Cloud & Linger
When operating a number of playout systems where multiple EPG generators are required it can be smart to operate a central server collecting all schedule data and then feeding output to multiple instances for playout.
Such a configuration can be setup by using the Cloud & Linger functionality.
![server with remote sites](concept.png)
Central Cloud server with remote Linger sites
The central server is grabbing event data in a classical manner like a normal cherryEPG system. The behavior is the same as in every installation. The builder generates transport stream chunks for each output EIT. The chunks can then be played locally on the central server itself or transferred to remote sites and the played from them.
The server is regularly updating all output files. Those for local playout are played by the local ringelspiel player, all other chunks are made available to be fetched by remote sites.
Remote sites are connecting to the server for synchronizing their copy of the chunk files over a secure encrypted ssh connection using a highly efficient compressed transfer mechanism - rsync.
The setup for the cloud/linger configuration is done in two steps.
Remote site
Once synchronized the remote site playout will linger until there is a new update. Therefore these sites are referred to here as Linger sites. In the scheme file below only the conf sheet is used. The only required setting is the IP address of the central server.
![conf sheet](linger.png)
configuration of linger site in the conf sheet
The linger site will periodically connect to this IP over TCP port 22 (ssh) and sync the configured chunk files. Now that we’ve uploaded this schema to the Linger site and activated it, we can verify the current configuration schema.
![the ssh key](key.png)
public key used for authentication
From the configuration we need the generated public_key. This needs to be copied and saved for later use.
Central server
The central server is configured to generate various output chunks. For this the existing sheets in the configuration scheme will be used.
In order for a remote site to connect to the central server, it must be placed in a location that the remote sites can freely access. It can be a cloud installation or any other installation. The only requirement is IP connection and that TCP port 22 (ssh) is accessible from the remote sites.
Remote sites must be granted access to the chunk files on the server. This is configured from the cloud sheet in the configuration scheme.
![conf sheet](cloud.png)
grant remote access
The configuration consists of a description or name of the remote site, the public key previously copied from the remote site, and a list of EIT chunks to sync.
After uploading and applying the schemes the generating and synchronizing takes place. There can be multiple linger sites synchronizing from the same server.