Re: connection failed, INET[www.example.com:80] via TCP is not ready for i|o -- Interrupted system call

[Jan-Henrik Haukeland]

Thank you very much for sharing! I've put it up on the wiki also, hope that is 
okay?
http://mmonit.com/wiki/Monit/FAQ#connection_failed

Jan-Henrik



On Feb 9, 2012, at 12:47 PM, Marcus Mülbüsch wrote:

> Hello all,
> 
>   hoping that this helps someone somewhere in the future. Skip the text and 
> jump to the solution at the bottom if you are not interested in my adventure. 
> I write this purely because googling for the error message did not show up 
> with a single useful entry.
> 
>   Since yesterday I received the message "connection failed, 
> INET[www.example.com:80] via TCP is not ready for i|o -- Interrupted system 
> call" every 5 minutes from a monit instance.
> 
>   Sometimes it skipped the five minutes and came back after ten minutes or 
> more (but always a multiple of five), sometimes it jumped one minute ahead 
> and faulted after six minutes, to continue then again after five.
> 
>   The server, however, *was* reachable and working (as it tested successfully 
> from another server).
> 
>   When I investigated further I discovered that the firewall did open all 
> necessary connections, so it wasn't a fault there.
> 
>   When I tcpdumped the traffic on the monit instance everything worked fine: 
> Monit opens a TCP connection and the whole process of sending SYN, SYN/ACK, 
> ACK, traffic and finally FIN, FIN/ACK etc. went smoothly.
> 
>   However, every five minutes monit sent a SYNC, received a SYNC/ACK, but 
> instead of acknowledging with an ACK the very next package was a RST.
> 
>   Duh!
> 
>   Replaying a configuration from the backup from the day before yesterday 
> didn't help.
> 
>   Finally I checked /var/log/messages (should have done that at first, but 
> you know how it goes), where I discovered the wonderful "init: Id "mo" 
> respawning too fast: disabled for 5 minutes".
> 
>   Yes, I start monit from inittab.
> 
>   Yesterday the switch where this server was connected to died. After 
> reconnecting to another switch everything was fine again, but somehow the 
> init process must have thought that monit was not running, tried to start it 
> only to find out it was already running...
> 
>   So the solution was very simple:
> 
> SOLUTION:
> --------
> 
> a) comment out the "mo:2345:respawn:/usr/bin/monit \-I" from /etc/inittab.
> b) restart the init process ("init q")
> c) stop monit ("monit quit")
> d) uncomment again the monit entry from inittab.
> e) Restart init again ("init q")
> d) watch your logfile. No more errors
> 
> Marcus
>