Restart on crash / Keepalive script.

It is no secret that the KAG linux server is beset by segfaults and random crashes that make a restart/keepalive mechanism imperative. If you don't want to use a cronjob/pid-check to restart a crashed server, the following "script" is for you; inverted comas, cause it only adds an until loop to the original dedicated.sh script.

To use, save as dedi.sh or whatever you fancy, chmod +x dedi.sh to make it executable, and start your linux servers by running this, instead of dedicated.sh

Code:

#!/bin/bash
echo "Running KAG dedicated server"
echo "TO SET IP/PORT/SLOTS/PASSWORD ADD THESE COMMAND PARAMS: ip 127.0.0.1 port 50213 slots 32 password pass123"
mv KAGdedi.tmp KAGdedi
chmod +x KAGdedi
until ./KAGdedi nolauncher autostart Scripts/dedicated_autostart.gm autoconfig Scripts/dedicated_autoconfig.gm; do
        echo "KAG server running"
        sleep 5
done

Pros:

• No PID-recycling, PID files going stale, and other stuff a bit over my head.

Cons:

• It will not survive a reboot, but this is linux we're talking about , you can do without reboots. :)
• I have only tried this in the relatively update-free 158 build. I have no idea how it handles an update. It should still work.

Note:

• Word-wrapping has to be off in your editor if you want this to work. If you use nano, make sure to start it with the -w flag (e.g nano -w dedi.sh)
• Hapi had issues with creating a script in windows and trying to run it in linux (the infamous /bin/bash^M error). If you don't want to use dos2unix (e.g. dos2unix dedi.sh), here's the easy and lazy solution: drop to your shell and
  
  Code:

  wget http://dl.dropbox.com/u/23114384/files/dedi.sh 

  then chmod+x dedi.sh and so on..

Update: 2012-01-26:
TheBeaz came up with a windows batch file that does exactly the same:

Create a new batch file in the same directory as the dedicatedserver.bat
Put this code in the file (with the information after "start /wait" being the KAG.exe line from the dedicatedserver batch file)

Code:

@ECHO off
 
:restart
echo (%time%) Server Started - close this window to prevent restart.
 
start /wait KAG.exe nolauncher autostart Scripts/dedicated_autostart.gm autoconfig Scripts/dedicated_autoconfig.gm
 
echo (%time%) WARNING: Server closed or crashed, restarting.
 
goto restart

 

Thank you, that's a great script :)

 

In build 228, since the introduction of GUI launcher etc, dedicated.sh is slightly altered:

Instead of

Code:

./KAG autostart Scripts/dedicated_autostart.gm autoconfig Scripts/dedicated_autoconfig.gm 

we have

Code:

./KAG nolauncher autostart Scripts/dedicated_autostart.gm autoconfig Scripts/dedicated_autoconfig.gm;

"Script" updated to reflect this change , both here and in dropbox.

 

In build 262 we have a dedicated binary (no pun intended) called KAGdedi, so the line in question changes to:

Code:

until ./KAGdedi nolauncher autostart Scripts/dedicated_autostart.gm autoconfig Scripts/dedicated_autoconfig.gm; do

"Script" updated to reflect this change , both here and in dropbox.

 

So restarting server every day since 255 or whatever is getting old. How could it be made to restart server every day at a set time?

 

Providing you're using the dedi.sh keepalive script above , you'll need to add a cronjob that kills KAGdedi with the correct signal (sighup) once a day or so. Here's just an example, there are numerous ways of achieving this

add the following line to crontab:

Code:

0 3 * * * pkill -1 KAGdedi

At 3am every day it will kill all processes named KAGdedi (potentially problematic if you're running more than 1 servers) and the loop in dedi.sh will take care of restarting the server 5 seconds later. Why didn't I think of this earlier is beyond me..

