opentelemetry-java-instrume.../dd-trace-ot/src/main/java/datadog/opentracing/DDTracer.java

522 lines
16 KiB
Java

package datadog.opentracing;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import datadog.opentracing.decorators.AbstractDecorator;
import datadog.opentracing.decorators.DDDecoratorsFactory;
import datadog.opentracing.propagation.Codec;
import datadog.opentracing.propagation.ExtractedContext;
import datadog.opentracing.propagation.HTTPCodec;
import datadog.opentracing.scopemanager.ContextualScopeManager;
import datadog.opentracing.scopemanager.ScopeContext;
import datadog.trace.api.DDTags;
import datadog.trace.api.interceptor.MutableSpan;
import datadog.trace.api.interceptor.TraceInterceptor;
import datadog.trace.api.sampling.PrioritySampling;
import datadog.trace.common.DDTraceConfig;
import datadog.trace.common.sampling.AllSampler;
import datadog.trace.common.sampling.RateByServiceSampler;
import datadog.trace.common.sampling.Sampler;
import datadog.trace.common.writer.DDAgentWriter;
import datadog.trace.common.writer.DDApi;
import datadog.trace.common.writer.Writer;
import io.opentracing.Scope;
import io.opentracing.ScopeManager;
import io.opentracing.Span;
import io.opentracing.SpanContext;
import io.opentracing.propagation.Format;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.ServiceConfigurationError;
import java.util.ServiceLoader;
import java.util.SortedSet;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentSkipListSet;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.atomic.AtomicInteger;
import lombok.extern.slf4j.Slf4j;
/** DDTracer makes it easy to send traces and span to DD using the OpenTracing API. */
@Slf4j
public class DDTracer implements io.opentracing.Tracer {
public static final String UNASSIGNED_DEFAULT_SERVICE_NAME = "unnamed-java-app";
/** Default service name if none provided on the trace or span */
final String serviceName;
/** Writer is an charge of reporting traces and spans to the desired endpoint */
final Writer writer;
/** Sampler defines the sampling policy in order to reduce the number of traces for instance */
final Sampler sampler;
/** Scope manager is in charge of managing the scopes from which spans are created */
final ContextualScopeManager scopeManager = new ContextualScopeManager();
/** A set of tags that are added to every span */
private final Map<String, Object> spanTags;
/** Span context decorators */
private final Map<String, List<AbstractDecorator>> spanContextDecorators =
new ConcurrentHashMap<>();
private final SortedSet<TraceInterceptor> interceptors =
new ConcurrentSkipListSet<>(
new Comparator<TraceInterceptor>() {
@Override
public int compare(final TraceInterceptor o1, final TraceInterceptor o2) {
return Integer.compare(o1.priority(), o2.priority());
}
});
private final CodecRegistry registry;
private final AtomicInteger traceCount = new AtomicInteger(0);
/** By default, report to local agent and collect all traces. */
public DDTracer() {
this(new DDTraceConfig());
}
public DDTracer(final String serviceName) {
this(new DDTraceConfig(serviceName));
}
public DDTracer(final Properties config) {
this(
config.getProperty(DDTraceConfig.SERVICE_NAME),
Writer.Builder.forConfig(config),
Sampler.Builder.forConfig(config),
DDTraceConfig.parseMap(config.getProperty(DDTraceConfig.SPAN_TAGS)));
log.debug("Using config: {}", config);
}
public DDTracer(final String serviceName, final Writer writer, final Sampler sampler) {
this(serviceName, writer, sampler, Collections.<String, Object>emptyMap());
}
public DDTracer(
final String serviceName,
final Writer writer,
final Sampler sampler,
final Map<String, Object> spanTags) {
this.serviceName = serviceName;
this.writer = writer;
this.writer.start();
this.sampler = sampler;
this.spanTags = spanTags;
registry = new CodecRegistry();
registry.register(Format.Builtin.HTTP_HEADERS, new HTTPCodec());
registry.register(Format.Builtin.TEXT_MAP, new HTTPCodec());
if (this.writer instanceof DDAgentWriter && sampler instanceof DDApi.ResponseListener) {
final DDApi api = ((DDAgentWriter) this.writer).getApi();
api.addResponseListener((DDApi.ResponseListener) this.sampler);
api.addTraceCounter(traceCount);
}
registerClassLoader(ClassLoader.getSystemClassLoader());
final List<AbstractDecorator> decorators = DDDecoratorsFactory.createBuiltinDecorators();
for (final AbstractDecorator decorator : decorators) {
log.debug("Loading decorator: {}", decorator.getClass().getSimpleName());
addDecorator(decorator);
}
log.info("New instance: {}", this);
}
public DDTracer(final Writer writer) {
this(
UNASSIGNED_DEFAULT_SERVICE_NAME,
writer,
new AllSampler(),
DDTraceConfig.parseMap(new DDTraceConfig().getProperty(DDTraceConfig.SPAN_TAGS)));
}
/**
* Returns the list of span context decorators
*
* @return the list of span context decorators
*/
public List<AbstractDecorator> getSpanContextDecorators(final String tag) {
return spanContextDecorators.get(tag);
}
/**
* Add a new decorator in the list ({@link AbstractDecorator})
*
* @param decorator The decorator in the list
*/
public void addDecorator(final AbstractDecorator decorator) {
List<AbstractDecorator> list = spanContextDecorators.get(decorator.getMatchingTag());
if (list == null) {
list = new ArrayList<>();
}
list.add(decorator);
spanContextDecorators.put(decorator.getMatchingTag(), list);
}
/**
* Add a new interceptor to the tracer. Interceptors with duplicate priority to existing ones are
* ignored.
