no access_log logging for UDP streams

Roman Arutyunyan arut at
Wed Feb 14 13:59:49 UTC 2018

Hi David,

On Tue, Feb 13, 2018 at 01:01:03PM -0800, David Kewley wrote:
> I'm using nginx 1.12.1 to proxy TCP and UDP streams. I have in my stream {}
> stanza:
>   log_format  test  '$time_local';
>   access_log  /var/log/nginx/stream-access.log  test  buffer=64k  flush=1s;
>   error_log   /var/log/nginx/stream-info.log    info;
> Both TCP and UDP streams log to /var/log/nginx/stream-info.log. Only TCP
> streams are logged in /var/log/nginx/stream-access.log; UDP streams are not.
> FWIW, client application behavior and tcpdump both show that the upstream
> UDP server is sending a response that makes it through nginx proxy to the
> client just fine.
> Is this lack of UDP stream access_log logging expected, or should I open a
> new bug?
> If you need to see more details to show exactly what I'm doing, let me know
> which details would be helpful.

Probably your UDP session is not considered finished by nginx.
Did you specify proxy_responses and proxy_timeout in your config?
If proxy_responses is unspecified and proxy_timeout is large, it may take a
long time for a UDP session to expire and be logged.

Roman Arutyunyan

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