In first part of this series, we have seen many combinations of different WordPress setup with different caching plugins. Today, we will use an altogether different way of caching!
Rather than asking a complex PHP-MySQL application like WordPress to do some extra work for caching, we will ask light-weight Nginx to cache WordPress content on its end.
Nginx has built-in support forfastcgi_cache but it doesn’t support conditional cache purge out of the box. Conditional cache purging is needed to rebuild cached content after you edit a post/page from WordPress dashboard or approve a comment on an article.
Install Nginx with fastcgi_cache_purge module
First, check if your nginx already supports this by running command
nginx -V 2>&1 | grep nginx-cache-purge -oIf you see nginx-cache-purge in output then you already have it. Otherwise run following commands to install nginx with fastcgi_cache_purge module.
sudo add-apt-repository ppa:brianmercer/nginx
sudo apt-get update
sudo apt-get install nginx-customInstall Nginx Helper Plugin
Above step ensures that Nginx can purge a page from its fastcgi_cache selectively. But Nginx cannot automatically find out which page to purge and when to purge?
So install Nginx helper plugin from WordPress plugin repository and activate it. Apart from other features, it provides cache purging options. Just activate it, go to its settings and turn on “Enable Cache Purge” option.
If you want more control over your cache purging rules, you can play with different purging options it provides.
Nginx Configuration for WordPress with fastcgi_cache_purge support
No matter how you are using WordPress, i.e. single or Multisite (with subdirectory/subdomain/domain-mapping)fastcgi_cache related configuration will remain similar.
Use ramdisk (tmpfs) to store cached content
You need give Nginx a folder storefastcgi_cache content. I will recommend using /var/run on Ubuntu as its mounted as tmpfs (in RAM). If you do not have ample RAM you can pick any other location.
If you are going with RAM, make sure you check size of /var/run folder. Its generally 20% of your total RAM size.
To verify it, run this command: df -h /var/run
You will see output like below:
Filesystem Size Used Avail Use% Mounted on
tmpfs 6.3G 364K 6.3G 1% /runIt looks like we have more than 6GB at our disposal! Our server has 32GB RAM by the way, so 6GB is close to 20%
Nginx Configuration for exmaple.com
Now make changes to /etc/nginx/sites-available/example.com file so it looks like one below:
#move next 3 lines to /etc/nginx/nginx.conf if you want to use fastcgi_cache across many sites
fastcgi_cache_path /var/run/nginx-cache levels=1:2 keys_zone=WORDPRESS:500m inactive=60m;
fastcgi_cache_key "$scheme$request_method$host$request_uri";
fastcgi_cache_use_stale error timeout invalid_header http_500;
server {
server_name example.com www.example.com;
access_log /var/log/nginx/example.com.access.log;
error_log /var/log/nginx/example.com.error.log;
root /var/www/example.com/htdocs;
index index.php;
set $skip_cache 0;
# POST requests and urls with a query string should always go to PHP
if ($request_method = POST) {
set $skip_cache 1;
}
if ($query_string != "") {
set $skip_cache 1;
}
# Don't cache uris containing the following segments
if ($request_uri ~* "(/wp-admin/|/xmlrpc.php|/wp-(app|cron|login|register|mail).php|wp-.*.php|/feed/|index.php|wp-comments-popup.php|wp-links-opml.php|wp-locations.php|sitemap(_index)?.xml|[a-z0-9_-]+-sitemap([0-9]+)?.xml)") {
set $skip_cache 1;
}
# Don't use the cache for logged in users or recent commenters
if ($http_cookie ~* "comment_author|wordpress_[a-f0-9]+|wp-postpass|wordpress_no_cache|wordpress_logged_in") {
set $skip_cache 1;
}
location / {
try_files $uri $uri/ /index.php?$args;
}
location ~ .php$ {
try_files $uri /index.php;
include fastcgi_params;
fastcgi_pass unix:/var/run/php5-fpm.sock;
fastcgi_cache_bypass $skip_cache;
fastcgi_no_cache $skip_cache;
fastcgi_cache WORDPRESS;
fastcgi_cache_valid 60m;
}
location ~ /purge(/.*) {
fastcgi_cache_purge WORDPRESS "$scheme$request_method$host$1";
}
location ~* ^.+\.(ogg|ogv|svg|svgz|eot|otf|woff|mp4|ttf|rss|atom|jpg|jpeg|gif|png|ico|zip|tgz|gz|rar|bz2|doc|xls|exe|ppt|tar|mid|midi|wav|bmp|rtf)$ {
access_log off; log_not_found off; expires max;
}
location = /robots.txt { access_log off; log_not_found off; }
location ~ /\. { deny all; access_log off; log_not_found off; }
}The line fastcgi_cache_use_stale is what makes caching on Nginx-side unique. This line tells Nginx to use old (stale) cached version of page if PHP crashes. This is something not possible with WordPress caching plugins.
