eZ SI can be downloaded at the ez project page.

1. Save and extract the eZ SI package in the "extension" folder in the root of your eZ Publish installation. This will create a folder called "ezsi" in "extension".
2. Next create a new database table for ezsi in the same database as eZ Publish. When using MySQL, use the following command:
   

   mysql -u <user> -p<password> <ezpublishdatabase> <  path/to/ezpublish/extension/ezsi/sql/mysql/schema.sql
   

3. Activate the extension in your eZ Publish installation by editing the file settings/override/site.ini.append.php. It is possible that this file does not exist, if so it must be created.

   In the file site.ini.append.php, add "ActiveExtensions[]=ezsi" to the block [ExtensionSettings]. It will then most likely look like this:

   [ExtensionSettings]
   ActiveExtensions[]=ezoe
   ActiveExtensions[]=ezodf
   ActiveExtensions[]=ezwebin
   ActiveExtensions[]=ezsi
   ...
   

4. Regenerate autoloads by running the script:

   php bin/php/ezpgenerateautoloads.php -e
   

   It is also possible to update the autoloads from the Administrator Interface. In the Setup tab, click on the Extensions link in the menu on the left. In the list displayed check the box next to "ezsi" and press the Regenerate autoload arrays for extensions button.

5. Set up a cronjob next. In order to update SI blocks, eZ SI is provided with a cronjob that calls all pages which contain SI blocks. You need to decide how frequent you launch the cronjob. It is recommended to add all your ttl's and calculate the average. This will give you enough information to define the best frequency.
   The following example, shows you how you can add the following line into your ezpublish.cron file (note that all the global variables are already set):

   0,15,30,45 * * * * cd $EZPUBLISHROOT && $PHP runcronjobs.php  -q siblockupdate 2>&1
   

   In this example expired SI-blocks will be updated every 15 minutes. So defining very short TTL values here, will not have the desired effect.