Maximum number of Apache processes¶

An Apache process uses around 12MB of RAM. Apache should be configured so that the maximum number of HTTPD processes times 12MB is lower than the amount of RAM. Otherwise the system begins to swap and the performance goes down.

KeepAlive should be configured with sensible defaults¶

The KeepAlive directive enables persistent HTTP connections, allowing multiple requests to be sent over the same TCP connection. This reduces latency by as much as 50%. Especially in combination with the periodic checks of the sync client the following settings are recommended:

KeepAlive On
KeepAliveTimeout 100
MaxKeepAliveRequests 200

mod_gzip¶

mod_gzip should be used because it speeds up the transfer of data and helps to free server memory, and HTTP connections are closed faster.

MPM¶

Apache prefork has to be used. Don’t use threaded mpm with mod_php because PHP is currently not thread safe.

Hostname Lookups¶

# cat /etc/httpd/conf/httpd.conf
...
HostnameLookups off

Log files¶

Log files should be switched off for maximum performance.

Comment out the CustomLog directive. Keep ErrorLog to be able to track down errors.

Nginx module check¶

As a first step, it is necessary to check if your Nginx installation has the nginx cache purge module compiled in:

nginx -V 2>&1 | grep ngx_cache_purge -o

If your output contains ngx_cache_purge, you can continue with the configuration, otherwise you need to manually compile Nginx with the module needed.

Compile Nginx with the nginx-cache-purge module¶

1. Preparation:

cd /opt
wget http://nginx.org/keys/nginx_signing.key
sudo apt-key add nginx_signing.key
sudo vi /etc/apt/sources.list.d/nginx.list

Add the following lines (if different, replace {trusty} by your distribution

name):

deb http://nginx.org/packages/mainline/ubuntu/ trusty nginx
deb -src http://nginx.org/packages/mainline/ubuntu/ trusty nginx

Then run sudo apt-get update

2. Download the Nginx source from the ppa repository

cd /opt
sudo apt-get build-dep nginx
sudo apt-get source nginx

3. Download module(s) to be compiled in and configure compiler arguments

ls -la

Please replace {release} with the release downloaded:

cd /opt/nginx-{release}/debian

If folder “modules” is not present, do:

sudo mkdir modules
cd modules
sudo git clone https://github.com/FRiCKLE/ngx_cache_purge.git
sudo vi /opt/nginx-{release}/debian/rules

If not present, add the following line at the top under:

#export DH_VERBOSE=1:
MODULESDIR = $(CURDIR)/debian/modules

And at the end of every configure command add:

--add-module=$(MODULESDIR)/ngx_cache_purge

Don’t forget to escape preceeding lines with a backslash \. The parameters may now look like:

--with-cc-opt="$(CFLAGS)" \
--with-ld-opt="$(LDFLAGS)" \
--with-ipv6 \
--add-module=$(MODULESDIR)/ngx_cache_purge

4. Compile and install Nginx

cd /opt/nginx-{release}
sudo dpkg-buildpackage -uc -b
ls -la /opt
sudo dpkg --install /opt/nginx_{release}~{distribution}_amd64.deb

5. Check if the compilation and installation of the ngx_cache_purge module was successful

nginx -V 2>&1 | grep ngx_cache_purge -o

It should now show: ngx_cache_purge

Show Nginx version including all features compiled and installed:

nginx -V 2>&1 | sed s/" --"/"\n\t--"/g

6. Mark Nginx to be blocked from further updates via apt-get

sudo dpkg --get-selections | grep nginx

For every nginx component listed run sudo apt-mark hold <component>

7. Regular checks for nginx updates

Do a regular visit on the Nginx news page and proceed in case of updates with items 2 to 5.

Configure Nginx with the nginx-cache-purge module¶

1. Preparation Create a directory where Nginx will save the cached thumbnails. Use any path that fits to your environment. Replace {path} in this example with your path created:

sudo mkdir -p /usr/local/tmp/cache

2. Configuration

sudo vi /etc/nginx/sites-enabled/{your-ownCloud-nginx-config-file}

Add at the beginning, but outside the server{} block:

# cache_purge
fastcgi_cache_path {path} levels=1:2 keys_zone=OWNCLOUD:100m inactive=60m;
map $request_uri $skip_cache {
     default 1;
     ~*/thumbnail.php 0;
     ~*/apps/galleryplus/ 0;
     ~*/apps/gallery/ 0;
}

set $skip_cache 1;
if ($request_uri ~* "thumbnail.php")      { set $skip_cache 0; }
if ($request_uri ~* "/apps/galleryplus/") { set $skip_cache 0; }
if ($request_uri ~* "/apps/gallery/")     { set $skip_cache 0; }

Add inside the server{} block, as an example of a configuration:

# cache_purge (with $http_cookies we have unique keys for the user)
fastcgi_cache_key $http_cookie$request_method$host$request_uri;
fastcgi_cache_use_stale error timeout invalid_header http_500;
fastcgi_ignore_headers Cache-Control Expires Set-Cookie;

location ~ \.php(?:$/) {
      fastcgi_split_path_info ^(.+\.php)(/.+)$;

      include fastcgi_params;
      fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
      fastcgi_param PATH_INFO $fastcgi_path_info;
      fastcgi_param HTTPS on;
      fastcgi_pass php-handler;

      # cache_purge
      fastcgi_cache_bypass $skip_cache;
      fastcgi_no_cache $skip_cache;
      fastcgi_cache OWNCLOUD;
      fastcgi_cache_valid  60m;
      fastcgi_cache_methods GET HEAD;
      }

upstream php-handler {
    server unix:/var/run/php5-fpm.sock;
    # or
    # server 127.0.0.1:9000;
  }

3. Test the configuration

sudo nginx -s reload

• Open your browser and clear your cache.
• Logon to your ownCloud instance, open the gallery app, move thru your folders and watch while the thumbnails are generated for the first time.
• You may also watch with eg. htop your system load while the thumbnails are processed.
• Go to another app or logout and relogon.
• Open the gallery app again and browse to the folders you accessed before. Your thumbnails should appear more or less immediately.
• htop will not show up additional load while processing, compared to the high load before.