# How to tune nginx for 800-1200 concurrent connections? **URL:** \ **Category:** NGINX\ **Created:** [September 19, 2011, 4:29pm UTC](https://www.ruby-forum.com/t/how-to-tune-nginx-for-800-1200-concurrent-connections/211993 "2011-09-19T16:29:56Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\ **Post date:** [September 19, 2011, 4:29pm UTC](https://www.ruby-forum.com/t/how-to-tune-nginx-for-800-1200-concurrent-connections/211993/1 "2011-09-19T16:29:56Z")
Dear all, I run nginx as stand-alone webserver (not as Apache proxy) on an image gallery website. The server has to handle up to 1,200 concurrent connections on Port 80, the average number throughout the day is around 500-600. During peak times, the server suffers a bit under its load and I wonder whether there is anything that I can do to decrease the load by tuning the nginx config. I should add that Apache went nuts handling the site and therefore nginx is already a great relief to have. The site has just around 3,000 unique visitors but up to 250,000 pageviews per day. ## Here are the relevant server specs: 4 cores at 2.1 GHz 1 GB RAM (average free RAM is around 800 MB even during peak times) ## Here is my current nginx.conf: user nginx nginx; worker\_processes 8; # default: 2 error\_log logs/error.log; pid logs/nginx.pid; events { worker\_connections 2048; # default: 1024 } http { include mime.types; default\_type application/octet-stream; client\_max\_body\_size 64M; sendfile on; tcp\_nopush on; ``` keepalive_timeout 20; #default: 3 gzip on; gzip_comp_level 2; gzip_proxied any; gzip_types text/plain text/css application/x-javascript ``` text/xml application/xml application/xml+rss text/javascript; ``` server_tokens off; include /etc/nginx/conf.d/*; ``` } ## Here are the fastcgi settings (The gallery is heavily PHP-driven): include fastcgi\_params; fastcgi\_intercept\_errors on; fastcgi\_index index.php; fastcgi\_param SCRIPT\_FILENAME $document\_root$fastcgi\_script\_name; try\_files $uri =404; fastcgi\_pass 127.0.0.1:9000; I would appreciate your comments and suggestions a lot - Thank you very much in advance! Kind regards -A Posted at Nginx Forum: > **[How to tune nginx for 800-1200 concurrent connections?](https://forum.nginx.org/read.php?2,215383,215383#msg-215383)** > > Dear all, I run nginx as stand-alone webserver (not as Apache proxy) on an image gallery website. The server has to handle up to 1,200 concurrent connections on Port 80, the average number throughout the day is around 500-600. During peak times, the... ---
**Author:** ![dullnicker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/47e85d/32.png) [@dullnicker](https://www.ruby-forum.com/u/dullnicker)\ **Post date:** [September 19, 2011, 4:52pm UTC](https://www.ruby-forum.com/t/how-to-tune-nginx-for-800-1200-concurrent-connections/211993/2 "2011-09-19T16:52:48Z")
are the images served through PHP? if so make them static and it will increase thoughrougput by tons. Additionally you could possibly reduce worker\_processes to 4-6 to reduce context switching. ---
**Author:** ![dullnicker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/47e85d/32.png) [@dullnicker](https://www.ruby-forum.com/u/dullnicker)\ **Post date:** [September 19, 2011, 10:40pm UTC](https://www.ruby-forum.com/t/how-to-tune-nginx-for-800-1200-concurrent-connections/211993/3 "2011-09-19T22:40:24Z")
- might consider turning up keepalive to 65 - depending on the nature of your content you might want to turn up when it expires – example: expires 10m; - looks like you have 2 workers per core – typically a worker process per core is recommended (or maybe your have intel cores with “hyerthreding”, in which case maybe 8 is the more relevant # - what’s your cpu load like? is your server cpu-bound or is IO the problem? if you can find some way to do fewer disk reads and more ram reads that will help ---
