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Re: New gpsd version with TCP reconnect
From: |
Gary E. Miller |
Subject: |
Re: New gpsd version with TCP reconnect |
Date: |
Wed, 2 Nov 2022 17:47:20 -0700 |
Yo Nick!
On Wed, 2 Nov 2022 09:54:13 +0000
Nick Taylor <nicktaylor@dataskill.uk> wrote:
> > My fail case is only when I use blackhole and wait around 15 mins
> > for socat to timeout. In this case gpsd doesn't seem to realise
> > that the connection has failed...
So I setup 2 test hosts. One send NMEA with socat this way:
# socat EXEC:'gpspipe -rB' TCP-LISTEN:2948,reuseaddr,fork
On a second host, i read that feed this way:
# gpsd -nND 10 tcp://192.168.99.27:2948
I get a good, feed. On the lcient host, I kill the feed:
# iptables -A INPUT -p tcp --source-port 2948 -j DROP
And I see input to gpsd stop, but the connection does not drop, because the
default Linux tcp timeout is two hours.
I reenable the feed:
# iptables -D INPUT -p tcp --source-port 2948 -j DROP
Socat had buffered a lot of data, and it all comes thourgh, then the
conenction back to normal.
What do you get when you do this on the client:
client ~ # ls /proc/sys/net/ipv4/tcp_keepalive* -l
-rw-r--r-- 1 root root 0 Nov 2 17:43 /proc/sys/net/ipv4/tcp_keepalive_intvl
-rw-r--r-- 1 root root 0 Nov 2 17:43 /proc/sys/net/ipv4/tcp_keepalive_probes
-rw-r--r-- 1 root root 0 Nov 2 17:43 /proc/sys/net/ipv4/tcp_keepalive_time
client ~ # cat /proc/sys/net/ipv4/tcp_keepalive*
75
9
7200
On mine, that shows 7200 seconds (2 hours), before dropping the conenction
due to keep alive.
RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
gem@rellim.com Tel:+1 541 382 8588
Veritas liberabit vos. -- Quid est veritas?
"If you can't measure it, you can't improve it." - Lord Kelvin
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- Re: New gpsd version with TCP reconnect, Nick Taylor, 2022/11/01
- Re: New gpsd version with TCP reconnect, Gary E. Miller, 2022/11/01
- Re: New gpsd version with TCP reconnect, Nick Taylor, 2022/11/02
- Re: New gpsd version with TCP reconnect, Gary E. Miller, 2022/11/09
- Re: New gpsd version with TCP reconnect, Nick Taylor, 2022/11/10
- Re: New gpsd version with TCP reconnect, Gary E. Miller, 2022/11/10
- Re: New gpsd version with TCP reconnect, Gary E. Miller, 2022/11/10
- Re: New gpsd version with TCP reconnect, Gary E. Miller, 2022/11/10
- Re: New gpsd version with TCP reconnect, Nick Taylor, 2022/11/11
- Re: New gpsd version with TCP reconnect, Nick Taylor, 2022/11/11