You can use the Tracer to monitor any active requestor session. However, a service usually runs in a new requestor session with a requestor ID that is not created until the service begins processing. At that point, the processing that the service performs in that requestor session occurs so quickly (in less than one second), that it can be hard to catch the event to trace it.

In this situation, it is recommended that you use the Trace Open Rule feature to trace the service rule. You can use this feature to trace a service request that is invoked from an external client application.

The ability to trace services comes with a performance impact even when you are not actively tracing, therefore it is recommended that you disable service tracing in production environments and during performance testing unless you are troubleshooting a related issue.

Service rule tracing is only enabled in environments where the trace/cluster/ServiceRuleWatchMaxProductionLevel Dynamic System Settings is greater than or equal to the production level. By default, trace/cluster/ServiceRuleWatchMaxProductionLevel is set to 4, which means that the ability to trace service rules would not work in a production level 5 environment until trace/cluster/ServiceRuleWatchMaxProductionLevel is increased to 5.

• Owning Ruleset: Pega-RulesEngine
• Setting Purpose: trace/cluster/ServiceRuleWatchMaxProductionLevel
• Value: <greater than or equal to the production level, for example, 5>

To use the Trace Open Rule feature to trace and debug a service rule:

1. Open the service rule. Note which ruleset the service rule belongs to.
2. Click ActionsTrace. The Tracer tool window opens.
3. Click Settings to open the Tracer Settings window.
4. In the Event Types to Trace section, select Services.
5. In the Rulesets to Trace section, select the rulesets that contain the service rule and service activity.
6. Click OK to close the Tracer Settings window.
7. Run the rule.
8. Watch the Tracer window as the rule runs. The window includes lines for the start and end of each service rule execution, lines for the start and end of request mapping, lines for the start and end of response mapping, and (if these options are selected in the Tracer Settings panel) lines for the start and end of parse rules, XML Stream rules, and HTML rules.

• Cluster-wide tracing of service rules

  You can trace service rules across a cluster. Cluster-wide tracing makes it easier for you to troubleshoot services in clustered configurations where a load balancer dynamically assigns service requests to nodes in the cluster. This functionality is especially useful for debugging mobile applications, RESTful Web Services, and other stateless service executions.

• Configuring trace conditions
• Cluster-wide tracing of service rules

• Application debugging using the Tracer tool