**Author:** ![dullnicker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/47e85d/32.png) [@dullnicker](https://www.ruby-forum.com/u/dullnicker)\ **Post date:** [September 20, 2011, 10:15am UTC](https://www.ruby-forum.com/t/how-to-tune-nginx-for-800-1200-concurrent-connections/211993/4 "2011-09-20T10:15:03Z")
On 19 September 2011 16:29, dullnicker [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Dear all, > > I run nginx as stand-alone webserver (not as Apache proxy) on an image > gallery website. The server has to handle up to 1,200 concurrent > connections on Port 80, the average number throughout the day is around > 500-600. > The site has > just around 3,000 unique visitors but up to 250,000 pageviews per day. So 80+ hits per person per day and 3 per second, but 550 concurrent connections? I haven’t seen a pattern like this before and I’d be interested to know how it works. There may be ways to optimize the application for it. I wouldn’t expect nginx to be the problem though. If any significant portion of that concurrency is being held by PHP, that’ll be tying up a lot of resources. Thomas ---
**Author:** ![dullnicker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/47e85d/32.png) [@dullnicker](https://www.ruby-forum.com/u/dullnicker)\ **Post date:** [September 20, 2011, 8:23am UTC](https://www.ruby-forum.com/t/how-to-tune-nginx-for-800-1200-concurrent-connections/211993/5 "2011-09-20T08:23:03Z")
I think the bottleneck may be the PHP, it is a piece of cake for ngx to handle 1k concurrent connections without any special tuning. ---
**Author:** ![dullnicker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/47e85d/32.png) [@dullnicker](https://www.ruby-forum.com/u/dullnicker)\ **Post date:** [September 25, 2011, 6:45pm UTC](https://www.ruby-forum.com/t/how-to-tune-nginx-for-800-1200-concurrent-connections/211993/6 "2011-09-25T18:45:59Z")
Lots of directions to go with this question, here are 2. 1. The IO bound questions: Your client\_max\_body\_size has me wondering how big these images actually are. Whats the average size of these images? 2. Your PHP app is inefficent: I run a php gallery (gallery2). Its pretty damn slow/cpu hungry. In order to speed things up make sure your php has something like [http://eaccelerator.net](http://eaccelerator.net) running. It increased my performance more then moving from apace1 (yes 1) to nginx. Posted at Nginx Forum: > **[Re: How to tune nginx for 800-1200 concurrent connections?](https://forum.nginx.org/read.php?2,215383,215807#msg-215807)** > > Dear all, I run nginx as stand-alone webserver (not as Apache proxy) on an image gallery website. The server has to handle up to 1,200 concurrent connections on Port 80, the average number throughout the day is around 500-600. During peak times, the... ---
**Author:** ![dullnicker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/47e85d/32.png) [@dullnicker](https://www.ruby-forum.com/u/dullnicker)\ **Post date:** [September 25, 2011, 9:21pm UTC](https://www.ruby-forum.com/t/how-to-tune-nginx-for-800-1200-concurrent-connections/211993/7 "2011-09-25T21:21:12Z")
On 09/25/2011 06:45 PM, tsaavik wrote: > proxy\_cache might be beneficial. You could just toss some ‘hot’ files > into a ramdrive (/dev/shm) and symlink them (ln -s) to test. The page cache will do something like this transparently. If there’s not enough ram left for the page cache to keep the files in memory then you also don’t have enough ram to add a ram drive. Regards, Dennis ---
**Author:** ![dullnicker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/47e85d/32.png) [@dullnicker](https://www.ruby-forum.com/u/dullnicker)\ **Post date:** [September 26, 2011, 11:31am UTC](https://www.ruby-forum.com/t/how-to-tune-nginx-for-800-1200-concurrent-connections/211993/8 "2011-09-26T11:31:09Z")
Dear all, thank you very much for your answers. What I did some days ago was installing APC (Alternative PHP Cache) on the server. I could not believe the results, but still - days after - they are as good as they were from the start. Server Load dropped like crazy. The momentary average server load is \< 0.60, while it was \>2.00 before. Therefore the need for any further optimization has vanished. Again, thank you both for taking the time to answer to my question. Kind regards -Amitz Posted at Nginx Forum: > **[Re: How to tune nginx for 800-1200 concurrent connections?](https://forum.nginx.org/read.php?2,215383,215831#msg-215831)** > > Dear all, I run nginx as stand-alone webserver (not as Apache proxy) on an image gallery website. The server has to handle up to 1,200 concurrent connections on Port 80, the average number throughout the day is around 500-600. During peak times, the...