Don’t Forget:
Always test your Nginx configuration and then reload it. All changes to Nginx config must be followed with these commands:
nginx -t && service nginx reloadMust Read:
- Checklist For Perfect WordPress-Nginx Setup - It will help you verify if your caching will work after PHP/MySQL crash.
For WordPress Multisite, you can either make necessary changes by following this guide or check my next posts.
Wow! Nice work! This is the first complete how-to and configuration that really works well
I do have 1 request. If I’m not mistaken, the cache of a post does not get purged when you edit a post. I think this rather essential (the homepage does get purged).
@Greg
Have you installed our Nginx Helper plugin?
Also, after plugin installation, you need to activate “Cache Purging” options.
Please let me know if you have done it already?
Yes of course
Check the options (and the code) when you update a post it does purge the homepage, but does not purge the posts itself.
Can you give me a post URL here? I will check now…
I’ve mailed some logging and the URL. Thanks for the quick response! And my compliments for this site!
Admin-note: Discussion is moved here.
@Greg
Please use support forum instead. Solution to your issue may help others as well.
Don’t worry. Nginx-Helper doesn’t log any sensitive information.
Thank you for this article. However when I try to install nginx-custom, I receive the following error:
The following packages have unmet dependencies:
nginx-custom : Depends: nginx-common (= 1.2.4-1ppa4~precise) but 1.2.4-2ubuntu0ppa1~precise is to be installed
E: Unable to correct problems, you have held broken packages.
Does this mean the repo is not updated for my version of nginx?
@Richard
I have tested everything on Ubuntu 12.04 (precise) which is same as yours.
Try running following commands:
Let me know if above works for you.
Unfortunaltely I receive the same error message as before. I followed the http://rtcamp.com/tutorials/installing-phpapc-mysql-postfix-nginx-and-wordpress-on-ubuntu/ tutorial before this one. Could it be that the nginx-stable repository from that tutorial is conflicting with the brianmercer from this one?
Most likely yes! Please remove
ppa:nginx/stablefrom/etc/apt/sources.list.dand try again. Don’t forget to runsudo apt-get updatein between.Just for info, on our server, I have
ppa:nginx/stableandppa:brianmercer/nginxboth coexisting together.Alternatively, packages from here http://www.dotdeb.org/instructions/ will also work (most likely)
I’ve removed the stable from sources, ran the apt-get update and tried installing nginx-custom, but still no luck. Think I will just start from scratch with a fresh install of my server. I was wondering, would you recommend using fast-cgi caching over W3TC, performance wise?
Also, if I may suggest a future tutorial, it would be about configuring linux for sftp or scp use. Specifically on setting the correct group/user permissions for a root user to add/modify files and folders using filezilla or winscp, while still maintaining ownership to www-data. I’ve tried multiple tutorials found online, but none of them seem to work for me. Anyway, thanks for your help and providing these ningx tutorials to the community. Much appreciated!
@Richard
I have done some benchmarks but its hard to conclude either way.
Once a page gets cached, nginx does all the work. So there is not much performance difference for “reading/serving” a cached page.
