Patterns: Implementing Self-Service in an SOA Environment

442 Patterns: Implementing Self-Service in an SOA Environment

򐂰 stack tracing

򐂰 standard tracing

򐂰 debug tracing

򐂰 JNI tracing

JNI tracing is usually the most useful of all traces. It is the JNI level between the

Java CICS TG and the native EXCI or CICS client.

The application can enable tracing programmatically. It can also be enabled

dynamically in the Gateway daemon using the TCPAdmin protocol handler, or

statically as a start option. CICS TG trace is recorded in the standard output file

or standard error file.

External CICS Interface trace

The External CICS Interface (EXCI) provides a programming interface for the

non-CICS address space to invoke CICS programs. CICS TG utilizes EXCI to

communicate with the CICS program. The CICS Transaction Gateway writes

trace entries to the EXCI trace when it issues an EXCI request. The trace entries

in a dump can be printed using standard z/OS utilities (GTF).

CICS trace

CICS Transaction Server provides a facility for recording CICS activity. In CICS

for MVS™, there are three destinations for trace entries: Internal trace, auxiliary

trace, and generalized trace facility (GTF).

12.6.2 Performance monitoring and tuning

In this section we briefly look at performance monitoring and tuning for J2EE

Connectors in WebSphere Application Server V6.0.

Using Tivoli Performance Viewer

The Tivoli Performance Viewer is a graphical performance monitor for

WebSphere Application Server V6. This can be accessed through the

WebSphere administrative console by selecting Monitoring and Tuning →

Performance Viewer. You can use the Performance Viewer to retrieve

performance data from application servers. Data is collected continuously by

application servers and retrieved as needed from within the Viewer.

You can regulate the impact of data collection by modifying the PMI settings.

These settings can be found viewed and modified by selecting Monitoring and

Tuning → Performance Monitoring Infrastructure (PMI). The counters in the

JCA Connection Pools category provides information about J2EE connectors,

such as the number of managed connections (ManagedConnections) and the

Chapter 12. J2EE Connector Architecture scenario 443

number of connection handles (connections). Figure 12-32 shows the PMI

options available under JCA connection pools.

Figure 12-32 Tivoli Performance Viewer JCA connection pool options

Tuning connection pooling properties

There are several parameters you can set to optimize connection pooling

properties using the WebSphere administrative console:

򐂰 Connection timeout

This is the number of milliseconds after which a connection request is

determined to have timed out and a ResourceAllocationException is thrown.

The wait might be necessary if the maximum value of connections has been

reached (MaxConnections). This value has no meaning if the maximum

connections property has not been set.