我正在尝试将 Jaeger 跟踪集成到 K-Streams 中。我计划将跟踪添加到几个最重要的管道中，并且想知道将 Traceid 从一个管道传递到另一个管道的好方法是什么？
这是我到目前为止所做的 - 在流处理管道开始时，我启动一个服务器范围并将 Traceid 保存到状态存储中。随后，在转换管道中，我访问状态存储并从 transform() 方法捕获跟踪。这是在流处理中处理跟踪的好方法吗？
input
.mapValues(toSomethingThatMyAppUnderstands)
.mapValues(this::startStreamTrace)
.filter((k, v) -> v.isPresent())
.mapValues(Optional::get)
.mapValues(doSomethingHereWith)
.flatMapValues(doSomethingElse)
.filter((k, v) -> isInterestingEvent(v))
.transform(() -> new TransformerWithTracing<SomeObjectA, SomeObjectB>(IN_MEM_STORE_NAME, someFunction), IN_MEM_STORE_NAME)
.flatMapValues(c -> c)
.to(outTopic, Produced.with(Serdes.String(), new EventSerde()));
public class TransformerWithTracing<V, VR> implements Transformer<String, V, KeyValue<String, VR>> {
final Function valueAction;
final String storeId;
private KeyValueStore<String, String> traceIdStore;
public TransformerWithTracing(String storeId, Function valueAction) {
this.storeId = storeId;
this.valueAction = valueAction;
}
@Override
public void init(ProcessorContext context) {
// KeyValueStore store = ((KeyValueStore<String, String>) context.getStateStore(storeId));
InMemoryKeyValueStore inMemoryKeyValueStore = (InMemoryKeyValueStore) store;
this.traceIdStore = store;
}
@Override
public KeyValue<String, VR> transform(String key, V value) {
System.out.println(traceIdStore.get(key));
// BuildTraceHeader
try(Scope scope = serviceTracer.startServerSpan(traceHeader, "Converting to Enterprise Event")) {
return KeyValue.pair(key, (VR) valueAction.apply(value));
}
}
@Override
public KeyValue<String, VR> punctuate(long timestamp) {
return null;
}
@Override
public void close() {
// if (streamId != null) traceIdStore.delete(streamId);
}
}