In theory, W3TC cached pages will be served faster when small number of pages are cached. For large sites, where 10000′s of pages are cached, fastcgi might be faster.
In terms of “creating/generating” a cached page, I feel nginx-fastcgi will take less resources.
Personally, I am using nginx-fastcgi for page-cache everywhere. I also use W3TC for Object-Cache, Database-Cache & CDN.
==
Regarding SFTP, we login with www-data user to edit files. So we never faced any permission issue.
Excellent article, thank you.
Do you know if it is possible to use a free control panel with the above configuration?
Thank you.
You can try ISPConfig. I will be posting about in few days.
Looking forward to this
It’s the only thing stopping me going ahead and trying this tbh, and I’m looking forward to experimenting with the added speed this would give WordPress, but retaining the ease of having a control panel for day to day task…
Thanks in advance.
Hi, In order for this line to work
A Python module had to be installed first on Ubuntu like this:
Without installing that, the command `add-apt-repository1 came back as not being recognized Do you have a repository to use for Ubuntu 10.10? since the one you recommend is for 12.04 which my host (Rackspace) has some problem with.
Thanks, Nick
Hi Nick,
This article is part of series – http://rtcamp.com/series/wordpress-nginx-tutorials/
Instruction to use
sudo apt-get install python-software-properties -yare covered in this previous article.I do not have repository for Ubuntu 10.10 but you can upgrade your Ubuntu to latest release.
Hi, I did. Created a new virtual server with 12.04 followed your instructions from step 1. Now I am on this step and the following line:
returns back the following:
Any ideas what to do? I tried every other suggestion written above on this page? Thanks, NIck
Actually I figured it out, had some depository in there that installed nginx that is newer than what the brianmercer/nginx could use.
Hi ,
I implemented it the way as described in tutorial but faced serious performance issue , I can see in configuration index.php is not getting cached ? is it so ? Can we enable caching for index.php ? Will the nginx helper plugin will work with it then.
Hi,
When I try to install, I get the following error:
E: Unable to locate package nginx-custom
Any ideas?
@Joe
Sorry for delayed reply. I am traveling from last 2-3 days.
Did u forget to run
apt-get updateafter addingsudo add-apt-repository ppa:brianmercer/nginx?Please paste here output of command:
apt-cache showpkg nginx. It might help me debugging your issue.Actualli I did the installation in centos , I recompiled the module with nginx it is the latest stable version so i dont think their is no problem with the package but it may be with the configuration please find below config -
Q1 : What does the below directive mean
fastcgi_cache_path /data1/nginx-cache1 levels=1:2 keys_zone=WORDPRESS:500m inactive=420m;
is 500m in MBs or minutes ?what is the ideal value for it and for inactive ?
Q2 : fastcgi_cache_valid 420m;
What does this directive mean ? is it in MB or minutes ? what is the ideal value , Our aim is to keep the cache for many days and it should refresh only when some does a new posting .
Q3: Is supercache in nginx better then Nginx with Fastcgi cache ? I tried varnish but had lot of problem ?
Help will be appreciated as we have around million hits in a day and during peak loads we get very high load on Mysql and PHP-FPm process.
Thanks ,
Abhishek
I see many inconsistencies in your config so for config part, please refer to my post above.
Regarding your questions:
A1. 500m is MB (size). You can find details about parameter here
Ideal value depends on your setup and requirement. We use inactive = 10m which is default. If load on server increases in future, we won’t mind using higher value.
A2. 420m is minute as its duration value. You can find details about parameter here
A3. I like nginx fastcgi-cache. Its bit complex to maintain but I enjoy using it. I am not sure about benchmarks but in theory, fastcgi-cache should perform better on large sites (1000s of cached pages)
For any site, you can tweak things at many level. Start with http://gtmetrix.com/ and see how your site scores. Optimize by following gtmetrix.com suggestion first. Then you can move over to Nginx, PHP-FPM and also mysql-optimization.
