APR_TCP_DEFER_ACCEPT error when starting Apache2

[bitcrazed]

Logging this issue here as information for others. Issue is benign and can be ignored.

• Your Windows build number: (Type ver at a Windows Command Prompt)
  15063

• What you're doing and what's happening: (Copy&paste specific commands and their output, or include screen shots)
  Starting Apache2 with:

$ sudo service apache2 restart

• What's wrong / what should be happening instead:
  Following error message is displayed:

* Restarting Apache httpd web server apache2
[Tue Apr 18 18:50:52.618691 2017] [core:warn] [pid 546:tid 140453865195392] (92)Protocol not available: 
AH00076: Failed to enable APR_TCP_DEFER_ACCEPT

[bitcrazed]

The TCP_DEFER_ACCEPT socket option is not natively supported by Windows.

WSL team are working with Windows networking team on this issue, but fix likely won't make it in RS3.

Doesn't block Apache2 from starting, just a warning. Pile-on below if otherwise.

[sunilmut]

Thanks @bitcrazed for reporting the issue. Your analysis above seems spot on.

[namiltd]

Add the following line to the end of the /etc/apache2/apache2.conf file:

AcceptFilter http none

[Jduret]

If you have this warning after enabling SSL (https), just add the following line to the end of the file :

/etc/apache2/apache2.conf

AcceptFilter https none

Keep in mind that this would just hide errors.

[JunaidQadirB]

I have added both http and https

AcceptFilter https none
AcceptFilter http none

[solracfirst]

Hello,

I have added

AcceptFilter https none
AcceptFilter http none

This worked on start, however, when I give restart it continues with the same error.

[jp-harvey]

@bitcrazed is there an issue somewhere open for the fix that can be tracked / voted on or is this it? Applications based on Apache Thrift currently do not work on WSL due to TCP_DEFER_ACCEPT not being available, eg. MapD

Thrift: Thu Aug 23 10:41:00 2018 TServerSocket::listen() setsockopt() TCP_DEFER_ACCEPT Protocol not available

#1953 (comment)

The TCP_DEFER_ACCEPT socket option is not natively supported by Windows.

WSL team are working with Windows networking team on this issue, but fix likely won't make it in RS3.

[bitcrazed]

This is one of the main issues tracking this problem, so please subscribe to this issue if you're interested in future progress. @tara-raj will triage with the team and get back to you.