When v3.0 comes. Sky-walking also provide rest-service for collector trace data, as we had already done in v2.x. But this time, even sky-walking agent will use this service to uplink data.

Here is a simple sample about TraceSegment in JSON format. This format will be used in Collector REST-Service POST /segments. In this service, trace segments are send in batch mode, so the Message is like this

(ref source class: com.a.eye.skywalking.trace.SegmentsMessage)

[
    {
        "ts": "Segment.1490097253214.-866187727.57515.1.1",
        "st": 1490097253198,
        "et": 0,
        "rs": [
            {
                "ts": "parent_trace_0",
                "si": 1,
                "ac": "REMOTE_APP",
                "ph": "10.2.3.16:8080"
            },
            {
                "ts": "parent_trace_1",
                "si": 5,
                "ac": "REMOTE_APP",
                "ph": "10.2.3.16:8080"
            },
            {
                "ts": "parent_trace_2",
                "si": 5,
                "ac": "REMOTE_APP",
                "ph": "10.2.3.16:8080"
            }
        ],
        "ss": [
            {
                "si": 1,
                "ps": -1,
                "st": 1490097253228,
                "et": 0,
                "on": "/serviceA",
                "ts": {
                    "span.layer": "http"
                },
                "tb": {},
                "ti": {},
                "lo": []
            },
            {
                "si": 2,
                "ps": 1,
                "st": 1490097253230,
                "et": 0,
                "on": "/db/sql",
                "ts": {
                    "span.layer": "db"
                },
                "tb": {},
                "ti": {},
                "lo": [
                    {
                        "tm": 1490097253234,
                        "fi": {
                            "stack": "java.lang.NullPointerException\n\tat com.a.eye.skywalking.trace.TraceSegmentTestCase.testSerialize(TraceSegmentTestCase.java:102)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)\n\tat sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)\n\tat java.lang.reflect.Method.invoke(Method.java:483)\n\tat org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)\n\tat org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)\n\tat org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)\n\tat org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)\n\tat org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)\n\tat org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)\n\tat org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)\n\tat org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)\n\tat org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)\n\tat org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)\n\tat org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)\n\tat org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)\n\tat org.junit.runners.ParentRunner.run(ParentRunner.java:363)\n\tat org.junit.runner.JUnitCore.run(JUnitCore.java:137)\n\tat com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)\n\tat com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)\n\tat com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:237)\n\tat com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)\n\tat sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)\n\tat java.lang.reflect.Method.invoke(Method.java:483)\n\tat com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)\n",
                            "error.kind": "java.lang.NullPointerException",
                            "event": "error"
                        }
                    }
                ]
            }
        ],
        "ac": "billing_app",
        "gt": [
            "Trace.1490097253227.-866187727.57515.1.2"
        ]
    }
]

• Abbreviation tables

As you can see from the ^^^ sample, we use many abbreviations, here is the table to show their meanings.

ClassName	FieldName	Type	Abbreviation
TraceSegment	traceSegmentId	String	ts
	startTime	long	st
	endTime	long	et
	refs	List of TraceSegmentRef	rs
	spans	List of Span	ss
	applicationCode	String	ac
	relatedGlobalTraces	List of DistributedTraceId	gt
TraceSegmentRef	traceSegmentId	String	ts
	spanId	int	si
	applicationCode	String	ac
	peerHost	String	ph
Span	spanId	int	si
	parentSpanId	int	ps
	startTime	long	st
	endTime	long	et
	operationName	String	on
	tagsWithStr	Map<String, String>	ts
	tagsWithBool	Map<String, Boolean>	tb
	tagsWithInt	Map<String, Integer>	ti
	logs	List of LogData	lo
LogData	time	long	tm
	fields	Map<String, String>	fi
DistributedTraceId	id	String	(as element of gt array)