Ошибка error 499

At the end of last week I noticed a problem on one of my medium AWS instances where Nginx always returns a HTTP 499 response if a request takes more than 60 seconds. The page being requested is a PHP script

I’ve spent several days trying to find answers and have tried everything that I can find on the internet including several entries here on Stack Overflow, nothing works.

I’ve tried modifying the PHP settings, PHP-FPM settings and Nginx settings. You can see a question I raised on the NginX forums on Friday (http://forum.nginx.org/read.php?9,237692) though that has received no response so I am hoping that I might be able to find an answer here before I am forced to moved back to Apache which I know just works.

This is not the same problem as the HTTP 500 errors reported in other entries.

I’ve been able to replicate the problem with a fresh micro AWS instance of NginX using PHP 5.4.11.

To help anyone who wishes to see the problem in action I’m going to take you through the set-up I ran for the latest Micro test server.

You’ll need to launch a new AWS Micro instance (so it’s free) using the AMI ami-c1aaabb5

This PasteBin entry has the complete set-up to run to mirror my test environment. You’ll just need to change example.com within the NginX config at the end

http://pastebin.com/WQX4AqEU

Once that’s set-up you just need to create the sample PHP file which I am testing with which is

<?php
sleep(70);
die( 'Hello World' );
?>

Save that into the webroot and then test. If you run the script from the command line using php or php-cgi, it will work. If you access the script via a webpage and tail the access log /var/log/nginx/example.access.log, you will notice that you receive the HTTP 1.1 499 response after 60 seconds.

Now that you can see the timeout, I’ll go through some of the config changes I’ve made to both PHP and NginX to try to get around this. For PHP I’ll create several config files so that they can be easily disabled

Update the PHP FPM Config to include external config files

sudo echo '
include=/usr/local/php/php-fpm.d/*.conf
' >> /usr/local/php/etc/php-fpm.conf

Create a new PHP-FPM config to override the request timeout

sudo echo '[www]
request_terminate_timeout = 120s
request_slowlog_timeout = 60s
slowlog = /var/log/php-fpm-slow.log ' >
/usr/local/php/php-fpm.d/timeouts.conf

Change some of the global settings to ensure the emergency restart interval is 2 minutes

# Create a global tweaks
sudo echo '[global]
error_log = /var/log/php-fpm.log
emergency_restart_threshold = 10
emergency_restart_interval = 2m
process_control_timeout = 10s
' > /usr/local/php/php-fpm.d/global-tweaks.conf

Next, we will change some of the PHP.INI settings, again using separate files

# Log PHP Errors
sudo echo '[PHP]
log_errors = on
error_log = /var/log/php.log
' > /usr/local/php/conf.d/errors.ini

sudo echo '[PHP]
post_max_size=32M
upload_max_filesize=32M
max_execution_time = 360
default_socket_timeout = 360
mysql.connect_timeout = 360
max_input_time = 360
' > /usr/local/php/conf.d/filesize.ini

As you can see, this is increasing the socket timeout to 3 minutes and will help log errors.

Finally, I’ll edit some of the NginX settings to increase the timeout’s that side

First I edit the file /etc/nginx/nginx.conf and add this to the http directive
fastcgi_read_timeout 300;

Next, I edit the file /etc/nginx/sites-enabled/example which we created earlier (See the pastebin entry) and add the following settings into the server directive

client_max_body_size    200;
client_header_timeout   360;
client_body_timeout     360;
fastcgi_read_timeout    360;
keepalive_timeout       360;
proxy_ignore_client_abort on;
send_timeout            360;
lingering_timeout       360;

Finally I add the following into the location ~ .php$ section of the server dir

fastcgi_read_timeout 360;
fastcgi_send_timeout 360;
fastcgi_connect_timeout 1200;

Before retrying the script, start both nginx and php-fpm to ensure that the new settings have been picked up. I then try accessing the page and still receive the HTTP/1.1 499 entry within the NginX example.error.log.

So, where am I going wrong? This just works on apache when I set PHP’s max execution time to 2 minutes.

I can see that the PHP settings have been picked up by running phpinfo() from a web-accessible page. I just don’t get, I actually think that too much has been increased as it should just need PHP’s max_execution_time, default_socket_timeout changed as well as NginX’s fastcgi_read_timeout within just the server->location directive.

