PHP-FPM and Nginx: 502 Bad Gateway

Question

Configuration

• Ubuntu Server 11.10 64 bit
• Amazon AWS, Ec2, hosted on the cloud
• t1.micro instance

Before I write an

Answer 1

All right after trying every solution on the web I ended up figuare out the issue using very simple method , first I cheked php-fpm err log

cat /var/log/php5-fpm.log 

and the most repeated error was

" WARNING: [pool www] server reached pm.max_children setting (5), consider raising it "

I edit PHP-fpm pools setting

nano /etc/php5/fpm/pool.d/www.conf

I chenged This Line

pm.max_children = 5

To new Value

pm.max_children = 10

BTW I'm using low end VPS with 128MB ram As everyone else I was thinkin redusing pm.max_children will make my server run faster consume less memory , but the setting we using were too low tho even start PHP-fpm process . I hope this help others since I found this after 24 hour testing and failing , ever my webhost support were not able to solve the issue .