// < ? php
// auth: Edoceo Inc.
// spec: pg_benchmark.php - automates the running of multiple benchmarking tests for PostgreSQL
// spec: will regenerate the pgbench database every run unless --noinit specified, must reinit after changing $clients
// note: Remember Heisenberg when running the test on the machine your testing

error_reporting(E_ALL);

$opt = isset($argv[1]) ? strval($argv[1]) : null;

$pgbench = '/usr/bin/pgbench';
$pgbench_db = 'pgbench';
$pgconf = '/var/lib/postgresql/data/postgresql.conf';

//putenv('PGHOST=localhost');
//putenv('PGPORT=5432');
putenv('PGUSER=postgres');

// Quick & Dirty Benchmarking
$clients = array(1,5);
$txtions = array(1,5);

// Not as quick, not as dirty
// $clients = array(5,10);
// $txtions = array(5,10,50);

// Very through but long benchmarking
#$clients = array(10,50,100);
#$txtions = array(10,50,100,1000,10000);

$scaling = max($clients); // Remember? at least max number of clients
$samples = 5; // "More testicals means more iron" - Lunch Lady Dorris

$c_c = count($clients);
$c_t = count($txtions);
$c_tests = 0;

$t0 = time();

// This displays some settings from the system
$buf = file_get_contents('/proc/sys/kernel/shmmax');
echo "Shared Memory Max is ".number_format($buf/1024/1024,2)."Mb\n";
$buf = `/usr/bin/ipcs -m`;
if (preg_match('/ postgres\s+600\s+(\d+)\s+(\d+) /',$buf,$m)) echo "PostgreSQL is using ".number_format($m[1]/1024/1024,2)."Mb\n";

if ($opt == '--noinit')
{
  echo "Initializing Benchmark Database ($pgbench_db) for scaling factor $scaling\n";
  unset($cmd,$out,$ret);
  $cmd = "$pgbench -i $pgbench_db -s $scaling 2>&1";
  //echo "exec: $cmd\n";
  exec($cmd,$out,$ret);
  if ($ret!=0) die($pgbench.': '.join("\n",$out));
}

// Spin Clients
for ($j=0;$j<$c_c;$j++)
{
  for ($k=0;$k<$c_t;$k++)
  {
    echo 'Testing: '.$clients[$j].' clients with '.$txtions[$k]." transactions ($samples samples)\n";
    $ex_tps=$in_tps=array();
    for ($l=0;$l<$samples;$l++)
    {
      $c_tests++;
      unset($cmd,$out,$ret);
      $cmd = $pgbench.' -c '.$clients[$j].' -t '.$txtions[$k].' '.$pgbench_db.' 2>&1';
      //echo "exec: $cmd\n";
      exec($cmd,$out,$ret);
      if ($ret!=0) die($pgbench.': '.join("\n",$out));
      $buf = join("\n",$out);
      if (preg_match('/tps = ([\d\.]+) \(including connections establishing\)/',$buf,$m))
      {
        $in_tps[] = $m[1];
        //echo "TPS: ".$m[1]."\n";
      }
      if (preg_match('/tps = ([\d\.]+) \(excluding connections establishing\)/',$buf,$m))
      {
        $ex_tps[] = $m[1];
        //echo "CTPS: ".$m[1]."\n";
      }
    }
    //print_r($in_tps);
    //print_r($ex_tps);
    echo "  TPS Min ".min($in_tps)."; Max: ".max($in_tps)."; Avg: ".avg($in_tps)."; Dev: ".dev($in_tps)."\n";
    echo "  CTPS Min: ".min($ex_tps)."; Max: ".max($ex_tps)."; Avg: ".avg($ex_tps)."; Dev: ".dev($ex_tps)."\n";
    /*
    $ex_avg = $ex_tps/$samples;
    $in_avg = $in_tps/$samples;
    echo "TPS: $in_tps/$samples\n";
    echo "CTPS: $ex_tps/$samples\n";
    */
  }
}
$t1 = time();


echo "pg_benchmark executed $c_tests tests in about ".($t1 - $t0)." seconds\n";

function avg($a)
{
  $sum = 0;
  foreach ($a as $x) $sum+=$x;
  return $sum/count($a);
}

// func: dev($a) - Standard Deviation
function dev($a)
{
  $sum = 0;
  $mean = avg($a);

  if (count($a)==0) return '0';
  foreach ($a as $x) $sum += pow(($x-$mean),2);
  $var = sqrt($sum/(count($a)-1));
  return $var;
}
?>