Thanks for the response , Can we cache index.php , In tutorial i can see you are not caching WordPress index.php , Will nginx nginx helper plugin work with it ?
index.phpis already cached. Its URL is “/” only.Nginx-helper should work with it. If you find any issue, please let us know.
I’ve got a question concerning this line: fastcgi_cache_path /var/run/nginx-cache
What ownership/permission does that folder need to have? It seems nginx created it automatically like this:
drwx—— 2 www-data root 4096 Jan 11 07:06 nginx-cache
@Ovidiu
Nginx automatically creates the required cache directory.
On our server also, we have same ownership & permissions:
I did not face any issue with that. Are you facing any problem with that?
Struggling a bit but I will raise this issue on the support forum if I can’t solve it. I was just making sure that permissions and rights are not causing problems.
@RahulBansal
1. From your comments above, I understand that you use nginx + fastcgi_cache for this site’s page caching, which implies that cached, static versions of the dynamic pages are served by Nginx, correct?
In that case, what’s the need for Object-Cache & Database-Cache using W3 Total Cache? The user requests don’t reach the database anyway, so, why?
2. Is this meant for a single server setup only? or does it work just fine on a setup with multiple load-balanced servers too?
Great job with the tutorials by the way!
@Aahan
#1. Object-Cache & Database-Cache will speed-up “write” to cache. On a busy site where cache-needs to be flushed periodically, this may provide significant performance improvement.
Also, on our network, we have support-forum, product-store and a community-blog. Together, they keep more than 50 users logged-in anytime. For logged-in user we do not use page-cache so object/database cache helps speed-up page-loading significantly.
Finally, on any site, wp-admin (backend) will surely benefit from presence of object/database cache.
#2. I haven’t tested this setup with load-balancer so this is tested with single-server setup only. Multiple load-balancers can be configured in many-ways so its hard to cover them here. Only thing I will suggest is to go with memcache in multiple-server setup.
Ah, makes sense. Thank you.
Oh, I missed this earlier.
How does this kind of caching handle widgets like “Latest Posts” or “Recent Comments” in sidebar on Post pages?
Here are some examples as to what I mean:
1. Infinite scrolling on Post pages showing the latest posts (among other things).
2. Latest posts in sidebar with infinite scrolling.
So, the question (again) is, how’s caching of such features handled in this method?
I am not sure how Mashable/ReadWrite guys are doing it but if you check browsers’ developer-console, you will see AJAX requests are made to fetch extra content from server.
For example, I saw request to a URL – http://readwrite.com/_ajax/article-list?page=3&count=10 on ReadWrite.com
I am not sure if calls to
/_ajax/article-listare routed to WordPress. Assuming they are routed to WordPress, object/database-level caching will directly reduce PHP’s work.You can tweak Nginx config also. Basically, you can ask Nginx to cache output of PHP if
request_uristarts with “/_ajax/”. Also you need to tell nginx to use fastcgi_cache even if query string is present (page, count vars in above URL).Make sure you adjust “fastcgi_cache_key” to include $args in Nginx config.
In our config => if browser sends a GET request (without query variable) to Nginx server, Nginx caches entire page-output it receives from PHP backend.
Things like “Latest Posts”, “Recent Comments” etc are not known to Nginx. Its WordPress things and falls under PHP-mysql business! This is where object/database-caching kicks in. For second-page, PHP has to do less work because it can find result for “Latest Posts”, “Recent Comments”, etc in object/database-cache. For this reason, I always recommend using object/database-caching no matter which type of page-caching is being used (or even if page-cache is not used at all)
Awesome tutorial, thanks for putting it together. I’ve setup three WordPress installations under a single domain:
http://www.mainsite.com, http://www.mainsite.com/blog1, http://www.mainsite.com/blog2
They all serve pages correctly, however only the two WordPress installations in subdirectories correctly cache for non-logged in visitors (registered users don’t see cache ever, as expected). In other words, http://www.mainsite.com/blog1/a-random-post will serve a nginx-cached page (timestamp from half an hour ago, for example, reloading does not change timestamp), but http://www.mainsite.com/another-random-post generates a new page every time it’s accessed (timestamp updates with every reload).
