---
title: Scala Akka HTTP core instrumentation
source: https://docs.newrelic.com/docs/apm/agents/java-agent/frameworks/scala-akka-http-core
---

With the introduction of Java agent release 7.8.0, changes were made to **remove** the default instrumentation of the `bindAndHandle` method, to eliminate scenarios that could result in erroenously duplicated transactions being reported. In some situations, it may be necessary for you to make explicit method calls to compensate for this change.

## Background: HttpExt instrumentation [#background]

Instrumentation for Akka HTTP Core is carried out in the `akka.http.scaladsl.HttpExt` class that serves as the
main entry point for a server. Two convenience methods from `HttpExt` that can be used to start an HTTP server have been instrumented:

-   `bindAndHandleAsync`: A convenience method which starts a new HTTP server at the given endpoint and uses a handler that is a function receiving an `HttpRequest` and returning a `Future[HttpResponse]`
-   `bindAndHandleSync`: A convenience method which starts a new HTTP server at the given endpoint and uses a handler that is a function receiving an `HttpRequest` and returning a `HttpResponse`

To eliminate the erroneous duplication of transactions from being reported, intrumentation is **no longer** being applied to the `bindAndHandle` method, which starts a new HTTP server using a `akka.stream.scaladsl.Flow` instance.

The duplication of transactions is due to a clash in the Akka Http Routing DSL instrumentation.

## Solution - explicitly call bindAndHandleAsync [#solution]

If you wish to start an HTTP server from an `akka.stream.scaladsl.Flow`, you must explicitly invoke the `bindAndHandleAsync` method. For example:

```scala
val flow: Flow[HttpRequest, HttpResponse, NotUsed] = ???
val asyncHandler: HttpRequest => Future[HttpResponse] = request => Source.single(request).via(flow).runWith(Sink.head)

Http().bindAndHandleAsync(asyncHandler, host, port)
```

> #### ⚠️ IMPORTANT
>
> A similar workaround, calling `bindAndHandle` when starting an HTTP server from a `akka.http.scaladsl.Route` using the Akka HTTP Routing DSL, is **not** necessary. Agent instrumentation will work normally when being called from other convenience methods.