Deploying Symfony 3.4.10 application error: Allowed memory size exhausted by StreamHandler.php

Question

Context

I am trying to deploy a fresh Symfony 3.4.10 application. It's the first time I deploy a Symfony application. It runs well in dev environment using the built-in php server.

I use nginx as webserver and php-fpm.

Problem

When I try to reach my application, an error is thrown in my logs saying:

2018/05/25 02:32:03 [error] 15819#15819: *1 FastCGI sent in stderr: 
    "PHP message: PHP Fatal error:  Allowed memory size of 1073741824 bytes exhausted 
    (tried to allocate 20480 bytes) 
    in /var/www/my-project/application/vendor/monolog/monolog/src/Monolog/Handler/StreamHandler.php 
    on line 107
PHP message: PHP Fatal error: 
    Allowed memory size of 1073741824 bytes exhausted 
    (tried to allocate 20480 bytes) 
    in /var/www/my-project/application/vendor/monolog/monolog/src/Monolog/Handler/StreamHandler.php 
    on line 107"
    while reading response header from upstream, 
    client: xx.xx.xx.xx, server: preprod.my-website.fr, 
    request: "GET / HTTP/2.0", 
    upstream: "fastcgi://unix:/var/run/php/php7.0-fpm.sock:", 
    host: "preprod.mywebsite.fr"

The page I try to load is just a connection form.

I allocated 1024MB in my php.ini, thinking it was because the app needed more RAM on the first call.

What seems really strange is that the log is telling the memory size is exhausted but the amount the app was trying to allocate is really low: 20480 bytes allocated for a maximum amount of 1073741824 bytes, I don't understand why it fails and how to solve this.

My website nginx configuration:

server {
    listen 443;
    listen [::]:443;

    server_name preprod.my-website.fr;
    root /var/www/my-project/application/web;

    location / {
        # try to serve file directly, fallback to app.php
        try_files $uri /app.php$is_args$args;
    }

    # PROD
    location ~ ^/app\.php(/|$) {
        fastcgi_pass unix:/var/run/php/php7.0-fpm.sock;
        fastcgi_split_path_info ^(.+\.php)(/.*)$;
        include fastcgi_params;
        # When you are using symlinks to link the document root to the
        # current version of your application, you should pass the real
        # application path instead of the path to the symlink to PHP
        # FPM.
        # Otherwise, PHP's OPcache may not properly detect changes to
        # your PHP files (see https://github.com/zendtech/ZendOptimizerPlus/issues/126
        # for more information).
        fastcgi_param SCRIPT_FILENAME $realpath_root$fastcgi_script_name;
        fastcgi_param DOCUMENT_ROOT $realpath_root;
        # Prevents URIs that include the front controller. This will 404:
        # http://domain.tld/app.php/some-path
        # Remove the internal directive to allow URIs like this
        internal;
    }

    # return 404 for all other php files not matching the front controller
    # this prevents access to other php files you don't want to be accessible.
    location ~ \.php$ {
        return 404;
    }

    error_log /var/log/nginx/my-project_error.log;
    access_log /var/log/nginx/my-project_access.log;

    # SSL configuration
    ssl on;
    ssl_certificate /etc/letsencrypt/live/preprod.my-website.fr/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/preprod.my-website.fr/privkey.pem;
}

server {
    listen 0.0.0.0:80;
    server_name preprod.my-website.fr;
    rewrite ^ https://$host$request_uri? permanent;
}

Answer 1

Ok, so I've figured how to make my application works! It was a problem of rights on my files, the user of php-fpm could not access the files and this resulted in Symfony trying to send an error.

I don't know why the exception thrown by Symfony LogicException: Missing stream url, the stream can not be opened. This may be caused by a premature call to close(). overloaded the memory limit so if someone has a clue on why, it would be super helpful to explain it!

Answer 2

This makes sense:

(1073741824b + 20480b)/1024/1024 = 1024mb

That extra 20480b put it right at the limit.

You could always up the setting in php.ini but the real question is why does it consume that much memory? Is it common for Symfony to consume that much? Also if there is some type of leak or unbounded memory consuming process it will likely crash on an increased amount of memory at some point.