Any clue why this would be happening? Any help would be greatly appreciated.
Here is the fastcgi part of my nginx config file:
Here is my domain specific config file:
Thanks again.
We have a similar setup like yours on our demo server.
Rather than following…
We are using…
Try above change to see if it works!
Thanks so much for your quick reply. I made the change in the domain specific config file. Unfortunately, I’m still seeing the same issue.
In a clean browser the two WordPress installs in subdirectories, http://www.mainsite.com/blog1 and http://www.mainsite.com/blog2, run as expected, they cache correctly (create a cache file and access it on subsequent page loads). However, the WordPress install in the root directory, http://www.mainsite.com, does not cache at all. Refreshing the page results in footers like this:
and a few seconds later:
The WordPress install in the root directory never accesses the cache, but seems to be generating new cache files continually, whereas the WordPress installs in the subdirectories, http://www.mainsite.com/blog1 and http://www.mainsite.com/blog2, cache a page and show in the footer that they’re accessing caches from 10, 20, 60 minutes ago, etc.
Any idea what might be happening?
Thanks again for the help.
Try adding following line:
fastcgi_ignore_headers Cache-Control Expires Set-CookieAfter line:
fastcgi_cache_use_stale error timeout invalid_header http_500;Do not forget to reload nginx config. Let me know if it works?
Important: When you comment out extra lines for blogs in subdirectories, does it activates caching for main-site (in root-dir)?
Bingo! I had tried that before, I thought, but it works perfectly now.
Thank you so much.
For reference for anyone in a similar situation, here is the cache section of my working nginx.conf:
# fastcgi cache config
fastcgi_cache_path /var/run/nginx-cache levels=1:2 keys_zone=WORDPRESS:100m inactive=180m;
fastcgi_cache_key “$scheme$request_method$host$request_uri”;
fastcgi_cache_use_stale error timeout invalid_header http_500;
fastcgi_ignore_headers Cache-Control Expires Set-Cookie;
And here is the domain specific conf file:
server {
listen 80;
#listen [::]:80 default ipv6only=on;
server_name http://www.mainsite.com mainsite.com;
root /home/mainsite/domains/mainsite.com/public_html;
access_log /home/mainsite/domains/mainsite.com/logs/access.log;
error_log /home/mainsite/domains/mainsite.com/logs/error.log;
index index.php;
error_page 404 /404.html;
set $no_cache 0;
# POST requests and urls with a query string should always go to PHP
if ($request_method = POST) {
set $no_cache 1;
}
if ($query_string != “”) {
set $no_cache 1;
}
# Don’t cache uris containing the following segments
if ($request_uri ~* “(/wp-admin/|/xmlrpc.php|/wp-(app|cron|login|register|mail).php|wp-.*.php|/feed/|index.php|wp-comments-popup.php|wp-links-opml.php|wp-locations.php|sitemap(_index)?.xml|[a-z0-9_-]+-sitemap([0-9]+)?.xml)”) {
set $no_cache 1;
}
# Don’t use the cache for logged in users or recent commenters
if ($http_cookie ~* “comment_author|wordpress_[a-f0-9]+|wp-postpass|wordpress_no_cache|wordpress_logged_in”) {
set $no_cache 1;
}
set $dir “”;
if ($request_uri ~ ^/([^/]*)/.*$ ) {
set $dir1 /$1;
}
location / {
try_files $uri $uri/ $dir1/index.php?$args;
}
location ~ .php$ {
try_files $uri /index.php;
include fastcgi_params;
fastcgi_pass unix:/var/run/php5-fpm-mainsite.sock;
fastcgi_cache_bypass $no_cache;
fastcgi_no_cache $no_cache;
fastcgi_cache WORDPRESS;
fastcgi_cache_valid 180m;
}
location ~ /purge(/.*) {
fastcgi_cache_purge WORDPRESS “$scheme$request_method$host$1″;
}
location ~* ^.+\.(ogg|ogv|svg|svgz|eot|otf|woff|mp4|ttf|rss|atom|jpg|jpeg|gif|png|ico|zip|tgz|gz|rar|bz2|doc|xls|exe|ppt|tar|mid|midi|wav|bmp|rtf)$ {
access_log off; log_not_found off; expires max;
}
location = /favicon.php { access_log off; log_not_found off; }
location = /robots.txt { access_log off; log_not_found off; }
location ~ /\. { deny all; access_log off; log_not_found off; }
}
Glad to know that your problem is solved.