Update 1

Having performed some further test to show that the problem is not that the client is dying I have modified the test file to be

<?php
file_put_contents('/www/log.log', 'My first data');
sleep(70);
file_put_contents('/www/log.log','The sleep has passed');
die('Hello World after sleep');
?>

If I run the script from a web page then I can see the content of the file be set to the first string. 60 seconds later the error appears in the NginX log. 10 seconds later the contents of the file changes to the 2nd string, proving that PHP is completing the process.

Update 2

Setting fastcgi_ignore_client_abort on; does change the response from a HTTP 499 to a HTTP 200 though nothing is still returned to the end client.

Update 3

Having installed Apache and PHP (5.3.10) onto the box straight (using apt) and then increasing the execution time the problem does appear to also happen on Apache as well. The symptoms are the same as NginX now, a HTTP200 response but the actual client connection times out before hand.

I’ve also started to notice, in the NginX logs, that if I test using Firefox, it makes a double request (like this PHP script executes twice when longer than 60 seconds). Though that does appear to be the client requesting upon the script failing

At the end of last week I noticed a problem on one of my medium AWS instances where Nginx always returns a HTTP 499 response if a request takes more than 60 seconds. The page being requested is a PHP script

I’ve spent several days trying to find answers and have tried everything that I can find on the internet including several entries here on Stack Overflow, nothing works.

I’ve tried modifying the PHP settings, PHP-FPM settings and Nginx settings. You can see a question I raised on the NginX forums on Friday (http://forum.nginx.org/read.php?9,237692) though that has received no response so I am hoping that I might be able to find an answer here before I am forced to moved back to Apache which I know just works.

This is not the same problem as the HTTP 500 errors reported in other entries.

I’ve been able to replicate the problem with a fresh micro AWS instance of NginX using PHP 5.4.11.

To help anyone who wishes to see the problem in action I’m going to take you through the set-up I ran for the latest Micro test server.

You’ll need to launch a new AWS Micro instance (so it’s free) using the AMI ami-c1aaabb5

This PasteBin entry has the complete set-up to run to mirror my test environment. You’ll just need to change example.com within the NginX config at the end

http://pastebin.com/WQX4AqEU

Once that’s set-up you just need to create the sample PHP file which I am testing with which is

<?php
sleep(70);
die( 'Hello World' );
?>

Save that into the webroot and then test. If you run the script from the command line using php or php-cgi, it will work. If you access the script via a webpage and tail the access log /var/log/nginx/example.access.log, you will notice that you receive the HTTP 1.1 499 response after 60 seconds.

Now that you can see the timeout, I’ll go through some of the config changes I’ve made to both PHP and NginX to try to get around this. For PHP I’ll create several config files so that they can be easily disabled

Update the PHP FPM Config to include external config files

sudo echo '
include=/usr/local/php/php-fpm.d/*.conf
' >> /usr/local/php/etc/php-fpm.conf

Create a new PHP-FPM config to override the request timeout

sudo echo '[www]
request_terminate_timeout = 120s
request_slowlog_timeout = 60s
slowlog = /var/log/php-fpm-slow.log ' >
/usr/local/php/php-fpm.d/timeouts.conf

Change some of the global settings to ensure the emergency restart interval is 2 minutes

# Create a global tweaks
sudo echo '[global]
error_log = /var/log/php-fpm.log
emergency_restart_threshold = 10
emergency_restart_interval = 2m
process_control_timeout = 10s
' > /usr/local/php/php-fpm.d/global-tweaks.conf

Next, we will change some of the PHP.INI settings, again using separate files

# Log PHP Errors
sudo echo '[PHP]
log_errors = on
error_log = /var/log/php.log
' > /usr/local/php/conf.d/errors.ini

sudo echo '[PHP]
post_max_size=32M
upload_max_filesize=32M
max_execution_time = 360
default_socket_timeout = 360
mysql.connect_timeout = 360
max_input_time = 360
' > /usr/local/php/conf.d/filesize.ini

As you can see, this is increasing the socket timeout to 3 minutes and will help log errors.

Finally, I’ll edit some of the NginX settings to increase the timeout’s that side

First I edit the file /etc/nginx/nginx.conf and add this to the http directive
fastcgi_read_timeout 300;

Next, I edit the file /etc/nginx/sites-enabled/example which we created earlier (See the pastebin entry) and add the following settings into the server directive

client_max_body_size    200;
client_header_timeout   360;
client_body_timeout     360;
fastcgi_read_timeout    360;
keepalive_timeout       360;
proxy_ignore_client_abort on;
send_timeout            360;
lingering_timeout       360;

Finally I add the following into the location ~ .php$ section of the server dir

fastcgi_read_timeout 360;
fastcgi_send_timeout 360;
fastcgi_connect_timeout 1200;

Before retrying the script, start both nginx and php-fpm to ensure that the new settings have been picked up. I then try accessing the page and still receive the HTTP/1.1 499 entry within the NginX example.error.log.