 

If I may, here is a solution for those with a Windows Server setup:

1. Create a new batch file in the same directory as the dedicatedserver.bat
2. Put this code in the file (with the information after "start /wait" being the KAG.exe line from the dedicatedserver batch file)

Code:

@ECHO off
 
:restart
echo (%time%) Server Started - close this window to prevent restart.
 
start /wait KAG.exe nolauncher autostart Scripts/dedicated_autostart.gm autoconfig Scripts/dedicated_autoconfig.gm
 
echo (%time%) WARNING: Server closed or crashed, restarting.
 
goto restart

3. Done!​

 

To clarify trelawney, just insert that line in the script in OP? (after done?)
Also my keepalive script gets killed whenever I kill KAGdedi I must be doin it wrong

 

You insert that line in your crontab. Google cron & cronjobs or man crontab and you'll see how and why. Briefly:
1.crontab -e (this will spawn your default editor)
2.paste 0 3 * * * pkill -1 KAGdedi
3.close editor. Cronjob installed!

It gets killed cause you're using a plain "kill" command, that defaults to a termination signal (15), kill -1 sends the correct signal (kill -l shows you a list). kill -9 should also work as expected.

thanks for the batch file theBeaz :) Adding to OP.

 

No problem. I'm looking into a way around a problem I'm having on Windows 2008 R2 (and may exist in other version) - when the server has crashed it's not actually completely crashed. It's just hanging and then Windows prompts with the "Windows has detected a problem with this program - [Close Program]" dialog box. Until Close Program is clicked, the script never gets a chance to re-fire. I'll keep looking into a solution for this.

[update]

Confirmed that the Windows batch script does work properly with commands such as "\rcon \restartserver". It's just with process hangs that a problem exists still. I have some possible solutions but I need the server to actually hang first to know if they actually work or not!

If anyone knows of any buggy \rcon commands I could use to simulate a server crash, please let me know.

 

Small issue with this on linux -- server will hang and not get restarted on strange cases.
Logs @ http://kagforum.com/index.php?threads/bad-delta-netobject-not-found.3447/

No crash, accepted connections, just no one could actually play or do anything but dc immediately on connect.

 

Hence why I was asking about a daily restart function Teemo, this has affected many (all?) servers since the updates of the past few weeks; the server always seems to run for over 24hours before this bug occurs.

 

I use a daily restart with a cronjob but my problem is that there's no way I can pull the "are there 0 players on? if so, restart" thing because KAG exposes no way to do that :(

 

Added to wiki.

 

(As a Debian user):
Why use these bothersome scripts to auto-reboot the server when you can just type this inside a screen:
while true; do ./dedicatedserver.sh; done;

And it will reboot the server everytime it crashes.

My current problem is that server tend to disconnect players and crash after and during the game pretty frequently. Does your version of auto restarter somehow manage to prevent disconnects?

 

I hate having to explain the obvious but your choice of words is forcing my hand to type: if usage of the script or the script itself annoys or irritates you, do not use it. Equally obvious should be the fact a bash script is more flexible than a screen while loop, for people might use other multiplexers/daemonisers (e.g tmux , nohup, dtach).

DISCLAIMER: The auto restarter script, contrary to all rumour and hearsay, will not make you rich, cure common cold, or make your server any more stable than the competition.

 

I get an error. Sry iam very new in this.

bash: ./dedi.sh: /bin/bash^M: bad interpreter: No such file or directory

Code:

#!/bin/bash
echo "IncetrixX KAG TTH Server DE | CUSTOM MAPS"
echo "ip 134.255.226.236 port 50310 slots 24"
mv KAGdedi.tmp KAGdedi
chmod +x KAGdedi
until ./KAGdedi nolauncher autostart Scripts/server_autostart.as autoconfig ../autoconfig.cfg; do
        echo "KAG server running"
        sleep 5
done

--- Double Post Merged, Dec 12, 2013, Original Post Date: Dec 11, 2013 ---

Can nobody help me?

 

I am by no means a veteran of Linux either, but I think your escape character got broken. That "^M" probably was supposed to be an end of that line, but if you moved the file from one PC/OS to another, it didn't get converted. Try just erasing the "^M" and see if that works.

 

yea i figured it out. Didnt see the text above. i use dos2unix command and now it works. Thank u anyway