*
* @param interceptor
* @return false if an interceptor with same priority exists.
*/
public boolean addInterceptor(final TraceInterceptor interceptor) {
return interceptors.add(interceptor);
}
public void addScopeContext(final ScopeContext context) {
scopeManager.addScopeContext(context);
}
/**
* If an application is using a non-system classloader, that classloader should be registered
* here. Due to the way Spring Boot structures its' executable jar, this might log some warnings.
*
* @param classLoader to register.
*/
public void registerClassLoader(final ClassLoader classLoader) {
try {
for (final TraceInterceptor interceptor :
ServiceLoader.load(TraceInterceptor.class, classLoader)) {
addInterceptor(interceptor);
}
} catch (final ServiceConfigurationError e) {
log.warn("Problem loading TraceInterceptor for classLoader: " + classLoader, e);
}
}
@Override
public ContextualScopeManager scopeManager() {
return scopeManager;
}
@Override
public Span activeSpan() {
final Scope active = scopeManager.active();
return active == null ? null : active.span();
}
@Override
public DDSpanBuilder buildSpan(final String operationName) {
return new DDSpanBuilder(operationName, scopeManager);
}
@Override
public <T> void inject(final SpanContext spanContext, final Format<T> format, final T carrier) {
final Codec<T> codec = registry.get(format);
if (codec == null) {
log.debug("Unsupported format for propagation - {}", format.getClass().getName());
} else {
codec.inject((DDSpanContext) spanContext, carrier);
}
}
@Override
public <T> SpanContext extract(final Format<T> format, final T carrier) {
final Codec<T> codec = registry.get(format);
if (codec == null) {
log.debug("Unsupported format for propagation - {}", format.getClass().getName());
} else {
return codec.extract(carrier);
}
return null;
}
/**
* We use the sampler to know if the trace has to be reported/written. The sampler is called on
* the first span (root span) of the trace. If the trace is marked as a sample, we report it.
*
* @param trace a list of the spans related to the same trace
*/
void write(final PendingTrace trace) {
if (trace.isEmpty()) {
return;
}
final ArrayList<DDSpan> writtenTrace;
if (interceptors.isEmpty()) {
writtenTrace = Lists.newArrayList(trace);
} else {
Collection<? extends MutableSpan> interceptedTrace = Lists.newArrayList(trace);
for (final TraceInterceptor interceptor : interceptors) {
interceptedTrace = interceptor.onTraceComplete(interceptedTrace);
}
writtenTrace = Lists.newArrayListWithExpectedSize(interceptedTrace.size());
for (final MutableSpan span : interceptedTrace) {
if (span instanceof DDSpan) {
writtenTrace.add((DDSpan) span);
}
}
}
traceCount.incrementAndGet();
if (!writtenTrace.isEmpty() && this.sampler.sample(writtenTrace.get(0))) {
this.writer.write(writtenTrace);
}
}
public void close() {
writer.close();
}
@Override
public String toString() {
return "DDTracer-"
+ Integer.toHexString(hashCode())
+ "{ service-name="
+ serviceName
+ ", writer="
+ writer
+ ", sampler="
+ sampler
+ ", tags="
+ spanTags
+ '}';
}
private static class CodecRegistry {
private final Map<Format<?>, Codec<?>> codecs = new HashMap<>();
<T> Codec<T> get(final Format<T> format) {
return (Codec<T>) codecs.get(format);
}
public <T> void register(final Format<T> format, final Codec<T> codec) {
codecs.put(format, codec);
}
}
/** Spans are built using this builder */
public class DDSpanBuilder implements SpanBuilder {
private final ScopeManager scopeManager;
/** Each span must have an operationName according to the opentracing specification */
private final String operationName;
// Builder attributes
private Map<String, Object> tags =
spanTags.isEmpty() ? Collections.<String, Object>emptyMap() : Maps.newHashMap(spanTags);
private long timestampMicro;
private SpanContext parent;
private String serviceName;
private String resourceName;
private boolean errorFlag;
private String spanType;
private boolean ignoreScope = false;
public DDSpanBuilder(final String operationName, final ScopeManager scopeManager) {
this.operationName = operationName;
this.scopeManager = scopeManager;
}
@Override
public SpanBuilder ignoreActiveSpan() {
this.ignoreScope = true;
return this;
}
private DDSpan startSpan() {
final DDSpan span = new DDSpan(this.timestampMicro, buildSpanContext());
if (DDTracer.this.sampler instanceof RateByServiceSampler) {
((RateByServiceSampler) DDTracer.this.sampler).initializeSamplingPriority(span);
}
return span;
}
@Override
public Scope startActive(final boolean finishSpanOnClose) {
