1"
      current_configs["pools"]["sharded_db"]["shards"]["0"]["servers"] << extra_replica

      processes.pgcat.update_config(current_configs) # with replica added
      processes.pgcat.reload_config
      correct_count = current_configs["pools"]["sharded_db"]["shards"]["0"]["servers"].count
      expect(admin_conn.async_exec("SHOW DATABASES").count).to eq(correct_count)

      current_configs["pools"]["sharded_db"]["shards"]["0"]["servers"].pop

      processes.pgcat.update_config(current_configs) # with replica removed again
      processes.pgcat.reload_config
      correct_count = current_configs["pools"]["sharded_db"]["shards"]["0"]["servers"].count
      expect(admin_conn.async_exec("SHOW DATABASES").count).to eq(correct_count)
    end
  end

  context "when removing then adding instance back using RELOAD" do
    it "works correctly" do
      admin_conn = PG::connect(processes.pgcat.admin_connection_string)

      current_configs = processes.pgcat.current_config
      correct_count = current_configs["pools"]["sharded_db"]["shards"]["0"]["servers"].count
      expect(admin_conn.async_exec("SHOW DATABASES").count).to eq(correct_count)

      removed_replica = current_configs["pools"]["sharded_db"]["shards"]["0"]["servers"].pop
      processes.pgcat.update_config(current_configs) # with replica removed
      processes.pgcat.reload_config
      correct_count = current_configs["pools"]["sharded_db"]["shards"]["0"]["servers"].count
      expect(admin_conn.async_exec("SHOW DATABASES").count).to eq(correct_count)

      current_configs["pools"]["sharded_db"]["shards"]["0"]["servers"] << removed_replica

      processes.pgcat.update_config(current_configs) # with replica added again
      processes.pgcat.reload_config
      correct_count = current_configs["pools"]["sharded_db"]["shards"]["0"]["servers"].count
      expect(admin_conn.async_exec("SHOW DATABASES").count).to eq(correct_count)
    end
  end

  describe "TCP Keepalives" do
    # Ideally, we should block TCP traffic to the database using
    # iptables to mimic passive (connection is dropped without a RST packet)
    # but we cannot do this in CircleCI because iptables requires NET_ADMIN
    # capability that we cannot enable in CircleCI
    # Toxiproxy won't work either because it does not block keepalives
    # so our best bet is to query the OS keepalive params set on the socket

    context "default settings" do
      it "applies default keepalive settings" do
        # We query ss command to verify that we have correct keepalive values set
        # we can only verify the keepalives_idle parameter but that's good enough
        # example output
        #Recv-Q Send-Q Local Address:Port  Peer Address:Port Process
        #0      0          127.0.0.1:60526    127.0.0.1:18432 timer:(keepalive,1min59sec,0)
        #0      0          127.0.0.1:60664    127.0.0.1:19432 timer:(keepalive,4.123ms,0)

        port_search_criteria = processes.all_databases.map { |d| "dport = :#{d.port}"}.join(" or ")
        results = `ss -t4 state established -o -at '( #{port_search_criteria}  )'`.lines
        results.shift
        results.each { |line| expect(line).to match(/timer:\(keepalive,.*ms,0\)/) }
      end
    end

    context "changed settings" do
      it "applies keepalive settings from config" do
        new_configs = processes.pgcat.current_config

        new_configs["general"]["tcp_keepalives_idle"] = 120
        new_configs["general"]["tcp_keepalives_count"] = 1
        new_configs["general"]["tcp_keepalives_interval"] = 1
        processes.pgcat.update_config(new_configs)
        # We need to kill the old process that was using the default configs
        processes.pgcat.stop
        processes.pgcat.start
        processes.pgcat.wait_until_ready

        port_search_criteria = processes.all_databases.map { |d| "dport = :#{d.port}"}.join(" or ")
        results = `ss -t4 state established -o -at '( #{port_search_criteria}  )'`.lines
        results.shift
        results.each { |line| expect(line).to include("timer:(keepalive,1min") }
      end
    end
  end

  describe "Extended Protocol handling" do
    it "does not send packets that client does not expect during extended protocol sequence" do
      new_configs = processes.pgcat.current_config

      new_configs["general"]["connect_timeout"] = 500
      new_configs["general"]["ban_time"] = 1
      new_configs["general"]["shutdown_timeout"] = 1
      new_configs["pools"]["sharded_db"]["users"]["0"]["pool_size"] = 1

      processes.pgcat.update_config(new_configs)
      processes.pgcat.reload_config

      25.times do
        Thread.new do
          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
          conn.async_exec("SELECT pg_sleep(5)") rescue PG::SystemError
        ensure
          conn&.close
        end
      end

      sleep(0.5)
      conn_under_test = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
      stdout, stderr = with_captured_stdout_stderr do
        15.times do |i|
          conn_under_test.async_exec("SELECT 1") rescue PG::SystemError
          conn_under_test.exec_params("SELECT #{i} + $1", [i]) rescue PG::SystemError
          sleep 1
        end
      end

      raise StandardError, "Libpq got unexpected messages while idle" if stderr.include?("arrived from server while idle")
    end
  end

  describe "Pool recycling after config reload" do
    let(:processes) { Helpers::Pgcat.three_shard_setup("sharded_db", 5) }

    it "should update pools for new clients and clients that are no longer in transaction" do
      server_conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
      server_conn.async_exec("BEGIN")

