Skip to content

Always add trace_id and span_id attributes to servlet requests #15485

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
laurit merged 1 commit into from
Dec 3, 2025
Merged

Always add trace_id and span_id attributes to servlet requests #15485

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 5 additions & 4 deletions instrumentation/servlet/README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,10 +2,11 @@

## Settings

| System property | Type | Default | Description |
|------------------------------------------------------------------------| ------- | ------- |-----------------------------------------------------|
| `otel.instrumentation.servlet.experimental-span-attributes` | Boolean | `false` | Enable the capture of experimental span attributes. |
| `otel.instrumentation.servlet.experimental.capture-request-parameters` | List | Empty | Request parameters to be captured (experimental). |
| System property | Type | Default | Description |
|----------------------------------------------------------------------------|---------|---------|-----------------------------------------------------|
| `otel.instrumentation.servlet.experimental-span-attributes` | Boolean | `false` | Enable the capture of experimental span attributes. |
| `otel.instrumentation.servlet.experimental.capture-request-parameters` | List | Empty | Request parameters to be captured (experimental). |
| `otel.instrumentation.servlet.experimental.add-trace-id-request-attribute` | Boolean | `true` | Add `trace_id` and `span_id` as request attributes. |

### A word about version

Expand Down
27 changes: 19 additions & 8 deletions ...t/src/main/java/io/opentelemetry/javaagent/instrumentation/servlet/BaseServletHelper.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@
import io.opentelemetry.instrumentation.api.instrumenter.LocalRootSpan;
import io.opentelemetry.instrumentation.api.semconv.http.HttpServerRoute;
import io.opentelemetry.javaagent.bootstrap.internal.AgentCommonConfig;
import io.opentelemetry.javaagent.bootstrap.internal.AgentInstrumentationConfig;
import io.opentelemetry.javaagent.bootstrap.servlet.AppServerBridge;
import io.opentelemetry.javaagent.bootstrap.servlet.MappingResolver;
import io.opentelemetry.javaagent.bootstrap.servlet.ServletAsyncContext;
Expand All @@ -23,8 +24,12 @@
import java.security.Principal;
import java.util.function.Function;

@SuppressWarnings("deprecation") // using deprecated semconv
public abstract class BaseServletHelper<REQUEST, RESPONSE> {
private static final boolean ADD_TRACE_ID_REQUEST_ATTRIBUTE =
AgentInstrumentationConfig.get()
.getBoolean(
"otel.instrumentation.servlet.experimental.add-trace-id-request-attribute", true);
Copy link
Member

@trask trask Dec 1, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

do you think config is needed (given that we've had this enabled in a lot of cases for a long time)?

Copy link
Contributor Author

@laurit laurit Dec 2, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I was thinking that maybe we want to disable it by default in the next major release. Could also remove the config option if you think it is better that way.

Copy link
Member

@trask trask Dec 3, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

that makes sense, I like the idea of disabling by default in next major release


protected final Instrumenter<ServletRequestContext<REQUEST>, ServletResponseContext<RESPONSE>>
instrumenter;
protected final ServletAccessor<REQUEST, RESPONSE> accessor;
Expand Down Expand Up @@ -53,13 +58,7 @@ public Context start(Context parentContext, ServletRequestContext<REQUEST> reque
Context context = instrumenter.start(parentContext, requestContext);

REQUEST request = requestContext.request();
SpanContext spanContext = Span.fromContext(context).getSpanContext();
// we do this e.g. so that servlet containers can use these values in their access logs
// TODO: These are only available when using servlet instrumentation or when server
// instrumentation extends servlet instrumentation e.g. jetty. Either remove or make sure they
// also work on tomcat and wildfly.
accessor.setRequestAttribute(request, "trace_id", spanContext.getTraceId());
accessor.setRequestAttribute(request, "span_id", spanContext.getSpanId());
addRequestAttributes(request, context);

context = addServletContextPath(context, request);
context = addAsyncContext(context);
Expand All @@ -69,6 +68,16 @@ public Context start(Context parentContext, ServletRequestContext<REQUEST> reque
return context;
}

private void addRequestAttributes(REQUEST request, Context context) {
if (!ADD_TRACE_ID_REQUEST_ATTRIBUTE) {
return;
}

SpanContext spanContext = Span.fromContext(context).getSpanContext();
accessor.setRequestAttribute(request, "trace_id", spanContext.getTraceId());
accessor.setRequestAttribute(request, "span_id", spanContext.getSpanId());
}

protected Context addServletContextPath(Context context, REQUEST request) {
return ServletContextPath.init(context, contextPathExtractor, request);
}
Expand Down Expand Up @@ -100,6 +109,8 @@ public Context updateContext(
result, servlet ? SERVER : SERVER_FILTER, spanNameProvider, mappingResolver, request);
}

addRequestAttributes(request, context);

return result;
}

Expand Down
8 changes: 8 additions & 0 deletions ...nt/src/test/java/io/opentelemetry/javaagent/instrumentation/tomcat/v10_0/TestServlet.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,14 @@ class TestServlet extends HttpServlet {
protected void service(HttpServletRequest req, HttpServletResponse resp) throws IOException {
String path = req.getServletPath();

// these are set by servlet instrumentation
if (req.getAttribute("trace_id") == null) {
throw new IllegalStateException("trace_id attribute not found");
}
if (req.getAttribute("span_id") == null) {
throw new IllegalStateException("span_id attribute not found");
}

ServerEndpoint serverEndpoint = ServerEndpoint.forPath(path);
if (serverEndpoint != null) {
AbstractHttpServerTest.controller(
Expand Down
8 changes: 8 additions & 0 deletions ...ent/src/test/java/io/opentelemetry/javaagent/instrumentation/tomcat/v7_0/TestServlet.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,14 @@ class TestServlet extends HttpServlet {
protected void service(HttpServletRequest req, HttpServletResponse resp) throws IOException {
String path = req.getServletPath();

// these are set by servlet instrumentation
if (req.getAttribute("trace_id") == null) {
throw new IllegalStateException("trace_id attribute not found");
}
if (req.getAttribute("span_id") == null) {
throw new IllegalStateException("span_id attribute not found");
}

ServerEndpoint serverEndpoint = ServerEndpoint.forPath(path);
if (serverEndpoint != null) {
AbstractHttpServerTest.controller(
Expand Down
Loading