Deluge Forum

Posted: **Sun Jul 17, 2022 11:50 am**

Hi,

I'm running deluge 2.1.1 on Manjaro. I get this message for the incoming port. It causes extreme slow upload speeds.
If I turn off syncookies requests get dropped. It must be a hardcoded value in deluge (TCP Listen Backlog, see https://access.redhat.com/solutions/30453). Changing parameters in sysctl has no effect.

I get this error with another python 3 based program (pyload). In this case, it's the web ui port. It doesn't cause any problems.

Testet qb and I don't get this error.

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ss -ntlp | more

shows Send-Q 5 for deluged and pyload. For example, qb has 30.

Please fix this since it causes slow upload speed. Thank you!

Posted: **Tue Aug 02, 2022 6:43 pm**

Which port are you getting the SYN flooding messages for?

What version of libtorrent are you using? libtorrent handles the bittorrent listen sockets so that it could be a setting or bug that needs resolved there.

Posted: **Wed Aug 03, 2022 1:02 am**

Thanks for reply.

Port 54979 and libtorrent-rasterbar-1:2.0.7-1.

I just found the setting in libtorrent:

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listen_queue_size

The default value is 5. Same in pyload's web server cheroot. I increased the value there and the kernel messages disappeared.

Under

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  # Increase the alert queue size so that alerts don't get lost.
        self.alert_queue_size = 10000
        self.set_alert_queue_size(self.alert_queue_size)

in alertmanager.py I added

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        component.get('Core').apply_session_setting(
                 'listen_queue_size', 512
        )

The message does not appear anymore.

Deluge Forum

Please fix this: TCP: request_sock_TCP: Possible SYN flooding on port X. Sending cookies. Check SNMP counters.

Please fix this: TCP: request_sock_TCP: Possible SYN flooding on port X. Sending cookies. Check SNMP counters.

Re: Please fix this: TCP: request_sock_TCP: Possible SYN flooding on port X. Sending cookies. Check SNMP counters.

Re: Please fix this: TCP: request_sock_TCP: Possible SYN flooding on port X. Sending cookies. Check SNMP counters.