How to switch between HTTP1 and HTTP2 protocols when using default otel exporters

[I576510]

Hi Team,

We are using default otel exporter in our java and node js applications. Can you please provide us ways to achieve this? we don't want to use gRPC or create a custom exporter. How can we switch between HTTP1 and HTTP2 protocols when using default otel exporters?

Please suggest options for both Java and node.js

Below is our understanding wrt to using HTTP2 with default exporter, please check

JAVA

• OpenTelemetry does not provide an automatic runtime toggle between HTTP/1.1 and HTTP/2.
• It does provide a way to switch between http/protobuf and grpc, which is effectively how you switch between HTTP/1.1 and HTTP/2 (because gRPC uses HTTP/2).
• If you're using default exporters, switching protocols generally means changing the exporter protocol (http/protobuf ↔ grpc).
• we can't create our custom HTTP client and set it explicitly in default OTEL exporter.

Node.js

• JavaScript (Node.js) doesn’t auto-switch protocols at runtime — you explicitly choose the protocol via the exporter you use (http or grpc).

• If you use @opentelemetry/exporter-trace-otlp-http → you're using HTTP/1.1 by default.

• If you use @opentelemetry/exporter-trace-otlp-grpc → you're using HTTP/2 (because gRPC requires HTTP/2).

• In JS, the "default exporter" is usually OTLP/HTTP, especially in examples or SDK auto-instrumentation.

  To use gRPC (i.e., HTTP/2), you need to:
  Manually install the gRPC exporter package:
  npm install @opentelemetry/exporter-trace-otlp-grpc
  And manually wire it up in your code.
  So in JS, switching from HTTP/1.1 to HTTP/2 is not just changing a config value — it requires using a different package/exporter.

[jack-berg]

Under the hood, the OtllpHttp{Signal}Exporters use either the JDK 11+ built-in HTTP client, or OkHttp.

Both JDK 11+ HTTP client and OkHttp implementation uses either http/2 or http/1.1 based on negotiation with the server, and prioritize http/2.

[I576510]

@jack-berg what is the case for node.js?

[trask]

@I576510 I'd recommend asking this in the JS repo