So, where am I going wrong? This just works on apache when I set PHP’s max execution time to 2 minutes.

I can see that the PHP settings have been picked up by running phpinfo() from a web-accessible page. I just don’t get, I actually think that too much has been increased as it should just need PHP’s max_execution_time, default_socket_timeout changed as well as NginX’s fastcgi_read_timeout within just the server->location directive.

Update 1

Having performed some further test to show that the problem is not that the client is dying I have modified the test file to be

<?php
file_put_contents('/www/log.log', 'My first data');
sleep(70);
file_put_contents('/www/log.log','The sleep has passed');
die('Hello World after sleep');
?>

If I run the script from a web page then I can see the content of the file be set to the first string. 60 seconds later the error appears in the NginX log. 10 seconds later the contents of the file changes to the 2nd string, proving that PHP is completing the process.

Update 2

Setting fastcgi_ignore_client_abort on; does change the response from a HTTP 499 to a HTTP 200 though nothing is still returned to the end client.

Update 3

Having installed Apache and PHP (5.3.10) onto the box straight (using apt) and then increasing the execution time the problem does appear to also happen on Apache as well. The symptoms are the same as NginX now, a HTTP200 response but the actual client connection times out before hand.

I’ve also started to notice, in the NginX logs, that if I test using Firefox, it makes a double request (like this PHP script executes twice when longer than 60 seconds). Though that does appear to be the client requesting upon the script failing

When managing and maintaining a website, there are a handful of HTTP status codes to be aware of. Some, such as the HTTP 499 error, can cause a timeout that interrupts your workflow. Therefore, you’ll need to ensure that your site is configured properly to avoid this issue.

Whether you’re seeing the HTTP 499 status code frequently or for the first time, it may indicate an issue with your website that needs to be addressed. The good news is that there are multiple steps you can take to resolve it.

Check Out Our Video Guide to Fixing the 499 Error

In this post, we’ll explain the HTTP 499 status code and what can cause the error. Then we’ll walk you through five potential solutions you can use to fix it. Let’s get started!

What the HTTP 499 Status Code Means

The HTTP 499 status code, also known as a “client closed request,” is a special case of the 502 Bad Gateway Error. It indicates that the client has closed the connection while the server is still processing the request.

HTTP 499 falls within the category of client-based errors. This means the issue is on the client side. Other common errors in this category include HTTP 400 Bad Request and HTTP 404 Not Found. With these errors, the problems are usually easy to define. However, HTTP 499 is more general.

The HTTP 499 error can happen on both Nginx and Apache servers. However, it is more common on Nginx servers because it was created by Nginx.

HTTP 499 is more common on Nginx because the server software handles client connections differently than Apache. With Nginx, each client connection is processed in a separate thread. Therefore, if one client connection takes a long time to process, it won’t slow down the other clients.

However, with Apache, all client connections are processed in the same thread. This can cause problems if one client connection takes a long time to process because it will slow down all other clients.

The HTTP 499 error can cause a timeout that interrupts your workflow- but with a little help from this guide, you can get right back on track 👩‍💻Click to Tweet

What Causes the HTTP 499 Error

Typically, the HTTP 499 error appears in Nginx logs. This can happen for several reasons, but most commonly, it’s due to either a browser timing out or a user canceling the request.

For example, a website may encounter an HTTP code 499 when it’s loaded with too much traffic. Alternatively, the error can happen when the request comes from algorithms that create issues within the site.

In some cases, this status code may also display when there is no response from the server, and the client has timed out waiting for a response. In these cases, it’s usually best to just try again later. However, if you are consistently getting this status code from a particular server, it may be worth investigating further to see if there is an overarching issue.

How To Fix the HTTP 499 Error (5 Potential Solutions)

Now that we understand more about the HTTP 499 error, let’s look at how to resolve it. Below are five potential solutions for the HTTP 499 status code!

1. Clear Your Browser Cache and Try Again

As we mentioned earlier, this error may be a temporary issue that can be resolved by simply trying to load the page again. It might be that your host or server is overloaded. Therefore, we recommend clearing your browser cache and trying again.

