Get MongoDB replication info

replication.php

<?php

function getReplicationInfo($m) {
  $db = $m->local;
  $result = array();

  $ol = $db->system->namespaces->findOne(array("name" => 'local.oplog.$main'));

  if ($ol && array_key_exists('options', $ol)) {
    $result['logSizeMB'] = $ol['options']['size'] / 1000 / 1000;
  } else {
    $result['errmsg'] = 'local.oplog.$main, or its options, not found in system.namespaces collection (not --master?)';
    return $result;
  }

  $c = $db->selectCollection('oplog.$main');
  $firstc = $c->find()->sort(array('$natural' => 1))->limit(1);
  $lastc = $c->find()->sort(array('$natural' => -1))->limit(1);
  if (!$firstc->hasNext() || !$lastc->hasNext()) {
    $result['errmsg'] = "objects not found in local.oplog.$main -- is this a new and empty db instance?";
    $result['oplogMainRowCount'] = $c->count();
    return $result;
  }

  $first = $firstc->getNext();
  $last = $lastc->getNext();
  $tfirst = $first['ts'];
  $tlast = $last['ts'];
  if ($tfirst && $tlast) {
    $tfirst = $tfirst->sec;
    $tlast = $tlast->sec;
    $result['timeDiff'] = $tlast - $tfirst;
    $result['timeDiffHours'] = round($result['timeDiff'] / 36) / 100;
    $result['tFirst'] = new MongoDate($tfirst);
    $result['tLast'] = new MongoDate($tlast);
    $result['now'] = new MongoDate();
  } else {
    $result['errmsg'] = "ts element not found in oplog objects";
  }
  return $result;
}

function printReplicationInfo($m) {
  $result = getReplicationInfo($m);

  if (array_key_exists('errmsg', $result)) {
    print_r($result);
    return;
  }

  echo "configured oplog size:   " . $result['logSizeMB'] . "MB\n";
  echo "log length start to end: " . $result['timeDiff'] . "secs (" . $result['timeDiffHours'] . "hrs)\n";
  echo "oplog first event time:  " . $result['tFirst']."\n";
  echo "oplog last event time:   " . $result['tLast']."\n";
  echo "now:                     " . $result['now']."\n";
}


function getSlaveReplicationInfo($x) {
  echo "source:   " . $x['host']."\n";
  $st = new MongoDate($x['syncedTo']->sec);
  $now = new MongoDate;
  echo "syncedTo: " . $st."\n";
  $ago = ($now->sec - $st->sec) / 1000 + ($now->usec - $st->usec) * 1000;
  $hrs = round($ago / 36) / 100;
  echo "          = " . round($ago) . "secs ago (" . $hrs . "hrs)\n";
}

function printSlaveReplicationInfo($m) {
  $db = $m->local;
  if ($db->sources->count() == 0) {
    echo "local.sources is empty; is this db a --slave?\n";
    return;
  }
  $cursor = $db->sources->find();

  while ($cursor->hasNext()) {
    $source = $cursor->getNext();
    //  foreach($cursor as $source) {
    getSlaveReplicationInfo($source);
  }
}

?>