Availability Guide for Application Design

Availability in the Pathway Transaction-Processing
Environment
Availability Guide for Application Design—525637-004
6-8
Pathway/XM and Highly Available Server Classes
•
Be sure to specify a list of processors when you specify a server class. Otherwise,
all members of the server class run in one processor; if you lose that processor
then you lose the entire server class.
•
Consider how many servers you should run in a server class. You need to ensure
that, at times of peak load, enough servers are running to handle all requests
within a response time specified in your company's business plans. You should
consider the effects of a processor or process failure during peak business activity
when setting this value.
•
Specify your PATHMON configuration to ensure that resources are distributed so
that adequate resources are always available—even in the event of a failure. That
is, there must be enough processor cycles, swap space, process control blocks,
and so on.
Pathway/XM and Highly Available Server
Classes
Pathway/XM supports NonStop TS/MP by:
•
Allowing the components of a complex Pathway environment to be defined in
terms of templates in logical configurations
•
Providing automated management features
Figure 6-3 on page 6-9 shows the major components of Pathway/XM and the
processes for which they provide services.
What Is Pathway/XM?
The major components of Pathway/XM are:
•
The PXMCOM process
•
The SuperCTL file
•
Process broker (PB) processes
•
Link control service (LCS) processes
•
An optional, site-written $CMON process