The process for clearing the cache will vary depending on your browser. If you’re using Google Chrome, you can navigate to the three vertical dots in the upper right-hand corner of the window, then go to More tools > Clear browsing data:

You’ll then be prompted to choose which data to clear from your browser cache:

When you’re done, reload your browser. You can also try using a different browser in the meantime. Then revisit your site to see whether the error message is still showing.

2. Disable Your Plugins and Extensions

Some users have reported that certain plugins cause the HTTP 499 status code error. Therefore, we recommend temporarily disabling your plugins to see if this resolves the issue.

You can do this by navigating to your Plugins screen in the WordPress dashboard, selecting all of them, then clicking on Deactivate > Apply from the bulk actions menu:

You can also connect to your site via a File Transfer Protocol (FTP) client or File Manager, then navigate to your plugins folder (wp_content > plugins). Right-click on the plugins folder and rename it to something such as “plugins_old.”

This will deactivate all of the plugins on your WordPress site. You can revisit your website to see whether the error message is still showing. If not, you can try activating your plugins one by one until you find the tool causing the issue.

3. Check Your Error Logs

When troubleshooting the HTTP 499 code, it’s essential to leverage your error logs. This approach will make it easier to narrow down the issue and determine whether it results from a specific plugin or tool.

If you’re not a Kinsta user, you can enable and view error logs by turning on WordPress debugging mode. However, if you’re a Kinsta user, you can quickly and easily see errors in the Log viewer from your MyKinsta dashboard:

You can also check your log files in Nginx (/var/log/nginx.error.log) and Apache (/var/log/apache2/error.log). Furthermore, Kinsta users can take advantage of our analytics tool to take a closer look at errors on your site. Then you can understand how often they’re occurring and whether the HTTP 499 error is an ongoing issue.

4. Use an Application Performance Monitoring (APM) Tool

When managing a website, it’s important to have reliable solutions for identifying and troubleshooting errors on your site. We recommend using an Application Performance Monitoring (APM) tool.

APM tools can help you narrow down which script or plugin may lead to various errors, such as HTTP 499. We include our Kinsta APM, as well as a variety of other DevKinsta tools, with all of our plans:

For example, your APM tool can help you collect valuable data and determine which applications are causing delays. Once enabled, you can use KinstaAPM to view the slowest transactions on your site, trace their timelines, and figure out the causes of issues. Our APM also provides insight into your PHP processes, MySQL queries, external HTTP requests, and more.

5. Contact Your Web Host and Request a Timeout Increase

As we’ve discussed, sometimes HTTP 499 errors can occur when a request is canceled because it’s taking too long. Some hosting providers use a ”kill script”.

In short, a kill script forces a request to be terminated after a certain amount of time. This script is often used in shared hosting environments to prevent long requests from impacting other sites.

If you’re a Kinsta user, this isn’t something you need to worry about. Each site hosted on our platform runs on an isolated software container that includes all resources and software. Everything is completely private, and none of your resources are shared, so we don’t run kill scripts.

However, when it comes to the HTTP 499 error, it’s important to note that the “client” may be a proxy, such as a Content Delivery Network (CDN) or load balancer. A load balancing service can act as a client to the Nginx server and proxy data between your server and users. This can cause a timeout that cancels the request to the Nginx server.

PHP timeouts happen if a process runs longer than the maximum execution time (max_execution_time) or max_input_time specified in your server’s PHP configuration. You may encounter timeouts if you have a busy website or scripts that need longer execution times. Therefore, it might be necessary to extend your timeout value.

Let’s say you have a request that is expected to take 20 seconds to complete. If you have an application with a timeout value of 10 seconds, the application will probably time out before completing the request. You’ll likely see the HTTP 499 status code in such an instance.

Therefore, it’s wise to check with your host about the values set on your server. At Kinsta, the default max_execution_time and max_input_time values are set to 300 seconds (5 minutes). The maximum PHP timeout values vary depending on your plan.

If necessary, you can reach out to your hosting provider to request a timeout increase. As a Kinsta user, you can open a ticket with our support team.

With help from this guide, you can ensure your site is properly configured to avoid seeing this error in the future. ✅ Here’s how… 🚀Click to Tweet

Summary

There are a wide variety of HTTP status codes to be aware of as a website owner. Some of the trickiest are client-based errors, such as the HTTP 499 code. The good news is that you can take a handful of steps to resolve this issue.

In this post, we discussed five potential solutions you can use to fix the HTTP 499 status code error. All of them are viable options; if one doesn’t work, another one should.

Do you want to troubleshoot and resolve issues in WordPress as painlessly as possible? Check out Kinsta hosting plans to learn how our APM tool and other solutions can streamline your website maintenance and management!

