I got a weird incident on a web server (CentOS 5):
It got completely unresponsive for a few minutes and came back up all on its own after 10 minutes or so.
All mrtg graphs (connections, data transfer, load) during this period are a flat line.
After the incident I logged in and could not find anything that could have caused the problem.
The apache access log was just silent for a few minutes, the server hadn't rebooted or anything, the load was low and just starting to pick up again.
This is the last entry on
/var/log/messages (I don't know if it is relevant):
srv01 kernel: IVD-TCP-13 : IN=eth0 OUT= MAC=<some_mac_address> SRC=18.104.22.168 DST=<my_ip> LEN=40 TOS=0x00 PREC=0x00 TTL=48 ID=62903 PROTO=TCP SPT=56832 DPT=80 WINDOW=65535 RES=0x00 FIN URGP=0
After that there's an interval of 10 or so minutes that this log has no entries.
Any idea on what I should be looking for?