9 Configuring Logging and Tracing

Classpath

With Log4j 2, instead of a single org.apache.log4j.jar file within the ./ocsg/modules folder, there are two jar files: org.apache.log4j-api.jar and org.apache.log4j-core.jar. The Class-Path attribute inside MANIFEST.MF of ./ocsg/modules/features/com.bea.wlcp.wlng.modules.jar references the two JAR files.

Configuration File

Runtime configuration changes are specified through the monitorInterval attribute of the Configuration element. Log4j2 uses the Log4j-config.xsd XSD Schema located within Log4j2 core jar, for example log4j-core-2.8.2.jar, for validation of the configuration file syntax.

Example 9-1 shows an Log4j 2.x configuration file, log4j2config.xml.

<?xml version="1.0" encoding="UTF-8"?>
<Configuration monitorInterval="30">
  <Appenders>
    <!--
    <RollingFile name="oauth2" fileName="servers/${sys:weblogic.Name}/oauth2_log/oauth2.log" filePattern="servers/${sys:weblogic.Name}/oauth2_log/oauth2-%i.log">
      <PatternLayout>
        <Pattern>[%d{MM-dd hh:mm:ss}:%p %F] %m%n%n</Pattern>
      </PatternLayout>
      <Policies>
        <SizeBasedTriggeringPolicy size="10 MB" />
      </Policies>
      <DefaultRolloverStrategy max="10" />
    </RollingFile>
    -->
 
    <RollingFile name="edr" fileName="servers/${sys:weblogic.Name}/edr_log/edr.json"
     filePattern="servers/${sys:weblogic.Name}/edr_log/edr-%d{MM-dd-yyyy}.json">
     <PatternLayout>
       <Pattern>%m%n</Pattern>
     </PatternLayout>
     <Policies>
      <TimeBasedTriggeringPolicy interval="1"/>
     </Policies>
     <DefaultRolloverStrategy max="7" />
    </RollingFile>

    <RollingFile name="cdr" fileName="servers/${sys:weblogic.Name}/cdr_log/cdr.json"
     filePattern="servers/${sys:weblogic.Name}/cdr_log/cdr-%d{MM-dd-yyyy}.json">
     <PatternLayout>
      <Pattern>%m%n</Pattern>
     </PatternLayout>
     <Policies>
      <TimeBasedTriggeringPolicy interval="1"/>
     </Policies>
     <DefaultRolloverStrategy max="7" />
    </RollingFile>
 
    <RollingFile name="alarm" fileName="servers/${sys:weblogic.Name}/alarm_log/alarm.json"
     filePattern="servers/${sys:weblogic.Name}/alarm log/alarm-%d{MM-dd-yyyy}.json">
     <PatternLayout>
      <Pattern>%m%n</Pattern>
     </PatternLayout>
     <Policies>
      <TimeBasedTriggeringPolicy interval="1"/>
     </Policies>
     <DefaultRolloverStrategy max="7" />
    </RollingFile>
 
    <RollingFile name="qos" fileName="servers/${sys:weblogic.Name}/qos_log/qos.log" filePattern="servers/${sys:weblogic.Name}/qos_log/qos.log.%i">
      <PatternLayout>
        <Pattern>[%d{MM-dd hh:mm:ss}:%p %F] %m%n%n</Pattern>
      </PatternLayout>
      <Policies>
        <SizeBasedTriggeringPolicy size="10 MB" />
      </Policies>
      <DefaultRolloverStrategy max="10" />
    </RollingFile>
 
    <!-- Initially for root logger output -->
    <RollingFile name="trace" fileName="servers/${sys:weblogic.Name}/trace/default.log" filePattern="servers/${sys:weblogic.Name}/trace/default.log.%i">
      <PatternLayout>
        <Pattern>[%d{MM-dd hh:mm:ss}:%p %F] %m%n</Pattern>
      </PatternLayout>
      <Policies>
        <SizeBasedTriggeringPolicy size="10 MB" />
      </Policies>
      <DefaultRolloverStrategy max="10" />
    </RollingFile>
  </Appenders>
 
  <Loggers>
    <!--
    <Logger name="oracle.ocsg.oauth2" level="debug" additivity="false">
      <AppenderRef ref="oauth2" />
    </Logger>
    -->
 
    <!-- change 'info' to 'debug' to log EDRs -->
    <Logger name="OCSG.EdrLogger" level="info" additivity="false">
     <AppenderRef ref="edr" />
    </Logger>
 
    <Logger name="OCSG.CdrLogger" level="info" additivity="false">
     <AppenderRef ref="cdr" />
    </Logger>
 
   <Logger name="OCSG.AlarmLogger" level="info" additivity="false">
    <AppenderRef ref="alarm" />
   </Logger>

   <Logger name="oracle.ocsg.plugin.qos.diameter" level="info" additivity="false">
    <AppenderRef ref="qos" />
   </Logger>

   <Root level="info">
    <AppenderRef ref="trace" />
   </Root>
  </Loggers>
</Configuration>

Configuring Logging Using the Administration Console

This section explains how to change the Services Gatekeeper logging level. The default logging level is INFO. By default, errors are logged to the domain_home/servers/servername/trace/default.log file.