In my case, I was impatient and ended up misinterpreting the log.

In fact, the real problem was the communication between nginx and uwsgi, and not between the browser and nginx. If I had loaded the site in my browser and had waited long enough I would have gotten a «504 — Bad Gateway». But it took so long, that I kept trying stuff, and then refresh in the browser. So I never waited long enough to see the 504 error. When refreshing in the browser, that is when the previous request is closed, and Nginx writes that in the log as 499.

Elaboration

Here I will assume that the reader knows as little as I did when I started playing around.

My setup was a reverse proxy, the nginx server, and an application server, the uWSGI server behind it. All requests from the client would go to the nginx server, then forwarded to the uWSGI server, and then response was sent the same way back. I think this is how everyone uses nginx/uwsgi and are supposed to use it.

My nginx worked as it should, but something was wrong with the uwsgi server. There are two ways (maybe more) in which the uwsgi server can fail to respond to the nginx server.

1) uWSGI says, «I’m processing, just wait and you will soon get a response». nginx has a certain period of time, that it is willing to wait, fx 20 seconds. After that, it will respond to the client, with a 504 error.

2) uWSGI is dead, or uWSGi dies while nginx is waiting for it. nginx sees that right away and in that case, it returns a 499 error.

I was testing my setup by making requests in the client (browser). In the browser nothing happened, it just kept hanging. After maybe 10 seconds (less than the timeout) I concluded that something was not right (which was true), and closed the uWSGI server from the command line. Then I would go to the uWSGI settings, try something new, and then restart the uWSGI server. The moment I closed the uWSGI server, the nginx server would return a 499 error.

So I kept debugging with the 499 erroe, which means googling for the 499 error. But if I had waited long enough, I would have gotten the 504 error. If I had gotten the 504 error, I would have been able to understand the problem better, and then be able to debug.

So the conclusion is, that the problem was with uWGSI, which kept hanging («Wait a little longer, just a little longer, then I will have an answer for you…»).

How I fixed that problem, I don’t remember. I guess it could be caused by a lot of things.

В конце прошлой недели я заметил проблему на одном из моих средних экземпляров AWS, где Nginx всегда возвращает ответ HTTP 499, если запрос занимает более 60 секунд. Запрошенная страница представляет собой скрипт PHP

Я провел несколько дней, пытаясь найти ответы, и попробовал все, что я могу найти в Интернете, включая несколько записей здесь, в Stack Overflow, ничего не работает.

• $ _SERVER не дает значения
• Nginx переписать не работает с расширением .php
• Ошибка nginx подключиться к php5-fpm.sock не удалось (13: отказ от прав)
• php-fpm разбился, когда curl или file_get_contents запросили https-url
• Сложность Ioncube с PHP 5.5

Я пробовал изменять настройки PHP, настройки PHP-FPM и настройки Nginx. Вы можете увидеть вопрос, который я поднял на форумах NginX в пятницу ( http://forum.nginx.org/read.php?9,237692 ), хотя он не получил ответа, поэтому я надеюсь, что я смогу найти ответьте здесь, прежде чем я вынужден вернуться к Apache, который, как я знаю, работает.

Это не та же проблема, что и ошибки HTTP 500 в других записях.

Я смог реплицировать проблему с помощью нового экземпляра micro AWS NginX с использованием PHP 5.4.11.

Чтобы помочь любому, кто хочет увидеть проблему в действии, я собираюсь провести вас через настройку, которую я запускал для последнего тестового сервера Micro.

Вам нужно будет запустить новый экземпляр AWS Micro (поэтому он бесплатный) с помощью AMI ami-c1aaabb5

Эта запись PasteBin имеет полную настройку для запуска, чтобы отразить мою тестовую среду. Вам просто нужно изменить example.com в конфигурации NginX в конце

http://pastebin.com/WQX4AqEU

Как только вы настроитесь, вам просто нужно создать образец файла PHP, который я тестирую, с которым

<?php sleep(70); die( 'Hello World' ); ?> 

Сохраните это в webroot, а затем проверьте. Если вы запустите скрипт из командной строки, используя php или php-cgi, он будет работать. Если вы получите доступ к скрипту через веб-страницу и закроете журнал доступа /var/log/nginx/example.access.log , вы заметите, что получите ответ HTTP 1.1 499 через 60 секунд.

