昨天，我偶然发现了一个奇怪的问题。突然某个特定的PHP脚本不再起作用，它抛出了502错误。当我启用error_reporting时，仅显示通知/警告，但页面的其余部分显示正确。当我再次禁用error_reporting("E_ALL"); ini_set("display_errors", 1);时，NGINX再次抛出502。
奇怪的是，当我使用以下代码片段捕获通知/警告时：
function myErrorHandler($errno, $errstr, $errfile, $errline)
{
if ($errno == E_USER_NOTICE){
}
}
set_error_handler("myErrorHandler");
页面也正确呈现，显然没有显示错误。
Debian版本：4.9.0-6-amd64＃1 SMP Debian 4.9.88-1 + deb9u1（2018-05-07）x86_64
PHP版本：php7.4-fpm
NGINX版本：nginx / 1.10.3
这可能是内存问题？或还有其他解释，为什么会这样？
代码未设置响应标头，因为我从未在任何地方设置任何标头。我也没有使用错误处理程序，只是在出现问题时激活error_reporting。如果一切正常，我将禁用display_errors，因此通知/警告将不会显示。
如果删除文件的以下行，它也可以正常运行而不会捕获错误：$list = $tn->getMassnahmen();
$ tn是我的类'teilnehmer'的一个实例：$tn = new teilnehmer;
'getMassnahmen'的代码：
function getMassnahmen()
{
$stmt = $this->db->prepare('SELECT * FROM `massnahmen_txt` ORDER BY `id` ASC');
if ($stmt->execute()) {
while ($row = $stmt->fetch()) {
$result[] = $row;
}
}
return $result;
}
'teilnehmer'是我的客户。客户端可以向其中添加文件（不同的数据库表）。如果客户端添加了文件，则只会以某种方式发生该错误。如果我注释掉代码中有关文件的整个部分，则仍然会发生错误。仅删除行$list = $tn->getMassnahmen();会有所帮助。但是此行与文件没有任何关系。他们只使用相同的类。
'teilnehmer'（$ tn）的类/实例在代码中被多次使用，没有任何错误。
错误日志：
Notice: Undefined variable: nocal in /PATH//html/inc/global.inc.php on line 34
Notice: Undefined variable: result in /PATH//html/classes/user.php on line 672
Warning: sizeof(): Parameter must be an array or an object that implements Countable in /PATH//html/inc/global.inc.php on line 57
Notice: Undefined variable: newdates in /PATH//html/inc/global.inc.php on line 101
Warning: sizeof(): Parameter must be an array or an object that implements Countable in /PATH//html/inc/global.inc.php on line 101
Notice: Undefined variable: list in /PATH//html/inc/global.inc.php on line 113
Notice: Undefined variable: is_index in /PATH//html/inc/global.inc.php on line 120
Notice: Undefined variable: result in /PATH//html/classes/user.php on line 898
Warning: sizeof(): Parameter must be an array or an object that implements Countable in /PATH//html/inc/global.inc.php on line 129
Notice: Undefined variable: calendar in /PATH//html/inc/global.inc.php on line 133
Notice: Undefined variable: result in /PATH//html/classes/user.php on line 898
Notice: Undefined variable: result in /PATH//html/classes/mandanten.php on line 48
Warning: sizeof(): Parameter must be an array or an object that implements Countable in /PATH//html/inc/global.inc.php on line 144
Notice: Undefined variable: result in /PATH//html/classes/user.php on line 1425
Warning: sizeof(): Parameter must be an array or an object that implements Countable in /PATH//html/inc/global.inc.php on line 190
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Warning: array_walk() expects parameter 2 to be a valid callback, class 'user' does not have a method 'htmlspecialcharsArray' in /PATH//html/classes/user.php on line 224
Notice: Undefined index: success in /PATH//html/teilnehmer_edit.php on line 17
Notice: Undefined index: removedfile in /PATH//html/teilnehmer_edit.php on line 21
Notice: Undefined index: successremovelog in /PATH//html/teilnehmer_edit.php on line 26
Notice: Undefined index: fehltag_add in /PATH//html/teilnehmer_edit.php on line 65
Notice: Undefined index: remove_fehltag in /PATH//html/teilnehmer_edit.php on line 142
Notice: Undefined variable: content in /PATH//html/teilnehmer_edit.php on line 248
Notice: Undefined variable: active_fehltage in /PATH//html/teilnehmer_edit.php on line 257
Notice: Undefined variable: kursdata in /PATH//html/teilnehmer_edit.php on line 281
Notice: Undefined variable: statusdata in /PATH//html/teilnehmer_edit.php on line 282
Notice: Undefined variable: tabledata in /PATH//html/classes/template.php on line 134
Notice: Undefined variable: result in /PATH//html/classes/teilnehmer.php on line 606
Warning: sizeof(): Parameter must be an array or an object that implements Countable in /PATH//html/teilnehmer_edit.php on line 300
Warning: sizeof(): Parameter must be an array or an object that implements Countable in /PATH//html/teilnehmer_edit.php on line 314
Notice: Undefined variable: filelist in /PATH//html/teilnehmer_edit.php on line 387
Notice: Undefined variable: fehlliste in /PATH//html/teilnehmer_edit.php on line 676
Notice: Trying to access array offset on value of type bool in /PATH//html/teilnehmer_edit.php on line 699
Notice: Undefined variable: aglist in /PATH//html/teilnehmer_edit.php on line 740
Notice: Undefined index: name in /PATH//html/teilnehmer_edit.php on line 742
Notice: Undefined index: name in /PATH//html/teilnehmer_edit.php on line 742
Notice: Undefined variable: result in /PATH//html/classes/teilnehmer.php on line 684
Warning: sizeof(): Parameter must be an array or an object that implements Countable in /PATH//html/teilnehmer_edit.php on line 752
Notice: Undefined variable: list1 in /PATH//html/teilnehmer_edit.php on line 776
Notice: Undefined variable: mlist in /PATH//html/teilnehmer_edit.php on line 796
感谢您的帮助！
设置后
fastcgi_buffer_size 64k;
fastcgi_buffers 4 64k;
在我的Nginx配置中，问题已解决。似乎fastcgi的缓冲区大小不足以响应。非常感谢您的帮助！