我有一个 Web 应用程序,自 2017 年以来一直在最新的 WAMP 堆栈中运行。它作为内部后台应用程序为大约 200-300 个用户提供服务。当前的 WAMP 堆栈:两个运行 Windows Server 2016 的虚拟机,应用服务器上:Apache 2.4.58、PHP 8.2.12,数据库服务器上:MySQL 8.0.33
直到大约半年前,它运行没有任何重大问题。
用户遇到的主要症状是尝试加载任何页面后浏览器出现白屏,并且选项卡停留在“加载状态”。它发生在随机用户身上,而不是一直发生。我无法确定它发生的频率或与哪个用户有关的任何模式。从浏览器中删除 PHP 会话 cookie 后,将恢复正常操作。所有用户都使用 Chrome(公司政策)。
在服务器端,我可以看到用户的请求“卡在”mod_status 页面上。如果他们在 cookie 删除之前尝试刷新站点,他们可以让多个工作人员处于“卡住”状态。
我所说的“卡住”是指,工作人员的“M - 操作模式”处于“W - 发送回复”状态(至少在 http/1.1 协议中),并且“SS - 自最近请求开始以来的秒数”远远高于配置的超时。将协议更改为 http/2 后,工作人员陷入“C - 正在关闭连接”,且“SS”值较高。
多个工作人员“陷入”“W”状态 - 使用 http/1.1 协议
单个工作人员“卡在”“C”状态 - 使用 http/2 协议
我尝试尽可能地重新配置 Apache,以下是相关部分:
# Core config
ThreadLimit 512
ThreadsPerChild 512
ThreadStackSize 8388608
MaxRequestsPerChild 0
KeepAlive On
KeepAliveTimeout 5
MaxKeepAliveRequests 500
TimeOut 60
ProxyTimeout 60
RequestReadTimeout handshake=0 header=10-40,MinRate=500 body=20,MinRate=500
# Http2 config
Protocols h2 http/1.1
H2Direct On
H2MinWorkers 64
H2MaxWorkers 512
H2MaxSessionStreams 512
H2StreamMaxMemSize 1048576
H2WindowSize 1048576
H2MaxWorkerIdleSeconds 10
H2StreamTimeout 60
在 Apache 配置中的更改不起作用,对 http2 协议的更改也不起作用,并且问题似乎与 PHP 会话处理有关,我也尝试重新配置。这是当前的 PHP 会话配置:
[Session]
session.save_handler = files
session.save_path = "c:/tmp"
session.use_strict_mode = 1
session.use_cookies = 1
session.cookie_secure = 0
session.use_only_cookies = 1
session.name = PHPSESSID
session.auto_start = 0
session.cookie_lifetime = 14500
session.cookie_path = /
session.cookie_domain =
session.cookie_httponly = 1
session.serialize_handler = php
session.gc_probability = 1
session.gc_divisor = 1000
session.gc_maxlifetime = 14500
session.referer_check =
session.cache_limiter = nocache
session.cache_expire = 180
session.use_trans_sid = 0
session.hash_function = sha512
session.hash_bits_per_character = 5
我尝试在我的应用程序中重写会话处理程序。以下是会话处理类的相关部分:
<?php
// Framework Session handler
class Session {
// Generic PHP session token
private $_session_id;
// Number of seconds after the session id is needs to be regenerated
private $_session_keepalive = 300;
// Error logging handler
private $_error = null;
/**
* @Function: public __construct($config);
* @Task: Default constructor for Framework session handler
* @Params:
* array $config: associative configuration array for construction
* Default: array() - Empty array
* Note: It can contain any of the class' configurable variables
* without the first underscore as key
* @Returns:
* Session
**/
public function __construct($config = array()) {
// Setting config
foreach(get_object_vars($this) as $key => $var) {
if($key != '_session_id' && isset($config[mb_substr($key,1)]))
$this->$key = $config[mb_substr($key,1)];
}
// Make sure use_strict_mode is enabled.
