IBM SG24-5131-00 用户手册

下载
页码 240
Cluster Planning 
43
2.5.3  Licensing Methods 
Some vendors require a unique license for each processor that runs an 
application, which means that you must license-protect the application by 
incorporating processor-specific information into the application when it is 
installed. As a result, it is possible that even though the HACMP for AIX 
software processes a node failure correctly, it is unable to restart the 
application on the failover node because of a restriction on the number of 
licenses available within the cluster for that application. To avoid this 
problem, make sure that you have a license for each system unit in the 
cluster that may potentially run an application.
This can be done by “floating licenses”, where a license server is asked to 
grant the permission to run an application on request, as well as “node-locked 
licenses”, where each processor possibly running an application must have 
the licensing files installed and configured.
2.5.4  Coexistence with other Applications
In case of a failover, a node might have to handle several applications 
concurrently. This means the applications data or resources 
must not conflict 
with each other. Again, the Application Worksheets can help in deciding 
whether certain resources might conflict with others. 
2.5.5  Critical/Non-Critical Prioritizations
Building a highly available environment for mission-critical applications also 
forces the need to differentiate between the priorities of a number of 
applications. Should a server node fail, it might be appropriate to shut down 
another application, which is not as highly prioritized, in favor of the takeover 
of the server node’s application. The applications running in a cluster have to 
be clearly ordered and prioritized in order to decide what to do under these 
circumstances.
Application start and stop scripts have to be available on the primary as 
well as the takeover node. They are not transferred during synchronization; 
so, the administrator of a cluster has to ensure that they are found in the 
same path location, with the same permissions and in the same state, i.e. 
changes have to be transferred manually.
Note