Cisco Model D9500 Switched Digital Video Server (NTSC and PAL) テクニカルリファレンス
December 2007
Operations Alert Bulletin
Session Synchronization Between the
DNCS and SDV Servers
Session Synchronization Between the
DNCS and SDV Servers
Background
There are several scenarios under which system operators may need to re-initialize
communications between the Switched Digital Video (SDV) server and the session
resource manager (SRM) subsystem of the Digital Network Control System (DNCS).
This document describes two of those scenarios and provides a recommendation for
system operators on the proper way to re-initialize communications.
One scenario involves those occasions when the system operator has removed
the persistdata file (/opt/sdb/persistdata/sdbserver00) from the SDV server.
After deleting the persistdata file from the SDV server, the system operator
should next tear down old shell sessions on the DNCS, of which the SDV server
is no longer aware. Otherwise, the SDV server will request new shell sessions
from the DNCS, which will conflict with existing sessions. The DNCS will not be
able to honor these new shell session requests because they conflict with existing
sessions.
Important: Our engineers do not recommend removing the persistdata file from
Important: Our engineers do not recommend removing the persistdata file from
the SDV server.
Another scenario occurs when all the SDV shell sessions are torn down on the
DNCS. All SDV servers will request new shell sessions simultaneously when
they detect that the SRM subsystem of the DNCS has been restarted, thereby
overloading the DNCS.
In most cases, restarting the SDV servers will re-initialize communications between
the SDV server and the DNCS. The restart of the SDV servers, however, needs to be
performed in a specific sequence in order to avoid subjecting the DNCS to unusually
heavy load conditions. In Recommendation (on page 2), we offer two methods for
restarting the SDV servers.