Its better if access to the purge URL is limited to localhost only:
You can restrict it if you want but purging a cache won’t do any harm apart from wasting some CPU cycles.
This unrestricted purge comes handy when a member of our team want to see his changes immediately. We have a big team working on different parts of this site. So whenever a dev working on http://rtcamp.com/store/ want to force cache-invalidation for store only, then can simply open http://rtcamp.com/purge/store/ in browser.
Give your team members SSH access and they can purge the cache using wget or curl.
Anyway one reason why the purge should be restricted is that the page Nginx displays in response to a purge contains the full path of your cache. It’s better not to reveal this information to outsiders.
Thanks for your suggestion but I still prefer
/purge/via browser. I have no energy to teach everyone SSH, etc specially for something so trivial as cache-purge.At the max, I will consider allowing direct-purges from our office-IP address. All machine’s gets same public-IP so that will be easy.
About full-paths… Nginx cache dir is not web-accessibles so unless someone gets into server, they won’t be able to do anything with cache-dir directly. In this case, I will focus more on hardening server so that a hacker won’t be able to log into server in the first place!
Please let me know if there is any serious known threat we can be subjected to just by exposing cache-dir location.
Another point, keys_zone in fastcgi_cache_path specifies how much shared memory is going to be used to store meta data about the cache. The point being that it is memory not disk space. So setting it to 500MB or something high like that is asking for trouble. The example given on the nginx wiki is a much more realistic 10MB.
If you want to restrict the maximum amount of disk space that the cache takes you have to use the max_size parameter.
We have 32GB RAM! So 500MB is too less here. In fact, its 1.5625% of all available RAM.
You are free to use whatever values you wish.
That may be the case for you but a lot of people using Nginx are on a low end VPS and they are using Nginx primarily to save memory.
That is the point! People can modify their config. In fact, they need to modify atleast domain name from example.com to their own domain.
I will prefer to have values that we use on our client sites so that we can speed-up our client work. Most of our clients use more than 16GB RAM so 500MB cache is still very much practical.
Another thing – rather than using VPS, you can go for dedicated servers from http://servercraft.co/dedicated-servers/. There are few more companies, which offer 4GB RAM for $49 and 8GB for $85. If you on Nginx, its better to go for such offerings IMHO.
Thanks for great tutorials. Is it possible to setup Varnish on top of Nginx? I would love see you doing a post about it.
We do not use Varnish. Reason – http://rtcamp.com/series/wordpress-nginx-tutorials/
Can you explain the reason why you don’t cache urls with a query string?
Just being curios
I think it depends on application and few other things. Sometime, query strings are unique so they generate unique results.
Rather than disabling cache for query_strings altogether, we use mix of conditions to decide which query strings to be cached.
You may find this discussion related -> http://rtcamp.com/support/topic/cache-urls-which-use-only-javascript-related-queries/
Ok, thanks, I’ve read that discussion and I understand but would you mind sharing some more tips from the way you are tweaking your caching? clearly this how-to here is kept “safe” for most people hence no caching of anything query related.
What do you suggest when you are running new repos that provides nginx-common @ ver
1.2.7-0ubuntu0ppa1~precisevs ver= 1.2.4-1ppa4~precisethat Brian’s ppa provides? I’d prefer to stick with prerolled tested debs rather than compiling at each ver update.Hello, ran into smalll problem
W: Failed to fetch http://ppa.launchpad.net/brianmercer/nginx/ubuntu/dists/quantal/main/source/Sources 404 Not Found
W: Failed to fetch http://ppa.launchpad.net/brianmercer/nginx/ubuntu/dists/quantal/main/binary-amd64/Packages 404 Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
Is there alternatives?
