HTTP/2 requests are 403 Forbidden error partically

[kunikotakahashi]

We develop a system using CanvasLMS of OSS(It was released on December 2023).
When endusers access to system from chrome browser by HTTP/2 protocol, 403 Forbidden error is occured partically.
The target API request is following, and it is called multiple at the same time(35 calls).
Under the same conditions, 403 error does not occur for HTTP/1.1 access.
We are thinking about because HTTP/2 protocol is stream access via same TCP connection, API concurrent execution is much ,compare to HTTP/1.1 access.
Please let me know how to resolve this issue, such as by increasing the quota per API.

Thank you very much!

[URL]
https://mydomain/api/v1/courses/:courceid/folders/root

[Response Headers]
Alt-Svc:clear
Content-Type:text/plain; charset=utf-8
Date:Wed, 10 Apr 2024 08:41:45 GMT
Server:Google Frontend
Set-Cookie:log_session_id=59463e05cd3e240089900e08f4bfb25c; path=/; secure; HttpOnly
Status:403 Forbidden
Strict-Transport-Security:max-age=63072000
Traceparent:00-d3ddd4720dca20f3e2566e02da721b6a-a4f861339a21f081-00
Via:1.1 google, 1.1 google
X-Canvas-Meta:b=1337456;m=1337456;u=0.01;y=0.00;d=0.00;
X-Cloud-Trace-Context:d3ddd4720dca20f3e2566e02da721b6a/11887358090701566081
X-Rate-Limit-Remaining:-99.69208135407996
X-Request-Context-Id:a0921b32-082a-4d3f-8524-330eea2d5ec3
X-Runtime:0.097255
X-Session-Id:59463e05cd3e240089900e08f4bfb25c

[kunikotakahashi · Accepted solution]

This issue was solved ourself.
We modified /app/middleware/request_throttle.rb with below settings.

[original settings]
:
{
maximum: 800,
hwm: 600,
outflow: 10,
up_front_cost: 50,
}.each do |(setting, default)|
:

[modified setting]
:
{
maximum: 3000,
hwm: 2500,
outflow: 10,
up_front_cost: 50,
}.each do |(setting, default)|
: