[collectd] Modbus segfault

[Matt Baker]

Hi Stefan,

I thought I would give your modified modbus.c file a try.   It worked fine for awhile, but then it started reporting:

[2012-02-01 14:00:47] plugin_read_thread: Handling `modbus-10.1.2.2'.
[2012-02-01 14:00:47] Modbus plugin: modbus_read_registers (10.1.2.2) failed. Giving up.
[2012-02-01 14:00:47] Modbus plugin: modbus_read_registers (10.1.2.2) failed. Giving up.
[2012-02-01 14:00:47] Modbus plugin: modbus_read_registers (10.1.2.2) failed. Giving up.
[2012-02-01 14:00:47] Modbus plugin: modbus_read_registers (10.1.2.2) failed. Giving up.
[2012-02-01 14:00:47] Modbus plugin: modbus_read_registers (10.1.2.2) failed. Giving up.
[2012-02-01 14:00:47] Modbus plugin: modbus_read_registers (10.1.2.2) failed. Giving up.
[2012-02-01 14:00:47] Modbus plugin: modbus_read_registers (10.1.2.2) failed. Giving up.
[2012-02-01 14:00:47] Modbus plugin: modbus_read_registers (10.1.2.2) failed. Giving up.


Looking at the code (and i'm not a C programmer), I was wondering if you thought it would be good idea if the code was changed so if it hit this sort of failure it tries to reestablish the host connection again using a mb_init_connection?


Cheers,

Matt


> Hi Matt,
> 
> by now I'm running a somewhat more changed version that I put up at https://github.com/snickl/collectd/tree/snickl/3-modbus-connect-handling (my first attempt on github btw).
> 
> I also noticed that data stopped coming in after several hours, but from the logs it looked more like modbus connection errors. Debug is enabled now, but no problem for over a day. I'll sure check on zero values if it stalls again.
> 
> Cheers, Stefan