Sybase 12.5.X Server User Manual


 
CHAPTER 2 Sybase Software Asset Management
37
Redundant servers As part of a failover plan or a load-balancing system,
you can have multiple servers running on the same Adaptive Server
configuration, using a redundant license across all servers. The redundant
server system can be connected by a local-area network (LAN) or by a wide-
area network (WAN). A redundant server system is an excellent load-balancing
mechanism for physically distant servers. The redundant license allows you to
specify local servers as the first in the queue, and make remote servers
available as backup.
The SySAM application attempts to check out a license from a license-file list,
starting with the first server. If that server fails for any reason, the second server
in the list is contacted, and so on.
The redundant server system also provides failover protection. If one server in
the list goes down for any reason, the second server responds to the license
request. If that server fails too, the next server in the list is contacted, and so on.
SySAM in the network environment
Before you begin installing additional Adaptive Servers in a network system,
the license manager must be installed and running on the license host. To install
Adaptive Server on secondary servers, you need to know:
The host name of the license host.
The port number on the license host where the asset manager listens for
connections (the default is 29722).
Redundant servers
As part of a failover plan or a load-balancing system, you may have multiple
servers running the same Adaptive Server configuration, using redundant
licenses across all servers. The redundant servers can be connected by LAN or
by WAN.
To configure redundant servers:
1 Follow the instructions in this guide to install Adaptive Server on each of
the servers in the redundant system.
2 As you install the software, make a note of the machine names and the
dedicated port numbers that SySAM uses on each machine. The default
port will be 29722.