      # No config change yet, client should set old configs
      current_datebase_from_pg = server_conn.async_exec("SELECT current_database();")[0]["current_database"]
      expect(current_datebase_from_pg).to eq('shard0')

      # Swap shards
      new_config = processes.pgcat.current_config
      shard0 = new_config["pools"]["sharded_db"]["shards"]["0"]
      shard1 = new_config["pools"]["sharded_db"]["shards"]["1"]
      new_config["pools"]["sharded_db"]["shards"]["0"] = shard1
      new_config["pools"]["sharded_db"]["shards"]["1"] = shard0

      # Reload config
      processes.pgcat.update_config(new_config)
      processes.pgcat.reload_config
      sleep 0.5

      # Config changed but transaction is in progress, client should set old configs
      current_datebase_from_pg = server_conn.async_exec("SELECT current_database();")[0]["current_database"]
      expect(current_datebase_from_pg).to eq('shard0')
      server_conn.async_exec("COMMIT")

      # Transaction finished, client should get new configs
      current_datebase_from_pg = server_conn.async_exec("SELECT current_database();")[0]["current_database"]
      expect(current_datebase_from_pg).to eq('shard1')

      # New connection should get new configs
      server_conn.close()
      server_conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
      current_datebase_from_pg = server_conn.async_exec("SELECT current_database();")[0]["current_database"]
      expect(current_datebase_from_pg).to eq('shard1')
    end
  end

  describe "Clients closing connection in the middle of transaction" do
    it "sends a rollback to the server" do
      conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
      conn.async_exec("SET SERVER ROLE to 'primary'")
      conn.async_exec("BEGIN")
      conn.close

      expect(processes.primary.count_query("ROLLBACK")).to eq(1)
    end
  end

  describe "Server version reporting" do
    it "reports correct version for normal and admin databases" do
      server_conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
      expect(server_conn.server_version).not_to eq(0)
      server_conn.close

      admin_conn = PG::connect(processes.pgcat.admin_connection_string)
      expect(admin_conn.server_version).not_to eq(0)
      admin_conn.close
    end
  end

  describe "State clearance" do
    context "session mode" do
      let(:processes) { Helpers::Pgcat.single_shard_setup("sharded_db", 5, "session") }

      it "Clears state before connection checkin" do
        # Both modes of operation should not raise
        # ERROR:  prepared statement "prepared_q" already exists
        15.times do
          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
          conn.async_exec("PREPARE prepared_q (int) AS SELECT $1")
          conn.close
        end

        conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
        initial_value = conn.async_exec("SHOW statement_timeout")[0]["statement_timeout"]
        conn.async_exec("SET statement_timeout to 1000")
        current_value = conn.async_exec("SHOW statement_timeout")[0]["statement_timeout"]
        expect(conn.async_exec("SHOW statement_timeout")[0]["statement_timeout"]).to eq("1s")
        conn.close
      end

      it "Does not send DISCARD ALL unless necessary" do
        10.times do
          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
          conn.async_exec("SET SERVER ROLE to 'primary'")
          conn.async_exec("SELECT 1")
          conn.close
        end

        expect(processes.primary.count_query("DISCARD ALL")).to eq(0)

        10.times do
          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
          conn.async_exec("SET SERVER ROLE to 'primary'")
          conn.async_exec("SELECT 1")
          conn.async_exec("SET statement_timeout to 5000")
          conn.close
        end

        expect(processes.primary.count_query("DISCARD ALL")).to eq(10)
      end
    end

    context "transaction mode" do
      let(:processes) { Helpers::Pgcat.single_shard_setup("sharded_db", 5, "transaction") }
      it "Clears state before connection checkin" do
        # Both modes of operation should not raise
        # ERROR:  prepared statement "prepared_q" already exists
        15.times do
          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
          conn.async_exec("PREPARE prepared_q (int) AS SELECT $1")
          conn.close
        end

        15.times do
          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
          conn.prepare("prepared_q", "SELECT $1")
          conn.close
        end
      end

      it "Does not send DISCARD ALL unless necessary" do
        10.times do
          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
          conn.async_exec("SET SERVER ROLE to 'primary'")
          conn.async_exec("SELECT 1")
          conn.exec_params("SELECT $1", [1])
          conn.close
        end

        expect(processes.primary.count_query("DISCARD ALL")).to eq(0)

        10.times do
          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
          conn.async_exec("SET SERVER ROLE to 'primary'")
          conn.async_exec("SELECT 1")
          conn.async_exec("SET statement_timeout to 5000")
          conn.close
        end

        expect(processes.primary.count_query("DISCARD ALL")).to eq(10)
      end
    end

    context "transaction mode with transactions" do
      let(:processes) { Helpers::Pgcat.single_shard_setup("sharded_db", 5, "transaction") }
      it "Does not clear set statement state when declared in a transaction" do
        10.times do
          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
          conn.async_exec("SET SERVER ROLE to 'primary'")
          conn.async_exec("BEGIN")
          conn.async_exec("SET statement_timeout to 1000")
          conn.async_exec("COMMIT")
          conn.close
        end
        expect(processes.primary.count_query("DISCARD ALL")).to eq(0)

        10.times do
          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
          conn.async_exec("SET SERVER ROLE to 'primary'")
          conn.async_exec("BEGIN")
          conn.async_exec("SET LOCAL statement_timeout to 1000")
          conn.async_exec("COMMIT")
          conn.close
        end
        expect(processes.primary.count_query("DISCARD ALL")).to eq(0)
      end
    end
  end
end