http2 - Can't send http/2 request in Gatling

Question

I've got a problem using gatling tool when trying to send http/2 request.

I've enable http/2 setting in protocol settings, even added mapping to make sure that client will communicate with server using http2 but still request is send using http/1.1.

In console output you'll see that server can communicate using http2 but for some reason request are sent only with http 1.1.

All headers are written according to the ones from browser.

Could someone help me please with this issue?

package test

import scala.concurrent.duration._

import io.gatling.core.Predef._
import io.gatling.http.Predef._
import io.gatling.jdbc.Predef._

class RecordedSimulation extends Simulation {

    val httpProtocol = http
        .baseUrl("https://sitename")
        .inferHtmlResources(BlackList(""".*.js""", """.*.css""", """.*.gif""", """.*.jpeg""", """.*.jpg""", """.*.ico""", """.*.woff""", """.*.woff2""", """.*.(t|o)tf""", """.*.png""", """.*detectportal.firefox.com.*"""), WhiteList())
        .acceptHeader("*/*")
        .acceptEncodingHeader("gzip, deflate")
        .acceptLanguageHeader("en-US,en;q=0.5")
        .userAgentHeader("Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:85.0) Gecko/20100101 Firefox/85.0")
            .enableHttp2
        .http2PriorKnowledge(Map("sitename" -> true))
        .disableCaching
      .disableWarmUp

    val headers_0 = Map(
        "Accept" -> "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
        "Cache-Control" -> "max-age=0",
        "sec-fetch-dest" -> "document",
        "sec-fetch-mode" -> "navigate",
        "sec-fetch-site" -> "none",
        "sec-fetch-user" -> "?1",
        "Upgrade-Insecure-Requests" -> "1")



    val scn = scenario("RecordedSimulation")
        .exec(http("request_0")
            .get("/auth?r=%2F&m=NOT_AUTHENTICATED")
            .headers(headers_0))
        .pause(2)

    setUp(scn.inject(atOnceUsers(1))).protocols(httpProtocol)
}

In console I see next:

DEBUG io.gatling.http.client.impl.DefaultHttpClient - ALPN led to HTTP/2 with remote sitename
DEBUG io.gatling.http.client.impl.Http2AppHandler - Write request WritableRequest{request=DefaultFullHttpRequest(decodeResult: success, version: HTTP/1.1, content: UnpooledByteBufAllocator$InstrumentedUnpooledUnsafeHeapByteBuf(ridx: 0, widx: 0, cap: 0))

GET https://sitename/auth?r=%2F&m=NOT_AUTHENTICATED HTTP/1.1
sec-fetch-site: none
Upgrade-Insecure-Requests: 1
If-Modified-Since: Fri, 29 Jan 2021 06:40:06 GMT
sec-fetch-dest: document
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Cache-Control: max-age=0
accept-encoding: gzip, deflate
If-None-Match: "1d6f60994776ee0"
user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:85.0) Gecko/20100101 Firefox/85.0
accept-language: en-US,en;q=0.5
sec-fetch-mode: navigate
sec-fetch-user: ?1
accept: */*

question from:https://stackoverflow.com/questions/66063443/cant-send-http-2-request-in-gatling

Answer 1

Those are internal Gatling logs. We use Netty in a way that it converts HTTP/1.1 payloads into HTTP/2 ones. From the logs you provided, it looks that Gatling is correctly using HTTP/2 here.