In the end of the content ingestion process all other Content Ingestion Servers from the system must be aware of the new torrent files in order to seed them. First of all, the new torrent files need to be locally accessible to them, so all torrent files can be shared by CIS machines on a \textit{distributed file system} such as NFS, LustreFS or GlusterFS. The overhead of using shared storage between CIS machines shouldn't affect performance, even if NFS is used, which serves files through a single machine. This is because torrent files are very small so concurrently accessing more files on the shared file system can affect performance in a negligible manner.
-When the web server is notified about the job completion (10) a seed request must arrive to each CIS so that they can start seeding the new torrent files available in the distributed file system. This request is originated from the web server and there is no need to do this on a single CIS system, because this is already done in step 8 from Figure \ref{fig:content-ingestion}, so the web server can be configured to skip this redundant step from its configuration. In a multiple CIS system this step is mandatory for ensuring high availability of the new video assets. Thus, a \textbf{seed request} is sent from web server to CIS-LB, which forwards this message to all CIS from its jurisdiction. Upon reception they will start seeding requested torrent files which are located in the distributed file system.
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+When the web server is notified about the job completion (10) a seed request must arrive to each CIS so that they can start seeding the new torrent files available in the distributed file system. This request is originated from the web server and there is no need to do this on a single CIS system, because this is already done in step 8 from Figure \ref{fig:content-ingestion}, so the web server can be configured to skip this redundant step from its configuration. In a multiple CIS system this step is mandatory for ensuring high availability of the new video assets. Thus, a \textbf{seed request} is sent from web server to CIS-LB, which forwards this message to all CIS from its jurisdiction. Upon reception they will start seeding requested torrent files which are located in the distributed file system.
+
+There may be situations when a seed request is lost by a CIS. For instance, a CIS is temporarily down or it has a temporary network failure and does not receive a seed request from CIS-LB. After recovery it will not know about the existence of new torrent files. This can lead to availability problems, so to solve this a CIS periodically scans the torrent directory for new torrent files.
+
+When a CIS daemon starts running it begins seeding all torrent files from the distributed file system.
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projects / living-lab-site.git / blobdiff