Sample Media Flow
In general - this is how it works for media files, with some technical details omitted:
A) File uploaded by site user to the original site server
B) If Admin approves the media file...
C) File is available to users of the site, with the file being served from original site server
D) File is sent to cdn backup server over public network
E) File sent from cdn backup server into Content Delivery Network (CDN)
F) File link changed from being served from the original server to instead be served from the Content Delivery Network (CDN)
This keeps original site server bandwidth requirements minimal.
From this point on, the file is served from the closest Content Delivery Network (CDN) node worldwide.
G) File deleted from site server
This keeps disc space needs on the original server to a minimum.
H) If the file is deleted later by admin or user, the file is deleted from the backup server and the content delivery network.
I) All transfers confirmed by SHA_1 HASH.
J) In case of a content deliver network failure, files can be served from the backup server and reloaded onto the content delivery network if needed.
K) In case of a backup server failure, the backup server can be reloaded from the content delivery network.
L) Backup servers have RAID5 3 TB (3000GB) arrays.
M) Media - being hard to back up (due to it's size and resulting disc space requirements) - and irreplaceable (due to the substantial time needed for users to upload it) - is always backed up and protected. Two copies of all media files at all times exist, on separate data storage devices.
For more information, please contact us.