Thank you!
@Lauris
That Launchpad repo is not updated with packages for Ubuntu 12.10, which is Ubuntu version you are using.
You can compile nginx with required module or give a http://www.dotdeb.org/ repo a try.
Yes, I am using Ubuntu 12.10.
I set up everything and works nice except for purge.
Thank you very much for providing all this mountain of knowledge
I will check that site.
Have a nice day.
Official/Default nginx package does not have https://github.com/FRiCKLE/ngx_cache_purge which is needed for conditional purging.
Rahul, my ubuntu server version is quantal, can i use this ngx_cache_purge by FRICKLE with Nginx helper plugin ? How to can i install the nginx-custom on my server? My nginx version is 1.2.7.
Thanks ;D
You will need to compile Nginx with required modules from sources or wait for Brian Mercer to add support for Ubuntu 12.10
If you decide to compile, have a look at – https://github.com/vladgh/VladGh.com-LEMP
hello Rahul
My nginx version is 1.2.7 i follow your guidance above, but i can not install nginx-custom.
if I see from https://launchpad.net/~brianmercer/+archive/nginx it states as follow:
PPA description
nginx_1.2.4 for 12.04 (precise).
so, what can i do???
It looks like you have installed nginx from official repo or some other repo.
Please remove/purge nginx and then add/install nginx-custom from https://launchpad.net/~brianmercer/+archive/nginx
My site was hosted in Virtual Private Server using Nginx in front of Apache (so it has Apache previously installed, NginX was used as reverse Proxy) along with SuPHP. I came here referred by WordPress Plugin NginX helper. Am I need that plugin or I can safely run my WordPress blog without it? I’m new to VPS so kindly suggest me with the plugin.
Thanks
@Arick
You won’t need nginx-helper as it looks like that you are not using Nginx’s
fastcgi_cache.For much better performance, I will recommend removing Apache and use Nginx + PHP-FPM – http://rtcamp.com/tutorials/installing-phpapc-mysql-postfix-nginx-and-wordpress-on-ubuntu/
You have a crucial typo: nginx -V 2>&1 | grep nginx-cache-purge -o
No one will find the module if it’s mispelled.
Should be: nginx -V 2>&1 | grep ngx-cache-purge -o
@Jon
That is not typo. Its correct on Ubuntu (atleast).
When you run
nginx -VYou get following output:
Hello.I used below configuration but it seems fastcgi_cache_bypass not work.
fastcgi_cache_path /dev/shm/nginx-cache levels=1:2 keys_zone=WORDPRESS:500m inactive=60m;
fastcgi_cache_key "$scheme$request_method$host$request_uri";
fastcgi_cache_use_stale error timeout invalid_header http_500;
…
set $skip_cache 0;#set $cache_uri $request_uri;
if ($request_method = POST) {
#set $cache_uri 'null cache';
set $skip_cache 1;
}
if ($query_string != "") {
#set $cache_uri 'null cache';
set $skip_cache 1;
}
if ($request_uri ~* "(/wp-admin/|/xmlrpc.php|/wp-(app|cron|login|register|mail).php|wp-.*.php|/feed/|index.php|wp-comments-popup.php|wp-links-opml.php|wp-locations.php|sitemap(_index)?.xml|[a-z0-9_-]+-sitemap([0-9]+)?.xml)") {
#set $cache_uri 'null cache';
set $skip_cache 1;
}
# Don't use the cache for logged in users or recent commenters
if ($http_cookie ~* "comment_author|wordpress_[a-f0-9]+|wp-postpass|wordpress_logged_in|w3tc_logged_out|wptouch_switch_toggle") {
#set $cache_uri 'null cache';
set $skip_cache 1;
}
location ~ /purge(/.*) {
fastcgi_cache_purge WORDPRESS "$scheme$request_method$host$1";
}
location / {
try_files $uri $uri/ /index.php?$args;
}
…
location ~ .*\.(php|php5)?$
{
try_files $uri =404;
fastcgi_cache_bypass $skip_cache;
fastcgi_no_cache $skip_cache;
fastcgi_cache WORDPRESS;
fastcgi_cache_valid 60m;
fastcgi_pass unix:/tmp/php-cgi.sock;
fastcgi_index index.php;
include fcgi.conf;
}
The problem is,if a visitor access a page[e.g.post or index] and generate this page cache,logged in user will unexpected get this page cache.Luckily the nginx isn’t generate page cache from logged in user.