You will select a log4j severity level during this task. See the log4j documentation for descriptions of the logging levels at the Apache web site here:

https://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html

To Configure Logging for a Services Gatekeeper server: 

1. Start the Administration Console. This is the default URL:

   IP_Addr:7001/console
   

   Where IP_addr is the IP address of the system running Services Gatekeeper, and 7001 is the default port.

2. Navigate to OCSG, then servername, then log4j, then log4j:Location=sername, logger=rootdefault

   Where servername is the name of the server you are configuring logging for.

   The Configuration and Provisioning on servername pane appears.

3. Click Lock & Edit.

4. Select the priority: checkbox.

5. Enter a log severity level in the priority text field. The options are:

   • ALL

   • DEBUG

   • ERROR

   • FATAL

   • INFO

   • OFF

   • TRACE

   • WARN

6. Click Update Attributes.

7. Click Release Configuration.

Log4J Hierarchies, Loggers, and Appenders

You can view the logging hierarchy in the WebLogic Server administration console by selecting the OCSG managed-server instance and expanding the Log4j node. This displays the OCSG Log4j 2 loggers and appenders.

There is a set of Log4J Dynamic MBeans shipped with Services Gatekeeper that come by default with appenders. Appenders deliver LogEvents to their destination.

One Log4J hierarchy and one location are defined and displayed in the Services Gatekeeper Administration Console under Log4J as:

• log4j:hiearchy=default,Location=AdminServer

The rootDefault logger is connected to the default hierarchy:

• log4j:Location=AdminServer,logger=rootDefault

You can add loggers, and add appenders to the loggers. You can change both the priority of the logger and the appender to use. You can also configure parameters for the loggers and appenders.

To persist Log4J settings, use this configuration file:

domain_home/log4j/log4j2config.xml

Understanding Basic Tracing

For basic tracing, the root logger rootdefault maintains the trace file.

Use these fields and methods to the TraceServiceMBean to configure and maintain basic tracing:

• TracingEnabled field

• attachAppender method

• flushBuffers method

• rollOver method

See "TraceServiceMBean Reference" for information on using this MBean.

Understanding Context Tracing

Services Gatekeeper uses context tracing to generate log messages filtered on the context of a request, for example for a certain service provider or application. This is in addition to basic tracing. A context filter has predefined filter types that define what to filter on. This enables you to trace on individual service providers, applications, and so on.

You can add new context trace files and context filters, and then apply context categories to these files to log messages from one or more Services Gatekeeper services.

To define a context trace file:

1. In the Services Gatekeeper Administration Console, choose Container Services then TraceService.

2. Select createContextTraceFile, or createRootContextTraceFile.

3. For each context category to add for the context trace file, use the addContextCategory method to TraceServiceMBean

4. For each context filter to add, use the addContextFilter method

See "TraceServiceMBean Reference" for information on using this MBean.

Configuring Trace for Access Tier servers

Trace configuration for network tier servers is performed through the Services Gatekeeper Administration Console by accessing Log4J for a server. For access tier servers, there are no management attributes or operations exposed in the Administration Console. This configuration must be done directly on the MBeans using a JMX-based Administration Console such as JConsole or using WLST.

For example, if you are using WLST, connect to the MBean server as described in "WebLogic Scripting Tool (WSLT)" and change to the custom tree where Services Gatekeeper MBeans are located. Change to the Log4J directory: cd('log4J').

The settings for the access tier servers can be changed in these directories:

• log4j:appender=default

• log4j:appender=default,layout=org.apache.log4j.TTCCLayout

• log4j:hiearchy=default

• log4j:logger=rootdefault

For example, to change the trace level for the access tier servers for the appender log4j:appender=default to WARN:

cd('log4j:appender=default')
set('threshold','WARN')

Example Log4J Configuration file

Example 9-2 declares these appenders:

• oauth2

• edr

• qos

• trace

These appenders all use the same class, org.apache.log4j.FileAppender.

