Mark all http status codes 5xx as an error.

dd-java-agent/instrumentation/servlet-3/src/test/groovy/JettyServletTest.groovy

@@ -166,6 +166,46 @@ class JettyServletTest extends AgentTestRunner {
     "sync" | "Hello Sync"
   }
 
+  @Unroll
+  def "test #path non-throwing-error servlet call"() {
+    setup:
+    def request = new Request.Builder()
+      .url("http://localhost:$PORT/$path?non-throwing-error=true")
+      .get()
+      .build()
+    def response = client.newCall(request).execute()
+
+    expect:
+    response.body().string().trim() != expectedResponse
+    writer.size() == 2 // second (parent) trace is the okhttp call above...
+    def trace = writer.firstTrace()
+    trace.size() == 1
+    def span = trace[0]
+
+    span.context().serviceName == "unnamed-java-app"
+    span.context().operationName == "servlet.request"
+    span.context().resourceName == "GET /$path"
+    span.context().spanType == DDSpanTypes.WEB_SERVLET
+    span.context().getErrorFlag()
+    span.context().parentId != 0 // parent should be the okhttp call.
+    span.context().tags["http.url"] == "http://localhost:$PORT/$path"
+    span.context().tags["http.method"] == "GET"
+    span.context().tags["span.kind"] == "server"
+    span.context().tags["component"] == "java-web-servlet"
+    span.context().tags["http.status_code"] == 500
+    span.context().tags["thread.name"] != null
+    span.context().tags["thread.id"] != null
+    span.context().tags["error"] == true
+    span.context().tags["error.msg"] == null
+    span.context().tags["error.type"] == null
+    span.context().tags["error.stack"] == null
+    span.context().tags.size() == 9
+
+    where:
+    path   | expectedResponse
+    "sync" | "Hello Sync"
+  }
+
   private static int randomOpenPort() {
     new ServerSocket(0).withCloseable {
       it.setReuseAddress(true)

dd-java-agent/instrumentation/servlet-3/src/test/groovy/TestServlet.groovy

@@ -13,6 +13,10 @@ class TestServlet {
       if (req.getParameter("error") != null) {
         throw new RuntimeException("some sync error")
       }
+      if (req.getParameter("non-throwing-error") != null) {
+        resp.sendError(500, "some sync error")
+        return
+      }
       resp.writer.print("Hello Sync")
     }
   }

dd-java-agent/instrumentation/servlet-3/src/test/groovy/TomcatServletTest.groovy

@@ -166,6 +166,46 @@ class TomcatServletTest extends AgentTestRunner {
     "sync" | "Hello Sync"
   }
 
+  @Unroll
+  def "test #path error servlet call for non-throwing error"() {
+    setup:
+    def request = new Request.Builder()
+      .url("http://localhost:$PORT/$path?non-throwing-error=true")
+      .get()
+      .build()
+    def response = client.newCall(request).execute()
+
+    expect:
+    response.body().string().trim() != expectedResponse
+    writer.size() == 2 // second (parent) trace is the okhttp call above...
+    def trace = writer.firstTrace()
+    trace.size() == 1
+    def span = trace[0]
+
+    span.context().serviceName == "unnamed-java-app"
+    span.context().operationName == "servlet.request"
+    span.context().resourceName == "GET /$path"
+    span.context().spanType == DDSpanTypes.WEB_SERVLET
+    span.context().getErrorFlag()
+    span.context().parentId != 0 // parent should be the okhttp call.
+    span.context().tags["http.url"] == "http://localhost:$PORT/$path"
+    span.context().tags["http.method"] == "GET"
+    span.context().tags["span.kind"] == "server"
+    span.context().tags["component"] == "java-web-servlet"
+    span.context().tags["http.status_code"] == 500
+    span.context().tags["thread.name"] != null
+    span.context().tags["thread.id"] != null
+    span.context().tags["error"] == true
+    span.context().tags["error.msg"] == null
+    span.context().tags["error.type"] == null
+    span.context().tags["error.stack"] == null
+    span.context().tags.size() == 9
+
+    where:
+    path   | expectedResponse
+    "sync" | "Hello Sync"
+  }
+
   private static int randomOpenPort() {
     new ServerSocket(0).withCloseable {
       it.setReuseAddress(true)

dd-java-agent/instrumentation/spring-web/src/test/groovy/test/SpringBootBasedTest.groovy

@@ -148,7 +148,6 @@ class SpringBootBasedTest extends AgentTestRunner {
     span1.context().operationName == "servlet.request"
     span1.context().resourceName == "GET /error"
     span1.context().spanType == DDSpanTypes.WEB_SERVLET
-    !span1.context().getErrorFlag()
     span1.context().parentId == 0
     span1.context().tags["http.url"] == "http://localhost:$port/error"
     span1.context().tags["http.method"] == "GET"
@@ -156,9 +155,10 @@ class SpringBootBasedTest extends AgentTestRunner {
     span1.context().tags["span.type"] == "web"
     span1.context().tags["component"] == "java-web-servlet"
     span1.context().tags["http.status_code"] == 500
+    span1.context().getErrorFlag()
     span1.context().tags["thread.name"] != null
     span1.context().tags["thread.id"] != null
-    span1.context().tags.size() == 8
+    span1.context().tags.size() == 9
   }
 
   def "validated form"() {

dd-trace-ot/src/main/java/datadog/opentracing/decorators/DDDecoratorsFactory.java

@@ -25,6 +25,7 @@ public class DDDecoratorsFactory {
     builtin.add(new OperationDecorator());
     builtin.add(new Status404Decorator());
     builtin.add(new URLAsResourceName());
+    builtin.add(new Status5XXDecorator());
 
     return builtin;
   }

dd-trace-ot/src/main/java/datadog/opentracing/decorators/Status5XXDecorator.java

@@ -0,0 +1,24 @@
+package datadog.opentracing.decorators;
+
+import datadog.opentracing.DDSpanContext;
+import io.opentracing.tag.Tags;
+
+/** Mark all 5xx status codes as an error */
+public class Status5XXDecorator extends AbstractDecorator {
+  public Status5XXDecorator() {
+    super();
+    this.setMatchingTag(Tags.HTTP_STATUS.getKey());
+  }
+
+  @Override
+  public boolean afterSetTag(final DDSpanContext context, final String tag, final Object value) {
+    if (Tags.HTTP_STATUS.getKey().equals(tag)) {
+      final int responseCode = Integer.parseInt(value.toString());
+      if (500 <= responseCode && responseCode < 600) {
+        context.setTag(Tags.ERROR.getKey(), true);
+        return true;
+      }
+    }
+    return false;
+  }
+}