FTL keeps stopping

Help
1

Please follow the below template, it will help us to help you!

If you are Experiencing issues with a Pi-hole install that has non-standard elements (e.g you are using nginx instead of lighttpd, or there is some other aspect of your install that is customised) - please use the Community Help category.

Expected Behaviour:

OS: Ubuntu 18.04.4 LTS
RAM: 1GB
CPU: 1vCPU

Service runs as expected

Actual Behaviour:

FTL stops after several minutes. I have tried manually restarting and running [Pihole -r] and steps listed here: DNS Service not running - #3 by jfb

Debug Token:

https://tricorder.pi-hole.net/7llpnr70hz

2

Please paste the output from:

sudo systemctl status --full --no-pager pihole-FTL.service

3

Thank you for your prompt response Dan. I got the following:

● pihole-FTL.service - LSB: pihole-FTL daemon
   Loaded: loaded (/etc/init.d/pihole-FTL; generated)
   Active: active (exited) since Wed 2020-07-08 14:25:05 UTC; 2h 17min ago
     Docs: man:systemd-sysv-generator(8)
  Process: 18964 ExecStop=/etc/init.d/pihole-FTL stop (code=exited, status=0/SUCCESS)
  Process: 19009 ExecStart=/etc/init.d/pihole-FTL start (code=exited, status=0/SUCCESS)

Jul 08 14:22:48 pihole_vm systemd[1]: Starting LSB: pihole-FTL daemon...
Jul 08 14:22:49 pihole_vm pihole-FTL[19009]: Not running
Jul 08 14:22:49 pihole_vm su[19052]: Successful su for pihole by root
Jul 08 14:22:49 pihole_vm su[19052]: + ??? root:pihole
Jul 08 14:22:49 pihole_vm su[19052]: pam_unix(su:session): session opened for user pihole by (uid=0)
Jul 08 14:25:04 pihole_vm pihole-FTL[19009]: FTL started!
Jul 08 14:25:05 pihole_vm systemd[1]: Started LSB: pihole-FTL daemon.
4

That all looks good, can we get the last 30 lines of the pihole-FTL log?

5

Also can you confirm the DNS server at 192.168.80.1 is authoritative for .local addresses and PTR records for 192.168.80.0/24?

    CONDITIONAL_FORWARDING=true
    CONDITIONAL_FORWARDING_IP=192.168.80.1
    CONDITIONAL_FORWARDING_DOMAIN=local
    CONDITIONAL_FORWARDING_REVERSE=80.168.192.in-addr.arpa
6 
pi@pihole_vm:~$ tail -n 30 /var/log/pihole-FTL.log
[2020-07-08 14:25:04.969 19065]  -> Unknown DNS queries: 28
[2020-07-08 14:25:04.969 19065]  -> Unique domains: 1735
[2020-07-08 14:25:04.969 19065]  -> Unique clients: 3
[2020-07-08 14:25:04.969 19065]  -> Known forward destinations: 3
[2020-07-08 14:25:04.969 19065] Successfully accessed setupVars.conf
[2020-07-08 14:25:05.003 19067] PID of FTL process: 19067
[2020-07-08 14:25:05.004 19067] Listening on port 4711 for incoming IPv4 telnet connections
[2020-07-08 14:25:05.004 19067] Listening on port 4711 for incoming IPv6 telnet connections
[2020-07-08 14:25:05.004 19067] Listening on Unix socket
[2020-07-08 14:25:05.012 19067] Reloading DNS cache
[2020-07-08 14:25:05.013 19067] Blocking status is enabled
[2020-07-08 14:25:05.036 19067] INFO: No regex blacklist entries found
[2020-07-08 14:25:05.036 19067] INFO: No regex whitelist entries found
[2020-07-08 14:25:05.048 19067] Compiled 0 whitelist and 0 blacklist regex filters in 18.5 msec
[2020-07-08 14:27:21.034 19067] Reloading DNS cache
[2020-07-08 14:27:21.034 19067] Blocking status is enabled
[2020-07-08 14:27:21.035 19067] SQLite3 message: file unlinked while open: /etc/pihole/gravity.db (28)
[2020-07-08 14:27:21.038 19067] INFO: No regex blacklist entries found
[2020-07-08 14:27:21.041 19067] INFO: No regex whitelist entries found
[2020-07-08 14:27:21.042 19067] Compiled 0 whitelist and 0 blacklist regex filters in 3.9 msec
[2020-07-08 14:36:38.483 19067] Resizing "/FTL-strings" from 49152 to 53248
[2020-07-08 14:37:53.029 19067] Resizing "/FTL-dns-cache" from 4096 to 8192
[2020-07-08 14:45:17.696 19067] Resizing "/FTL-strings" from 53248 to 57344
[2020-07-08 14:45:50.350 19067] Resizing "/FTL-dns-cache" from 8192 to 12288
[2020-07-08 14:53:30.205 19067] Resizing "/FTL-strings" from 57344 to 61440
[2020-07-08 15:00:07.985 19067] Resizing "/FTL-dns-cache" from 12288 to 16384
[2020-07-08 15:01:18.843 19067] Resizing "/FTL-queries" from 1043857408 to 1044119552
[2020-07-08 15:01:26.695 19067] Resizing "/FTL-queries" from 1044119552 to 1044381696
[2020-07-08 15:01:34.602 19067] Resizing "/FTL-queries" from 1044381696 to 1044643840
[2020-07-08 15:01:42.568 19067] Resizing "/FTL-queries" from 1044643840 to 1044905984
7

Okay, that log tail doesn't show any crashes or halts. Is there anything listening on port 53/tcp|udp right now?

8

May be part of my issue. I have a Ubiquiti USG and have been trying to get things to work:

Ubiquiti USG [192.168.80.1] -----> DNS/DHCP ----> pi-hole [192.168.80.3]

However this has been hard to troubleshoot as I wake up and DNS/FTL isn't running in the morning. I would then switch back to the USG and set up conditional forwarding on the pi-hole so as to get hostnames.

It seems I am going about this wrong... but not sure why FTL keeps stopping.

9

hmmmmm...... only thing listening seems to be 22 and 80

10

Turn off conditional forwarding and see if that stabilizes things. If it does then we can look at why forwarding is not working. If you tail the pi-hole logs (not the FTL logs) you'll see a number of requests being forwarded to the USG and no response coming back for them. That can cause heavy loads and DNS loops that may trigger issues.

11

Thanks Dan, I will report back (good, or bad)

1 Like
12

Thanks to DanSchaper I think the conditional forwarding did it. I probably borked the config and created a loop.

13

This topic was automatically closed 21 days after the last reply. New replies are no longer allowed.