org.apache.pulsar.structuredeventlog

Interface StructuredEventLog

All Known Implementing Classes:

Slf4jStructuredEventLog

public interface StructuredEventLog

Structured event logging interface Allows resources and attribute key value pairs to be attached to a logged event. Basic usage:

 StructuredEventLog logger = StructuredEventLog.newLogger();
 logger.newRootEvent()
     .resource("remote", remoteAddr)
     .resource("local", localAddr)
     .attr("path", request.getPath())
     .log(Events.READ_REQUEST);
 

Method Summary

Modifier and Type	Method and Description
EventResources	newEventResources() Create an new event resources object, which can be used across multiple root events.
static StructuredEventLog	newLogger() Create a new logger object, from which root events can be created.
Event	newRootEvent() Create a new root event.
Event	unstash() Retrieves an event from the call stack.

Method Detail

newRootEvent

Event newRootEvent()

Create a new root event. Root events occur in response to some external stimulus, such as a user request, a timer being triggered or a threshold being crossed. The level of the event is INFO by default. The root event will generate a new traceId, and will have a empty parent Id. If this information is provided, as can be the case with a user request, they can be set with Event#traceId(String) and Event#parentId(String).

newEventResources

EventResources newEventResources()

Create an new event resources object, which can be used across multiple root events.

unstash

Event unstash()

Retrieves an event from the call stack. This can be used, along with Event#stash(), to bridge an event across an API without having to modify the API to pass the event object. For example, the child event, METHOD2, in the following example, will share the traceId with METHOD1, and METHOD1's id will be match the parentId of METHOD2.

 void method1() {
    Event e = logger.newRootEvent()
        .timed()
        .resource("foo", bar);

    e.stash();
    unmodifiableMethod();
    e.log(Events.METHOD1);
 }

 void unmodifiableMethod() {
    logger.unstash().newChildEvent().log(Events.METHOD2);
 }
 

This should be used sparingly.

newLogger

static StructuredEventLog newLogger()

Create a new logger object, from which root events can be created.