Installing The Change Log Daemon

If you want to make use of the Cxense Semantic plug-in's automated tagging functionality, then as well as installing the Cxense Semantic plug-in itself, you also need to install a change log daemon - a program that scans the Content Engine change logs looking for changed content items, and submits them to Cxense for tagging if necessary. You can configure it to only submit certain content types, and to only submit content items in certain states.

The instructions below should provide enough information for you to install and configure the autotagging daemon, but if you want to know more about how change log daemons in general work, then take a look at the Change Log Daemon documentation.

The Autotagging change log daemon checks for new and/or modified content items and submits them to Cxense for tagging. You can configure it to only submit certain content types, and to only submit content items in certain states. To install it:

Download the Change Log Daemon distribution from the Content Engine downloads page, and unpack it in an appropriate location (/opt/escenic/semantic/autotagging, for example).
Change directory to the new folder you have created and start the daemon at least once with the following command:
```
$ java -jar changelog.jar
```
This creates a few required folders and configuration files.
Open config/Daemon.properties for editing and set the following properties:
url
The URI of your publication's change log. For example:
```
url=http://editorial-host-ip-address/webservice/escenic/changelog/publication/publicationId
```
Where editorial-host-ip-address is the host name of IP address of your editorial-host, and publicationId is your publication's ID.
username

The username of the Content Engine user that will be used access the change log.

password

The password of the above user.

The change log daemon is now configured with sufficient information to read your publication's change log. You now need to add the agent that manages the tagging of new and changed content items. To do this:

Change directory to the autotagging daemon folder. For example:
```
$ cd /opt/escenic/semantic/autotagging/changelog-daemon
```
Copy the content of /opt/escenic/engine/plugin/semantic-cxense/misc/changlog/lib to the empty lib folder.
```
$ cp /opt/escenic/engine/plugin/semantic-cxense/misc/changlog/lib/* lib
```
Create a folder tree under the empty classes folder:
```
$ mkdir -p classes classes/com/escenic/daemon/
```
Copy /opt/escenic/engine/plugins/semantic-cxense/misc/example/SemanticAgent.properties to the classes/com/escenic/daemon/ folder you have created:
```
$ cp /opt/escenic/engine/plugins/semantic-cxense/misc/example/SemanticAgent.properties \
      classes/com/escenic/daemon/
```
Open the copied file for editing and set the following properties:
webserviceEndpoint
Set this property to the URI of your Content Engine web service:
```
webserviceEndpoint=https://host:port/webservice/
```
where host and port are the host name and port number of your Content Engine host.
keepLastModified
You can use this property to determine whether or not the autotagging daemon updates content items' LastModified property when it adds tags to them:
- true: LastModified is not updated when tags are added by the daemon
- false: LastModified is updated when tags are added by the daemon. This is the default setting.

Copy /opt/escenic/engine/plugins/semantic-cxense/misc/example/SemanticConfiguration.properties to the same folder:

$ cp /opt/escenic/engine/plugins/semantic-cxense/misc/example/SemanticConfiguration.properties \
      classes/com/escenic/daemon/

Open the copied file for editing and set the following properties:
endpoint
Set this property to the URI of your semantic web service:
```
endpoint=https://host:port/webservice-extensions/semantic/webservice
```
where host and port are the host name and port number of your Content Engine host.
state.draft, state.approved, state.submitted
Use these properties to specify the content type/state combinations that you want to be automatically tagged. For example:
```
state.draft=story,review
state.approved=story
state.submitted=
```
The above example specifies that new or changed story and review content items will be automatically tagged if they are in a draft state. In addition new or changed story content items will also be automatically tagged if they are in an approved state. No content items will be automatically tagged while they are in the submitted state.

Your tagging daemon is now fully configured and ready to use. You can start it with the following command:

$ java -jar changelog.jar

You should probably add this command to the start-up script of your server.