63
FLASH
MEDIA
SERVER
4.5
CONFIGURATION
AND
ADMINISTRATION
Configuring the server
Last updated 11/28/2012
2
Packager 2's connection to the encoder fails. The connection between Packager 2 and the proxy continues
running. Suppose that at the time of this failure, the last successfully written fragment on Packager 2 was still
#700 with current media time as X.
3
A short amount of time elapses, in this case, 10 fragment intervals.
4
The server-side now suffers from liveness. Packager 2 is serving stale bootstrap information. Packager 2
indicates that there has been no update in the bootstrap after time X, even though more recent fragments are
available on Packager 1 (that is, the current media time is greater than X.)
5
Playback stalls at the player end.
•
Dropout
- is a server-side situation in which a packager has gaps in its bootstrap (that is, gaps in its fragment list).
The following scenario describes a dropout situation:
1
The stream has been running normally for some time on the server side.
2
Packager 2's connection to the encoder fails. The connection between Packager 2 and the proxy continues running.
Suppose that at the time of this failure, the last successfully written fragment on Packager 2 was still #700.
3
A short amount of time elapses, in this case, 10 fragment intervals.
4
Packager 2's encoder connection is restored and remains restored for a long time.
5
The server-side now suffers from dropout. Packager 2's bootstrap is missing entries for #701-710, even though
those fragments are still available on Packager 1.
6
Playback stalls at the player end.
HTTP Streaming failover provides a two-part solution:
•
Best-effort fetch
•
Control plane management
Enable best-effort fetch
Best-effort fetch enables the OSMF and iOS video players to continue playback as normally as possible in the presence
of short-term liveness and dropout problems on the server-side.
You enable best-effort fetch by adding and configuring a
<bestEffortFetchInfo>
element in the manifest.xml file
on the server side, as as illustrated in the following:
<?xml version="1.0" encoding="UTF-8"?>
<manifest xmlns="http://ns.adobe.com/f4m/2.0">
<dvrInfo windowDuration="7200"/>
<bestEffortFetchInfo
segmentDuration="40.000"
fragmentDuration="4.000"
maxForwardFetches="2"
maxBackwardFetches="2"
/>
<baseURL>http://www.example.com/media</baseURL>
<media href="low.f4m" bitrate="512" />
<media href="medium.f4m" bitrate="1296" />
<media href="high.f4m" bitrate="3500" />
</manifest>
No client-side configuration is required. For more information, see Manifest.xml.