XMS Configuration Guide
6-1
6 R
EPLICATION
OF
THE
XMS S
ERVER
’
S
D
ATABASE
Replication enables full redundancy of an Xmedia Server that is available for near instant
failover with no interruption in services including on-air playout.
The Xmedia Server implements a simple technique of replicating all events that change the
database and/or virtual database (VDB). Two identically versioned Xmedia Servers
(Primary and Secondary) communicate with each other to ensure database replicas by
queuing all commands that alter the state of the database (and/or VBD) to disk. These
commands are then sequentially executed on the secondary server as if it were a normal
client with a few distinctions.
The primary server’s connection to the secondary server is distinct in that the secondary
server does not send normal replies to the primary server. Instead, it replies with simple
acknowledgements. Most data altering commands consist of user-invoked changes such
as Template saving, whereas other hidden changes, such as publish history and licensing
changes such as soft-key ingestion, are also replicated.
At all times both servers are running and the secondary server is ready to take control when
a failover condition arises at any time. Both servers contain identical licensing information
and each has their own dongle with matching customer IDs. Each server is responsible for
monitoring network conditions and each other’s availability.
The following sections further describe the conditions and behavior of the Xmedia Servers
replication. Instructions are also provided to guide you through the process of setting up and
enabling server replication.
•
“Conditions that trigger a failover” on page 6-2
•
“MOS Enabled Replication” on page 6-3
•
“Replication settings on the Xmedia Server Control Panel” on page 6-4
•
“Setting up and enabling Xmedia Server replication” on page 6-6