final DDSpan span = startSpan();
final Scope scope = scopeManager.activate(span, finishSpanOnClose);
log.debug("Starting a new active span: {}", span);
return scope;
}
@Override
@Deprecated
public DDSpan startManual() {
return start();
}
@Override
public DDSpan start() {
final DDSpan span = startSpan();
log.debug("Starting a new span: {}", span);
return span;
}
@Override
public DDSpanBuilder withTag(final String tag, final Number number) {
return withTag(tag, (Object) number);
}
@Override
public DDSpanBuilder withTag(final String tag, final String string) {
if (tag.equals(DDTags.SERVICE_NAME)) {
return withServiceName(string);
} else if (tag.equals(DDTags.RESOURCE_NAME)) {
return withResourceName(string);
} else if (tag.equals(DDTags.SPAN_TYPE)) {
return withSpanType(string);
} else {
return withTag(tag, (Object) string);
}
}
@Override
public DDSpanBuilder withTag(final String tag, final boolean bool) {
return withTag(tag, (Object) bool);
}
@Override
public DDSpanBuilder withStartTimestamp(final long timestampMicroseconds) {
this.timestampMicro = timestampMicroseconds;
return this;
}
public DDSpanBuilder withServiceName(final String serviceName) {
this.serviceName = serviceName;
return this;
}
public DDSpanBuilder withResourceName(final String resourceName) {
this.resourceName = resourceName;
return this;
}
public DDSpanBuilder withErrorFlag() {
this.errorFlag = true;
return this;
}
public DDSpanBuilder withSpanType(final String spanType) {
this.spanType = spanType;
return this;
}
public Iterable<Map.Entry<String, String>> baggageItems() {
if (parent == null) {
return Collections.emptyList();
}
return parent.baggageItems();
}
@Override
public DDSpanBuilder asChildOf(final Span span) {
return asChildOf(span == null ? null : span.context());
}
@Override
public DDSpanBuilder asChildOf(final SpanContext spanContext) {
this.parent = spanContext;
return this;
}
@Override
public DDSpanBuilder addReference(final String referenceType, final SpanContext spanContext) {
log.debug("`addReference` method is not implemented. Doing nothing");
return this;
}
// Private methods
private DDSpanBuilder withTag(final String tag, final Object value) {
if (this.tags.isEmpty()) {
this.tags = Maps.newHashMap();
}
this.tags.put(tag, value);
return this;
}
private long generateNewId() {
// Ensure the generated ID is in a valid range:
return ThreadLocalRandom.current().nextLong(1, Long.MAX_VALUE);
}
/**
* Build the SpanContext, if the actual span has a parent, the following attributes must be
* propagated: - ServiceName - Baggage - Trace (a list of all spans related) - SpanType
*
* @return the context
*/
private DDSpanContext buildSpanContext() {
final long traceId;
final long spanId = generateNewId();
final long parentSpanId;
final Map<String, String> baggage;
final PendingTrace parentTrace;
final int samplingPriority;
final DDSpanContext context;
SpanContext parentContext = this.parent;
if (parentContext == null && !ignoreScope) {
// use the Scope as parent unless overridden or ignored.
final Scope scope = scopeManager.active();
if (scope != null) parentContext = scope.span().context();
}
// Propagate internal trace
if (parentContext instanceof DDSpanContext) {
final DDSpanContext ddsc = (DDSpanContext) parentContext;
traceId = ddsc.getTraceId();
parentSpanId = ddsc.getSpanId();
baggage = ddsc.getBaggageItems();
parentTrace = ddsc.getTrace();
samplingPriority = ddsc.getSamplingPriority();
if (this.serviceName == null) this.serviceName = ddsc.getServiceName();
if (this.spanType == null) this.spanType = ddsc.getSpanType();
// Propagate external trace
} else if (parentContext instanceof ExtractedContext) {
final ExtractedContext ddsc = (ExtractedContext) parentContext;
traceId = ddsc.getTraceId();
parentSpanId = ddsc.getSpanId();
baggage = ddsc.getBaggage();
parentTrace = new PendingTrace(DDTracer.this, traceId);
samplingPriority = ddsc.getSamplingPriority();
// Start a new trace
} else {
traceId = generateNewId();
parentSpanId = 0L;
baggage = null;
parentTrace = new PendingTrace(DDTracer.this, traceId);
samplingPriority = PrioritySampling.UNSET;
}
if (serviceName == null) {
serviceName = DDTracer.this.serviceName;
}
final String operationName =
this.operationName != null ? this.operationName : this.resourceName;
// some attributes are inherited from the parent
context =
new DDSpanContext(
traceId,
spanId,
parentSpanId,
serviceName,
operationName,
this.resourceName,
samplingPriority,
baggage,
errorFlag,
spanType,
this.tags,
parentTrace,
DDTracer.this);
return context;
}
}
}