Websocket connection drops

[makavity]

After fix #8, my websocket connection still drops on big chunks.
Here is the config:

<VirtualHost *:443>
    ServerName iamlab-biometry.nces.by
    
    TLSEngine 443
    
    TLSCertificate /etc/httpd/tls/nces.by.pem /etc/httpd/tls/nces.by.key

    ProxyPreserveHost On
    ProxyRequests On

    RequestHeader set X-Real-IP "%{REMOTE_ADDR}s"
    RequestHeader set X-Forwarded-For "%{REMOTE_ADDR}s"

    ProxyPass / http://localhost:8001/ upgrade=websocket flushpackets=on

    ErrorLog /var/log/httpd/iamlab-biometry.nces.by_error.log
    CustomLog /var/log/httpd/iamlab-biometry.nces.by_access.log combined
</VirtualHost>

Here is the logs from drop moment:

Details

[Fri Nov 21 10:15:36.679425 2025] [proxy:trace8] [pid 8:tid 8] proxy_util.c(5657): [client 192.168.88.82:56191] proxy: websocket: polling (client=31, origin=31)
[Fri Nov 21 10:15:36.728752 2025] [proxy:trace8] [pid 8:tid 8] proxy_util.c(5681): [client 192.168.88.82:56191] AH10215: proxy: websocket: woken up, 1 result(s)
[Fri Nov 21 10:15:36.728801 2025] [proxy:trace8] [pid 8:tid 8] proxy_util.c(5688): [client 192.168.88.82:56191] proxy: websocket: #0: origin: 1/31
[Fri Nov 21 10:15:36.728819 2025] [proxy:trace8] [pid 8:tid 8] proxy_util.c(5567): [client 192.168.88.82:56191] proxy: websocket: origin input ready
[Fri Nov 21 10:15:36.729037 2025] [proxy:trace2] [pid 8:tid 8] proxy_util.c(5357): [client 192.168.88.82:56191] ap_proxy_transfer_between_connections complete (from [::1]:8001)
[Fri Nov 21 10:15:36.729058 2025] [proxy:trace8] [pid 8:tid 8] proxy_util.c(5657): [client 192.168.88.82:56191] proxy: websocket: polling (client=31, origin=31)
[Fri Nov 21 10:15:36.890971 2025] [proxy:trace8] [pid 8:tid 8] proxy_util.c(5681): [client 192.168.88.82:56191] AH10215: proxy: websocket: woken up, 1 result(s)
[Fri Nov 21 10:15:36.890988 2025] [proxy:trace8] [pid 8:tid 8] proxy_util.c(5688): [client 192.168.88.82:56191] proxy: websocket: #0: client: 1/31
[Fri Nov 21 10:15:36.890993 2025] [proxy:trace8] [pid 8:tid 8] proxy_util.c(5567): [client 192.168.88.82:56191] proxy: websocket: client input ready
[Fri Nov 21 10:15:36.891114 2025] [proxy:trace2] [pid 8:tid 8] proxy_util.c(5357): (11)Resource temporarily unavailable: [client 192.168.88.82:56191] ap_proxy_transfer_between_connections complete (to [::1]:8001)
[Fri Nov 21 10:15:36.891122 2025] [proxy:trace8] [pid 8:tid 8] proxy_util.c(5657): [client 192.168.88.82:56191] proxy: websocket: polling (client=31, origin=31)
[Fri Nov 21 10:15:36.892793 2025] [proxy:trace8] [pid 8:tid 8] proxy_util.c(5681): [client 192.168.88.82:56191] AH10215: proxy: websocket: woken up, 1 result(s)
[Fri Nov 21 10:15:36.892804 2025] [proxy:trace8] [pid 8:tid 8] proxy_util.c(5688): [client 192.168.88.82:56191] proxy: websocket: #0: client: 1/31
[Fri Nov 21 10:15:36.892809 2025] [proxy:trace8] [pid 8:tid 8] proxy_util.c(5567): [client 192.168.88.82:56191] proxy: websocket: client input ready
[Fri Nov 21 10:15:36.892931 2025] [proxy:debug] [pid 8:tid 8] proxy_util.c(5257): (5)Input/output error: [client 192.168.88.82:56191] AH03308: ap_proxy_transfer_between_connections: error on client - ap_get_brigade
[Fri Nov 21 10:15:36.892936 2025] [proxy:trace2] [pid 8:tid 8] proxy_util.c(5357): (5)Input/output error: [client 192.168.88.82:56191] ap_proxy_transfer_between_connections complete (to [::1]:8001)
[Fri Nov 21 10:15:36.892941 2025] [proxy:trace1] [pid 8:tid 8] proxy_util.c(5793): [client 192.168.88.82:56191] AH10223: proxy: websocket: tunneling returns (500)
[Fri Nov 21 10:15:36.892946 2025] [proxy:debug] [pid 8:tid 8] proxy_util.c(2832): AH00943: http: has released connection for (localhost:8001)

[makavity]

I am sending 5 photo per second in websocket channel.
Each photo is 430kb sized.

[makavity]

Looks like the problem is with ap_get_brigade with empty payload.