Each appender writes to a file whose name is given in the filename attribute. The appenders also use the same layout class, org.apache.log4j.PatternLayout, and ConversionPattern.

The appenders are used by a set of categories, where the name attribute defines which class to trace. The categories also define which Log4J priority is logged.

In the example, the following services are logged:

• oracle.ocsg.oath2

• com.bea.wlcp.wlng.edr.publisher

• oracle.ocsg.plugin.qos.diameter

<?xml version="1.0" encoding="UTF-8"?>
<Configuration monitorInterval="30">
  <Appenders>
    <!--
    <RollingFile name="oauth2" fileName="servers/${sys:weblogic.Name}/oauth2_log/oauth2.log"    filePattern="servers/${sys:weblogic.Name}/oauth2_log/oauth2-%i.log">
      <PatternLayout>
        <Pattern>[%d{MM-dd hh:mm:ss}:%p %F] %m%n%n</Pattern>
      </PatternLayout>
      <Policies>
        <SizeBasedTriggeringPolicy size="10 MB" />
      </Policies>
      <DefaultRolloverStrategy max="10" />
    </RollingFile>
    -->
 
    <RollingFile name="edr" fileName="servers/${sys:weblogic.Name}/edr_log/edr.log" filePattern="servers/${sys:weblogic.Name}/edr_log/edr-%i.log">
      <PatternLayout>
        <Pattern>[%d{MM-dd hh:mm:ss}:%p %F] %m%n%n</Pattern>
      </PatternLayout>
      <Policies>
        <SizeBasedTriggeringPolicy size="10 MB" />
      </Policies>
      <DefaultRolloverStrategy max="10" />
    </RollingFile>
 
    <RollingFile name="qos" fileName="servers/${sys:weblogic.Name}/qos_log/qos.log" filePattern="servers/${sys:weblogic.Name}/qos_log/qos-%i.log">
      <PatternLayout>
        <Pattern>[%d{MM-dd hh:mm:ss}:%p %F] %m%n%n</Pattern>
      </PatternLayout>
      <Policies>
        <SizeBasedTriggeringPolicy size="10 MB" />
      </Policies>
      <DefaultRolloverStrategy max="10" />
    </RollingFile>
 
    <!-- Initially for root logger output -->
    <RollingFile name="trace" fileName="servers/${sys:weblogic.Name}/trace/default.log" filePattern="servers/${sys:weblogic.Name}/trace/default-%i.log">
      <PatternLayout>
        <Pattern>[%d{MM-dd hh:mm:ss}:%p %F] %m%n</Pattern>
      </PatternLayout>
      <Policies>
        <SizeBasedTriggeringPolicy size="10 MB" />
      </Policies>
      <DefaultRolloverStrategy max="10" />
    </RollingFile>
  </Appenders>
 
  <Loggers>
    <!--
    <Logger name="oracle.ocsg.oauth2" level="debug" additivity="false">
      <AppenderRef ref="oauth2" />
    </Logger>
    -->
 
    <!-- change 'info' to 'debug' to log EDRs -->
    <Logger name="com.bea.wlcp.wlng.edr.publisher" level="info" additivity="false">
      <AppenderRef ref="edr" />
    </Logger>
 
    <Logger name="oracle.ocsg.plugin.qos.diameter" level="info" additivity="false">
      <AppenderRef ref="qos" />
    </Logger>
 
    <Root level="info">
      <AppenderRef ref="trace" />
    </Root>
  </Loggers>
</Configuration>

TraceService MBean Attributes

The TraceService MBean has the following attributes:

• AspectTracingEnabled: True or False. If true, tracing of aspects is enabled. Disable to improve performance. Scope: cluster.

• TracingEnabled: True or False. If true, tracing is enabled. Scope: cluster.

TraceService MBean Operations

The TraceService MBean supports the following operations:

• addContextCategory

  Adds a category to an existing context trace file.

• addContextFilter

  Adds one of the predefined filter types to the appender with the identified name.

• attachAppender

  Allows adding a named appender to named loggers.

• createContextTraceFile

  Creates a context trace file under root trace directory.

• createRootContextTraceFile

  Creates a new root context trace file.

• flushBuffers

  Flushes log buffers.

• removeContextTraceFile

  Removes a context trace file.

• resetContextFilters

  Removes all filters associated with a context trace file.

• rollOver

  Rotates the log files.

For more information about these operations, see the TraceServiceMBean interface in Oracle Communications Services Gatekeeper OAM Java API Reference.