Node service (traces) – IBM SC30-3865-04 User Manual

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By manually setting the values of the

maximum shared memory, percent of

APPN shared memory to be used for buffers, and the maximum cached directory
entries tuning parameters using the talk 6 option of the command line interface.

By selecting values for the

maximum number of ISR sessions, maximum number

of adjacent nodes and other parameters shown in Table 8 on page 97, and
having the tuning algorithm automatically calculate the

maximum shared memory

and

maximum cached directory entries tuning parameter values.

Use the Configuration Program to invoke the tuning algorithm.

The

maximum shared memory parameter affects the amount of storage available to

the APPN network node for network operations. For example, you can allow APPN
to have a 4K RU size by setting

maximum shared memory to at least 1 Megabyte

and setting

percent of APPN shared memory used for buffers to a sufficiently large

value to allow at least 1 Megabyte of memory to be available to the buffer manager.

The

maximum cached directory entries parameter affects the amount of directory

information that will be stored or cached to reduce the time it takes to locate a
resource in the network.

In general, tuning the APPN network node involves a trade-off between node
performance and storage usage. The better the performance, the more storage
required.

Tuning Notes

1. The tuning parameter settings should reflect anticipated growth in your network.

2. If you define connection networks within your APPN network and you anticipate

that most end nodes will initiate LU-LU sessions with other end nodes on the
same connection network, you should set the

maximum number ISR sessions

parameter to a smaller value (1). Using connection networks in this manner
reduces the shared memory requirements for the router network node because
most LU-LU sessions will not flow through the APPN component in the router.

3. Because the

maximum shared memory parameter affects storage allocation

within the router, you should use care when explicitly defining this parameter.
Use the defaults as a guide when increasing or reducing maximum shared
memory manually.

Node Service (Traces)

The APPN Node Service (Traces) option allows you to start any APPN trace
through talk 6 or the Configuration Program. The traces are activated when the
configuration file is applied to the router. The traces will continue to be active until
they are stopped when a new configuration that stops the traces is applied to the
router.

Note: Running traces on the router can affect its performance. Traces should be

started only when needed for node service and should be stopped as soon
as the required amount of trace information is gathered.

The APPN traces are grouped into the following 5 categories:

Node-level traces specify traces concerning the overall APPN network node.

Inter-process signals traces specify component-level traces concerning signals
between APPN components.

APPN

Chapter 1. APPN