// use_strict_mode is mandatory for security reasons.
ini_set('session.use_strict_mode', 1);
ini_set('session.cookie_secure', 1);
// Start the session
$this->start();
// Create error logging handler
$this->_error = new Error_Logging();
}
/**
* @Function: public __destruct();
* @Task: Destructor for Framework Session handler
* @Params: None
* @Returns: void
**/
public function __destruct() {
// Destroy variables
foreach(get_object_vars($this) as $key => $var)
unset($this->$key);
// Releases the session file from write lock
session_write_close();
}
/**
* @Function: private start()
* @Task: Starts the PHP session
* @Params: none
* @Returns: none
**/
private function start() {
session_start();
// Store the session id
$this->_session_id = session_id();
// Set CreatedOn if not set
if(!$this->exists('CreatedOn'))
$this->set('CreatedOn', date('Y-m-d H:i:s'));
// Do not allow the use of old session id
$time_limit = strtotime(' - ' . $this->_session_keepalive . ' seconds');
if(!empty($this->get('DeletedOn', '')) && strtotime($this->get('DeletedOn', '')) <= $time_limit) {
session_destroy();
session_start();
$this->set('CreatedOn', date('Y-m-d H:i:s'));
// Store the new session id
$this->_session_id = session_id();
}
// Regenerate the session when older than required
if(strtotime($this->get('CreatedOn', '')) <= $time_limit) {
$this->regenerate();
}
}
/**
* @Function: private regenerate()
* @Task: Regenerates the current PHP session
* @Params: none
* @Returns: none
**/
public function regenerate() {
// Call session_create_id() while session is active to
// make sure collision free.
if(session_status() != PHP_SESSION_ACTIVE) {
$this->start();
}
// Get all session data to restore
$old_session_data = $this->get_all();
// Create a new non-conflicting session id
$this->_session_id = session_create_id();
// Set deleted timestamp.
// Session data must not be deleted immediately for reasons.
$this->set('DeletedOn', date('Y-m-d H:i:s'));
// Finish session
session_write_close();
// Set new custom session ID
session_id($this->_session_id);
// Start with custom session ID
$this->start();
// Restore the session data except CreatedOn and DeletedOn
if(isset($old_session_data['CreatedOn']))
unset($old_session_data['CreatedOn']);
if(isset($old_session_data['DeletedOn']))
unset($old_session_data['DeletedOn']);
if(!empty($old_session_data))
$this->set_multi($old_session_data);
}
/**
* @Function: public set($key, $val);
* @Task: Set Session variable
* @Params:
* mixed key: Key of the session array variable
* mixed val: Value of the session variable
* @Returns:
* bool
**/
public function set($key, $val) {
// Return variable
$response = false;
try{
// check if session is started
if(empty(session_id()))
throw new Exception('Session Error [0001]: Session is not started.');
// check if key is not null
if(empty($key))
throw new Exception('Session Error [0002]: Session key cannot be empty.');
// set session key
$this->write($key, $val);
$response = true;
}
// Handle errors
catch(Exception $e) {
$this->_error->log($e->getMessage());
}
return $response;
}
/**
* @Function: public get($key);
* @Task: Get session variable
* @Params:
* mixed key: Key of the session array variable
* mixed default: Default value if result is empty
* @Returns:
* bool/mixed
**/
public function get($key, $default = '') {
// Return variable
$response = false;
try{
// check if session is started
if(empty(session_id()))
throw new Exception('Session Error [0001]: Session is not started.');
// check if key is not null
if(empty($key))
throw new Exception('Session Error [0002]: Session key cannot be empty.');
// get session key if exists, else false
$response = $this->read($key, $default);
}
// Handle errors
catch(Exception $e) {
$this->_error->log($e->getMessage());
}
return $response;
}
/**
* @Function: public exists($key);
* @Task: Check if session variable exists
* @Params:
* mixed key: Key of the session array variable
* @Returns:
* bool
**/
public function exists($key) {
// Return variable
$response = false;
try{
// check if session is started
if(empty(session_id()))
throw new Exception('Session Error [0001]: Session is not started.');
// check if key is not null
if(empty($key))
throw new Exception('Session Error [0002]: Session key cannot be empty.');
// get if exists
$response = isset($_SESSION[$key]);
}
// Handle errors
catch(Exception $e) {
$this->_error->log($e->getMessage());
}
return $response;
}
/**
* @Function: public set_multi($params);
* @Task: Set multiple session variables
* @Params:
* array params: Associative array of key/val pairs to be set as session variables
* @Returns:
* bool
**/
public function set_multi($params) {
// Return variable
$response = false;
try{
// check if session is started
if(empty(session_id()))
throw new Exception('Session Error [0001]: Session is not started.');
// check if key is not null
if(empty($params))
throw new Exception('Session Error [0003]: Params array cannot be empty.');
$res = array();
foreach($params as $key => $val) {
// check if key is not null
if(empty($key))
throw new Exception('Session Error [0002]: Session key cannot be empty.');
// set session key
$this->write($key, $val);
$res[] = true;
}
// Check if all set succeded
$response = count($params) == count($res);
}
// Handle errors
catch(Exception $e) {
$this->_error->log($e->getMessage());
}
return $response;
}
/**
* @Function: public get_all();
* @Task: Get all session variables
* @Params: None
* @Returns:
* array
**/
public function get_all() {
// Return variable
$response = false;
try{
// check if session is started
if(empty(session_id()))
throw new Exception('Session Error [0001]: Session is not started.');
$res = array();
$keys = array_keys($_SESSION);
foreach($keys as $key) {
// get session key
$res[$key] = $this->read($key);
}
// Check if all set succeded
$response = $res;
}
// Handle errors
catch(Exception $e) {
$this->_error->log($e->getMessage());
}
return $response;
}
/**
* @Function: private write($key, $val);
* @Task: write session variable
* @Params:
* mixed key: key of the session variable to be stored
* mixed val: value of the session variable to be stored
* @Returns:
* void
**/
private function write($key, $val) {
$_SESSION[$key] = $val;
}
/**
* @Function: private read($key, $default);
* @Task: get session variable
* @Params:
* mixed key: key of the session variable to be retrieved
* mixed default: default value, if session not found
* @Returns:
* mixed
**/
private function read($key, $default = '') {
if(!isset($_SESSION[$key]))
return $default;
else
return $_SESSION[$key];
}
}
我不知道我还能做什么,也不知道我哪里搞砸了。任何帮助是极大的赞赏。 如果有人需要更多信息,请随时询问!
到今天为止,问题似乎已经解决了。但我不确定该解决方案是否正确,因此如果有人有更多提示,将受到欢迎。
线索是重复出现的错误,
MySQL server has gone away
,但一开始我以为这是一个单独的问题,这就是为什么我没有包含在上面的问题描述中。
首先,我在数据库处理程序类中编写了一个重新连接函数,并在每次在 MySQL 服务器上执行任何查询之前调用它。这是重新连接功能:
/**
* @Function: private reconnect();
* @Task: Reconnect to database if the connection has gone away
* @Params: None
* @Returns: void
**/
private function reconnect() {
try {
if($this->_db === null || !(@$this->_db->ping())) {
if($this->_reconnect_count > $this->_reconnect_try_max) {
throw new Exception('Database Error [0012]: MySqli connector could not reconnect.');
}
else {
// Count the reconnect trys
$this->_reconnect_count++;
// Dump old connection
unset($this->_db);
// Create MySQLi connector
$this->_db = new mysqli($this->_host, $this->_user, $this->_pass, '', $this->_port);
// Check if MySQLi connection is established
if($this->_db->connect_errno != 0) {
// Wait before re-try
sleep($this->_reconnect_wait);
$this->reconnect();
}
else {
// Reset the reconnect counter
$this->_reconnect_count = 0;
}
}
}
}
catch(Exception $e) {
// Log the error
$this->_error->log($e->getMessage());
// Terminate connection
header('location: ' . get_url() . '/500.html');
die(0);
}
}
此方法检查数据库连接是否仍然存在(使用
$mysqli->ping()
函数),如果连接消失,则每秒尝试重新连接,最多 _reconnect_try_max
次。
但一开始,这并没有帮助,因为事实证明,
ping()
方法是抛出错误的方法,而不是像预期的那样重新调整false
。
因此,在 @
ping()
) 后(如上面的代码所示)以及在调用 $mysqli->ping()
的任何点,“Mysql 消失”错误消失了,并且没有自那时起(截至撰写本文时,已连续 7 天),Apache 工作人员“陷入困境”。