User`s guide

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10: Clip Mirror Configuration
Clip Mirror Service Overview
Clip cache mirroring is performed using a TCP/IP network communications interface.
The clip mirror subsystem transfers clip cache content from the primary
SGI Media Server to the clip mirror platform. The transfer is unidirectional and
automatic between the primary and mirror platforms and is accomplished using FTP.
The media transfer consumes both network and real-time filesystem bandwidth and,
thereby, diminishes the allocated resources on the primary SGI Media Server platform.
Wise allocation planning can minimize over-subscription of the real-time filesystem
resource, which may adversely affect the performance of the primary SGI Media Server
during playout or recording. The speed of FTP operations depends on the clip bit rate,
the network infrastructure connecting the servers, and the available compute cycles to
initiate the transfer.
Automatic Clip Cache Transfers
The clip mirror service is event-driven. Certain actions performed with the primary
SGI Media Server infrastructure generate clip cache activity that generates a concurrent
and simultaneous action on the mirror platform. Removing clip content, creating clips,
clip metadata modification, and other activities generate mirror platform actions.
Automatic clip cache transfers to the mirror platform is subject to the following specific
conditions, constraints, and events:
• New content generated by or transferred to the primary SGI Media Server effects an
automatic transfer.
• Upon initial clip mirror activation, if the mirror’s clip content is newer (more recent
modification date) than that of the primary SGI Media Server, the clip is considered
synchronized; that is, no transfer takes place.
• Upon initial clip mirror activation, if the size of the clip content on the mirror is
identical to that on the primary and the clip content modification date on the
primary SGI Media Server is more recent, the mirror clip content is considered
synchronized.
• Media content modification or metadata changes (such as protection attribute
modifications) to the content on the primary SGI Media Server effects transfers.