Теперь, когда вы можете увидеть таймаут, я рассмотрю некоторые изменения конфигурации, которые я сделал как для PHP, так и для NginX, чтобы попытаться обойти это. Для PHP я создам несколько файлов конфигурации, чтобы их можно было легко отключить

Обновите PHP FPM Config, чтобы включить внешние файлы конфигурации

 sudo echo ' include=/usr/local/php/php-fpm.d/*.conf ' >> /usr/local/php/etc/php-fpm.conf в sudo echo ' include=/usr/local/php/php-fpm.d/*.conf ' >> /usr/local/php/etc/php-fpm.conf 

Создайте новую конфигурацию PHP-FPM для переопределения таймаута запроса

 sudo echo '[www] request_terminate_timeout = 120s request_slowlog_timeout = 60s slowlog = /var/log/php-fpm-slow.log ' > /usr/local/php/php-fpm.d/timeouts.conf 

Измените некоторые глобальные настройки, чтобы обеспечить интервал аварийного перезапуска 2 минуты

 # Create a global tweaks sudo echo '[global] error_log = /var/log/php-fpm.log emergency_restart_threshold = 10 emergency_restart_interval = 2m process_control_timeout = 10s ' > /usr/local/php/php-fpm.d/global-tweaks.conf 

Затем мы изменим некоторые параметры PHP.INI, снова используя отдельные файлы

 # Log PHP Errors sudo echo '[PHP] log_errors = on error_log = /var/log/php.log ' > /usr/local/php/conf.d/errors.ini sudo echo '[PHP] post_max_size=32M upload_max_filesize=32M max_execution_time = 360 default_socket_timeout = 360 mysql.connect_timeout = 360 max_input_time = 360 ' > /usr/local/php/conf.d/filesize.ini 

Как вы можете видеть, это увеличивает тайм-аут сокета до 3 минут и помогает регистрировать ошибки.

Наконец, я отредактирую некоторые параметры NginX, чтобы увеличить тайм-аут той стороны

Сначала я редактирую файл /etc/nginx/nginx.conf и добавляю его в директиву http fastcgi_read_timeout 300;

Затем я редактирую файл / etc / nginx / sites-enabled / example, который мы создали ранее (см. Запись pastebin), и добавьте следующие параметры в директиву сервера

 client_max_body_size 200; client_header_timeout 360; client_body_timeout 360; fastcgi_read_timeout 360; keepalive_timeout 360; proxy_ignore_client_abort on; send_timeout 360; lingering_timeout 360; 

Наконец, я добавляю следующее в раздел ~ .php $ сервера dir

 fastcgi_read_timeout 360; fastcgi_send_timeout 360; fastcgi_connect_timeout 1200; 

Прежде чем повторять сценарий, запустите nginx и php-fpm, чтобы убедиться, что новые настройки были подняты. Затем я пытаюсь получить доступ к странице и все еще получаю запись HTTP / 1.1 499 в файле NginX example.error.log.

Итак, где я иду не так? Это просто работает на apache, когда я устанавливаю максимальное время выполнения PHP до 2 минут.

Я вижу, что настройки PHP были подобраны, запустив phpinfo () с веб-страницы. Я просто не понимаю, я действительно думаю, что слишком много было увеличено, так как это должно было просто потребовать изменения max_execution_time PHP, default_socket_timeout, а также fastcgi_read_timeout от NginX только в директиве location-> server .

Обновление 1

Проведя еще один тест, чтобы показать, что проблема заключается не в том, что клиент умирает, я модифицировал тестовый файл

 <?php file_put_contents('/www/log.log', 'My first data'); sleep(70); file_put_contents('/www/log.log','The sleep has passed'); die('Hello World after sleep'); ?> 

Если я запустил скрипт с веб-страницы, я увижу, что содержимое файла будет установлено в первую строку. Через 60 секунд в журнале NginX появляется ошибка. Через 10 секунд содержимое файла изменяется на вторую строку, доказывая, что PHP завершает процесс.

Обновление 2

Установка fastcgi_ignore_client_abort; изменяет ответ от HTTP 499 на HTTP 200, хотя ничего не возвращается конечному клиенту.

Обновление 3

Установив Apache и PHP (5.3.10) на поле прямо (используя apt), а затем увеличивая время выполнения, проблема также возникает и на Apache. Симптомы такие же, как и у NginX, ответ HTTP200, но фактическое время соединения с клиентом перед раздачей.

Я также начал замечать в журналах NginX, что если я тестирую с помощью Firefox, он делает двойной запрос (например, этот PHP-скрипт выполняется дважды, когда он длится более 60 секунд ). Хотя, похоже, это клиент, запрашивающий при неудачном сценарии