php创建的日志在写入时被损坏

Question

我是根据下面的PHP代码捕获网页查看器日志的…

$viewerlog = "../SiteLogFiles/live-smoothstreaming-" . date('Ymd') . ".txt";
$fp = fopen($viewerlog,"a");
if ($fp) {
    fputs($fp,"-----------------------------------------------------------------------rn");
    fputs($fp,"Server Date:           $nowrn");
    fputs($fp,"IP Address:            $iprn");
    fputs($fp,"City:                  $cityrn");
    fputs($fp,"State:                 $statern");
    fputs($fp,"Country Name:          $countrynamern");
    fputs($fp,"Continent:             $continentrn");
    fputs($fp,"-----------------------------------------------------------------------rn");
    fclose($fp);
}

它产生了一个像这样的日志…

-----------------------------------------------------------------------
Server Date:           2013-01-06T05:32:06-06:00
IP Address:            157.55.32.61
City:                  Unknown
State:                 Unknown
Country Name:          United States
Continent:             North America
-----------------------------------------------------------------------
-----------------------------------------------------------------------
Server Date:           2013-01-06T06:02:40-06:00
IP Address:            157.55.32.187
City:                  Unknown
State:                 Unknown
Country Name:          United States
Continent:             North America
-----------------------------------------------------------------------

但是每隔一段时间，日志就会被损坏，看起来像这样…

-----------------------------------------------------------------------
Server Date:           2012-12-21T18:27:27-06:00
IP Address:            99.54.103.128
City:                  Columbus
State:                 Ohio
Country Name:          United States
Continent:             North America
-----------------------------------------------------------------------
-----------------------------------------------------------------------
Server Date:           2012-12-21T18:27:53-06:00
IP Address:            75.97.98.115
City:                  Palmerton
State:                 Pennsylvania
--------------------------------------Continent:             North America
Server Date:           2012-12-21T18:27:54-06:00
---------------------
IP Address:            70.76.36.232
City:                  Saskatoon
State:                 Saskatchewan
Country Name:          Canada
Continent:             North America
-----------------------------------------------------------------------
-----------------------------------------------------------------------
Server Date:           2012-12-21T18:28:04-06:00
IP Address:            173.17.240.190
City:                  Springfield
State:                 Missouri
Country Name:          United States
Continent:             North America
-----------------------------------------------------------------------

可能值得注意的是，我正在使用使用http://www.easyjquery.com从IP地址获取位置信息。

因此，许多人建议使用SQL数据库进行日志记录，而不是使用纯文本日志。有了这些建议，我就可以建立SQL数据库了。我能够在1秒内写7条记录(和我按F5一样快)，没有任何问题。

使用的PHP代码如下…

try {
    $dbh = new PDO("sqlsrv:Server=localhost;Database=ViewerLogs", "", "");
    $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $stmt = $dbh->query("INSERT INTO dbo.LiveSmoothStreaming (DateTime, Ip, City, State, Country, Continent) VALUES('$now', '$ip', '$city', '$state', '$countryname', '$continent')");
    $stmt->setFetchMode(PDO::FETCH_ASSOC);
    $dbh = null;
}
catch(PDOException $e) {
    echo $e->getMessage();
}

但是有一个问题。我的平面文本日志似乎比SQL日志捕获了更多的记录。

平面文本日志正在生成…

Tue 5:58pm  68.55.34.32 Laurel      Maryland    United States   North America
Tue 5:58pm  70.88.57.62 Port Charlotte  Florida United States   North America
Tue 5:59pm  98.19.198.54    Eastview        Kentucky    United States   North America
Tue 5:59pm  71.3.202.110    Cape Coral      Florida United States   North America
Tue 5:59pm  173.218.32.154  Branson     Missouri    United States   North America
Tue 5:59pm  184.38.238.64   Unknown     Unknown United States   North America
Tue 5:59pm  67.239.18.161   Naples      Florida United States   North America

SQL日志正在生成…

2013-02-05T17:58:45-06:00   68.55.34.32 Laurel      Maryland    United States   North America
2013-02-05T17:58:52-06:00   70.88.57.62 Port Charlotte  Florida     United States   North America
2013-02-05T17:59:06-06:00   71.3.202.110    Cape Coral  Florida     United States   North America
2013-02-05T17:59:23-06:00   67.239.18.161   Naples      Florida     United States   North America

你可以看到，在短短几分钟内，有不同。在几个小时的过程中，差异可能会有数百个。

在这个特殊的平面文本日志中没有损坏，所以我不知道它怎么可能是错的。这将指向SQL日志的一个问题。我在我的PHP错误日志中查找可能的问题，没有看到任何明显的问题(我只是搜索有问题的页面并查看这些错误)。

有什么想法为什么SQL不会捕获记录，平面文本日志是?在我的代码中，SQL日志直接出现在平面文本日志之后(也许将SQL放在平面文本之前会产生相反的结果?)。

Answer 1

据我所知，您可以使用文件锁定或syslog。既然你似乎想让你的应用程序编写不间断的文本块，我认为锁定是可取的。

$lockwait = 2;       // seconds to wait for lock
$waittime = 250000;  // microseconds to wait between lock attempts
// 2s / 250000us = 8 attempts.
$myfile = '/path/to/file.log';
if( $fh = fopen($myfile, 'a') ) {
  $waitsum = 0;
  // attempt to get exclusive, non-blocking lock
  $locked = flock($fh, LOCK_EX | LOCK_NB); 
  while( !$locked && ($waitsum <= $lockwait) ) {
    $waitsum += $waittime/1000000; // microseconds to seconds
    usleep($waittime);
    $locked = flock($fh, LOCK_EX | LOCK_NB);
  }
  if( !$locked ) {
    echo "Could not lock $myfile for write within $lockwait seconds.";
  } else {
    // write out your data here
    flock($fh, LOCK_UN);  // ALWAYS unlock
  }
  fclose($fh);            // ALWAYS close your file handle
} else {
  echo "Could not open $myfile";
  exit 1;
}

你也可以使用这个稍微复杂一点的算法来做一个随机的"后退"等待，类似于TCP和CSMA/CD使用来避免拥塞。

$max_wait   = 1000000; //  1 s
$min_interval = 10000; // 10 ms
$max_interval = 50000; // 50 ms
$cur_wait = $min_interval;
$tot_wait = 0;
$locked = flock($fh, LOCK_EX | LOCK_NB); 
while( !$locked && ($tot_wait <= $max_wait) ) {
  tot_wait += $cur_wait;
  usleep($cur_wait);
  cur_wait += rand($min_interval, $max_interval);
  $locked = flock($fh, LOCK_EX | LOCK_NB);
}
if( !$locked ) {
  echo "Could not lock $myfile for write within $lockwait seconds.";
} else {
  // write out your data here
  flock($fh, LOCK_UN);
}
fclose($fh);

如果无法获得锁，脚本将在两次锁尝试之间等待越来越长的时间，直到超过$max_wait中定义的时间。

在写完所有这些之后，我认为你可能只是想考虑将所有这些插入到数据库中，如果你需要一个日志文件，那么每天运行一次cron作业，一次将文件写出来，并可选择清空表。