So it seems fastcgi_cache_bypass not work.But i checked this configuration and NginX-wiki number of times.Everything looks correct.
Server Environment:
NginX 1.2.8[complied --with-http_ssl_module --with-http_gzip_static_module --with-ipv6 --add-module=../ngx_cache_purge-master]
PHP 5.3.23 FPM-FCGI
CentOS 5.9
Please refer this article – http://rtcamp.com/tutorials/debugging-nginx-configuration/ to debug your nginx config.
Okay.I used
error_log /home/wwwlogs/fcgidebug.log debug;
to debug it.But no error was logged.
It just logged something like this:
2013/04/14 16:08:26 [info] 19708#0: *12 client 182.118.22.* closed keepalive connection
2013/04/14 16:08:26 [info] 19708#0: *14 client 182.118.22.* closed keepalive connection
closed keepalive connectionis something you no need to worry about.May be you can try using our free support forum here – https://rtcamp.com/support/forum/wordpress-nginx/
We can try to debug it there in-depth.
At an overall level, what would you recommend between fastcgi_cache vs page caching using W3 Total Cache? Does it depend on volume of traffic?
Mine is not a MU set-up and I don’t have data on traffic as the project is not live yet.
I like fastcgi_cache as I am more comfortable playing with Nginx.
In terms of traffic, there shouldn’t be much difference. Once a page gets cached, a proper configuration will always use Nginx alone to serve cached page.
If your MU was created before WordPress 3.5, then this article can make a lot of difference – http://rtcamp.com/tutorials/nginx-map-wordpress-multisite-static-files-handling/
How about using Memcached for page caching? Somehow am not very comfortable in making disk calls too often for caching.
Btw, I am on Amazon EC2 and planning to use Memcached like this – http://www.kingletas.com/2012/08/full-page-cache-with-nginx-and-memcache.html. Whats your take?
For memcache, you will need a plugin on WordPress side to create cached version of page. Nginx can only read from memcached.
For disk I/O issue, I am already using tmpfs (RAMDisk). I already mentioned about it in above article.
By the way, even if you use disk based caching, as long as you have enough free memory, OS will cache static html pages in-memory like it caches any frequently accessed items.
Hi Rahul ,
It seems loop-page-home.php is not getting cached ….
@Abhishek
Might be some headers invalidating caching.
Try solution posted in this comment.
Add extra header for browser cache
First, we are not suppose to cache output of backend php scripts. If we do so, user-2 may see dashboard view of user-1 and so on!
Second, it you want to force caching use
expires max.expires epochis used to disable caching.Yes, i meant not to cache to browser side using expires epoch; and add_header Cache-Control “no-cache, no-store, must-revalidate, max-age=0″; and not to cache on nginx cache set $skip_cache 1;
Actualy i’m not implemented nginx cache for my heavy traffic website because i’m using varnish to cached it. Nginx is too complicated to purge cache but varnish is more simple.
You dont’ need to add any extra code if you are using Nginx only. I guess you faced issues because you have put Varnish in front of Nginx.
As far as purging is concerned, you can use a plugin like nginx-helper – http://wordpress.org/plugins/nginx-helper/ to control it.
We do not use or recommend Varnish. Reason – http://rtcamp.com/tutorials/why-we-never-use-varnish-with-nginx/
Of course, if you are happy with Nginx + Varnish together, you can continue to use the same.